针对储层流体中高含CO2和H2S 腐蚀性气体的油气田，为了优化防腐选材，使用现场腐蚀检测装置开展实验。指出了现有腐蚀检测装置存在的不足，分析了以辅助评价材质现场腐蚀为目的腐蚀检测装置应具备的结构特点，并设计加工了油气田现场腐蚀检测装置。在设计阶段对现场腐蚀检测装置进行了强度校核，设计了聚四氟乙烯材质的腐蚀挂片悬挂件及与之匹配的梯形横截面腐蚀挂片；在加工完成后进行了试压，确保能够满足现场的最高工作压力。针对该现场腐蚀检测装置提出了具体的应用方法。在米桑油田选择有代表性的生产井，在井口缓释剂投注点之前安装该腐蚀检测装置，进行现场腐蚀实验。设备能够满足现场要求，在规定的时间内完成了预定数量和不同材质的测试，实验结果表明，在含有0.2 MPa CO2储层中，油套管应选用马氏体不锈钢13Cr 不锈钢材质，在含有1.3 MPa CO2及0.8 MPa H2S 的储层中，超级13Cr 不锈钢未发现局部腐蚀且腐蚀速率极低。
In optimizing the selection of corrosion-resistant materials and safe and economic casing and tubing materials for oil & gas fields with high content of CO2 and H2S, the oilfield coupon corrosion test plays an important role. The weakness of the current detecting devices of corrosion is shown and the structural features that a detecting device of corrosion should have for the assessment of the steel corrosion under oilfield conditions are analyzed. Based on these analyses, an on-line detecting device of corrosion is designed and manufactured. During the design phase, the strength of the on-line detecting device of corrosion is checked and a PTFE (polytetrafluoroethylene) holder and the coupons with the trapezoidal cross sectional shape are specially designed. After the device is manufactured, the pressure test is carried out to check the device for the maximum working pressure and the specific operation method. The corrosion detecting devices are installed in wells of the Missan oilfield. The device is in the wellhead and before the injection point of the corrosion inhibitor and can meet the requirement of the oilfield. The oilfield test covers the scheduled amount for different materials of coupons during 3 months. The results show that 13Cr martensitic stainless steel can work under the condition of 0.2 MPa CO2 and under the condition of 1.3 MPa CO2, 0.8 MPa H2S, the 13Cr super-martensitic stainless steel shows no local corrosion with a very low corrosion rate.
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