Abstract :
Two-phase flow of oil and gas is often found in production oil wells, not only in vertical and horizontal pipe segments but also in inclined pipes with several different angles. In addition, sometimes gas is injected into the cylinder to increase the oil production rate. Therefore, it is very important to determine the two-phase flow. The flow pattern of 2-phase flow is more complicated than that of single-phase flow. That's because of the interaction between phase 1 and other phases, to find out the 2-phase flow pattern in the vertical pipe, a mechanistic model calculation is used, it is known that the flow pattern in well X is bubble flow. The mechanistic method is a model used for multiphase flow calculations to predict pressure drop in pipes, especially in situations that are not easily modeled in the laboratory. Well X is classified as an old well, this causes the need for an evaluation of the production performance of the well. Based on the calculation of the pressure loss of the 2-phase fluid using the mechanistic model method which in this case uses the Ansari method and it is found that the pressure drop that occurs is 483.1759.