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Project Management

2010;():1-7. doi:10.1115/IPC2010-31088.

OSBRA is a 20″ multiproduct pipeline operated by TRANSPETRO that supplies Diesel oil, gasoline and liquefied petroleum gas (LPG) from REPLAN, the Brazilian major refinery, to five Tank Farms located along the country Midwestern region. In 2001, five years after OSBRA first commissioning, TRANSPETRO initiated several projects to improve the pipeline and Tank Farms operational performance on quality, measurement, safety and environmental care. A project portfolio management system was established in order to keep control of projects conducted along the 964 kilometers of pipeline, its Tank Farms and two unmanned pump stations. Learned lessons and good practices were adopted from typical project management cases on the pipeline industry, such as: tank drainage, effluents and fire protection systems; improvements on pipeline measurement and control systems; improvements on pipeline leak detection system; tank construction; short length pipelines construction; truck loading and unloading terminal facilities; jet fuel receiving, storage and delivering system; technology developing projects and so on. Some of these projects were conducted based on PETROBRAS traditional experience on project management, some were conducted according to the Independent Project Analysis Institute - IPA and the best recommended practices from the PMI’s PMBOK® Guide, and others were conducted considering a mix of both practices. During the project, the members of the project team and its stakeholders were geographically spread out through several sites. This paper presents how the OSBRA project portfolio has been managed by a reduced multi-disciplinary team, including safety and environmental professionals, in order to keep each project aligned to meet its essential operational and business objectives.

Commentary by Dr. Valentin Fuster
2010;():9-13. doi:10.1115/IPC2010-31154.

Economic contrast of crude oil transportation charge between pipeline and railway affects the pipe network and rail network planning of the area, and the relevant studies have not been seen in literature. On the basis of evaluation methods and parameter and other relevant provisions of construction projects regulated by China National Petroleum Corporation (CNPC), the paper conducted a comparative study on the transportation charge of crude oil by the pipeline and railway. The transportation charge by the pipeline was calculated based on the minimum attractive rate of return (MARR). The results show that transportation charge is 0.06∼0.14 CNY/ton·km and will decrease with the size of the diameter of the pipe and increase with the distance of the transportation. The study on railway transportation charge shows that the charge is 0.13∼0.25 CNY/ton·km, which will decrease with the distance but has no relation with the amount of crude oil. The thicker the diameter of pipe, the lower the charge is by the pipe, which is relevant to the loading rate. When the loading rate is 38–72%, the transportation charge by the two ways are almost the same.

Commentary by Dr. Valentin Fuster
2010;():15-20. doi:10.1115/IPC2010-31303.

Pipeline operators, contractors and governments face important challenges when planning, designing, constructing and operating pipelines which connect the hydrocarbon reserves in the Amazonian basin with population and shipping centers on the Pacific coast. These pipelines cross portions of the Amazonian rainforest, the mountain rainforest along the eastern flank of the Andes, the Andean plateau, and the rural and urban low lying desert areas along the Pacific coast. The need for these pipelines will continue and offers a tremendous opportunity to promote sustainable economic development. However, there are several challenges in safeguarding the integrity of the pipeline, environment, local population, and socio-economic fabric of the region. Failure to properly address these risks could have significant financial, engineering, environmental and social, or reputational consequences for operators, contractors, financiers and governments. In this context, companies need to understand the specific challenges present and implement an encompassing project and risk management strategy that entails leadership, team work, effective communication and collaboration in a manner that proactively meets anticipated needs and responds to evolving conditions. During design and construction management, engineers and scientists are challenged by geology, topography, limited or no field data, limited access to the right-of-way (RoW), and socio-environmental aspects. Major training efforts are needed for the construction workforce, in a manner applicable to educational and cultural characteristics. Special road safety measures are required and in many instances the right-of-way will be the only means of transporting construction material. Other special logistical challenges are presented by the rich cultural history of the Andes. During operation, special consideration needs to be given to external natural hazards like landslides, soil creep, seismicity, and river scour. Management needs to maintain good communication with all parties affected by the project and proactively promote broad socio-economic development in the project area. The recognition of these specific challenges and upfront investment will facilitate mutually beneficial project advancement and be of particular benefit in instances of anticipatable but uncontrollable events. This paper describes several of these challenges and provides guidance on how to minimize project specific risks and adverse effects to society and environment.

Commentary by Dr. Valentin Fuster
2010;():21-30. doi:10.1115/IPC2010-31356.

Decision-making on modern pipeline projects is subject to a broader and more complex range of influences and risk drivers than ever before. Issues such as new and tightening regulations, public health and safety, construction constraints, water constraints, arctic geotechnical issues, carbon management, Aboriginal interests and increased stakeholder participation all impact the lifecycle costs and benefits of pipeline project options. These are in addition to the more traditional issues that need to be addressed, which include point of origin, terminus location, routing, volumetric sizing and expansion scenarios. Superior decisions may be achieved on pipeline projects by the application of a structured triple-bottom line risk assessment at the front end of project planning. By adopting a broader view of the impacts of project operations, optimized solutions can be identified and proven, ultimately leading to a more profitable and lower risk commercial operation.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2010;():31-39. doi:10.1115/IPC2010-31497.

Operators of large and complex pipeline systems face numerous risks and verification is a means to manage risk. Important factors to be considered when selecting a verification strategy are; legislative requirements and expectations, contracting philosophy, interface management, communication strategy, project technical challenges and quality assurance philosophy. To assist project managers in planning and communicating the verification strategy, a standardized three tiered verification scope is described.

Commentary by Dr. Valentin Fuster
2010;():41-48. doi:10.1115/IPC2010-31509.

The high competitiveness in the oil sector, the velocity of changes in the world and the increasingly short life cycles of projects, have forced the large companies in this sector to maintain extensive project portfolios in engineering. These demand efficient management and balancing, because otherwise the competitive position relative to other companies is placed at risk. These companies have the challenge of developing appropriate methodologies to manage the portfolios and provide support to the decision makers, aiming at maximizing the results of the projects. One of the activities of portfolio management, and perhaps the most difficult, is the adequate prioritization of the projects, because it involves great subjectivity in the direct comparison of highly different projects, with different objectives and at times contrary in the use of criteria that depend on sensitivity evaluations. An example is the improvement in society’s perception of the company’s image that a project may provide. For the prioritization of these projects, it becomes necessary to employ multiple-criteria analyses, and for this, the organization needs to define how many, and which criteria are going to be utilized, together with their relative importance. This article has the purpose of describing the implantation of a prioritization methodology for projects utilizing the Analytic Hierarchy Process (AHP) analysis technique in a regional office of the largest logistics company in South America, Transpetro. The company forms part of the Brazilian oil system; more specifically in the transport and storage of oil and oil products. The company operates a fleet of 55 ships having the transport capacity of 2.9 million deadweight tons, 7,033 km of oil pipelines and 3,600 km of gas pipelines, 20 land-based terminals and 26 water-based terminals. The dynamic of the implantation will be presented as the results, demonstrating a preliminary sensitivity analysis, the choice of analytical technique utilizing multiple criteria, the development of a tool and the result of prioritizing the portfolio. In addition, the results of the analysis of this prioritization relative to the existing portfolio will be presented.

Commentary by Dr. Valentin Fuster
2010;():49-54. doi:10.1115/IPC2010-31513.

The speed of the changes that have occurred in the world have forced organizations to adapt themselves and offer new products to the consumers in increasingly shorter timeframes, or risk being overtaken by the competition. The cycle of project life is being reduced, making the management increasingly complex both for the projects and portfolios of projects. Included in this scenario are companies from the oil sector that act to develop management systems that manage to aggregate greater chances of success for its projects as well as the capacity to manage multiple projects simultaneously. The concept of success itself is controversial, because on the one hand it is one of the most researched topics, on the other there is still no consensus among those interested. It becomes necessary then to understand the concept of success for projects, and to establish ways of measuring it, and try to identify the critical factors of success and the critical factors of failure, so that organizations can manage their own projects adequately. Companies with extensive project portfolios confront greater challenges, because they have to develop efficient methodologies to manage and maintain their portfolios, in addition to having to develop competences to accompany the management of multiple projects, identifying possible corrective actions for the deviations identified in time. One efficient manner of pro-actively controlling extensive portfolios of projects being executed simultaneously at different geographical locations is the utilization of a tool via web that integrates all the management activities. This tool must have as a basic premise its utility for the work of the management team, and not only be a communication tool, since in this case it would call for an effort by the management team that adds no value to the project. This article has the objective of showing the results of research carried out to identify how Transpetro, the largest logistics company in South America, which operates a fleet of 55 ships with transport capacity of 2.9 million deadweight tons, 7,033 km of oil pipelines and 3,600 km of gas pipelines, 20 land-based terminals and 26 water-based terminals, controls its engineering projects, directing its efforts in an attempt to achieve greater chances of success so as to comply with its strategic planning.

Commentary by Dr. Valentin Fuster
2010;():55-60. doi:10.1115/IPC2010-31679.

In early 2005, Kuwait Oil Company (KOC) initiated a Total Pipeline Integrity Management System (TPIMS ) implementation in order to carry out a major integrity assessment of its operating facilities, equipment, buried plant piping and pipeline network and to establish a continuing integrity management program. KOC Transit System is a complex infrastructure consisting of over three hundred pipelines, thousands of wellhead flow lines, and consumer and offshore lines for which there was a significant loss of data when the facilities were destroyed during a military invasion in 1990. An initial pipeline system assessment identified issues and actions regarding condition of the pipelines, corridors, requirements on in-line inspection (ILI), documentation, RISK assessment, status of international code compliance, and overall state of the system. Following recommendations from that initial assessment led to the development of a long term strategy; the execution of which required the implementation of a comprehensive integrity management program. This case study discusses the results obtained after five years of implementation of TPIMS at KOC. It will demonstrate some of the complex components involved in managing the integrity of the Transit System that have been made possible through the implementation of the system. The general concept and structure of TPIMS will be described, and how it deals with the complexity of the KOC pipeline system. The system made it possible to integrate and manage data from various sources, by conducting integrity assessment using ILI, Direct Assessment and hydrostatic testing, as well as structure a comprehensive RISK & Decision Support mechanism. This is one of the world’s first implementations of this magnitude which encompasses such a wide range of services and variables; all being managed in a single environment and utilized by a multitude of users in different areas at KOC. The biggest challenge in a project of this scope is data management. Examples will be shown of the integration structure to illustrate the benefits of using a single comprehensive and versatile platform to manage system requirements; ultimately providing system reliability and improving overall operational efficiency.

Commentary by Dr. Valentin Fuster

Environment

2010;():61-75. doi:10.1115/IPC2010-31015.

Government policies currently in place or in development will require the reduction of greenhouse gas emissions from industry, including gas transmission systems. Most of the natural gas transmission systems are powered by gas turbines of sizes up to 30 MW per unit. A typical gas turbine of this size can emit 6 ktonnes of CO2 per MW-year, equivalent to about 180 ktonnes per year. Reduction in greenhouse gas emissions can be accomplished through post-combustion systems (separation of CO2 from flue gases through chemical absorption, physical adsorption, membrane or cryogenic systems) or through oxy-fuel combustion, where fuel is combusted in pure O2 leading to sequestration of CO2 by compression and dehydration of the exhaust gases. The purpose of the current work is to explore the application of the latter concept, simplify and enhance the cycle, and to provide an economic valuation of the cost per tonne of CO2 abated. Innovations explored for enhancement include elimination of excess power production, simplification of capital equipment requirements, and optimization of the power to the booster produced from the gas turbine and steam turbine. The paper presents various innovation options arrived at, detailed thermodynamic parameters, and a cost and economic evaluation of these options. Particular emphasis was placed on the application of this technology to a typical compressor station on a natural gas transmission system as this application is vastly different than a typical power plant contemplating or employing carbon capture and storage (CCS) systems, most notably from the small power size, the remote location, and the self-containment perspectives.

Commentary by Dr. Valentin Fuster
2010;():77-87. doi:10.1115/IPC2010-31016.

A Predictive Emission Monitoring (PEM) model has been developed for a non-DLE GE LM2500 gas turbine used on a natural gas compressor station on the TransCanada Pipeline System in Alberta. The PEM model is based on an optimized Neural Network (NN) architecture which takes four fundamental engine parameters as input variables. The model predicts NOx emission in ppmv-dry-O2 corrected and in kg/hr as NO2 . The NN was trained using Continuous Emission Monitoring (CEM) measurements comprising two sets of actual emission data collected over two different dates in 2009, when the ambient ambient temperatures were vastly different (∼1° C and 24 °C), respectively. These training data were supplemented by other emission data generated by GE ‘Cycle-Deck’ tool to generate emission data at different ambient temperatures ranging from −30 to +30 °C. The outcome is a total of 1872 emission data of engine emissions at different operating conditions covering the range of the engine operating parameters (402 data points from CEM and 1470 data points from GE Cycle-Deck). The PEM model comprises a simple single hidden layer perceptron type NN with only two neurons in it. The performance of the NN-based model showed a correlation coefficient greater than 0.99, and error standard deviation of 4.5 ppmv of NOx and 1.4 kg/hr as NO2 . Uncertainty analysis was conducted to assess the effects of uncertainties in the engine parameters on the NOx predictions by PEM. It was shown that for uncertainty in the ambient temperature of ±1 °C, the uncertainty in the NOx prediction is ± 0.9 to ±3.5%. Uncertainties of the order of ±1% in the other three input parameters results in uncertainties in NOx predictions by ±2.5 to ±6%. Finally, the PEM model was implemented in the station CEHM (Compressor Equipment Health Monitoring) system and NOx prediction were reported online on a minutely basis. These data are presented here over the first three months since implementation.

Commentary by Dr. Valentin Fuster
2010;():89-98. doi:10.1115/IPC2010-31048.

Noise is generated at gas turbine-based compressor stations from a number of sources, including turbomachinery (gas turbines and compressors), airflow through inlet ducts and scrubbers, exhaust stacks, aerial coolers, and auxiliary systems. Understanding these noise sources is necessary to ensure that the working conditions on site are safe and that the audible noise at neighbouring properties is acceptable. Each noise source has different frequency content, and the overall sound pressure level (OSPL) at any location in the station yard or inside the compressor building is the result of a superposition of these noise sources. This paper presents results of multiple-point spectral noise measurements at three of TransCanada’s compressor stations on the Alberta System. A method is described to determine the overall noise map of the station yard using Delaunay Triangulation and Natural-Neighbour Interpolation techniques. The results are presented in OSPL maps, as well as animated pictures of the sound pressure level (SPL) in frequency domain which will be shown on a video at the conference. The latter will be useful in future work to determine the culprit sources and the respective dominant frequency range that contributes the most to the OSPL.

