Time-dependent failure analysis of inclined boreholes in fluid-saturated formations

This paper presents time-dependent poroelastic failure analyses of borehole s drilled porous formations. The work is based on a recently derived analyt ical solution. The in directions inclined to the far-field stress principal axes in fluid-saturated isotropic analyses include collapse as well as fra cturing failures. The time-dependent failures in relation to borehole incli nation, azimuth, and mud pressure are presented. The critical roles of poro elastic constants in borehole stability are also demonstrated.