Simulation of a sub-sea gas pipeline in persian gulf to estimate the physical parameters

摘要

Two-phase gas-liquid flow along pipeline will tend to unavoidable non-stable condition e.g. slugging flow. Slug flow can pose serious problems to the equipments and operator of these flow systems. High fluctuating rates of gas and liquid can severely reduce the production and in the worst case shutdown or damage topside equipments like free water knock out drums. The modelling of two-phase flow systems over recent years become commonplace. This has been a direct result of stringent requirements to adopt the latest technology in health, safety and pipeline integrity analysis. In recent study, the carbon steel sub-sea pipeline with outer diameter 32 inch (ID. 30 inch) in order to transfer sour gas from South Pars gas field to a gas refinery with capacity 2000 MMSCFD for two phases (each phase 1000 MMSCFD) in south of Iran which has approximate length of 87 km is considered to simulate with PIPESIM software based on Beggs & Brill correlation for slug prediction in both vertical and horizontal pipes as well as Peng-Robinson equation of state to estimate gas physical properties. Based on our studies by increasing flow rate the amount of holdup and slug is decreased so that from 200 MMSCFD up to 1000 MMSCFD this value is almost decreased 32% in the riser. In such simulation, care must be taken during the gathering of data for the parameters like pipeline elevation changes, flow and composition of fluids and pipeline operational pressure and ambient temperature.