用于CO注气驱的油井缓蚀剂加注工艺优化研究

Optimization of Injection Technique of Corrosion Inhibitor in CO-flooding Oil Recovery

张德平 马锋 吴雨乐 董泽华

ZHANGDeping MAFeng WUYule DONGZehua

东北石油大学石油工程学院, 黑龙江 大庆 163318 国家能源CO₂驱油与埋存技术研发(实验)中心, 吉林 松原 138000 中国石油吉林油田公司, 吉林 松原 138000 华中科技大学化学与化工学院, 湖北 武汉 430074

School of Petroleum Engineering, Northeast Petroleum University, Daqing, Heilongjiang 163318, China National Energy and CO₂ Flooding and Sequestration Technology Research(Experiment) Center, Songyuan, Jilin 138000, China Jilin Oilfield Company, CNPC, Songyuan, Jilin 138000, China School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China

吉林某油田CO注气驱油井受CO分压、温度、采出液含水率以及细菌含量等诸多因素影响，造成井下管柱的严重腐蚀。为减缓腐蚀，当前主要采用井筒加注咪唑啉缓蚀剂来保护油井井筒和井下设备。通过研究CO、SRB等多因素条件下的腐蚀规律和腐蚀主因素，从降低防腐蚀成本的角度考虑，考察了缓蚀剂类型、加药方式、加药浓度、加药周期对井下油套管腐蚀的抑制效率和长期有效性，并根据现场情况制定了合理的加药制度，提高了缓蚀剂的作用效率，延长其服役寿命，使区块整体腐蚀速率低于0.076 mm/a，实现了井下腐蚀的防护效率与成本的最优化。通过工艺优化，不仅延长井下设备的服役寿命，也降低了防腐蚀成本。

Severe downhole corrosion occurred during Jilin CO flooding in an oilfield in Jilin due to the high pressure of CO, high concentration of saline water and sulfate reducing bacteria (SRB) in the produced fluid. Currently, addition of corrosion inhibitors is one of the common methods to protect the oil well and tubes. Through studies of corrosion mechanism and main factor analysis, the effects of inhibitor type, concentration, and injection technique on their filed inhibition efficiency and long-term durability were investigated, aiming at lowering the cost of corrosion management. Then a suitable injection regulation of inhibitor is proposed based on the filed situation in order to improve the long-term efficacy of inhibitor. Injection optimization tests indicate that the corrosion rate has been decreased to <0.076 mm/a. This optimized injection technique of inhibitor not only increases the service life of downhole device and tubes but also decrease the cost of corrosion management.

10.11885/j.issn.1674-5086.2019.05.08.01