油田电泵井套管杂散电流腐蚀排流设计及应用  

Design and Application of Discharge Technique for Control of Stray Current Corrosion to Electric Pumps at Oil Wells of Daqing Oil Fields

作　　者：李福军[1] 孙洪志[2] 张庆杰[2] 史远[1] 

机构地区：[1]大庆石油学院校办产业管理处,黑龙江大庆163318 [2]大庆油田责任有限公司第三采油厂,黑龙江大庆163300

出　　处：《材料保护》2009年第4期61-63,共3页Materials Protection

摘　　要：为加强对油田电泵井套管的腐蚀控制,通过室内模拟交流杂散电流腐蚀试验,考察了交流杂散电流对电泵井套管的腐蚀性。结果表明:试样腐蚀速率随着电压的增加而增大,随介质电阻率的增大而减小,电泵井套管的腐蚀存在杂散电流腐蚀及土壤电化学腐蚀的双重强腐蚀。该区域土壤具有较强的腐蚀性,虽然杂散电流并不连续,但可加剧土壤电化学腐蚀。确定采用排流保护法并设计了牺牲阳极排流方案来控制腐蚀。现场测试表明,管地电位波动范围由措施前的124.0 mV减少至27.1 mV,管地电位可负移至-850.0mV(相对饱和硫酸铜参比电极),保护率为78.1%,达到了石油行业标准规定的防腐蚀要求。The corrosion of the casings of electric pumps at oil wells by alternate stray current was examined by making use of simulated indoor corrosion test in the presence of alternate stray current, aiming at more efficiently controlling the corrosion of the casings bv alternate stray current.The method of discharge protection was explored. Results show that the corrosion rate increased with increasing voltages and de-creased with increasing specific resistance of soil. The corrosion of the casings of electric pumps at oil wells was dominated by gal-vanic corrosion and electrochemical corrosion. The soil under study was highly corrosive, and stray current, even though dis-continuous, accelerated electro - chemical corrosion process. Therefore it was suggested to apply sacrificial anode for discharge protection and corrosion control. Field test results showed that af-ter applying sacrificial anode discharge protection, the fluctuation scope of the casing-ground electric potential was greatly reduced from 124.0 mV to 27. 1 mV. The casing-ground electric potential negatively shifted to - 850. 0 mV ( with reference to Cu/CuSO4 electrode) , and the protection rate reached 78. 1 % , meeting with the standardized requirements for corrosion control in petroleum industry.

关 键 词：杂散电流腐蚀 电泵井 套管 牺牲阳极 排流保护 

分 类 号：TE983[石油与天然气工程—石油机械设备]