Abstract
Two-phase flow is commonly encountered during the transportation of hydrocarbon mixtures through land-based or subsea pipelines. An important task during the design and simulation of pipelines is to predict pressure and temperature variations along the pipe length and to estimate the build-up of liquid slugs at different locations, particularly in the hollows of the pipelines. The information for the liquid build-up is required to compute both pressure variations as well as the volume of slugs during pigging operation. The above information is also vital in the mechanical design of pipeline and pipe supports and in the stress analysis. A rigorous approach to this problem involves dividing the whole pipe length into several finite length elements (FLE) and carrying out in each of them phase equilibrium, heat transfer, and pressure drop calculations sequentially. Depending upon the available data and the objectives of the task, the calculations may have to be carried out starting from the upstream end, downstream end, or from some intermediate locations. In view of the coupled nature of the physical Processes and consequently the calculation techniques, digital computer application is essential to perform the computations. This paper presents general organization and calculation logic of a computer program developed to simulate two-phase flow line carrying hydrocarbon mixtures. The program has been tested by using IBM PC AT on a 30 miles long pipeline for which data was available in the literature [4].