Poroelastic solutions in transversely isotropic media for wellbore and cylinder

This paper presents closed-form solutions for the pore pressures and stress fields for the inclined borehole and the cylinder, induced by boundary stress perturbation in an-anisotropic poroelastic medium. The governing equations for the transversely isotropic poroelastic materials under the cylindrical coordinate system are presented. The solution for the inclined borehole, subjected to a three-dimensional far-field anisotropic stress field, is derived with the borehole generator coinciding with the material axis of symmetry; while the solutions for the cylinder are obtained under various loading conditions that are encountered in laboratory testing procedures. The analysis shows, in addition to the effect of time on stress and pore pressure variations, that poromechanical anisotropic material coefficients also play an important role in calculating the inplane stress fields, which is not the case using the classical anisotropic theory of elasticity. (C) 1998 Elsevier Science Ltd. All rights reserved.