公开(公告)号：EP2078185A1

公开(公告)日：2009-07-15

申请号：EP07833704.5

申请日：2007-10-30

Applicant: Korea Institute of Geoscience and Mineral Resource

Inventor： RYU, Chang-Ha ,  RYU, Dong-Woo ,  CHOI, Bung-Hee ,  JOHN, Loui, Porathur ,  SYNN, Joong-Ho

IPC: G01L1/00

CPC classification number: E21B49/006 ,  E21B43/26

Abstract: Disclosed is a method and apparatus for measuring in-situ stress in rock using a thermal crack. The method involves forming a borehole, cooling a wall of the borehole, applying tensile thermal stress, forming a crack in the borehole wall, and measuring temperature and cracking point. Afterwards, the borehole wall is heated to close the formed crack, the borehole wall is cooled again to re-open the crack, and temperature is measured when the crack is re-opened. The in-situ stress of the rock is calculated using a first cracking temperature at which the crack is formed and a second cracking temperature at which the crack is re-opened. Further, the apparatus cools, heats and re-cools the borehole wall, thereby measuring the first cracking temperature, the second cracking temperature, and the cracking point.