Numerical Simulation Study On Erosion Of Typical Components Of Shale Gas Gathering Pipeline

During the gathering of shale gas,a certain amount of solid particles will be contained in the pipeline,which will continue to hit the pipe wall and pipe fittings under the carrying of high-speed flowing gas,causing erosion.Especially in the elbows where the velocity and direction change drastically,the erosion phenomenon is more serious.Therefore,studying the fluid flow characteristics and erosion laws of the gas-solid two-phase flow pipeline is of great significance to ensure the safe operation of the shale gas gathering and transportation pipeline and the design of the shale gas gathering pipeline in subsequent projects.In this paper,for the shale gas gathering and transportation network of a shale gas field in southwest China,ANSYS 19.0 Fluent software is used to carry out numerical simulation research on erosion and wear of gas-solid two-phase pipe flow.Through comparison with experimental data,it is verified that the Realizable k-epsilon turbulence model,DPM model and Generic erosion model can accurately calculate the wall erosion rate of gas-solid two-phase tube flow.Based on the numerical simulation calculations based on laboratory operating conditions and field operating conditions,the study found that the maximum erosion rate of the pipe wall was positively correlated with the particle incidence velocity and particle mass flow,and negatively correlated with the pipe diameter and bending diameter ratio.Incident velocity and particle mass flow rate have the greatest influence on the maximum erosion rate of the pipe wall.The results of numerical simulation calculations show that in actual production,the flow rate should be controlled below 10m/s to avoid erosion of the elbow;the 80 mm pipe diameter can be used as a "critical pipe diameter" that comprehensively considers safety and economy;Elbows with small bend-to-diameter ratios should be avoided at the corners of shale gas gathering pipelines;a safe working condition diagram for small-diameter working conditions in the later stage of production is given to provide suggestions for on-site working condition adjustment.Finally,this paper compares the numerical simulation calculation results with the calculation results of three erosion prediction models that are widely used in engineering.Among them,the predicted value of the Tulsa E/CRC model for the erosion rate of gas-solid two-phase flow pipes is in good agreement with the actual working conditions.Provide reference and basis for on-site working condition adjustment and gathering pipeline technology design.