POROELASTIC SOLUTIONS IN TRANSVERSELY ISOTROPIC MEDIA FOR WELLBORE AND CYLINDER

This paper presents closed-form solutions for the pore pressures and s tress fields for the inclined borehole and the cylinder, induced by bo undary stress perturbation in an-anisotropic poroelastic medium. The g overning equations for the transversely isotropic poroelastic material s 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 coinc iding with the material axis of symmetry; while the solutions for the cylinder are obtained under various loading conditions that are encoun tered in laboratory testing procedures. The analysis shows, in additio n to the effect of time on stress and pore pressure variations, that p oromechanical 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 Elsevie r Science Ltd. All rights reserved.