塔河油田注气井井筒氧腐蚀机理研究

发布时间：2019-02-20 09:55

【摘要】：塔河油田缝洞型油藏采用氮气驱可有效提高剩余油的采出程度,但注入的氮气中含2%~5%的氧气,使得井筒腐蚀严重。采用失重法、EIS极化曲线法和电化学阻抗法研究了塔河油田在注氮气提高采收率条件下的氧腐蚀特点,得到了腐蚀速率、腐蚀阻抗谱和腐蚀动力学曲线。研究表明,腐蚀速率随着温度和压力的增加而增加,腐蚀速率在井深2 500 m处达到了0.446 mm/a;注气柱塞泵下入井深1 818 m时,泵经过117 h工作后已经被腐蚀产物全充满,这与现场的检泵周期基本吻合。据此建议塔河油田注气抽油泵下入深度应不超过2 500 m;注气井筒在焖井过程中应加入除氧剂,并可以考虑用稀油代替水作为顶替液。
[Abstract]:Nitrogen flooding can effectively improve the recovery degree of remaining oil in the fracture-cavity reservoir of Tahe Oilfield, but the injected nitrogen contains 2% oxygen, which makes the wellbore corrode seriously. The oxygen corrosion characteristics of Tahe oil field under the condition of enhanced recovery by nitrogen injection were studied by weightlessness method, EIS polarization curve method and electrochemical impedance method. The corrosion rate, corrosion impedance spectrum and corrosion kinetics curves were obtained. The results show that the corrosion rate increases with the increase of temperature and pressure, and the corrosion rate reaches 0.446 mm/a; at the depth of 2 500m. When the injection plunger pump enters the well at a depth of 1 818 m, the pump has been completely filled with corrosion products after 117 hours of operation, which is basically consistent with the period of pump inspection in the field. It is suggested that the depth of gas injection pump should not exceed 2 500 m in Tahe Oilfield, and the deoxidizer should be added in the gas injection wellbore, and the use of thin oil instead of water as displacement fluid should be considered.
【作者单位】：中国石油新疆油田勘探开发研究院;长江大学石油工程学院;中国石油新疆油田工程技术研究院;
【基金】：中石化西北局“缝洞型油藏注气提高采收率技术研究”,编号:2014H1121 国家自然青年科学基金“Gemini表面活性剂对原油-水界面性质的影响”,编号:51404039;国家自然青年科学基金“基于温敏聚合物的水基钻井液体恒流变特性研究”,编号:51404040
【分类号】：TE983

【相似文献】