CO_(2)复合蒸汽驱采出井中抽油杆的腐蚀规律及腐蚀预测

Corrosion Law and Corrosion Prediction of Sucker Rod in CO_(2) Composite Steam Flooding Production Well

针对CO_(2)复合蒸汽驱采出井抽油杆的腐蚀问题,在高温高压釜中进行了模拟腐蚀试验,研究了温度(60~120℃),CO_(2)分压(0.1~0.3 MPa)和氯离子含量(1~3 g/L)对抽油杆腐蚀的影响,并建立了预测抽油杆腐蚀速率的数学模型,绘制了综合考虑多因素的腐蚀速率预测图版。结果表明:随温度的升高,抽油杆的腐蚀速率先升高后降低,90℃时达最大值(0.9391 mm/a);随着CO_(2)分压和氯离子含量的升高,腐蚀速率均逐渐增大,腐蚀主控因素为CO_(2)分压;腐蚀预测图版的预测结果与试验结果吻合良好,腐蚀预测图版具有较好的预测精准度和实用性。

Aiming at the corrosion problem of sucker rod in CO_(2)composite steam flooding production well,simulated corrosion tests were carried out in a high temperature and high pressure autoclave to study the effects of temperature(60-120℃),partial pressure of CO_(2)(0.1-0.3 MPa)and chloride ion concentration(1-3 g/L)on the corrosion of the sucker rod.A mathematical model for predicting the corrosion rate of sucker rods was established,and a corrosion rate prediction chart with comprehensive consideration of multiple factors was drawn.The results show that the corrosion rate of sucker rod increased first and then decreased with the increase of temperature,and reached the maximum value of 0.9391 mm/a at 90℃.With the increase of partial pressure of CO_(2)and chloride ion concentration,the corrosion rate of sucker rod gradually increased,and the main controlling factor of corrosion was partial pressure of CO_(2).The predicted results from the corrosion prediction plate were in good agreement with the experimental results,so the corrosion prediction plate had good prediction accuracy and practicability.