Determining maximum horizontal stress in an earth formation
US8024124B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 12, 2008 |
| Grant date | Sep 20, 2011 |
| Priority date | — |
| Expiry date | May 13, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a method for determining maximum horizontal stress in an earth formation. The method includes obtaining fast shear wave velocities (Vs1) and slow shear wave velocities (Vs2) for various depths in the earth formation, calculating shear wave anisotropy (Adata) using Vs1 and Vs2, obtaining vertical stress (Sv) and minimum horizontal stress (Sh) for the formation, representing maximum horizontal stress (SH) using a parameterized function having at least one parameter and using Sh and Sv as input, determining a value of the at least one parameter by minimizing a cost function that represents a measure of difference between Adata and Apred for the various depths and Apred is predicted shear wave anisotropy determined using Sv, Sh, and SH, calculating SH using the parameterized function and the value of the at least one parameter, and storing SH in relation to the earth formation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.