Commentary by Dr. Valentin Fuster
2010;():99-103. doi:10.1115/IPC2010-31049.

Gasoducto Nor Andino is a 1,100 km long natural gas pipeline which runs through one of the most critical environmental and social areas of Argentina and Chile. The area is inhabited by aboriginal communities that face a progressive deterioration of their cultural values and traditional customs. The beginning of the construction of Gasoducto Nor Andino triggered a strong reaction in the local communities and environmental organizations such as Greenpeace. Such reaction soon extended throughout the country, generating a strong debate as to the value of Economic & Technological Progress vs Environmental Conservation. All the problems were successfully solved by actions conducted in accordance with the Company’s ethical values. The different stakeholders involved were called together and agreements were implemented with nongovernmental organizations (NGOs), such as Greenpeace, representatives of the aboriginal communities, local and environmental authorities (National Park Administration, Environmental Secretariat of Salta Province, etc.). This paper describes the non-traditional and innovative actions taken to solve the problems and the remarkable results achieved.

Commentary by Dr. Valentin Fuster
2010;():105-116. doi:10.1115/IPC2010-31131.

Adsorption of hydrocarbons by activated carbon (AC) has been the subject of recent development and advancement. One of the applications of this technology is in the capture of planned blowdown gases for the purpose of reducing greenhouse gas emissions. A conceptual design of a large AC-based adsorbed natural gas (ANG) storage system has been configured to capture at least 35–40% of the blowdown gases released from high pressure (60 bar) facilities. This design consists of 46 × 14″ diameter pipe modules mounted on a trailer. A smaller ANG unit consisting of a standard gas cylinder or a pressure vessel filled with AC has also been designed to capture blowdown gases from small-volume systems such as compressor casings. The performance of both storage units has been evaluated numerically, and important design parameters are quantified for a given range of operating conditions. Results of this evaluation and future work are highlighted.

Commentary by Dr. Valentin Fuster
2010;():117-123. doi:10.1115/IPC2010-31134.

Evidence of compliance with the corporate policy of social and environmental responsibility of a company is not always fully matched to the daily lives of each of its regional managers or business units. Consolidated information on business reporting often generalizes individual experiments and thus hides the lack of capacity of the company to meet the parameters of social management and environmental responsibility. This article records the experience of the Management of Land and Oil Terminals Transpetro in the Midwest to face the challenge of overcoming this trend by developing mechanisms to regionally monitor performance in various dimensions of environmental responsibility and the relationship with internal public, environment, communities, government and society, among other things. The work was initiated in 2008 with the creation of the Center for Environmental and Social Responsibility, made up of professionals from different sectors of management, whose first task was to make a diagnosis which would position Transpetro Midwestern regarding the fulfillment of general requirements of social responsibility corporately as well as those specific requirements of the gas sector and energy. Compared with the “Corporate Social Responsibility Indicators”, this diagnosis has provided an overview of environmental responsibility actions already undertaken in the management system, and has pointed to those areas that require greater commitment. This allows the business unit to demonstrate why Petrobras is considered a benchmark for social and environmental responsibility in Brazil and the world.

Commentary by Dr. Valentin Fuster
2010;():125-134. doi:10.1115/IPC2010-31139.

The Osbra (Oleoduto São Paulo–Brasília) System is one of the main pipeline systems for Petrobras Transportes S. A. - Transpetro and its function is to carry gasoline, diesel oil and liquefied petroleum gas throughout the Midwest region of Brazil. Since the beginning of the operation of Osbra in 1996, the Environmental Management System (EMS) has evolved following the development of the company, nationally and globally. The basis of environmental management is ISO 14001, in which the system has been certified since 2001. The evolution of the management system has significant marks, among which we highlight the Program for Excellence in Environmental Management and Safety, the Program Process Safety and the Project on Excellence. The positive performance of the EMS is demonstrated in the excellent performance of indicators, such as, zero spills from pipeline and one of the best evaluations in the Program of the Evaluation of Environmental Management for the Company. This paper provides a review of this initiative, including the main processes, programs, difficulties, solutions, tools and indicators that contributed to the success in over fourteen years of operation of the Osbra System.

Commentary by Dr. Valentin Fuster
2010;():135-143. doi:10.1115/IPC2010-31148.

This paper approaches the environment impact mitigation measures adopted in the Cabiúnas-Reduc-3 project (Gasduc-3), completed in January 2010. This high complexity project has great strategic importance to the Company and for the extension of natural gas offer in Brazil. Due to the large size of the project and its interference with environmentally sensitive areas, several programs and actions have been carried out in the influenced areas what allowed the team to conclude Gasduc-3 and, at the same time, follow through with the premise of sustainable development.

Commentary by Dr. Valentin Fuster
2010;():145-148. doi:10.1115/IPC2010-31151.

This paper examines regulations for oil pipeline repair and considers some best practices to streamline permitting and assure compliance in the U.S. In the U.S., the federal government does not regulate construction or abandonment for oil pipelines, as it does with natural gas pipelines through the Federal Energy Regulatory Commission (the FERC). Instead, a number of federal, state, and local authorities have jurisdiction over oil pipelines and may regulate these activities differently. Because oil pipelines cross many jurisdictional boundaries, applicants find it challenging to navigate permitting requirements. For example, determining which permits are required for pipeline repair in U.S. waters can be difficult because, while such waters are defined by federal statute, the application of those rules is not uniform in all jurisdictions. In this paper, we present best practices for assuring compliance and streamlining the permitting process for oil pipeline construction, routine maintenance and repair in the U.S. To the extent possible, best practices mimic the FERC process, promote dialogue between regulators and oil pipeline companies, and foster a more transparent and effective environmental regulatory process. This paper presents the challenges encountered by the oil pipeline industry as a result of multiple agencies regulating the repair of oil pipelines. The paper then presents some discussion of the regulatory process and approaches to addressing challenges associated with this process. Following best practices to meet regulatory requirements is not only efficient and cost effective, but also helps assure long term regulatory compliance which affects the success of both small and larger scale projects.

Commentary by Dr. Valentin Fuster
2010;():149-158. doi:10.1115/IPC2010-31179.

On February 25, 2009, OCP Ecuador S.A. faced its first incident; an oil spill consisting of 11,700 barrels of heavy crude oil in an area of high biodiversity in eastern Ecuador. An earth movement caused stress in the pipeline causing its breakage. The temporarily impacted area covered 30 hectares of soil and gravel along 180 kilometers of three rivers that form the high watershed of the Amazon River; these rivers are the Santa Rosa, Quijos and the Coca. During the emergency, while workers rallied to contain the spill and clean the affected area, other workers took safety precautions regarding the health of the inhabitants of the area. Consequently, 1,258 residents from the Gonzalo Pizarro and Orellana cantons received medical assistance in order to rule out patients with pathologies related to the oil spill. OCP executed a joint effort with the Emergency Operations Committee (COE) stationed in Coca in order to supply water for the citizens that reside in the affected area. OCP responded to the requirements claimed by residents, all of which were approved by the COE. Communities affected by the event participated in cleaning efforts through the creation of temporary jobs for them. OCP strictly adhered to the regulations passed by the Ministry of the Environment and those of internationally accepted best practices for these types of events. The media and the citizenry were kept continuously abreast of developments. In addition, all corresponding works and reliability tests were performed on March 4 in order to restart pumping activities. On September 30th, 2009, and following a rigorous process of cleaning and remediation (L&Rr—in Spanish) activities, all tasks were completed in all affected areas prior to an inspection and a walking tour of the area performed by governmental authorities, community members and independent observers. For the collective benefit of affected communities, the environment and OCP, local authorities and international auditors recognized the model established during the event. OCP created a taskforce charged with the execution of the Environmental Remediation Program (PRA—in Spanish) and environmental authorities prepared and approved this program. The Environmental Remediation Taskforce (UPRA) covered the following aspects related to the incident: legal, environmental, cleaning and remediation technical aspects, as well as social, environmental, financial, insurance, internal and external communication aspects, along with a rigorous oversight of contractors. The model implemented is the first of its kind deployed in Ecuador. National and international regulations in force validated the methodology used to remediate the soil, riverbanks and surface water contaminated with the oil caused by the incident. The application of this methodology, aptly deployed in response to the distress situation present at the various affected areas, allowed a reduction in a short period, of the total hydrocarbon concentrations established in the environmental standard, to equal or lower values than those previously indicated for sensitive ecosystems. OCP developed and implemented a technical, environmental and economic matrix that allowed the Company to choose and justify the remediation methods used in affected areas.

Topics: Crude oil
Commentary by Dr. Valentin Fuster
2010;():159-165. doi:10.1115/IPC2010-31207.

The Ruby Pipeline is a 42-inch diameter pipeline that will transmit natural gas 675 miles from Opal, Wyoming, to Malin, Oregon. The pipeline alignment crosses landforms designated as playas at several locations in Utah and Nevada. Federal agencies reviewing environmental documents requested mitigation based on the concept that playas collect and hold rainwater on impervious clay bottoms for long periods of time, and that an open-cut trench could drain ephemeral lakes by penetrating impervious clay bottom soil layers and permanently alter the surface water hydrology of the playas. Trench plugs, segregation of excavated impervious soil, limited construction right-of-way, impervious backfill, and construction during the ‘dry’ season were the recommended mitigation measures, presumably to reduce the potential for surface water collected on the playa to drain into the subsurface through a trench cut across the playa. The surface-water hydrology concern may pertain to playa environments in semiarid areas such as the southern High Plains of the United States, notably northern Texas. The playas crossed by the Ruby Pipeline are lakebeds of major ancient lakes (Lake Bonneville in Utah, and Lake Lahontan and Lake Meinzer in Nevada) that were hundreds of feet deep and occupied extensive, topographically closed drainage basins. These lakebed playas are dominated by shallow groundwater. Surface water collects on the playa surfaces but is not responsible for playa formation or preservation. The water tends to be salty in lakebed playas in Utah and Nevada compared to fresh water in the ephemeral playa lakes in northern Texas. This brief case history describing playas dominated by groundwater instead of surface water may help advance the understanding that mitigation useful for surface-water dominated playas is not needed for groundwater-dominated playas. Geotechnical investigation included soil borings, test pits, laboratory testing, and surface geophysical surveys (seismic refraction and refraction microtremor [ReMi] methods).

Commentary by Dr. Valentin Fuster
2010;():167-172. doi:10.1115/IPC2010-31358.

This paper describes a multi-year program to assess pipeline crossings of sensitive watercourses along a major pipeline project. During the Front End Engineering and Design (FEED) phase a sensitive watercourse assessment team (SWAT) was established to provide a biophysical and construction assessment of selected watercourses to be crossed by a proposed pipeline project in western Canada. The SWAT comprised a fisheries biologist, a pipeline watercourse construction specialist and other technical support personnel. The field work included assessing biophysical data, fish habitat values, access to the crossing location, construction issues, site-specific mitigative measures and potential habitat compensation options, as well as providing photo documentation and a conceptual crossing sketch. The advantages of the SWAT assessment at a crossing site were: • It provided an effective and efficient field assessment of the proposed watercourse crossing in the early phase of the project. • It was a multidisciplinary assessment. • It provided a recommendation as to a preferred crossing location at the site. • It provided a recommendation as to preferred crossing method and timing of construction at the site. • The data were site-specific to the preferred crossing location. Three consecutive years of baseline biophysical field data were compiled and site reports generated using a custom designed database. Over 200 sensitive watercourses were identified based on environmental, geotechnical, and constructability factors and were visited by the SWAT team, sometimes more than once, for a total of 271 individual site assessments. Data collected during the FEED phase included site-specific information that can be used for ongoing project discussions, regulatory and community consultations, permitting and Fisheries and Oceans Canada (DFO) authorizations. The SWAT program also provided recommendations for minor or significant shifts in crossing location for 40% of the sites visited, resulting in changes to the pipeline alignment during the route evolution process.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2010;():173-177. doi:10.1115/IPC2010-31610.

HDD projects in the Lower Mainland of British Columbia face a myriad of regulatory policies and community and stakeholder interests due to concerns associated with land use, zoning requirements, and sensitive archaeological, agricultural and environmental areas. As a result, the Terasen Gas Incorporated (TGI) Fraser River South Arm Crossing Upgrade Project aka “the South Arm Crossing” was subject to review by several regulatory agencies and local municipalities and underscores the importance of effective communication and collaboration with regulators, the community, and stakeholders. This paper provides an overview of the regulatory authorizations and permitting requirements of the South Arm Crossing and identifies key stakeholders affected by the project. The South Arm Crossing reveals the importance of effective communication with regulatory agencies, land owners, businesses, and communities in the early stages of a project. Furthermore, agency and stakeholder cooperation can be enhanced with increased responsiveness to regulatory issues, and by incorporating stakeholder concerns into the project’s development. The lessons learned from the South Arm Crossing will enhance the pipeline community’s understanding of the federal and provincial regulations required to complete HDD projects in the Lower Mainland and provide strategies for developing communications and relationships with community members and stakeholders.

Topics: Rivers
Commentary by Dr. Valentin Fuster
2010;():179-185. doi:10.1115/IPC2010-31669.

Since the 1920s, over 400,000 km of petroleum pipelines have been installed in Alberta. Pipeline abandonment is an increasingly relevant issue as the pipeline network ages. The full or partial abandonment of pipeline systems is necessitated by factors such as wind or water erosion issues, pipeline integrity issues, changes in source supply and customer demand, urban development encroachment and regulatory requirements. Pipeline abandonment-in-place is generally the preferred option based on the technical condition and environmental sustainability of the pipeline, however, in some cases pipeline removal or partial removal cannot be avoided. In all cases, the planning process for abandonment includes technical evaluation, risk assessment, environmental assessment, landowner consultation and/or evaluation of future land use. Abandonment plans must also include environmental protection measures to be implemented during the removal of any pipeline segment and consideration of the post-abandonment implications of any pipeline left in place. These measures include topsoil conservation, erosion/sediment control and reclamation. This paper discusses environmental protection measures for pipeline abandonment, using issues faced during abandonment of one of the oldest natural gas pipelines in Alberta as a case study. Challenges faced during this project included gathering of appropriate historical information including leak history and maintenance records, removal of all aboveground facilities, accommodations for future land use plans including road development and measures taken to minimize the risk of the abandoned pipeline becoming a water conduit. In addition, the paper will discuss the extensive planning and construction effort required to undertake pipeline abandonment at several fish-bearing watercourse crossings, where pipeline exposures during high water events necessitated pipeline removal. A primary objective in the planning and the removal of the abandoned pipeline was minimal disturbance of the land.

