In-situ stress measurement in Narwapahar Mine by hydraulic fracturing technique

摘要

The insitu stress has been determined in Narwapahar mine of Uranium Corporation of lndia Limited (UCIL), Singhbhum district in Bihar by hydraulic fracturing technique. The hydraulic fracturing tests followed by fracture impression tests have been carried out at three levels (75m, 105m and 140m level). The direction and magnitude of the principal in-situ stresses were computed with the help of a new approach called "shut-in " pressure method. In this method, the shut-in pressure was considered equal to the normal stress acting perpendicular to the fracture plane. The stresses obtained by the shut-in pressure have been compared with that of conventional method. ft has been concluded that the principal stresses follow the major structural features: schistosity and foliation in Narwapahar mine.