极限工况条件下膨胀衬管长度设计方法研究与应用

Study and application of design method for expansion liner length under limiting operational condition

根据海上油田开发后期调整钻分支井的实际情况,采用弹塑性力学分析方法对膨胀衬管的塑性极限应力进行了分析,同时根据膨胀衬管坐挂斜向器承受钻分支井时的轴向载荷及开窗侧钻时的钻头扭矩等工况,提出了极限工况条件下膨胀衬管长度设计方法,即当轴向承载和扭矩这两个条件同时得到满足时才能确定膨胀衬管长度。这一研究成果已在渤海油田开发后期调整钻分支井中得到了成功应用。

According to the adjustment branch wells drilled in later development stage of offshore oil fields, the plasto elasticity analytic method was used to analyze plastic limit stress of expansion liner, at the same time, the design method for expan- sion liner length was proposed for limiting operational condition based on the axial load on whipstock during drilling branch hole and the torque on bit during window cutting and sidetracking, that is the expansion liner length can be determined when both the axial load and the torque on bit are satisfied. This study results have been applied successfully in the adjustment branch wells drilled in later development stage of Bohai oil fields.