Topics: Pipelines
Commentary by Dr. Valentin Fuster

GIS/Database Development

2010;():187-192. doi:10.1115/IPC2010-31147.

Recently enacted U.S. regulations will require distribution system operators to develop Distribution Integrity Management Programs (DIMP). The purpose of this regulation is to reduce system operating risks and the probability of failure by requiring operators to establish a documented, systematic approach to evaluating and managing risks associated with their pipeline systems. Distribution Integrity Management places new and significant requirements on distribution operators’ Geographic Information System (GIS). Operators already gather much of the data needed for meeting this regulation. The challenge lies in efficiently and accurately integrating and evaluating all system data so operators can identify and implement measures to address risks, monitor progress and report on results. Similar to the role geospatial solutions played in helping transmission pipeline operators meet Integrity Management Program requirements, this paper will discuss the role GIS can play in helping operators meet the DIMP regulations. Data requirements, storage and integration will also be presented. The paper will give examples of how risk-based decision making can improve operational efficiency and resource allocation.

Commentary by Dr. Valentin Fuster
2010;():193-199. doi:10.1115/IPC2010-31339.

There are a number of geomatics tasks required to support a Geohazard Management Program (Program). For the program implemented by BGC Engineering Inc. for several midstream pipeline operators, these tasks range from identification of potential geohazards (landslide, river erosion), to setup and support for field navigation, through to geohazard database management. Doing these in an efficient and effective manner requires substantial amounts of spatial data and a toolset containing both software and hardware components. For this Program geohazards are classified as hydrotechnical (e.g. a pipeline crossing a river) or geotechnical (e.g. a pipeline traversing a slope). Lists of potential geohazards are generated and provided to field crews who then navigate to each site and perform a field inspection. Navigation and inspection observations are accomplished with the aid of a ruggedized laptop connected to wireless GPS. Upon return from the field, sites are uploaded to Cambio™, an internet database for managing geohazards. Each site is assigned a frequency of action commensurate with the estimated level of risk. Assigned actions include follow-up ground inspections, detailed investigations, monitoring, maintenance and mitigation. An audit trail of site inspections, surveys and mitigation reports, photos, and site survey drawings, are all available for review within Cambio™, allowing access to the information from any site with an internet connection. This paper will present an overview of the Geohazard Management Program from a geomatics perspective, highlighting the integration of geomatics tools into a system designed to be used by engineering personnel, field technicians, and project managers.

Commentary by Dr. Valentin Fuster
2010;():201-207. doi:10.1115/IPC2010-31382.

Today’s’ high resolution ILI tools often incorporate extremely accurate Inertial Mapping Units (IMU) which provide spatial coordinates for every feature within a pipeline. This data may be useful across many levels of an organisation and so it is important to make the information available and practical. Google provides two near universally available mapping packages that may be easily leveraged to display GIS style data while in the field or in the office; Google Maps™ displays 2D information, while Google Earth™ provides 3D viewing. This paper presents several case studies where the use of Google Earth imagery combined with high resolution; inertially mapped MFL data provides immediate value to the pipeline operator.

Commentary by Dr. Valentin Fuster
2010;():209-211. doi:10.1115/IPC2010-31438.

Development of web based GIS application often requires high cost on base map datasets and software licenses. Web based GIS Pipeline Data Management Application can be developed using the benefit of Google Maps datasets combined with available local spatial datasets resulting comprehensive spatial information. Sharp Map is an easy-to-use mapping library for use in web and desktop applications. It provides access and enables spatial querying to many types of GIS data. The engine is written in C# and based on the .Net 2.0 frameworks and provides advantages for integration with Pipeline Data Model such as PODS using .NET technology. Sharp Map enables development of WMS and web services for serving pipeline data management information on internet/intranet web based application. Open Layers is use to integrate pipelines data model and Google Maps dataset on single map display with user friendly and dynamic user interfaces. The use of Sharp Map and Open Layers creating powerful Pipeline Data Management web based GIS application by combining specific information from pipelines data model and comprehensive Google Maps satellites datasets without publishing private information from local datasets. The combination on Sharp Map, Open Layers, Google Maps datasets, and .NET technology resulting a low cost and powerful Pipeline Data Management web based GIS solution. Impact zone of the event then we can calculate their consequences and finally we can figure their risk.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2010;():213-219. doi:10.1115/IPC2010-31635.

Computer hardware and software have played a significant role in supporting the design and maintenance of pipeline systems. CAD systems allowed designers and drafters to compile drawings and make edits at a pace unmatched by manual pen drawings. Although CAD continues to provide the environment for a lot of pipeline design, Geographic Information Systems (GIS) are also innovating pipeline design through routines such as automated alignment sheet generation. What we have seen over the past two or three decades is an evolution in how we manage the data and information required for decision making in pipeline design and system operation. CAD provided designers and engineers a rapid electronic method for capturing information in a drawing, editing it, and sharing it. As the amount of digital data available to users grows rapidly, CAD has been unable to adequately exploit data’s abundance and managing change in a CAD environment is cumbersome. GIS and spatial data management have proven to be the next evolution in situations where engineering, integrity, environmental, and other spatial data sets dominate the information required for design and operational decision making. It is conceivable that GIS too will crumble under the weight of its own data usage as centralized databases become larger and larger. The Geoweb is likely to emerge as the geospatial world’s evolution. The Geoweb implies the merging of spatial information with the abstract information that currently dominates the Internet. This paper and presentation will discuss this fascinating innovation, it’s force as a disruptive technology, and oil and gas applications.

Commentary by Dr. Valentin Fuster

Facilities Integrity Management

2010;():221-228. doi:10.1115/IPC2010-31064.

The reciprocating compressor has become one of the most important equipments in petroleum and chemical industry. Study on vibration of the reciprocating compressor has a great significance to monitor the safety and reliability of the compressor. But it’s very difficult to predict the compressor and achieve the desired goal due to the complicated structure and operational aspect of the compressor. Experimental solution is expensive and time consuming. Therefore, finite element analysis (FEA) method is proposed to predict and locate the breakage of several key components on reciprocating compressor in compressor station. Non-destructive fault diagnosis and troubleshooting of the compressor can be achieved by application of FEA. The reasonable and simplified 3D model of the reciprocating compressor, which is validated with the actual prototype, is built by a CAD drawing software-SolidWorks. Then the ANSYS FE model is created by importing the 3D model into a FEA software-ANSYS. The ANSYS FE model can be used for stress analysis as well as intrinsic property analysis of the structural components. In this paper there are several ANSYS FE models of key components presented, including crankshaft, connecting-rod, crosshead and air valve. Then FEA method is applied to the fault localization of those components. According to the simulation results, the sites vulnerable to failure can be fixed on key components. The conclusions are consistent with the problems during the normal operation. Therefore, FEA is an effective and prospective method on fault prognosis of the reciprocating compressor.

Commentary by Dr. Valentin Fuster
2010;():229-232. doi:10.1115/IPC2010-31065.

Large storage tanks for oil storage are widely used in petrochemical industry. Corrosion in the tank floor and wall is a serious threat for environmental and economic safety. Owing to their unique potential for long-range, in-plane propagation through plates, Ultrasonic Guided Waves (UGW) offer an obvious solution in the development of an on-board structural health-monitoring (SHM) system, providing assessment of structural integrity for storage tank floor and wall defect in-situ inspection. This paper presents this application by focusing on their propagation through the plate structure. Even very small mechanical discontinuity or geometry change of plate structure, e.g. corrosion defect on tank floor, will influence the propagation characteristic of the guided waves. These effects are measured as mode changes, frequency shifts or filtering, reflection and diffraction of new ultrasonic modes or overall distortion of the original ultrasonic signals. By capturing and analyzing these changes we can deduct the corrosion defect of the tank floor and wall which causes the ultrasonic signal change and interactions. The T/R transducers are required to be attached on the outer edge of the tank floor and outer surface of the tank wall. The technique is developed based on the Lamb wave transmission tomography. Starting from the dispersion curve and choosing the appropriate wave mode, the propagation of the guided waves in the tank floor and wall has been carried out through numerical simulation and the experiment has been conducted for verification using the full-size oil storage tank. The low frequency guided waves can propagate longer distance in planar and tubular structures. The later has been already used in pipeline inspection. The complexity of the application of ultrasonic guided wave in tank floor inspection lies in the object containing multiple lap joint welds along the large diameter of the tank (up to 100 m) and the complicated reconstruction of the two-dimensional defect distribution information. The main scope of the investigation was the application of the ultrasonic transmission tomography for localization of non-uniformities of inside tank floor, taking into account ultrasonic signal losses due to the loading with oil on the top and ground support at the bottom for the tank floor, and the loading with oil inside for the vertical tank wall.

Commentary by Dr. Valentin Fuster
2010;():233-239. doi:10.1115/IPC2010-31080.

Much manpower is needed and a lot of materials are wasted when the floor of large above-ground storage tank (AST) is inspected with conventional methods which need to shut down the tank, then to empty and clean it before inspection. Due to the disadvantages of that, an in-service inspection method using acoustic emission (AE) technology is presented. By this mean the rational inspection plan and integrity evaluation of tank floors can be constructed. First, specific inspection steps are established based on the acoustic emission principle for large AST’s floors and the practical condition of AST in order to acquire the AE corrosion data. Second, analysis method of acoustic emission dataset is studied. Finally, maintenance proposes are provided based on results of analysis for the corrosion status of the tank floors. In order to evaluate the performance of our method, an in-service field inspection is practiced on product oil tank with a volume of 5000 cubic meters. Then a traditional inspection procedure using magnetic flux leakage (MFL) technology is followed up. Comparative analysis of the results of the two inspection methods shows that there is consistency in localizing the position of corrosion between them. The feasibility of inservice inspection of AST’s floors with AE is demonstrated.

Commentary by Dr. Valentin Fuster
2010;():241-246. doi:10.1115/IPC2010-31104.

As an important production facility, storage tank plays a more and more important role in the storage and transportation of crude oil and chemical product. The remaining life prediction of storage tank is to forecast the thinning trend of plate thickness, and forecast remaining life on the premise that remaining strength of storage tank meets the tank operation and safety requirements. Maximum corrosion depths of tank bottom plate obey the maximum extreme value distribution. Based on maximum extreme value distribution and statistics of corrosion data, the calculation formula of the remaining life prediction for large-scale crude oil storage tank was obtained by formula derivation. Compared with API STD 653 and EEMUA 159, the inspection interval specified by China standard SY/T 5921 is relatively conservative. The remaining life of a certain crude oil storage tank (tank A) in china is determined by the remaining life of tank bottom plate. The remaining life of tank A at the reliability of 0.99, 0.999 and 0.9999 are 25 years, 20 years and 17 years, respectively. For the acceptable failure probability of 1×10−4 , the inspection interval of tank A can be extended from required 5–7 years specified by China standard SY/T 5921 to 17 years. The remaining life of crude oil storage tank predicted by the method proposed in this paper can be used as an important reference in the determination of inspection interval and tank’s maintenance.

Commentary by Dr. Valentin Fuster
2010;():247-253. doi:10.1115/IPC2010-31352.

Pipeline facilities are ageing and will likely soon come under closer scrutiny from federal regulation. It is imperative that sound reliability based inspection procedures be established that meet the goals of an organization while controlling time and cost. DNV Columbus has developed a statistically based sequential inspection decision support system for this purpose. This system was implemented for an international petroleum company and quickened the inspection process by making a “stop inspections” or a “continue inspections” decision after each inspection at a facility. This system allows inspections to be stopped because the desired reliability metrics have been met. This means that the point of diminishing returns has been met based on inspections that did not reveal a significant amount of corrosion. At this point, further sampling would provide minimal additional value to the reliability assessment. Inspections can also be stopped because the estimated reliability metrics have not been met. Stopping for this reason indicates the facility may need more significant repair or replacement. Engineers and managers can then make a decision that includes a variety of factors including safety and the economic feasibility of alternates. In contrast, when using this method, inspections continue because insufficient data have been collected to determine whether the reliability metrics have been met. This system will be illustrated with actual data. It will also describe the use of four key safety factors in developing site specific reliability goals. These factors are consequence, off site migration probability, product type, and facility size. This work can result in a major savings in time and financial expenditures for an inspection cycle. This reliability based inspection methodology leads to the following improvements: 1) Quicker decisions to save time and money, and allows more sites to be inspected in a timelier manner, 2) The reliability of a group of inspections performed is quantified after each inspection, 3) Results at a facility are broken down by database driven categories into a scorecard, 4) Methodology kept generic to be easily adapted to a wide variety of situations.

Commentary by Dr. Valentin Fuster
2010;():255-261. doi:10.1115/IPC2010-31357.

While in-line inspection tools have been around for many years, the primary focus for this technology has always been on long sections of mainline pipe. The recent increased attention on facility integrity, as well as US Department of Transportation (DOT) baseline assessment requirements, have made it necessary to develop inspection tools and techniques for pipelines that have previously been considered non-piggable. Within industry, the term non-piggable has been used to describe pipelines that cannot be inspected with traditional free swimming mainline inspection tools using standard launch and receive traps. Typical reasons for classifying a pipeline as non-piggable include: • No launch or receive facilities; • Mechanical design (number/type of bends, diameter changes, offtakes etc.); • Operating conditions (zero/low/high pressure, zero/low/high flow, type of product, pipeline cleanliness etc.). Within the Enbridge system, a lack of launch and receive facilities has been the main obstacle on laterals and delivery/receipt pipelines. However, mechanical design and operating conditions have been factors on certain pipelines. The preferred method to inspect these pipelines, whenever possible, is to use in-line inspection tools, as opposed to other options such as External Corrosion Direct Assessment (ECDA) or hydrostatic test. While inspecting these short sections of pipe has proven challenging, various in-line inspection tools and techniques have been developed to meet this requirement. This paper will discuss some of the challenges faced and different solutions that have been developed to successfully inspect these types of pipelines.

Topics: Inspection , Pipelines
Commentary by Dr. Valentin Fuster
2010;():263-269. doi:10.1115/IPC2010-31368.

