- journal_title：Geophysics
- Contributor：Xinding Fang ; Michael Fehler ; Zhenya Zhu ; Tianrun Chen ; Stephen Brown ; Arthur Cheng ; M. Nafi Toksöz
- Publisher：Society of Exploration Geophysicists
- Date：2013-05-01
- Format：text/html
- Language：en
- Identifier：10.1190/geo2012-0145.1
- journal_abbrev：Geophysics
- issn：0016-8033
- volume：78
- issue：3
- firstpage：D143
- section：Borehole Geophysics and Rock Properties
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. To properly account for the formation property alteration, we propose an iterative numerical approach to calculate stress-induced anisotropy around a borehole by combining a rock physics model and a finite-element method. We tested 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 a 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.