Research On Erosion-Corrosion Of Gathering Pipeline In Halfaya Oilfield

Erosion-corrosion exists in the process of oil and gas field development.It is also a major problem of oil and gas production for a long time.Due to the transported medium containing quicksand and other solid particles,erosion is usually seen in the vicinity of the wall in crude oil gathering pipeline.In this paper,CFD numerical simulation study is carried out on the main parts of the crude oil gathering pipeline,such as the elbow and the tee pipe,and then the wearing characteristics of the liquid-solid two-phase flow on pipeline is summarized.Secondly,by using the rotating cylinder electrode RCE,the erosion experiments were carried out to provide a database for analyzing the erosion corrosion of the pipeline（1）According to the research status of erosion corrosion on pipeline flow,several main scouring theories and scouring models are introduced.Based on the study of erosion corrosion theory,the numerical simulation model is established.The numerical simulation method is used to study the main pipeline erosion-corrosion.（2）The numerical simulation of liquid-solid two-phase flow pipe is carried out to analyze the velocity field,the pressure field and the erosion of the elbow.Changing the entrance velocity,particle concentration,particle size and the type of pipe placement,and the influence of these factors on the wearing of the elbow was analyzed.（3）The numerical simulation of liquid-solid two-phase flow pipe is carried out to analyze the velocity field,the pressure field and the erosion of the tee.Changing the entrance velocity,particle concentration,and the type of pipe placement,and the influence of these factors on the wear of the elbow was analyzed.（4）In the solution of the produced liquor in the field,the erosion corrosion of pipeline flow was studied by using rotating cylinder electrode RCE,the corrosion current density of the X80 increases with the increase of the fluid velocity,and the erosion rate increases with the increase of the fluid velocity.In the solution of 3.5%Nacl+0.72%NaHCO₃,the erosion rate of the X80 is consistent with the law of the flow rate in the produced liquor.However,compared with the experimental results of the produced liquor,the corrosion potential is low and the corrosion rate is small;it is attributed to the fact that the anodic polarization curve was inhibited in the produced liquor.By comparing the erosion rate of different sediment concentration and the erosion-corrosion rate of the produced liquor,it is found that the erosion rate of pipeline containing corrosive medium can be characterized by the difference of sediment concentration.