Computational analysis of high pressure water jetting for natural gas pipeline

Abstract

Nowadays, pipeline system has become lifeblood of modern civilization, industrial society and residential community. Gas transmission and distribution lines transfer natural gas from a source to points of utilization. Typically, gas distribution pipeline is laid adjacent to water pipeline facility. This may pose a great danger through the release of high pressure water leakage that subsequently induced surrounding soil to form erosive slurry. If the hit is directed towards metal pipe, slurry could directly cause continuous wall thinning of pipe that may lead to its point of failure. Therefore, this research is aimed to observe and evaluate the erosion pattern on natural gas pipeline due to water jetting. The Computational Fluid Dynamics (CFD) technique was employed to estimate the hydrodynamic characteristics, erosion patterns and locating the ruptured locations on the pipe in more expanded version. The study also focused on the fluid velocity, sand wall shear, water wall shear and total pressure generated on surface of natural gas pipe. This work was validated by the incident of NPS8 carbon steel gas pipeline failure in April 2006. CFD simulation results showed that water jetting location at angle 45°, 60° and 75° on the NPS8 pipe surface had similar impact such as leakage point, surface roughness and smoothness. The enhanced CFD simulation results successfully showed similar hydrodynamic characteristics as the NPS8 rupture incident.