The occurrence of accidents which resulted in lost work time, since 2007, prompted the Company to invest in a new Educational Program to prevent accidents. The program was divided into several parts. One of these parts was the project on Safety Culture. The Safety Culture project had been implemented since September, 2009, at PETROBRAS TRANSPORTES S.A. – TRANSPETRO, in Guarulhos, São Paulo, Brazil. The project had intended to change the employee’s behavior, informing the employees, who are exposed the risks, to know and understand the risks associated with their tasks, delivering a higher perception of the risks and making possible a change of behavior resulting in employees reaching a safe attitude. The Safety Culture project was developed specifically for TRANSPETRO. The project was divided in three parts: Safety Culture Visual, Procedures and Leading with Safety. This paper will discuss the content one part, Safety Culture Visual. The Safety Culture Visual concept has as its main objective to completely change the visual of the Company. In this concept about Safety Culture Visual, the Company wanted to demonstrate its concern with employee’s safety. Although the goal of the project was to change worker’s behavior, it was important first to communicate that having a strong Safety Culture is a main objective of the Company’s culture. The beginning of the paper discusses how the company can change its visual. By changing your visual, the company can demonstrate to workers that they are interested in their safety and their lives. Posting warning signs at the entrance of the company, at the entrance of the offices, streets, work areas, and other settings where employees must go were all small signs that the company had started to focus on the importance of having a safety culture. By installing warning signs everywhere, workers who are exposed to the risks can better know and understand the risks associated with their tasks. This greater awareness of the risks associated with their tasks provide the employee a greater insight to the risks, enabling a behavior change and helping them reach a complete attitude on safety. The methodology that the Company has been using to implement this change in vision is an “Andragógico Model”, exploring the experience of the person; with a focus on the day by day work and daily life situations. The project has been applied in the form of weekly leadership meetings, where everybody has the opportunity to suggest ideas as to promote the change. Expecting results and consequence of the Project: • to turn the concept of safety into a real value to the worker; • to preserve the integrity and to give value to the life of the employee; • pursue a lasting and stable changing of behavior, with a culture based on safety; and • to support the management safety system and reduction of accidents. This project has reduced worker’s exposure to risks and has diminished the number of industrial accidents. Accidents with lost time: using a different concept to deal with safety, focusing directly on the behavior of the worker, leading the worker to a shaper perception of the risks and thus enabling a change of behavior towards a safer attitude.

Topics: Safety
Commentary by Dr. Valentin Fuster
2010;():271-280. doi:10.1115/IPC2010-31460.

Enbridge Energy Partners (EEP) (“Enbridge”) purchased a Tank Storage Facility in Cushing, Oklahoma in 2004. After the acquisition, it was discovered that pipe records were incomplete and hydrotest documents were unavailable for some of the pipe segments in the tank facility. In order to comply with the Code of Federal Regulations (CFR) 49 Part 195, it was determined that piping at the Cushing Facility should be operating under “low stress” conditions. To determine if this condition could be met, the internal design pressure and yield strength (“YS”) were required for each pipe segment. Without pipe records, neither the internal design pressure, nor the YS was known. In 2007, a project was undertaken by Enbridge to inspect and test all pipe segments identified to have missing pipe records. The project’s objectives were: (1) To establish procedure and process for nondestructive evaluation of tensile properties of in-service pipe; (2) To collect pipe characteristic information (i.e. diameter, wall thickness); (3) To determine if the piping could be considered low stress piping; and (4) If the piping could not be considered low stress, to select a course of action from the following options: a. Lower the Maximum Operating Pressure (MOP), b. Hydrotest the piping, c. Remove/Abandon all unnecessary lines. Two existing reports justified the use of hardness as a means of determining the YS of in-situ piping. Based on these reports, Enbridge developed the following project scope: (1) For all piping with missing records: a. to collect hardness data of in-situ pipe using two portable hardness testers (any hardness measurements taken with these portable hardness testers are hereinafter referred to as “field hardness”), b. to measure wall thickness of in-situ pipe; (2) To collect field hardness, lab hardness, YS and tensile strength data of pipe coupons of various diameters in order to establish a field hardness to YS correlation; (3) To determine the YS of the in-situ pipe using field hardness measurements and the established field hardness to YS correlation determined above; (4) To determine if the pipe could be considered low stress at existing operating pressures; (5) For pipe segments not deemed low stress at existing operating pressures, to calculate an internal design pressure (Allowable Working Pressure or “AWP”) required to maintain low stress conditions. This paper will describe the method used to determine YS and AWP of in-service piping using field hardness and compare the results obtained using this method to the YS and AWP determined using CFR Title 49 Part 195.106.

Commentary by Dr. Valentin Fuster
2010;():281-287. doi:10.1115/IPC2010-31492.

The casings in a gas storage or production well can have large longitudinal loads in addition to the hoop stress resulting from internal pressure. Under certain circumstances these loads need to be taken into account when evaluating the remaining strength of corroded areas. The most commonly used method for corrosion evaluation is based on B31G which does not include longitudinal loads. This paper outlines the range of longitudinal loading where the B31G approach is valid. In addition, it presents a method to evaluate the remaining strength of the corroded area where the B31G approach is not valid. The procedure has been validated by burst tests of casing with real and machined metal loss under axial loading.

Topics: Stress
Commentary by Dr. Valentin Fuster
2010;():289-303. doi:10.1115/IPC2010-31537.

Pipelines and piping frequently suffer from metal loss that threatens their integrity and serviceability. Multiple repair options exist for straight sections of pipe; however, repair options for pipe fittings such as elbows and tees are typically limited to composite repair systems, or section replacement. The latter method can be costly as it often requires at least a partial shut down of the pipeline while the section is replaced. A composite repair system however, can be performed in place during operations at a greatly reduced cost. The main challenge with the composite repair system is the required demonstrated ability to restore integrity and serviceability to the same level as the original metal system. Over the past 10 years, Stress Engineering Services, Inc. has been greatly involved in evaluating the ability of many composite repair systems to restore the original pipeline structural integrity by testing methods and analysis methods. The current paper investigated the ability of the Armor Plate Pipe Wrap (APPW) system to restore the burst pressure of tee and elbow pipe fittings with 60% metal loss to that of a nominal thickness system. In this program four full scale burst tests were conducted: on 12-inch nominal pipe size (NPS) Y52 tee and elbow pipe fittings. All four fittings had 60% metal loss; two were repaired with APPW, and the other two were not repaired. Prior to burst testing, elastic plastic finite element analyses (FEA) were performed to adequately size the repair thickness. The results of the FEA calculations predicted the restoration of the burst pressures of the repaired fittings up to a 1.6% agreement with the actual burst pressure results. Furthermore, the burst pressure of the 60% metal loss tee was increased from 3,059 psi (unrepaired) to 4,617 psi, or a 51% improvement. The burst pressure of the 60% metal loss elbow was increased from 2,610 psi to 4,625 psi, or a 77% improvement. Both the analysis and testing results demonstrated that composite materials can restore the pressure integrity of corroded tee and elbow pipe fittings.

Commentary by Dr. Valentin Fuster
2010;():305-310. doi:10.1115/IPC2010-31654.

In response to strong customer demand, Enbridge Midstream Inc. (Enbridge) expanded its’ crude oil contract terminal facilities which included a new terminal near Hardisty, Alberta. Commissioned in 2009, the new Hardisty Contract Tankage (HCT) terminal provides services to accumulate medium- and long-term liquid crude volumes on a fee-for-service basis. Stantec Consulting Ltd. (Stantec) was selected to perform the conceptual and detailed design based on their terminal experience and working relationship with Enbridge. Given the inherent intermittent operation of this facility it was deemed critical to design integrity management into the facility. The conceptual and detailed design project team included members from Enbridge’s Integrity Management team to enhance the design.

Commentary by Dr. Valentin Fuster
2010;():311-316. doi:10.1115/IPC2010-31656.

The South East Supply Header (SESH) is a relatively new pipeline placed into service in September of 2008. The 42″ /36″ pipeline originates near Delhi, Louisiana and ends near Coden, Alabama. The pipeline has a nominal capacity of 1 BSCFD and includes three (3) mainline compressor stations, two (2) booster stations and numerous meter stations.

Commentary by Dr. Valentin Fuster
2010;():317-324. doi:10.1115/IPC2010-31681.

Electron backscattered diffraction (EBSD) investigations were carried out to obtain the microtexture, grain boundary character, and physical microstructural parameters, such as the grain size and grain shape distributions, of API X65 pipeline steel that experienced extensive intergranular stress corrosion cracking (IGSCC). The orientation distribution functions (ODF) and the grain boundary character distributions (GBCD) of the cracked and crack-arrest microstructures were obtained from the EBSD data of the corresponding regions. First, a Voronoi algorithm based microstructure reconstruction model has been utilized to generate model microstructure that resembles the experimentally observed ones. Subsequently, a Markov Chain–Monte Carlo model, coupled with the grain boundary character and orientation dependent vulnerability statistics, has been employed to simulate the crack propagation behavior. The simulation results are in good agreement with the experimental observations.

Commentary by Dr. Valentin Fuster

Operations and Maintenance

2010;():325-336. doi:10.1115/IPC2010-31018.

Movements of pigs in gas pipelines are subject to more stringent parameters than that in liquid pipelines, predominantly due to the compressibility of gas. This is accentuated when the pig has to negotiate an upward inclination in the section of the pipeline, where the gravity force due to its weight can compromise the driving pressure drop across it. On a downward slope, a pig can accelerate to a velocity higher than the maximum required for the proper operation the instrumentation (which is typically around 5 m/s). On the other hand, in-line inspection tools often face challenges at wall thickness transitions or bends. The ability to accurately predict the functional performance of pigs is vital in the design and operation of pipelines and their associated pigging programs. The present paper provides a general formulation for the motion of pigs in an inclined pipeline section, taking into account effects of gas properties, wall friction, by-pass flow for speed control, differential pressure across the pig, seal efficiency, and gap flows, among other parameters. Comparison between model prediction and actual data from pigging a 158 km NPS 18 gas pipeline on TransCanada’s pipeline system in Alberta, Canada is presented. The elevation profile along this pipeline contains both positive (upward) and negative (downward) slopes. This is a lateral line which features 28 gas receipt points along the line, all were feeding in gas during the pigging program. Good agreement between model prediction and field data is demonstrated within ± 8% of St. Deviation. Example of a problem occurring at wall thickness transition at a valve section is demonstrated by a sudden stop of an MFL tool followed by a shootout at a higher velocity once the pressure is built up behind it.

Commentary by Dr. Valentin Fuster
2010;():337-343. doi:10.1115/IPC2010-31098.

A new technology for external rehabilitation of pipelines, known as XHab™, has been developed. This method involves wrapping multiple layers of ultra-high strength steel (UHSS) strip in a helical form continuously over an extended length of pipeline using a dedicated forming and wrapping machine. The reinforcement afforded by the strip can be used to bring a defective section of pipe (e.g. externally corroded or dented) back to its original allowable operating conditions, or even to increase the allowable operating pressure if the desired operating conditions exceed the original pipeline design limits. This paper describes the design, manufacture and testing process for a self-propelled wrapping machine for in-field rehabilitation. The wrapping apparatus consists of several major components including an opening sufficiently wide to receive the pipe, a movement assembly, a winding head, a preforming device, an accumulator and an oscillating adhesive applicator. The wrapping apparatus uses the winding head to wrap the reinforcing steel strip around the pipe. The movement assembly uses a pair of tracks in contact with the pipe to drive the wrapping apparatus along which enables helical wrapping of the reinforcing strip material. The oscillating adhesive assembly applies structural adhesive to the pipe immediately before the strip is wound. The winding head, motive assembly and adhesive applicator are electronically synchronized to one another to enable precise control of pitch and adhesive volume. The paper also describes the field application of XHab including mobilization/demobilization of equipment and interaction with other rehabilitation equipment, as well as specific aspects such as initiation and termination of wrapping, protection of rehabilitated area and implementation of cathodic protection.

Topics: Steel , Pipelines , Strips
Commentary by Dr. Valentin Fuster
2010;():345-349. doi:10.1115/IPC2010-31122.

A crude oil pipeline transporting Daqing crude in the Northeast of China had not been carried out pigging for four years. The wax deposition in it increased gradually over past four years. In this paper, from the operation data of the pipeline among the four years, the average hydraulic wax deposition thicknesses are calculated and analyzed statistically. Based on the results, the increment of the wax deposition in the long-term unpigged crude oil pipeline is concluded qualitatively and so a mathematical model for predicting the average hydraulic wax deposition thickness of such a pipeline is created. The physical meanings of the coefficients in the model are explained in the paper. Also, as an example for showing how to use this model, the statistical results on certain section of the pipeline are selected and the determination for the coefficients is introduced in detail.

Commentary by Dr. Valentin Fuster
2010;():351-358. doi:10.1115/IPC2010-31171.

A crude oil pipeline transporting heated Daqing crude in the Northeast of China had not carried out pigging for four years and the wax deposition in it was very serious. The existence of wax deposition layer decreased the heat loss of the crude in the pipeline during its normal running, but this did not mean it would also make the pipeline cool down slowly after the shutdown of the pipeline, that is, the wax deposition does not always benefit to the heat preservation of a long-term unpigged hot crude pipeline. So the restart safety of a long-term unpigged hot crude pipeline could not be derived directly from that of the same pipeline pigged before shutdown, even qualitatively. In this paper, study on the safety of the restart of a long-term unpigged crude pipeline is conducted based on numerical simulation and significant conclusions are drawn.

Topics: Safety , Pipelines , Crude oil
Commentary by Dr. Valentin Fuster
2010;():359-367. doi:10.1115/IPC2010-31245.

It is often recommended that the operating pressure of a pipeline be reduced prior to investigating suspected mechanical damage in the field, due to the unknown severity of the damage. The primary question is: knowing only what can be inferred from in-line inspection and the characteristics of the pipeline, what is the appropriate amount of pressure reduction? Secondarily, operators also question whether the same pressure reduction is necessary for all pipelines, e.g. different Location Classes, and all modes of damage, e.g. rock-induced damage as opposed to encroachment damage. Two levels of assessment are provided: a conservative “Level 1” assessment relying on mainly qualitative information and requiring no calculation, and a “Level 2” assessment that is considerably more involved but which could justify a smaller pressure reduction in response to the damage. The choice of assessment level will depend on the information available to the operator, as well as on the degree of conservatism the operator desires to invoke.

