Erosion Evaluation Experiment Of Oil-solid Mixed Fluid In Metal Mesh Sand Control Screen In Deep Offshore Oilfield

Metal mesh screen pipe is the main mechanical sand control tool in offshore oil field.The erosion failure of downhole screen pipe caused by a large amount of sand production seriously affects the normal operation of downhole screen pipe in major oil fields,greatly reduces the effective service life of screen pipe,which is the key technical problem hindering the safe and stable development of offshore oil field at present.Therefore,it is of great significance to carry out relevant research on the service life of the screen tube under the condition of erosion to ensure the safety of production and improve the production capacity of offshore oil field.On the basis of erosion and wear experiment of metal mesh sand screen in offshore oil field,a mathematical model for erosion rate prediction is established.By using fluent numerical simulation,the erosion failure mechanism of metal mesh sand screen pipe is discussed.The main research contents and achievements are as follows:(1)Discussion on hedging erosion mechanismThe erosion failure mechanism of metal mesh screen was discussed by investigating the literature on erosion failure of sand control screen in recent years.The important factors affecting erosion rate such as impact velocity,particle content and impact Angle were screened out.Based on the original Finne model,the influence of particle content was introduced and the basic mathematical model was designed.(2)Laboratory experiment of oil sand mixed fluid erosion and establishment of erosion modelLaboratory experiments were carried out on MSH rotary erosion single wire and screen with sand concentration and impact velocity as variables.A mathematical model for predicting the erosion rate of metal fillet was developed based on the experimental data of single fillet.(3)Establishment of numerical simulation model for sand fluid erosion of metal mesh screenA 3D physical model of optimized metal mesh cloth sand control screen was established,and the erosion hot spots of metal mesh cloth sand control screen were discussed by using discrete flow(DPM)as the basic analysis method and combining with the prediction mathematical model of erosion rate.The simulation results show that the maximum velocity distribution on the first layer of metal mesh cloth is 6 times of the inlet velocity,and the erosion rate is much higher than that of the second layer of mesh and protective shell.(4)Field application exampleAccording to the actual production data,the fluid impact velocity and sand concentration in the 120 m offshore oil field were calculated.The actual data to the established mathematical model for the metal mesh cloth to predict life of sand control screen,compared with the actual screen sand control time limit,the predicted value and actual value of absolute error analysis,the final metal mesh erosion rate forecast model was verified with actual metal mesh cloth sand control in offshore oil field screen sand control life consistent rate of 95%.In this study,a complete life prediction model is established for predicting the erosion life of metal mesh screen in offshore oil field,which provides a new method for predicting the erosion life of metal mesh in offshore oil field.