In-Situ Stress Determination Based Upon Borehole Imaging and Rock-Sample Analyses: A Comparison Among Anelastic Strain Recovery (ASR), Acoustic Velocity, and Acoustic Tomography

摘要

The orientation of the horizontal in-situ stresses in an oil well at the Potiguar Basin, Northeast of Brazil, was estimated through three different methods: Anelastic Strain Recovery Test -ASR-3D, wellbore Electrical Micro Imaging -EMI, and acoustic velocities anisotropy -VELAN. A fourth and very promising method for acquiring in-situ stress orientation from rock cores, acoustic tomography, is also presented in this paper. The goal of the work was to compare methods dealing with different sources of data, in order to identify a more reliable, though simple and cheap procedure for inferring the in-situ stress orientation. The three methods had very similar results, finding the maximum horizontal in-situ stress at N42,6E (ASR method); N45E (EMI method); and N42E (VELAN method).