Topics: Pressure
Commentary by Dr. Valentin Fuster
2010;():369-377. doi:10.1115/IPC2010-31308.

The purpose of this paper is to present the study concerning the evaluation of the repair logistics of gas pipeline Urucu-Coari-Manaus (extension of 600 km), that was constructed to operate in the Amazon Brazilian region. Repair logistics is a challenge, regarding specific operation conditions in the jungle, environment and flood variations, difficulty on accessing pipeline right-of-way, difficulty on transportation, etc. Workshops were held, gathering most experienced company personnel from different PETROBRAS sectors (engineering, operation, repair centre, integrity area, Brazilian Army, offshore sector, etc.), in order to evaluate and establish strategies for each identified failure scenario, considering type of repair, logistics, resources and costs. The first step of the study was to incorporate the experience obtained from the engineering team, responsible for the construction of Urucu-Coari-Manaus gas pipeline as they had to face unexpected and adverse conditions. Based on their experience, different pipeline sections were defined, considering specific features, like isolation, flooded areas, river crossings, access limitations, etc. The second step was brain-storming workshops with the purpose of providing the best PETROBRAS evaluation of pipeline sections repair strategies, logistics and resources. Failure frequencies were raised and addressed, as well as variables like: - time for failure detection, for digging, for repair, for resources arrival, considering different logistics and transportation modes (using specific boats, helicopters with special characteristics, such as suitable for long line operations (load line greater than one rotor diameter in length), capable of transporting heavy equipment, etc.). Innovative ways of repair were conceived and proposed to be used. Supply contract conditions for thermo plants, industrial and residential consumers were considered. Finally, a cost/benefit analysis was performed, considering expenses on logistics and resources and benefits associated with avoided losses for each specific failure scenario, in order to provide support for decision making process.

Commentary by Dr. Valentin Fuster
2010;():379-382. doi:10.1115/IPC2010-31346.

Double Block and Bleed (DBB) is the preferred approach used to maximize safety while performing piping maintenance. The aim of the paper is to outline an innovative method of achieving DBB on pressurized piping or pipelines. DBB is traditionally achieved by several methods, for example, through using Two Valves, a Valve & a STOPPLE® plugging head, a STOPPLE plugging head & an Isolation Plug or Tandem STOPPLE plugging heads. There are also several DBB methods which utilize inflatable bags or bladders. The STOPPLE Train is a patent pending tool that uses 2 STOPPLE® plugging heads. Only one hot tap is required in the piping for which the STOPPLE Train is inserted. The first STOPPLE plugging head is the trailing plugging head and forms a primary seal. The second STOPPLE plugging head is the leading plugging head and forms a secondary seal. Once sealed, the bleed is accomplished through a relief port allowing downstream maintenance to commence.

Commentary by Dr. Valentin Fuster
2010;():383-385. doi:10.1115/IPC2010-31349.

A major nitrogen gas pipeline provider in Latin America was faced with an emergency situation when a local hot tapping contractor failed to perform what seemed to be a simple hot tapping job on an 8″ nitrogen gas line. The tapping machine became stuck and caused a gas leak. Faced with a leaking pipe and a hot tapping machine that was stuck to the pipeline, the pipeline provider called upon TDW to resolve the multiple issues and perform the hot tap as originally intended. A customized solution was required and a special plugging head was designed that included a plug holder with a urethane plugging head. A 6″ hot tap was made on the part of the pipeline that was direct opposite to the faulty hot tap, and the hole from the faulty hot tap was immediately plugged with the urethane plugging head. The tapping machine was subsequently removed and valve finally closed. The focus of this paper is intended to illustrate the importance of safety and introduce a unique back-up solution that can be put together in the event of an emergency.

Topics: Pipelines , Nitrogen
Commentary by Dr. Valentin Fuster
2010;():387-392. doi:10.1115/IPC2010-31393.

Arc blow is a phenomenon associated with the deviation of the arc that usually occurs during arc welding of pipelines under repair. This phenomenon is most commonly observed after the pipeline has been inspected using an in-line magnetic flux leakage (MFL) inspection tool, which magnetized the pipe wall during the inspection run. Among the different welding techniques, DC arc welding is one of the most popular in the oil and gas industry due to its versatility and relative low cost. The interaction between the magnetic field associated with the current flowing through the electrode, and the residual magnetic field in the pipeline under repair can produce arc blow. In this work, a simple method to reduce arc blow during DC arc welding of pipelines has been developed. In contrast to the methods so far available in the literature [1,2], the method proposed here gives simple rules to be followed by welders with little background on magnetism. Residual magnetic field levels from different pipelines in southern Mexico were measured in the gap after damaged pipeline sections had been cut, and in the V groove once the new pipeline sections had been inserted. Magnetic finite element simulations were performed with freeware (FEMM) for the residual magnetic field compensation using real-life pipeline dimensions and field parameters. A large number of simulations were performed, using as variables the residual magnetic field in the groove, the number of coil turns required for the residual magnetic field compensation, the DC current flowing through the coil and the electrode, the position of the coil with respect to the groove, and the pipeline wall thickness and diameter. An empirical predictive equation was developed for the compensation of the residual magnetic field from the results obtained during the simulations. Most of the procedures developed in the past propose to adjust the current in order to compensate for the magnetic field in the groove, which is a disadvantage during DC arc welding since the electrodes specifications do not cover a wide range of current values. In contrast, the method proposed herein supersedes this disadvantage by granting the possibility of properly selecting the number of coil turns and the position of the coil with respect to the groove, in order to compensate for the residual magnetic field in the groove.

Commentary by Dr. Valentin Fuster
2010;():393-398. doi:10.1115/IPC2010-31462.

In order to improve the operational management of a products pipeline, we need to identify a suitable formula to calculate the volume of the contaminated product accurately when it arrives at the end point of the products pipeline. This paper presents a calculation method of mixing volume in a products pipeline. By combining the empirical formula of Austin-Palfrey with field data, we establish a new formula which meets the characteristics of the products pipeline. The flow characteristics and growth rules of mixed oil products are considered in the formula of Austin-Palfrey, but many influential factors are not taken into account, such as the structure and the terrain of the pipeline, the characteristics of mixed oil products in pumping stations and the distribution of the products along the pipeline. We obtain a group of coefficients from field data which are collected from a products pipeline. This new formula is proved by the validation of field data; it not only can improve the accuracy of the mixed oil products volume prediction, but also can be easily used for field application. This paper also discusses the relationship between mixing volume calculation and the terrain of products pipeline.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2010;():399-403. doi:10.1115/IPC2010-31480.

In the restart process of pipeline containing waxy crude oil after shutdown, the rheological properties of oil, including viscosity, yield stress and thixotropy is studied. The entire restart process is decided by various factors; in this paper the effects of outlet temperature, shutdown and restart temperature as well as shutdown time duration to the rheological property are taken into the consideration. The measurements are employed using a controlled shearing rheometer to investigate rheological property based on different restart conditions. In addition, this paper has also researched affection of emulsion and blended samples mixing with two types of crude oil in various ratios. Finally comprehensive rheological evaluation to restartability is obtained.

Topics: Pipelines , Crude oil
Commentary by Dr. Valentin Fuster
2010;():405-412. doi:10.1115/IPC2010-31603.

Objective: This work aims to present to the Plan of Communications and Relationship with Communities implemented by TBG as a tool for the Bolivia-Brazil Pipeline integrity management. Scope: In studies carried out by the European Gas Pipeline Incident Data Group (EGIG), global statistics demonstrate that most accidents involving pipelines are caused by improper actions of third parties. The expansion of sugar cane crops and the improvements in utilities, such as telephone, electricity, water and sewage services in the cities along the pipeline have increased the number of events of interference in the right-of-way. These facts have evidenced the need for creating a Plan of Communications and Relationship with landowners and neighboring communities to assure the continuous monitoring of the Bolivia-Brazil Pipeline right-of-way. The Plan of Communications and Relationship with Communities is designed to reduce the risk of accidents caused by the improper action of third parties. The strategy of action is focused on strengthening the relationships among the right-of-way technical staff, TBG subcontractors, and other publics affected by the pipeline. It also encourages the use of the toll-free Gas Hotline (0800 026 0400) - TBG main communication channel with communities. The intensive publicity targeted at specific audiences ensures that local populations and other relevant publics raise their awareness on the importance of preserving the right-of-way, and the precautions that must be taken in their neighborhoods, mainly in cases of interferences, such as urban improvement projects and farming activities by keeping permanent contact with TBG through the Gas Hotline. This work will also present the interfaces among the right-of-way technical staff, the corporate communications team, and specific target audiences; communication resources, guidelines, technical training programs, Gas Hotline monitoring and management plans, indicators of services provided to the communities and landowners, and the results of the Gas Pipeline Management Program.

Topics: Pipelines
Commentary by Dr. Valentin Fuster

Pipeline Automation and Measurement

2010;():413-419. doi:10.1115/IPC2010-31006.

The risks to the local population, infrastructure and the environment posed by fluid spills associated with oil and gas pipelines running throughout the Greater Toronto Area (GTA) are evaluated using fuzzy inference rules encoded using JESS and fuzzy J. The evaluation uses data obtained in real time from web services, such as weather, Geographic Information Systems (GIS), for example, distances of event from emergency services and Supervisory Control and Data Acquisition (SCADA) systems, where available. These risks are diverse depending on the local infrastructure or lack thereof (in the case of the environment) indicated by the zoning of the area of the spill, population densities and other factors. The application uses an advanced Human Machine Interface (HMI) accessible via Hypertext Transfer Protocol (HTTP) from anywhere on the Web. It is intended to support decision making in emergency response scenarios.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2010;():421-435. doi:10.1115/IPC2010-31017.

Multi-objective optimizations were conducted for a compressor station comprising two dissimilar compressor units driven by two dissimilar gas turbines, two coolers of different size, and two parallel pipeline sections to the next station. Genetic Algorithms were used in this optimization along with detailed models of the performance characteristics of gas turbines, compressors, aerial coolers, and downstream pipeline section. Essential in these models is the heat transfer between the gas and soil as it affects the pressure drop along the pipeline, and hence relates back to the coolers and compressor flow/pressure settings. Further investigative techniques were developed to refine the methodology as well as to minimize the downstream gas temperature at the suction of the next station. Current operating conditions at the station were compared to the optimized settings, showing that there is room for improving the efficiency of operation (i.e. lower energy consumption) with minimum effort on the station control strategy. Two threshold throughput conditions were determined in so far as single vs. multi-unit operations due to the dissimilarity in the compressor units and associated gas turbine drivers. The results showed that savings in the energy consumption in the order of 5–6% is achievable with slight adjustment to unit load sharing and coolers by-pass/fan speed selections. It appears that most of the savings (around 70–75%) are derived from optimizing the load sharing between the two parallel compressors, while the balance of the savings is realized from optimizing the aerial coolers settings. In particular, operating the aerial coolers at 50% fan speed (if permitted) could lead to substantial savings in electric energy consumption in some cases.

Commentary by Dr. Valentin Fuster
2010;():437-443. doi:10.1115/IPC2010-31019.

In Brazil, National Metrology Institute, INMETRO, elaborated an N° 64 Ordinance, on April 11th 2003 [1], based on OIML [2]. This document approves the Metrological Technical Regulation, establishing the metrological and technical requirements applicable to measurement systems supplied with flow meters used in the measurement of oil, its derivatives liquid, alcohol anhydrous and hydrous alcohol fuel. For custody transfer purposes, liquefied petroleum gas (LPG) volumes are generally stated at a fixed base temperature and saturation pressure. As most volume transfers occur at temperatures and pressures other than standard conditions, these volumes are adjusted to standard conditions through the use of correction factors. The measurement uncertainty of these custody transfer systems must be controlled. Based in norms ASTM, IP, ISO and API – MPMS, the mathematical model for the calculation of the volume, it basically depends on quantities as: K factor, density, pulse number, turbine meter factor, temperature and pressure corrections. This work develops a methodology to calculate the LPG mass uncertainty that is completely different form the other liquid oil derivatives. This work details this calculation showing the complex temperature and pressure algorithms, including the equilibrium bubble point pressure. Based on this methodology, it is noticed that the pressure uncertainty contribution is not less than 43% overall the process and the expanded uncertainty is less than 1%, as required by INMETRO.

Commentary by Dr. Valentin Fuster
2010;():445-451. doi:10.1115/IPC2010-31056.

Architecture of the leak detection system is presented, and the leak detection method based on dynamic pressure and wavelet analysis is studied in this paper. The feature of dynamic pressure which is generated by the leakage of pipeline is analyzed. The dynamic pressure signal of pipeline internal pressure is acquired by dynamic pressure sensor when leakage occurs, and the signal is analyzed by wavelet analysis method to detect the singularity, and the singularity is used to recognize and locate the leak. From the comparison of analysis results between dynamic pressure and static pressure, in order to improve the sensitivity and stability of the leak detection system, a polling rule between dynamic and static pressure is implemented. Field tests of the leak detection system are presented and analyzed. The results of the field tests demonstrate that the leak detection method based on dynamic pressure and wavelet analysis can detect pipeline leak rapidly and locate the leak precisely. This leak detection system has been applied in 5000 km pipeline or so.

Commentary by Dr. Valentin Fuster
2010;():453-456. doi:10.1115/IPC2010-31063.

Oil storage tanks are crucial components in the petrochemical industry for transportation and storage. Corrosion of the tank floor and vertical walls is one of the most important safety concerns. In-situ inspection of the tank floor and walls with ultrasonic guided wave technique by edge- and wall-mounted transducers is still an active research area nowadays. A great deal of research has been conducted in detecting the defect of plate-like structures using Lamb waves. This application has been motivated by the fact that the Lamb wave velocity is the function of frequency and structural geometry (thickness), also the Lamb waves can propagate with low attenuation for long distance in plate structure. However, the complexity due to the existence of multiple Lamb wave modes weakens its applicability. Lamb waves are typically excited by transducers mounted on the surface of the inspected plates. Higher order modes are generated if the frequency-thickness product exceeds a certain threshold value that is dependent on the material of the plates. Low frequency guided waves can reduce this complication as only a small number of wave modes are generated. So operation with low frequency guided waves is usually recommended, but it encounters a problem that the resolution gets degraded hence small defects (compared to the wavelength) are difficult to detect. Our investigation considers the generation of guided waves in tank floor and vertical wall by edge excitation and wall-mounted excitation, respectively. Only when there is no access to the edge of the vertical wall, the wall-mounted excitation (surface excitation) is used. When the frequency-thickness product is small Lamb waves are generated, otherwise, longitudinal waves are generated. We investigate the intermediate frequency-thickness products where a pulse train of semi-longitudinal waves is excited. The pulse train is comprised of a leading pulse and some railing pulses, which have been predicted by the acoustic theory. The transition from Lamb wave to semi-longitudinal wave is investigated. In addition, energy transport from leading pulse to trailing pulses and the interaction of these trailing pulses with defects are studied. The results revealed that the semi-longitudinal wave is a viable option for tank floor and wall defect inspection.

