Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9716485 | International Journal of Rock Mechanics and Mining Sciences | 2005 | 11 Pages |
Abstract
Elasticity theory predicts formation of both transverse and axial drilling-induced tensile fractures (DITFs) in vertical wells depending on the magnitude of the principal in situ stresses, pore-pressure and mudweight. Drilling-induced tensile fractures initiate in very specific stress environments. Axial DITFs can closely constrain a lower bound to the maximum horizontal stress (SH max) magnitude where the minimum horizontal (Sh min) stress is known. If transverse DITFs are observed, they can constrain a lower bound to maximum and minimum horizontal stress magnitudes. The observation of transverse DITFs on image logs can constrain the stress field to one on the border of strike-slip and reverse faulting (SHmax⪢Shminâ¼Sv) without requiring knowledge of the Sh min or SH max magnitude. The observation of transverse DITFs in the West Tuna area combined with wireline log data, leak-off tests and pore pressure data are used to constrain the in situ stress tensor. The interpreted in situ stress tensor lies on the border of a strike-slip and reverse faulting regime (SH maxâ¼40.5 MPa/km>Sh minâSvâ¼21 MPa/km). Interpreted data from leak-off tests in the West Tuna area confirm that Sh minâ¼Sv.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geotechnical Engineering and Engineering Geology
Authors
E.J. Nelson, J.J. Meyer, R.R. Hillis, S.D. Mildren,