Influence of Porous Flow on Wellbore Stability for an Inclined Well With Weak Plane Formation
Lu, YH*; Chen, M; Jin, Y; Ge, WF; An, S; Zhou, Z
The criterion of slip condition and wellbore instability are strongly affected by porous flow in weak plane formation, which leads to wellbore instability in the formation with weak planes. Considering influence of porous flow, a mechanical model of wellbore stability was established for inclined well with weak planes under porous flow, and the influence of various hole deviation angle, hole deviation azimuth, and weak plane occurrence on wellbore stability were analyzed. The results show that porous flow has worsened wellbore instability, and inclined wellbore stability is highly dependent on the weak plane occurrence, hole deviation azimuth, and deviation angle under porous flow. The mechanical model of wellbore stability for inclined well with weak planes under porous flow is applied to sidetracked hole in an oilfield of western China.