摘要
钻头破碎岩石形成井眼后,钻井液代替了破碎后的岩石对井壁起到了支撑作用,在一定程度上维持着井壁的稳定。长期以来针对井壁稳定性的研究都是基于理想的圆形井眼,而对非圆形井眼井壁稳定性的研究很少;然而,在实际情况中井壁受钻柱的碰磨、井内介质的冲刷、地层应力以及岩石本身的力学性质等因素的影响而表现为非圆形的井眼,因此有必要分析非圆形井眼井壁稳定性情况。通过建立数值仿真模型分析了井壁在最大主应力方向和最小主应力方向受损后的井眼应力情况,结果表明:基于圆形井眼计算出的泥浆密度窗口要大于基于受损井眼所得出的密度窗口,所以,如果基于圆形井眼的计算结果去调节泥浆密度是不理想的,应该根据实际井眼的计算结果来做相应的调节。
After drill hole formations,the drilling fluid replacing the crushed rock and plays a supporting role.The studies about wellbore stability are based on the ideal circular borehole for a long time;however,in practice,the wellbore performance as a non-circular borehole due to the impact and rubbing by drill string,wellbore medium erosion,formation stress and rock mechanical properties or other factors.Through the establishment of the numerical simulation model to analyze the damaged wellbore in the direction of the maximum principal stress and minimum principal stress directions wellbore stress,the results showed that：in the drilling mud, if expanded caliper appears in the case of the maximum horizontal stress direction,more prone to tension failure;in gas drilling,if the expansion occurs at the minimum horizontal stress direction,wellbore wall is more prone to shear failure.
出处
《化工设计通讯》
CAS
2016年第5期139-142,共4页
Chemical Engineering Design Communications
关键词
井筒内压
受损井眼
井壁稳定
主应力
wellbore pressure
damaged wellbore
wellbore stability
principle stress
