多层滤网机械防砂完井筛管动态腐蚀试验研究

针对机械防砂筛管腐蚀寿命预测方法尚未形成的问题,采用防砂筛管动态腐蚀评价系统,模拟南海某高温高压气藏条件,对多层滤网机械防砂完井筛管的基管、挡砂介质和外保护罩组件进行了动态腐蚀试验评价,使用平均腐蚀速率评价法对腐蚀性能进行数据分析和评价,建立了多层滤网机械防砂完井筛管腐蚀寿命预测方法。研究结果表明:在CO2分压1.5 MPa、温度160℃及Cl^-质量浓度6400 mg/L的气水腐蚀环境中,筛管不同组件的腐蚀速率有较大差别,基管的腐蚀速率最大,外保护罩次之,两者均为中度腐蚀,挡砂介质腐蚀速率最小,为轻度腐蚀;当CO2分压在0.0~5.0 MPa内增大时,腐蚀速率增长缓慢,当CO2分压超过5.0 MPa后,腐蚀速率随分压增长迅速;虽然挡砂介质腐蚀速度最慢,但由于其较细的金属丝交错结构,导致其寿命最短;CO2分压在1.5~14.5 MPa范围内,筛管总体寿命为5~24 a,平均为10~15 a。研究结果可为高温高压气藏机械防砂完井筛管的寿命预测提供参考。

Dynamic Corrosion Experiment of Multi-Layer Metal Mesh Screen for Sand Control Completion

The corrosion life prediction method of mechanical sand control screen has not been formed.To address the problem,the sand control screen dynamic corrosion evaluation system is used to simulate the condition of a high temperature and high pressure gas reservoir in the South China Sea,so as to conduct dynamic corrosion evaluation of the base pipe,the sand-retaining medium and the outer protective cover assembly of the multi-layer mesh mechanical sand control completion screen.The corrosion performance was analyzed and evaluated by the average corrosion rate evaluation method.The corrosion life prediction method of the multi-layer mesh mechanical screen was established.The results show that in the gas-water corrosion environment with the CO2 partial pressure of 1.5 MPa,the temperature of 160℃ and the Cl^- mass concentration of 6400 mg/L,the corrosion rate of different components of the screen tube is quite different.The corrosion rate of the base tube is the largest,followed by the cover,which both are moderate corrosion.The sand-retaining medium has the smallest corrosion,which is mild corrosion.When the CO2 partial pressure increases within 0.0~5.0 MPa,the corrosion rate increases slowly.When the CO2 partial pressure exceeds 5.0 MPa,the corrosion rate increases rapidly.Although the corrosion rate of the sand-retaining medium is the slowest,it has the shortest life due to its thin wire interlaced structure.With the CO2 partial pressure in the range of 1.5 to 14.5 MPa,and the overall life of the screen is 5 to 24 a,with an average of 10 to 15 a.The study can provide references for the life prediction of mechanical sand control completion screens in high temperature and high pressure gas reservoirs.