稠油注蒸汽热采过程中射孔段套管热应力仿真模拟

Thermal Stress Simulation of Perforated Casing in the Prossess of Producting Heavy Oil by Injection Steam

我国稠油资源约占总石油资源的30%。稠油油藏以蒸汽吞吐开采为主。一个蒸汽吞吐循环周期包括蒸汽注入阶段、焖井阶段和采油阶段。其中,造成稠油热采井套管损坏的主要原因之一是热采井高温及温度剧烈变化。利用ABAQUS有限元软件建立了三维井筒模型,分析了蒸汽注入阶段、闷井阶段的热传导过程及射孔段套管的热应力分布,其中射孔部位是稠油热采过程中较易破坏的地方。经过几个吞吐周期后套管上会积累较高的残余应力而使套管发生塑性破坏。

Heavy oil resource is about 30% of the total oil resource in our country.Most of heavy oil yield produce through steam huff.A steam stimulation cycle includes steam injection stage,soak stage and production stage.High temperature and temperature changes are main reason that it makes casing damage for thermal recovery wells.Through ABAQUS finite element software build 3D wellbore model.The study shows that heat conduction process and the thermal stress distribution of perforated casing in steam injection stage and shut-in stage.The perforation site is a easily damaged place in the process of the thermal recovery.After a few stimulation cycles,the casing will accumulate high levels of residual stress and make the casing plastic failure.