南海某油田CO2回注井防腐选材实验

目的 开展腐蚀选材实验,确定经济合理的井下油套管材质.方法 分别模拟回注气层(114℃、CO2分压为24.89 MPa、凝析水Cl–质量浓度为1000 mg/L)、回注水层(117℃、CO2分压为28.39 MPa、凝析水Cl-质量浓度为20000 mg/L)工况,利用高温高压釜开展室内模拟腐蚀实验,评价3Cr、13C...

Anti-corrosion Material Selection Experiment of CO2 Reinjection Well in an Oil Field in South China Sea

Corrosion material selection experiments are carried out to determine economical and reasonable downhole tubing and casing materials.The reinjection gas layer(114℃,CO2 partial pressure of 24.89 MPa,condensate water Cl^–concentration of 1,000 mg/L),reinjection water layer(117℃,CO2 partial pressure of 28.39 MPa,condensate water Cl–concentration of 20,000 mg/L)working conditions are simulated respectively to conduct indoor simulated corrosion experiments using high temperature autoclaves,and the materials of 3Cr,13Cr,super 13Cr and 22 Cr duplex stainless steels are evaluated.3Cr has severe uniform corrosion and pitting corrosion;the maximum uniform corrosion rate is up to 1.0973 mm/a under the reinjection water layer condition,and the maximum pitting corrosion rate is up to 0.4241 mm/a under the reinjection water layer condition.The uniform corrosion rate of 13Cr is relatively low;the highest corrosion rate is up to 0.0274 mm/a under the reinjection gas layer condition,and the pitting corrosion rate is 0.3833 mm/a under the reinjection water layer condition.The uniform corrosion rate of S13Cr is low;the highest corrosion rate is 0.0113 mm/a under the reinjection gas layer;no pitting corrosion.22Cr has uniform corrosion rate lower than 0.0011 mm/a,without pitting corrosion.The overall rule is that the corrosion rate under the condition of the reinjection water layer is greater than that of the reinjection gas layer.The main corrosion product is FeCO3.For pipes above 13Cr,the main form of corrosion is pitting.For CO2 reinjection deep wells,gas reservoirs should be selected for reinjection as much as possible.Under the conditions of CO2 partial pressure of 24.89 MPa,formation temperature of 117℃,and formation water Cl^–concentration of 20,000 mg/L,Super 13Cr is recommended as reinjection well tubing.