Study of Erosion Behavior of Shale-Gas Gathering Pipeline Elbow Based on Fluid–Solid Coupling

The erosion of elbows in shale gas-gathering pipelines is influenced by both internal tensile stress and solid particle erosion. However, scholarly attention to the occurrence of elbow erosion in such pipelines under stress is lacking. To address this gap, this study establishes a numerical model accounting for the two-way coupling between elbows and natural gas under internal pressure while also considering particle erosion under stress. Numerical simulations were conducted to analyze the erosion behavior of elbows under varying gathering pressures, gas flow rates, and particle sizes. The results indicate that the location of maximum stress coincides with the position of the highest erosion rate, suggesting that stress concentration renders the material highly susceptible to erosion. Additionally, an increase in collector pressure exacerbates the impact of stress on the erosion process. Gray-scale correlation analysis subsequently identifies the priority order of factors influencing the maximum erosion rate in the elbow as follows: collector pressure has the highest influence, followed by gas flow rate, and then particle size.