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f Geomechanical Considerations in Drilling, Completions and Stimulation of Shale Gas/Oil Reservoirs
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, AAPG/EAGE/SPE Shale Gas Workshop, Oct 2012, cp-318-00016
Abstract
Shale formations have laminated structures that result in directionally dependent geomechanical properties and anisotropic horizontal stresses. Traditional isotropic stress approaches typically used in pre-drill wellbore stability analysis do not consider 3D azimuthal anisotropy present in shales. Ignoring anisotropy generally results in underestimation of stresses, which can lead to incorrect safe trajectories or mud-weights predictions. Similarly, completion design approaches used in conventional reservoirs do not take material anisotropy or the laminated nature of shales into consideration. This has often led to incorrect conclusions about lateral landing points and perforation intervals.