To improve the capacity of the two-phase fluid movement through the horizontal pipes, in the turbulent regime, it is necessary to determine as correctly as possible the turbulent drag coefficient and to be estimated the associated energetic balance. For a hydrodynamic flow, the gas-liquid interfacial distribution may have different possible forms, with effect in various flow patterns, due to the different flow rates of the fluid and gas. Usually, we may express the dimensionless pressure gradients as drag coefficients. During the time, some analytical available methods, described the two-phase flows in the horizontal tubes. In previous researches, the author has tested four models: the homogeneous model, the separated-flow model, the mechanistic models, and the drift-flux model. In the present paper, there were selected to accomplish the research, the results obtained from the first three mentioned models. The theoretical and experimental results proved that there are more accurate and more suitable for the actual dedicated applications. The two-phase flow is important in a large variety of applications from engineering, such as natural gas production, oil transportation, the drilling, the food processing, polymer processing industry, pharmaceutical domains, etc. In the case of flow for a single phase, the shear forces on the wall create friction, losses, followed by a pressure decreasing, known as linear hydraulic losses. In the case of the two-phase flows, an additional interaction appears between the two phases, having as consequence a supplementary difficulty in the evaluation of the pressure drop. For the mentioned models, there were considered different flow rates for oil and gas. We vary in laboratory the gas flow rate. For each model the variables were made dimensionless, to enable generalization at different types of horizontal tubes, pipelines, with different diameters. The accuracy of the developed correlations from this paper is evaluated by comparing the predictions of previous calculations and correlations with the measured and obtained results, and with the data from technique literature. The relation between the pressure gradient and mass flow is expressed also in dimensionless form, as a relation between the drag factor and the Reynolds number, considered for the two-phase flow. This one was correlated with the generalized Reynolds number, with values from 6000 to 140000. For this Reynolds range were tested in the laboratory more than 200 measurements points, for each of the three selected models. The analyzed cases allowed the estimation in a proper manner of the accuracy of the drag turbulent factor, by calculating all 10 statistical parameters, for pipes up to 80 cm.