Commentary by Dr. Valentin Fuster
2010;():457-461. doi:10.1115/IPC2010-31069.

Pipe is a very important tool for long-distance transportation of nature gas. In the long-term running, there will be inevitably an appearance of a rupture, leak or damage usually caused by manmade event or by nature disaster. Leaks may generate dangerous clouds of gas escaping from the high-pressure pipe and produce serious incidences involving fire and explosion endangering the life and property safety of people in and around the area. Monitoring of natural gas pipeline leaks will timely find out and locate these dangerous occurrences and reduce loss. Within the leak monitoring, the core contents are the accurate location of leaks as well as the rapid identification of different signal sources reducing false alarm ratio. Once a leak occurs, the supersonic jet of escaping gas can generate a non-linear & chaotic negative pressure wave signal based on static pressure measurement and an acoustic signal based on dynamic pressure measurement [1]. By properly interpreting these two kinds of signals together, it is possible to detect and locate the leak along the pipe. However, useful signals usually mix in the powerful backdrop signals and noises. In order to resolve the problem, the wavelet packet decomposition technique [2] is used to reduce the noises and get the feature signals of negative pressure wave and acoustic wave. Furthermore, a lot of different condition regulating signals for instance compressor start-stop, valve adjusting and gas turbulence can interfere with the accurate identification of leaks and result in false alarm. It is quite required to classify these similar signals. Thus, BP neural network [3] is used to quickly recognize the different pressure fluctuation signals. Finally, an integrated system developed by LabView is introduced to timely monitor the operation condition and locate the leak. Field tests indicate this system using negative pressure wave method, acoustic wave method, wavelet packet decomposition technique as well as BP network has a good effect.

Commentary by Dr. Valentin Fuster
2010;():463-470. doi:10.1115/IPC2010-31070.

This paper describes a new approach of data source fusion based on process fusion entropy for leak detecting of product pipelines. Data sources are either single-channeled or multi-channeled: single-channeled data sources can be structured or semi-structured process steady entropy, whereas multi-channeled sources are singular spectrum entropy and power spectrum entropy. In order to develop data sources fusion systems for pipeline leak detection in real-time contexts, we need to study all issues raised by the matching paradigms. This challenging problem becomes crucial with the dominating role of the internet. Classical approaches of data integration, based on schemas mediation, are not suitable to the pipeline SCADA (Supervisory Control and Data Acquisition) environment where data is frequently modified or updated. Therefore, we develop a loosely integrated approach that takes into consideration both steady and transient states which must be separated correctly in order to integrate new data sources. Moreover, we introduce a process fusion entropy-based Multi-data source Fusion Method (MFM) that aims to define and retrieve conflicting data from multiple data sources.

Commentary by Dr. Valentin Fuster
2010;():471-476. doi:10.1115/IPC2010-31087.

Identification of negative pressure waveform is the key of pipeline leakage detection. The feature extraction and the choice of the classifier are two main contents to solve the recognition problem. In this paper, a new feature extraction method based on the Projection Singular Value is presented. First of all, the two orthogonal singular value decomposition matrixes of the typical leakage waveform are extracted as the standard bases. Then the projection singular value features of the other pressure wave matrixes are extracted by being projected to the two standard bases. As the pipeline leakage is a small probability event, it is difficult to obtain the leakage samples. A multi-classification Support Vector Machine, which has the advantage of small sample learning, is constructed to classify these features in this paper. The field experiments indicate that the leakage detection based on this feature extraction and recognition model has a higher accuracy of leakage recognition.

Commentary by Dr. Valentin Fuster
2010;():477-484. doi:10.1115/IPC2010-31110.

The objective of this paper is to describe the effect of the differences between the pipe and the ultrasonic flowmeter internal diameters on the flow-rate measurement results, and to compare the values found with the differences on the pipe balance. The work included field analysis, numerical simulation and meter calibration. The ultrasonic meter balance differences were the reason for this research. The field analysis presents the balance and internal diameter differences. The numerical simulations comprise one, two and three-path meters with arrangements similar to the OSBRA meters. Three flowmeters were calibrated with water and different internal diameter meter runs. The results of the calibrations were compared with the results of the simulations, and also a comparison was made between the simulations and the actual field measurements. The conclusion is that internal diameter differences may generate differences in the ultrasonic flowmeter result, but the differences expected for OSBRA flowmeter results were less than 0.5% which is significantly less than the observed balance differences.

Topics: Flowmeters , Pipelines
Commentary by Dr. Valentin Fuster
2010;():485-490. doi:10.1115/IPC2010-31119.

The coupled method is usually used to solve the non-linear governing equations in oil/gas pipeline simulation applications, particularly for compressible fluid flow. In this paper, a segregated method with mesh refinement is proposed. The segregated method presents the advantage of the reduced computational memory and CPU time cost. In addition it also improves the convergence for the reason that the condition number is decreased as the matrix size is significantly reduced compared with the coupled method. In the presented method, a coarse mesh is adopted firstly. When the solution point for the nodes of this mesh is close enough to the optimal solution point, indicated by a certain criteria, a refine mesh is constructed by the solver thereafter. The value on the computing nodes for the refine mesh is computed by interpolation based on the previous solution point. Then the final solution for the refine mesh is obtained by the new segregated solver. Typical applications for oil/gas pipeline simulation are given. Results obtained by the method are compared with those obtained by using a “standard” software package to validate its accuracy. Results show that the average error between those solution obtained by different solvers is less than 1.0%. The efficiency of the new method is compared with the efficiency of a traditional coupled method. Numerical tests show that the method saves more than 50% of computational cost and the matrix size is reduced significantly.

Topics: Simulation , Pipelines
Commentary by Dr. Valentin Fuster
2010;():491-499. doi:10.1115/IPC2010-31133.

The São Paulo–Brasília pipeline (OSBRA) is a collection of installations built to transport, store and deliver Diesel oil, gasoline and Liquefied Petroleum Gas (LPG), from the Refinaria do Planalto (REPLAN) to several distribution companies located in the Brazilian Midwestern region. The volumes of these fuels are usually measured before deliverance at two serial measurement points: at the OSBRA tank farm installations and at the customer tank farm installations. At the OSBRA tank farms, the volume of each delivered batch product is usually measured by turbine type custody Measurement Station, called EMED. On the other side, at the customer tank farm, the received volume is usually measured by tank gauge systems or, in a few cases, by the customer EMED. The procedure used by PETROBRAS in Brazil is to compute the differences between these measurements and to compare these differences each month with a pre-established data range. If the differences computed are lesser than that benchmark values, the measurement is considered good. Otherwise, inspections of the measurement installations must be done, looking for the causes which deviates the measurement differences out of the desired range. That pre-established data range was built over historical data and using statistical tools. In this paper it is proposed to use statistical tools to analyze the behavior of the already existing historical data differences, rather than see only the differences magnitudes. These tools can give more information about each pair of measurement system, like the existence of systematic errors, the variability of each individual system and even if an observed difference greater than the pre-established data has real significance. These tools can be used to analyze other measurement system, like to verify the accuracy of operational measurement devices and to check if the mass conservation among the entries and withdraws of a system is being achieved. Furthermore, a real data analyze between two tank-farms is presented.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2010;():501-506. doi:10.1115/IPC2010-31159.

The dynamic pressure transmitter based on piezoelectric dynamic pressure transducer is designed. The characteristic of dynamic pressure transmitter when pipeline leak happened is analyzed. The dynamic pressure signal is suitable for pipeline leak detection for quick-change of pipeline internal pressure, while the static pressure is suitable for slow-change of pipeline internal pressure. This paper indicated that the dynamic pressure signal could be adjust to this detection that the pressure changes quickly in the pipeline. Field tests show that the proposed method detects pipeline leak rapidly and precisely. The field test in 68.2 km pipeline shows that the least detected leakage ratio with dynamic pressure method is 0.6 percent pipeline throughput and location error is 80 m.

Topics: Pressure , Pipelines , Leakage
Commentary by Dr. Valentin Fuster
2010;():507-514. doi:10.1115/IPC2010-31170.

Because of the smallness of flux and low of pressure it is difficult to judge the characteristic signal when leak occurs. In this paper, a new instantaneous energy (IE) distribution characteristics extraction method based on Hilbert-Huang transformation (HHT) was presented and it was used to recognize different states in pipelines, such as, normal state, valve operating, compressor operating and leak. Firstly, the physical relationship between instantaneous energy and structural state variation of a system was analyzed theoretically. With HHT, the instantaneous energy distribution feature of an unstable pressure signal was obtained, according to the relative contribution method of the instantaneous energy, its noise was eliminated. In order to judge the leak the typical character of the instantaneous energy of pressure in the input and output ends was discussed using correlative analysis. The experimental results showed that this method is effective.

Topics: Pipelines , Leakage
Commentary by Dr. Valentin Fuster
2010;():515-521. doi:10.1115/IPC2010-31177.

The São Paulo–Brasília Pipeline was designed and constructed to be highly automated and is remotely operated by the National Pipeline Control Center in Rio de Janeiro. The terminals along the pipeline are largely unmanned nights and weekends. The PETROBRAS quality control standard establishes practices for tracking, sampling and analyzing product batches transported through the pipeline. A prototype of an automatic sampling system was designed to collect up to ten flow proportional and or instantaneous (“spot”) samples of different product batches transported through the pipeline for any given programmed schedule. This would eliminate the need for operators to be present at the terminals during weekends, holidays and night time to manually collect samples. This paper describes the successful implementation of this project from technical specification of the development of an Automatic Sampling System, the solutions proposed for its special features, the main characteristics of the Technical Cooperation Agreement (TCA) used to develop it and the systematic approach used for design, and factory / field testing phases.

Commentary by Dr. Valentin Fuster
2010;():523-529. doi:10.1115/IPC2010-31194.

The National Control Center Operation TRANSPETRO created an information site that allows obtaining in real-time, using a system PIMS (Plant Information Management Systems), the information of process plants involved in the operations of our pipelines. The site provides different views for different clients. It also indicates the logistics transportation schedule progress, pipelines operation rates, comparative graphs (like global movement historical by period), transportation summaries by product or regions, covering all pipeline operations in Brazil. We also have links to process data of some plants long and short oil pipeline and for transfer of custody, obtaining information on pumps, valves, control valves, pressure and flow of the operation in progress. The pipeline location maps have a dynamic representation using geographic maps and showing the pipeline status. We are still developing applications to improve the information quality for clients, what give us feedback about the site’s stage progress. When we created the site of the National Control Center Operation TRANSPETRO we seek the principal function of technology PIMS “collect data from all areas of a plant and provides them for any type of application and makes it a great diffuser of information across the various organizational levels” [1].The benefits obtained from deploying the site using the PIMS technology brings potential gains support for the “decision-making of strategic and tactical levels of the enterprise” [2].

Commentary by Dr. Valentin Fuster
2010;():531-537. doi:10.1115/IPC2010-31247.

This paper will provide an overview of a novel acoustic reflectometry method that has been developed to detect features, such as blockages and leakages in industrial gas-filled pipelines. The basic concept of the technique is to inject a pulse of sound into a pipeline and then measure the reflections produced as this signal travels along the length of the pipe. Wherever the internal cross sectional area of the pipeline changes then there will be a refection produced. With knowledge of the speed of sound in the gas, the time of flight can be determined and the location of the change in cross sectional area can be identified. The technique is non-invasive and can be used to accurately detect many pipeline features, such as holes, blockages and other objects including valves and even welding joints. The paper will present the results from laboratory tests and field trials which will show the accuracy of the technique in detecting and locating blockages and valve status in industrial pipelines with lengths exceeding 10km and containing high pressure gas. In particular, details of a test where the method was used to identify valve status in a live offshore pipeline, containing high pressure gas will be provided. The difficulties associated with detecting abnormalities in pipelines containing flowing gas will be discussed and suitable signal processing methods will be described which should enable the technique to be applied as a continuous monitoring tool for offshore gas pipelines.

Commentary by Dr. Valentin Fuster
2010;():539-550. doi:10.1115/IPC2010-31248.

The OLAPA pipeline (Oleoduto Araucária–Paranaguá) is a 12in diameter pipeline and, with its 97,6 km in length, crosses a mountain region called “Serra do Mar” attaining elevations of about 900m in a dense forest region. Besides that, this pipeline crosses cities, farms, rivers, including a short submerse stretch in the Paranaguá’s bay. An incident in this pipeline could result in severe consequences, especially under the environmental point of view. Therefore, this pipeline was chosen to test the performance of a new leak detector system in Transpetro. The test consists in comparing the theoretical results with practical values of alarm times obtained from a controlled removal of product in an adequate point, in the middle of the pipeline, simulating a real leak. The system chosen to be tested was the LeakWarn system, which is a computational system that uses the mass balance principle with line pack change to analyze the pipeline operational parameters in order to alert when there is a risk of product leak. This test had the objective to evaluate the LDS and help Transpetro’s management team to analyze and decide whether or not to replace its current leak management system, since this new one showed the expected results and was compatible with the excellence level already achieved in the company. The field test was performed in July 7th 2009, through a vent valve far from the ends of the pipeline and it was made in three different conditions: 1) A big leak in the steady state of operation; 2) A small leak also in the steady state of operation; and 3) A big leak in the transient state of operation (immediately after the pump station start up). In order to proceed this test, a multidisciplinary team was assigned and several resources were used such as: Two tank trucks, a specially designed leakage line with control valves, measuring system, flexible hoses, communication systems and emergency equipments. The complete operation was monitored from the Control Center in Transpetro’s Headquarter, Rio de Janeiro. This paper describes the way the tests were performed and presents the results in order to contribute with useful information to be used in any field test for any other leak detection system. It shows how planning were done in order to insure that all operations would be performed according to strict procedures and in a safe way. It also describes the milestones and the work of each team involved in the activity, as well as their constraints and difficulties that had to be overcome during the planning and execution phases, that lasted approximately one year.

