Numerical Simulation of Pigging Operation through Curved Pipeline Coupling a T-Abrupt and Bend Drain Pipe

Abstract

Pigging technology is currently widely used in the oil and gas industry. The unstable movement of the pig in the pigging process after a water pressure test will not only affect the operation of pipes, but may even cause them to burst. In this paper, a transient hydraulic model of the pigging process after a water pressure test is established in a two-grid system. The model combines the mass and motion equations of the gas and liquid and then is solved by the method of characteristics. The combined method of computational fluid dynamics (CFD) software simulation and a semiempirical formula is used to study the gas-liquid flow pressure drop characteristics of T-abrupt and bend drain pipe. It is applied to the pig tracker and hydraulic pulse prediction to obtain the pig’s position and speed. Finally, the field data and the simulation results are basically consistent after comparison, which verifies that the established model is correct and the calculation results are reliable. Hence, we can provide a reliable and effective theoretical basis for the on-site pigging scheme.