Method and apparatus for measuring three dimensional stress in rock surrounding a borehole

摘要

A method for measuring the three dimensional stress in rock surrounding a borehole comprises the steps of cutting slots into the wall of a borehole at different angles relative to the borehole axis so as to effect stress relaxation and strain deformations which are representative of the stresses normal to the angle of the respective slots, and measuring the respective strain deformations adjacent to the slots that are being cut into the borehole wall at a sufficient number of angles to satisfy the mathematical requirement of six independent equations to solve for the three dimensional stress tensors so as to determine the three dimensional stress field surrounding the borehole from measurements in a single borehole.