An approach for predicting stress-induced anisotropy around a borehole
Name
Fang-Fehler-Zhuetal_An_Approach_for_Predicting_stree_induced_anisotropy_around_a_borehole.pdf
Size
724.54 KB
Format
Adobe PDF
Checksum (MD5)
35592d6ff5cda06a6db4b39502c97884
Author(s)
Fang, Xinding
Fehler, Michael
Zhu, Zhenya
Chen, Tianrun
Brown, Stephen
Cheng, Arthur
Toksoz, M. Nafi
Date Issued
2012
Publisher
Massachusetts Institute of Technology. Earth Resources Laboratory
Series/Report no.
Earth Resources Laboratory Industry Consortia Annual Report;2012-09
Abstract
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 the rock physics model of Mavko et al. (1995) 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.
Subjects
Logging
Inversion
Persistent DSpace Link
