注CO采油井油管柱腐蚀速率预测

Prediction of Tubing String Corrosion Rate in CO-injection Production Wells

张智 刘金铭 张华礼 李玉飞 罗伟

ZHANGZhi LIUJinming ZHANGHuali LIYufei LUOWei

“油气藏地质及开发工程”国家重点实验室·西南石油大学, 四川 成都 610500 中国石油西南油气田分公司采气工程研究院, 四川 成都 610017

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China Gas Production Engineering Research Institute, PetroChina Southwest Oil and Gas Field Branch, Chengdu, Sichuan 610017, China

针对注CO采油井生产中油管柱存在的腐蚀现象，开展了注CO采油井不同阶段的油管腐蚀规律研究。对油管柱CO腐蚀进展进行了概述，基于动力学原理与金属的电化学腐蚀理论，考虑油气生产过程的产液量、含水率、井口温度、生产压差、流体流速等因素，得到油管内温度压力分布，研究了CO采油井油管腐蚀速率预测方法。对实例井的油管柱腐蚀速率做出了预测，并开展主控因素下油管柱腐蚀速率随时间、井深的变化规律研究。结果表明，在整个吞吐周期中，油管腐蚀主要发生在生产阶段。腐蚀情况预测结果与现场实测腐蚀情况吻合较好。

The pattern of tubing corrosion in different stages in CO production wells was investigated from the viewpoint of the phenomenon of tubing string corrosion. Moreover, the progression of CO corrosion in the tubing string is summarized. Based on kinetic principles and the theory of electrochemical corrosion of metals, factors such as the liquid production, water cut, wellhead temperature, production pressure difference, and fluid flow rate were considered. Further, the internal temperature and pressure distribution of the tubing were obtained, and methods for predicting the corrosion rate in CO production well tubing were investigated. The corrosion rates of the tubing string in actual wells were predicted, and the pattern of variation in the tubing string corrosion rate with the time and depth was investigated under the principal control factors. The results show that tubing corrosion occurs primarily in the production stage throughout the throughput cycle. The prediction results of corrosion conditions are in good agreement with the corrosion conditions measured in the field.

10.11885/j.issn.1674-5086.2018.06.07.01