Topics: Leakage
Commentary by Dr. Valentin Fuster
2010;():551-558. doi:10.1115/IPC2010-31249.

This paper will discuss guidelines for the selection of pressure control valves (PCV) with electro-hydraulic actuators for use in liquid petroleum pipelines. The performance criteria for PCVs functioning in pipeline pressure control applications are distinct from those used in other industrial applications. Also, PCVs required for large diameter petroleum pipeline represent a relatively small number of total control valve applications. For these reasons, general practitioners of control valve selections, typically engineers at EPCs, commonly apply selection strategies that are effective in other industrial applications, but tend to be less so in pipeline applications. This paper will discuss control valve selection criteria including Critical Threshold Capacity, Effective Control Region and Valve Gain Band. Actuator selection criteria discussed in this paper includes Torque Requirements, Speed of Response, and Positioning Resolution.

Commentary by Dr. Valentin Fuster
2010;():559-564. doi:10.1115/IPC2010-31283.

Only a few parts per million of hydrogen are needed to produce detrimental results in higher strength pipeline steels. The cost of removal and subsequent replacement of a pipeline coating is high; thus a working hydrogen detector for field measurements must operate through the pipeline coating. An in-field sensor must utilize technology that provides rapid (or real-time) non-contact nondestructive measurements. Nondestructive low frequency impedance measurements can be used to determine hydrogen content in operating pipeline steel and weldments as well as through structural coatings. Low frequency impedance measurements have been correlated to hydrogen content in pipeline steel both in the laboratory and in the field. The use of real-time low frequency impedance measurements to monitor hydrogen content in coated steel weldments is presented.

Commentary by Dr. Valentin Fuster
2010;():565-576. doi:10.1115/IPC2010-31490.

The Bolivia Brasil Gas Pipeline (GASBOL) is a pipeline extending from the gas producing fields of Rio Grande, Bolivia, to Canoas, Brazil. It distributes gas to five states in Brazil, with a total extension of 3 160 km (1,970 mi) and a rated operating pressure of 100 kgf/cm2g (1,420 psig). GASBOL is owned and operated by Transportadora Brasileira Gasoduto Bolivia-Brasil S.A., TBG, a company whose shareholders are Petrobras, AEI América do Sul, Transredes, BBPP Holdings and Bear Gás. After several occurrences of flow turbine failures caused by large flow variations at some city gates, the design of new stations was modified to include a control valve upstream of the interconnection point with consumers. For operational city gates such functionality would imply delivery interruption to perform costly hot tapping procedures in order to install a flow control valve. Therefore, TBG’s engineering team was challenged to develop a cheaper and quicker solution. This paper describes TBG’s answer to that challenge, developing a low cost flow control solution at ten selected city gates along the pipeline. The stations were chosen based on several aspects such as volume capacity, line packing to the consumer, etc. The main objective is to ensure that the daily volume effectively delivered does not exceed the contracted volume, avoiding delivery failures due to imbalances caused by unplanned withdrawals, as a means to improve planning of the pipeline operational profile.

Topics: Flow control
Commentary by Dr. Valentin Fuster
2010;():577-585. doi:10.1115/IPC2010-31567.

The demand of natural gas in the Brazilian energy market is increasing very fast over the few years and it was necessary to enhance the operational performance and safety of the gas distribution. The perfect operation of the natural gas citygate stations is essential to guarantee the delivery of natural gas for the end users like local distribution companies, thermoelectric power plants and large industrial customers within the contracted marketing conditions. These stations receive natural gas directly from high pressure pipelines and reduce the pressure using regulation valves that provoke a temperature reduction due the Joule-Thompson (JT) behavior, typical of natural gases. This temperature loss is compensated by forcing part of the gas flow through water/glycol bath heaters that use natural gas as fuel in the heating process. Usually the downstream gas temperature condition is controlled above a minimal set point while modifying the three-way valve position that regulates hot and cold streams flows. A numerical tool has been developed to simulate the dynamic process inside the natural gas citygate station, and proved to be a reliable tool to analyze the transient performance of the main equipments (filter, three way valve, heater, JT valve, relief valves) when submitted to abnormal conditions or changes in capacity. The methodology developed is able to handle a variety of citygate design.

Commentary by Dr. Valentin Fuster
2010;():587-593. doi:10.1115/IPC2010-31577.

This paper describes a case of a Proportional Integral (PI) Fuzzy controller development, in order to optimize pipeline transportation capacity. Real process data were acquired so that a real pipeline could be simulated. The fuzzy adaptive PI controller system was developed and interacts with a hydraulic simulator, working on the set-point of a conventional PI controller. A conducted research prior to this work has shown that holding the intermediate delivery valves open as much time as possible, even if this results in a low flow delivering, is better than do a fast delivering in terms of pipeline transportation capacity. The objective of this system is to control the amount of products to be delivered to intermediate stations in such a way that the control valve remains open while the batch is running. Besides that, the control valve opening fraction is changed very smoothly preventing transients in the pipe, until it is closed, which occurs when the station has received the expected demand. In order to accomplish that some information have to be loaded in the software like product demand per station, operational limits of the valve being controlled (minimum and maximum flow, the flow meter operational limits were also observed) and products transported at the segment monitored. The software developed can be easily deployed as a specialist system generating logic to be embedded in SCADA Systems or standalone software.

Commentary by Dr. Valentin Fuster
2010;():595-604. doi:10.1115/IPC2010-31589.

The nature of real time advanced functions or systems for gas pipelines carrying two phase mixtures is complex, especially when the dominant phase is gaseous. In this case, the flow quite often requires periodic pig runs, among several other specific operational procedures. Thus, a robust, accurate, reliable and fast kernel is mandatory for good performance on leak detection, location and quantification, as well as any other real time function such as virtual instrumentation or inventory management and reconciliation. This work aims at comparing different transient two-phase one-dimensional kernels under the perspective highlighted above. Specifically, one may cite: (i) a two-fluid model, implemented in 20 years consolidated commercial flow simulator, bringing a kernel of first order in time and second-order in space, three continuity equations, and three momentum equations, where 2 different pressures are possible to be calculated; (ii) a simple two-fluid model to serve as the basis of a different way to approach the same problem. The main focus of this paper is on real time applications, then its main goal is to provide considerations and comparisons on accuracy, reliability and processing speed (CPU performance) coming from six different numerical methods and schemes. The commercial flow simulator is then being used as the basis of comparison, as it is considered highly reliable and robust by the market.

Commentary by Dr. Valentin Fuster
2010;():605-610. doi:10.1115/IPC2010-31607.

This paper presents a new concept — the mixing-volume-equivalent-pipe concept (MVEPC) — which is used to compute transmix volumes in complex batch transfers in an easy, quickly and very simple way. By taking advantage of the MVEPC, the mixing volume of a transfer carried out in a complex pipeline, with varying diameters and flow rates, can be calculated as if it had a unique diameter and a constant flow rate. To illustrate the applicability of the proposed methodology, a numerical example is presented for a transfer of typical products. The transmix volumes predicted by the MVEPC are compared with those obtained by solving the nonlinear initial-value problem for the dispersion of matter parabolic equation. The excellent agreement observed between these two methods, with relative error up to a maximum of 2.65%, enables the use of the MVEPC as a promising tool for estimating transmix volumes in real world batch transfer operations.

Topics: Pipes
Commentary by Dr. Valentin Fuster
2010;():611-615. doi:10.1115/IPC2010-31614.

Standards and Recommended Practices require periodic updating so they represent current technology and industry practices. Canadian Standards Association (CSA) Z662 “Oil and Gas Pipeline Systems” contains Annex E that covers software-based leak detection for liquid hydrocarbon pipelines. The CSA Technical Committee determined that is was time to update Annex E. A Task Force of industry experts and regulators met over a period of 18 month to draft a new Annex E. This paper outlines some of the significant features of the new Annex and where possible does a comparison with the similar section in American Petroleum Institute’s API 1130 which covers recommended practice for software based leak detection in the US. A pipeline operator should consider using both Annex E and API 1130 in the implementation and use of a software-based leak detection system. The CSA Task Force did not want to copy and modify API 1130 to provide a new Annex E, so both documents provide necessary information.

Topics: Leakage
Commentary by Dr. Valentin Fuster
2010;():617-625. doi:10.1115/IPC2010-31650.

Most liquid pipelines design and operational control is based on steady state flow analysis. This neglects dynamic effects that occur as a result of occurrence of surges in a pipeline caused by rapid changes in pressure as a consequence of changes in the flow rate. A transient analysis of liquid pipelines on the other hand assures pipeline performance under all conditions (steady state and dynamic situations) including evaluating the following: • Impact from pump station start up, delivery restriction or shutdown (zero delivery); • Pump unit trip/failure; • Rapid mainline valve closures including Slam shut of a non-return (check) valve; • Effect of running the pipeline with minimum flow and maximum pump discharge pressure operating condition; • Variation in demand including rapid reduction/curtailment of delivery volumes; • Bubble collapse (the transition from slack-line to tight-line flow); • Unintentional changes in operational position of control valves; • Fluid property delivery conditions; • Liquid injection assessment; • Surge protection including pressure relief/control system evaluation; • Restart requirement to avoid slack-line conditions prevalent in hilly/mountainous parts right of way (ROW). Such a dynamic analysis would indicate whether liquid surges are of concern from design, as well as system operational conditions. It also would provide an evaluation of an automated control or potential automated strategies for overpressure protection. In this paper the dynamic analysis of liquid pipelines resulting in design and operational benefits will be described. Finally their benefits in application to a heavy oil pipeline facilities “Keystone” will be highlighted.

Commentary by Dr. Valentin Fuster

Pipelining in Northern and Offshore Environments

2010;():627-634. doi:10.1115/IPC2010-31115.

Pipes and tubular members are used in offshore applications as structural elements such as columns or in transport pipelines, risers etc. When subjected to dynamic loads, weld defects or geometrical stress raisers can initiate fatigue cracks causing the columns or pipelines to fail prematurely. In order to investigate the fatigue behaviour of pipe joints, a resonant bending fatigue setup was designed, suitable for testing pipes within a diameter range from 6″ to 20″ . In this setup the pipe, filled with water, is subjected to a dynamic excitation force with a frequency close to the natural frequency of the filled pipe. The force is applied using a unique drive unit with excentric masses. The pipe is supported in the nodes of its natural wave-form, so that no dynamic forces are transmitted to the setup. The deformation of the pipe is measured at discrete locations using an optical 3D dynamic measuring system. Through thickness fatigue cracks can be detected by pressurizing the water in the pipe and applying a pressure gauge. In this paper some unique aspects of the design of the resonant bending fatigue setup are discussed by presenting the results of a semi-analytical model used for calculating the deformation and bending stress in the excitated pipe and by comparing these results to the deformation measurements made by the dynamic measuring system. The working principles of the setup are illustrated by showing the preliminary test results for a 12″ diameter X65 steel pipe with a wall thickness of 12.7mm. It is demonstrated that the model predicts the behaviour of the pipe in the setup very accurately.

Commentary by Dr. Valentin Fuster
2010;():635-645. doi:10.1115/IPC2010-31125.

Recently Petrobras has been developing a production module of Roncador field through the P-52 platform in the Campos Basin, offshore Brazil. This platform is a floating production facility located in deep water and was tied back to the PRA-1 platform in shallow water by an 18-inch pipeline in order to export the oil production. This pipeline operates under high pressure and high temperature (HP/HT) conditions and was laid on the seabed. As a result of the extreme operating conditions, this pipeline is highly susceptible to lateral buckling and a buckle initiation strategy based on triggers to control the buckling behavior was designed. Thus sleepers and distributed buoyancies were designed and installed along the pipeline route. In addition to the buckles at the triggers, some additional, on-bottom, buckles were assessed in order not to compromise the design strategy. In recent geophysical data surveys carried out along the route length with the pipeline in operation, both engineered and on-bottom buckles were identified. This paper aims to present the thermo-mechanical design of the P-52 oil export pipeline, performing a comparison between some results obtained in design and observed during operation. Thus this paper intends to evaluate the pipeline as-built plus the operational pipeline configurations, and to assess the robustness of the design strategy applied regarding lateral buckling behavior.

Commentary by Dr. Valentin Fuster
2010;():647-655. doi:10.1115/IPC2010-31189.

Deepwater pipelines and high pressure casing and tubing are prone to buckling and unstable collapse under compressive loading and external pressure. The most important parameters governing the unstable collapse behaviour of perfectly round pipes and tubes are the circumferential yield stress of the material, the Young’s modulus and the ratio of diameter over thickness (D/t). Initial imperfections in the geometric shape of the pipe, like wall thickness variations or ovality, can have a pronounced influence on the collapse resistance of a pipe. Local dents can reduce the collapse pressure significantly, and trigger propagating buckles along the line. In this paper, buckling and unstable collapse of seamless pipes and tubes are studied. First, collapse pressure experiments for High Collapse Casing grades L80HC and P110HC are presented, showing that the seamless pipe production at ArcelorMittal Tubular Products in Ostrava (Czech Republic) is under tight quality control and complies with the API standards. Then, the critical collapse pressure is calculated for different scenarios. Depending on the ratio of diameter to wall thickness, four regimes are identified: yielding collapse, followed by plastic collapse, a transition range, and finally elastic collapse. For each condition, closed form expressions are derived for the critical collapse pressures. In addition, simplified design equations are reviewed to quickly estimate the collapse pressure. Then, the influence of initial imperfections on the collapse resistance is studied. Both the effects of geometric imperfections (ovality and wall thickness eccentricity) and material properties (especially yield stress and residual stresses) are addressed. In the end, an enhanced design equation is proposed to predict the critical collapse pressure of dented seamless pipes. This equation is validated by collapse experiments, can account for different initial imperfections, and is valid for a wide range of D/t ratios.

Topics: Pipes , Buckling , Collapse
Commentary by Dr. Valentin Fuster
2010;():657-663. doi:10.1115/IPC2010-31231.

In recent years, requirement for the consideration of global buckling due to high pressure/high temperature (HP/HT) condition has increased in the detailed design of offshore pipelines on a seabed. The interaction between pipeline and seabed including support structures or sleepers gives a significant effect on buckling behavior. Global lateral buckling analysis has been carried out to assess the stability of offshore HP/HT pipelines considering the interaction between HP/HT submarine pipeline system/foundation structure and seabed. A non-linear finite element method is used in the present static analysis using the ABAQUS program. The FE model considers concrete sleepers as well as 3-D profile of the seabed. The stress distribution and lateral amplitude of the pipeline were evaluated and remedial measures were suggested to ensure that pipe stresses and strains are kept within allowable limits. Sleepers are designed as a buckle trigger which can provide artificial imperfection to allow pipe to move laterally and mitigate axial force. Comparative study could provide design strategy of pipeline related to sleeper supports.

