求解井眼围岩塑性区应力状态与变形的一种方法  

A Method for Solving the Plastic Stress State and Distortion of Borehole Rock

作　　者：孙学增[1,2,3] 赵黎安[1,2,3] 张文[1,2,3] 孙茂凤[1,2,3] 王恒贵 

机构地区：[1]大庆石油学院石油工程系 [2]大庆石油管理局钻井一公司 [3]大庆石油高等技术学校

出　　处：《大庆石油学院学报》1999年第1期21-24,共4页Journal of Daqing Petroleum Institute

基　　金：国家"九五"科技攻关项目

摘　　要：应用弹、塑性应力－应变理论，根据井眼围岩应力状态对岩石塑性体积应变影响的假设条件，弹、塑性岩石的应力－应变简化曲线，以及极限强度和残余强度准则，推导出了求解岩石变形参数关系式．并分析了井眼围岩的临界井眼压力状态，建立了求解弹、塑性地层井眼围岩应力状态方程，为合理预测和过后分析井眼缩径和井壁的稳定性提供了计算方法．计算实例表明，当轴向应力较小时，会导致井壁岩石产生较大的塑性屈服区；塑性区半径会随井眼压力的增大而减小．The rock distortion parameter formula is derived and solved based on elastoplastic stress strain theory with the assumed condition of the effect of the borehole rock strain state on the rock plastic volume strain, and the simplified stress strain curve, limit strength and remaining strength criteria, and then the critical borehole pressure state is analyzed. The established state equation of the borehole rock in elastoplastic stratum can be used to reasonablly calculate and predicthe the borehole contraction and the stability of borehole. The cases which the calculation are conducted with the established equation in this paper show that the less the axial stress of the borehole is, the bigger the area of the borehole plastic yield region; and the radius of plastic region may reduce as the borehole pressure increases.

关 键 词：井眼围岩 强度参数 变形 应力状态 钻井 

分 类 号：TE21[石油与天然气工程—油气井工程]