Predicting stress-induced anisotropy around a borehole
Author(s)
Fang, Xinding; Fehler, Michael; Zhu, Zhenya; Chen, Tianrun; Brown, Stephen; Cheng, Arthur; Toksoz, M. Nafi; ... Show more Show less
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Other Contributors
Massachusetts Institute of Technology. Earth Resources Laboratory
Metadata
Show full item recordAbstract
Formation elastic properties near a borehole may be altered from their original state due to the stress concentration around the borehole. This could result in a biased estimation of formation properties but could provide a means to estimate in situ stress from sonic logging data. In order to properly account for the formation property alteration, we propose an iterative numerical approach to calculate the stress-induced anisotropy around a borehole by combining Mavko’s rock physics model and a finite-element method. We show the validity and accuracy of our approach by comparing numerical results to laboratory measurements of the stress-strain relation of a sample of Berea sandstone, which contains a borehole and is subjected to uniaxial stress loading. Our iterative approach converges very fast and can be applied to calculate the spatially varying stiffness tensor of the formation around a borehole for any given stress state.
Date issued
2012Publisher
Massachusetts Institute of Technology. Earth Resources Laboratory
Series/Report no.
Earth Resources Laboratory Industry Consortia Annual Report;2012-08
Keywords
Logging, Inversion