热采井套管受力有限元模拟研究

Finite Element Simulation Study on Stress State of Casing in Thermal Recovery Wells

热采井套管服役情况较为复杂,套管损坏情况日益严重。采用数值模拟手段对热采井套管的受力情况进行了研究,研究结果表明:相比于注汽前,注汽后产生的热应力致使套管有效应力增加较大,显著提高了套损的发生概率,随着注汽湿度、注汽速度和井底压力的增加,套管有效应力逐渐增加,但增加幅度逐渐减小最后趋于平缓,而井底套管有效应力随着注汽温度的增加呈线性增加。

The service situation of thermal recovery wells＇ casing is complicated,and casing damage is becoming more and more serious.In this paper,the stress state of casing in thermal recovery wells was studied by adopting numerical simulation method. The results shows that： after steam injection,thermal stress has caused large increasing of effective stress on casing than before,the risk of the casing damage was also increased significantly. With the increase of humidity,the speed of steam injection and the bottom hole pressure,the effective stress of casing increases gradually,but its increasing amplitude decreases,then finally become flat,and the effective stress of downhole casing increases linearly with the increase of the steam injection temperature.