Study On Erosion Mechanism And Numerical Modeling Of Flow Field In Multiphase Mixed Pipeline

A mixture of oil and gas extracted from an oil and gas well that flows through the components of a manifold in a complex gas-liquid multiphase flow.The crude oil and natural gas extracted from it usually contain a certain amount of solid particles or a large number of instantaneous particles.If these particles are accumulated for a long time or eroded seriously in a short time,they will cause erosion impact on valves,resistor valves,T-tubes and elbow parts to a certain extent.In this paper,the erosion phenomenon of solid particles carried by gas-liquid two-phase flow in curved pipe and T-pipe is studied by means of similarity experiment platform and numerical simulation method.According to the actual engineering conditions,the design and calculation of the similarity experiment platform and the erosion experiment of gas-liquid-solid multiphase flow are carried out.The gas-liquid-solid multiphase flow erosion test loop was built,and the detachable test elbow and T-pipe were used to carry out the similarity experiment.By changing the inlet velocity of gas and liquid and the mass flow rate of solid particles,the weight loss rates of the inner wall hanging pieces of bend pipe and T-pipe were compared and analyzed under the condition of gas-liquid-solid multiphase flow,and then the erosion phenomenon of solid particles on the inner wall of pipe in multiphase flow was studied.The results show that the erosion of the elbow is mainly concentrated on the outer arch side of the elbow,and the erosion of the T-pipe is mainly concentrated on the bottom of the horizontal pipe facing the vertical pipe and the outer pipe wall near the vertical pipe.The erosion rate increases gradually with the increase of inlet velocity and mass flow rate of solid particles,and the relationship between the two increases exponentially.Through the establishment of the simulation model of elbow and T-tube,the phenomenon of erosion wear is analyzed,and the movement track of solid particles in the pipeline under the condition of multiphase flow is obtained,so as to reflect the location of erosion damage to the pipeline.The control variable method is used to determine the gas-liquid inlet velocity,particle size,mass flow and location from the aspects of velocity distribution,solid particle trajectory,erosion rate and erosion location.The results show that the erosion rate increases with the increase of inlet velocity.When the inlet velocity reaches a certain value,the growth rate also increases;The results show that the erosion rate decreases with the increase of solid particle size in a small range,and increases with the increase of solid particle size;With the increase of mass flow rate of solid particles,the erosion rate increases gradually.The simulation model is compared with the experimental results,and the results show that the maximum erosion position of the simulation is in good agreement with the results of the similarity experiment,which verifies the correctness of the simulation.According to the flow characteristics of solid particles carried by gas and liquid in the bent pipe and T-pipe,the protective measures and optimal design of the bent pipe and T-pipe are put forward.