Commentary by Dr. Valentin Fuster
2010;():665-671. doi:10.1115/IPC2010-31449.

This paper will discuss both the present situation and future developments in Pipeline Integrity Monitoring. It will also highlight how integrity monitoring is a vital part of any Pipeline Integrity Management System (PIMS). To give the true picture of a pipeline’s condition, the integrity monitoring systems must identify those elements of the pipeline which are at most risk to any potential modes of failure. Pipeline integrity monitoring offshore tends to be the periodic monitoring of specified components above and below the water surface. This being in the form of long and short term monitoring programs, which are derived from threat identification, risk assessment and mitigation processes. These programs normally follow the relevant industry standards that define specific monitoring activities and frequencies, especially for the safety critical components. PIMS documentation review cycles can be long and complex, but should be undertaken on a regular basis. When these reviews are undertaken they don’t always use new data sources that could give us more information about potential failure modes. At present these processes tend to be more reactive or lagging in nature. The future monitoring of pipeline integrity should be more forward-looking and be proactive as well as being reactive. Where are the next major developments? We need to make better use of the data we have by studying trends, changes and impacts wherever possible. Also, have a better understanding of the in-service behaviour and how this can change over the life cycle of a pipeline system.

Commentary by Dr. Valentin Fuster
2010;():673-679. doi:10.1115/IPC2010-31485.

The inspection of the vertical section of an offshore pipeline, known as the riser, plays a critical part of any integrity management program. This section connects the pipe that runs on the seabed to the production facility, be it a floating platform or a FPSO. Hanging from the platform over deep waters, risers are subject to very extreme operating conditions such as high loads and underwater currents. Corrosion, fatigue, abrasion and damages caused by stray object collisions are factors that must be taken into account, so that oil and gas production are not compromised. A flexible pipeline, a well engineered solution used in most riser installations, provides high reliability while requiring little maintenance but, in spite of advances in project and installation, the inspection of riser pipelines is an immature field where technology has not yet met the user’s demands. In the search for better riser inspection techniques, a project was started to design a new inspection tool. The basic concept consists of an autonomous vehicle, the Autonomous Underwater Riser Inspection tool (AURI), that uses the riser itself for guidance. The AURI tool can control its own velocity and is suited to carry different types of inspection devices. The first AURI prototype is designed to perform visual inspection with an built-in camera system, covering 100% of the external riser surface. The AURI can reach water depths up to a thousand meters. It was built with several embedded security mechanisms to ensure tool recovery in case of failure and also to minimize chances of damage to the pipeline or other equipment. It uses two electrical thrusters to push it along the riser. The mission is set to a maximum depth to be inspected and is considered complete when one of the following conditions is met: (1) maximum pressure on depth sensor is reached or (2) the length of the run is achieved or (3) maximum mission duration is exceeded or (4) maximum allowed tilt is detected by the inclinometer. Thanks to its positive buoyancy, the AURI will always return to the surface even if the electronics fail or the batteries get exhausted. This paper presents the first AURI prototype as well as the preliminary test results.

Commentary by Dr. Valentin Fuster
2010;():681-688. doi:10.1115/IPC2010-31518.

Sandwich Pipes (SP) can be considered as an enhanced design configuration for Pipe in Pipe (PIP) systems. By improving the structural properties of the core layer and the components’ interface adhesion, SP systems can be an effective design alternative for deepwater applications. However, designing such a hybrid structure demands more knowledge of the response of the system under the governing loading and environmental conditions. A SP system would be a suitable design alternative for offshore pipelines that are subjected to very large hydrostatic pressure in deepwater. Therefore, full understanding of the behavior of such systems under the external hydrostatic pressure is a prerequisite for designing optimum SPs. In this paper a set of parametric models are generated based on practical design configurations. The Finite Element (FE) software package, ABAQUS, is used to create the models and analyze them. The FE models are analyzed through eigenvalue buckling and post-buckling analyses with the assumptions of linear and nonlinear buckling. Appropriate initial imperfections and FE parameters are administered. Moreover, the integrity of FE models is investigated through a mesh convergence study and also by considering various types of element locking mechanism. The results of these three methods of analysis are compared and the discrepancy between the results obtained through the linear analysis in comparison to the nonlinear post-buckling analysis is highlighted. Moreover, the influence of using various material plasticity models on the buckling and post-buckling responses is also investigated. Different models describing the materials stress-strain curves in the form of the elastic perfectly plastic, elastic followed by plastic exponential hardening, as well as the existence of the Lüder’s bands are also considered. Furthermore, the effect of core material’s stiffness on the buckling and post-buckling response of the system is also examined. Based on the equivalent plastic strain, it will be shown that in order to ensure system’s effective composite sandwich action, the core must have a certain minimal stiffness. Finally, the influence of the enhancement in the steel grade used to form either the internal or external pipe on the stability response of both PIP and SP systems will be illustrated.

Topics: Plasticity , Pipes
Commentary by Dr. Valentin Fuster
2010;():689-702. doi:10.1115/IPC2010-31526.

The design of offshore subsea pipelines is facing new challenges as the pipeline industry is moving into environments requiring high pressure design. Conventional pipeline design codes such as ASME B31.4 and B31.8 establish pressure limits based on percentage of the pipe material’s minimum specified yield strength. While this has traditionally worked for relatively thin-walled pipe at moderate pressures, there are concerns that full utilization of the material’s capacity is not being realized when designing for high pressure conditions. Additionally, there are concerns regarding the ability to achieve high quality manufacturing and consistently fabricate welds in thick-wall pipes. This paper presents details on a testing program that incorporated full-scale burst testing to qualify the design pressure for an 18-inch × 0.75-inch, Grade X65 subsea gas pipeline using the methodology of API RP 1111. A lower bound burst pressure was established based on the recorded burst pressures to which a design margin of 0.72 was applied to determine a design pressure. Had the pipeline been conventionally-designed using ASME B31.8, the design pressure would have been 3,900 psi. However, using the experimentally-based design option in API RP 1111 the resulting design pressure was 4,448 psi. This results in a net increase in the design pressure of 14 percent. When one considers either the potential cost savings in material requirements at construction or the additional throughput associated with higher design pressures for a given pipeline system, it is not difficult to demonstrate the economic benefits derived in performing a more rigorous material qualification and limit state design process based on experimental methods as presented in API RP 1111.

Commentary by Dr. Valentin Fuster
2010;():703-710. doi:10.1115/IPC2010-31611.

Enbridge Pipelines Inc. has operated a 324 mm diameter, 870 km crude oil pipeline from Norman Wells, Northwest Territories to Zama, Alberta since 1985. This pipeline is the first completely buried oil pipeline constructed within the discontinuous permafrost zone of Canada. This pipeline was constructed over two winter seasons, and since 1985 has transported roughly 200 million barrels of crude oil to southern markets without significant interruption. This paper will review the design, construction, and operational challenges of this pipeline through the past 25 years. Unique and innovative aspects of this pipeline include measures taken during construction to minimize thermal disturbance to the soil, insulating permafrost slopes to minimize post-construction thaw, operating at temperatures that minimize thermal effects on the surrounding ground, accommodating ground movement caused by frost heave/thaw and slope instabilities, and evaluating the effects of moving water bodies adjacent to the pipeline right-of-way. The use of in-line inspection tools (GEOPIG) has been valuable as a supplement to conventional geotechnical monitoring, for the evaluation and assessment the effects of ground movement to the pipeline. Finite element pipe/soil interaction models have been developed for selected sites in order to assess the potential for slope movement to generate strains in the buried pipeline that exceed the strain capacity. This paper will review new monitoring data and findings since previous publications. In addition, the implications of long-term trends of increasing ground temperatures and associated changes to the geotechnical and permafrost conditions along the pipeline route will also be discussed and are relevant to other proposed pipeline and linear infrastructure projects along the Mackenzie Valley.

Topics: Pipelines
Commentary by Dr. Valentin Fuster
2010;():711-718. doi:10.1115/IPC2010-31622.

Free span assessment has more and more become an important part of modern pipeline design. The reason for this is partly that the remaining hydrocarbon reservoirs are located in more challenging places, e.g. with very uneven seabed. Another explanation is that the pipeline design codes a few decades ago did not allow for vibrating free spans, while the modern, state-of-the-art pipeline codes, such as DNV-OS-F101 “Submarine Pipeline Systems” (2007) [1] and its Recommended Practices, opens for long spans that are allowed to vibrate as long as the structural integrity is ensured. By opening for longer free spans significant seabed intervention costs associated with trenching, rock dumping and supporting spans by other means are saved. One of the governing parameters to ensure the structural integrity of free spans is the natural frequency of the span. This is a parameter that the designer can to some degree control by means of moderate seabed intervention, e.g. span support. Since the natural frequency of the span together with the water flow velocity normal to the span determine the vibrations and the cyclic loading it is of vital importance to be able to estimate a realistic value of this frequency. The natural frequency is influenced by several effects. One of them is the effect of the internal pressure. This may represent a challenge since the effect of the pressure is the opposite of what one instantaneously thinks is correct. Quite recently some discussion about the effect of internal pressure on free spans were raised and some experimental data presented that claimed to prove that the way the internal pressure was handled in the DNV-RP-F105 “Free Spanning Pipelines” (2006) [2] is wrong. The intention of this paper is to show how the internal pressure influences on the structural response of free spans, and that the DNV codes and standard non-linear FE software, e.g. Abaqus, handle this effect in an adequate manner.

Commentary by Dr. Valentin Fuster
2010;():719-734. doi:10.1115/IPC2010-31626.

Designing and constructing subsea flowlines to address the implications of aggressive hydrocarbon well fluids — and selecting suitably corrosion-resistant materials for such applications — typically proves challenging and often leads to the specification of clad, lined, or solid corrosion resistant alloy (CRA) linepipe materials. Design and construction guidance for such flowline systems is presently not comprehensive in offshore pipeline standards, even for cases where the thickness of the CRA layer is ignored in the structural design. Acergy are designing, procuring and installing a series of technically challenging infield flowlines within the Encana Deep Panuke gas prospect located off the coast of Sable Island, Nova Scotia. Presently being developed, first gas from the Deep Panuke field is scheduled for the third quarter of 2010 following the tie-in of the infield flowlines to their respective subsea production wellheads. These flowlines are to be installed using the Acergy Falcon, a vessel which has an installation system based on a variable angle J-lay principle and plastic deformation of the pipe. The four 8in production flowlines are clad linepipe comprising a 12.5 mm WT grade 415 (X60) carbon steel substrate with an internal 2.5mm Incoloy Alloy 825 clad layer that is metallurgically bonded to the mother pipe. The single 3in acid gas flowline is solid Inconel Alloy 625. The nominal level of installation plastic strain for the project ranges up to 1.675% in the case of the 8in line. Both lines will be welded by manual GTAW using Inconel 686 filler material. The pipelines are designed and fabricated in accordance with DNV OS-F101 supplemented by new guidance emerging from a DNV joint industry project on clad and lined materials. Metallurgically clad and mechanically bonded (lined) products present a mixture of common and unique challenges when designing and welding flowlines. The existing production limits for pipe dimensions in clad material have for some time now existed on the very cusp of design requirements, especially when using only the thickness of the steel substrate to resist the design loads. Indeed, recently the design demands of some projects have clashed with the available linepipe geometry and the mechanical properties of the clad layer material have of necessity been taken account of in the structural design. The dominant offshore design code, DNV OS-F101, is presently unable to offer specific guidance for including the clad layer and it is only in 2009 that joint industry research has established a viable design methodology for pressure containment wall thickness design which includes the strength effect of the clad layer. In addition to discussing the Deep Panuke design challenges and the welding philosophy for clad pipe, this paper also draws on approaches to welding and NDT successfully taken for the Statoil Tyrihans project in Norway, which used lined pipe material. The general welding philosophy adopted accommodates the continued inability of AUT systems to reliably inspect CRA weldments without false indications from normal metallurgical weld features. A proven approach is taken using intermediate inspection of the root and hot pass using real-time radiography (RTR); effecting any repairs needed; and then re-inspecting the weld upon fill and completion using RTR again. The importance of — and difficulty in — achieving adequate weld metal yield strength in CRA weldments is also discussed.

Topics: Welding , Design
Commentary by Dr. Valentin Fuster
2010;():735-748. doi:10.1115/IPC2010-31642.

Execution of projects for the decommissioning and abandonment of platforms, facilities and pipelines have long been considered by oil and gas Operators as an issue and a significant financial burden best deferred for the future. However with increasing environmental awareness and legislation, decommissioning & abandonment projects can be effectively carried out today, by considering the options and adopting an environmentally acceptable and pragmatic solution whilst also avoiding the risk of more stringent future legislation. This paper is focused on the strategy and operational planning aspects of the decommissioning and abandonment of two 36″ offshore oil export and one 30″ ballast pipelines from a marine terminal to offshore PLEMs for PEMEX in Mexico. These pipelines were shutdown and isolated in 1990 pending decommissioning and since then suffered from a very poor failure record. As a result of these failures, the pipelines have been under the scrutiny of the Mexican Environmental Authority (PROFEPA), in order to monitor and manage the ongoing environmental risk. The paper reviews the applicable international standards and legislation with respect to pipeline decommissioning and includes a review of the decommissioning and abandonment options & considerations in this case.

Commentary by Dr. Valentin Fuster
2010;():749-758. doi:10.1115/IPC2010-31649.

Up to the present, most of the pipes used in offshore applications installed with methods introducing plastic deformation have been seamless pipes; however, welded pipes can also be used. Welded pipes offers benefits over seamless pipe in terms of improved lead times, lower project costs, tighter dimensional tolerance and good control of mechanical properties and chemistry resulting in excellent weldability. During installation of welded pipes, failure by fracture, plastic collapse and local buckling may occur. In this work, the occurrence of the local buckling phenomenon, produced during the installation method, was evaluated. Numerical models were developed to study the effect of materials and geometrical parameters on the local bucking of pipes subjected to bending. Specifically, the loads and strains at which the plastic instability occurs were determined for each particular condition. In addition, the influence of longitudinal and girth welds on the local bucking occurrence was assessed.

Commentary by Dr. Valentin Fuster

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