The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 20, 2011
Filed:
Oct. 30, 2007
Chang-ha Ryu, Daejeon, KR;
Dong-woo Ryu, Daejeon, KR;
Byung-hee Choi, Daejeon, KR;
Loui Porathur John, Dhanbad, IN;
Jung-ho Synn, Seoul, KR;
Chang-Ha Ryu, Daejeon, KR;
Dong-Woo Ryu, Daejeon, KR;
Byung-Hee Choi, Daejeon, KR;
Loui Porathur John, Dhanbad, IN;
Jung-Ho Synn, Seoul, KR;
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.