It is well established that time-dependent processes are responsible for stability and failures in wellbore drilling. Stability problems account for a significant amount of lost drilling rig time and substantial costs during drilling. The coupled time-dependent processes are well described in the realm of the poroelasticity theory and some of their solutions and applications to the inclined wellbore problem in the general three-dimensional state of the in-situ stress have been published. In this paper, in addition to the analyses conducted on the previously derived solutions, thermal and pore fluid diffusion, the time-dependent solution for stresses and pore pressure for the inclined wellbore taking into account the mud and formation shale activities, are also derived. The aforementioned solutions are implemented in the user-friendly software, PBORE-3D, which can perform analyses of stress/pore pressure, formation failure, mud weight and mud salinity design for drilling in shale formations. Also included in this software are the thermal and viscous effects.

Keywords:
equation, poroelasticity, spe 56759, gradient, reservoir characterization, roegier, university, variation, mud-weight window, wellbore design
Subjects:
Wellbore Design, Reservoir Characterization, Reservoir Fluid Dynamics, Formation Evaluation & Management, Wellbore integrity, Reservoir geomechanics, Flow in porous media
Copyright 1999, Society of Petroleum Engineers
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