New development of hydraulic fracturing technique for in-situ stress measurement at great depth of mines

Meifeng Cai1), Hua Peng1,2), and Hongguang Ji1) 1) School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China 2) Research Institute of Geomechanics, Beijing 100080, China

摘 要：In-situ stress measurement using the hydraulic fracturing technique was made at Wanfu Coal Mine in Shandong Province, China. To solve problems caused by great measuring depth and extra thick overburden soil layers in the mine, a series of improved techniques were developed for the traditional hydraulic fracturing technique and equipment to increase their pressure-enduring ability and to ensure safe and flexible removal of the sealing packers with other experimental apparatus. Successful in-situ stress measure-ment at 37 points within 7 boreholes, which were mostly over 1000 m deep, was completed. Through the measurement, detailed in-formation of in-situ stress state has been provided for mining design of the mine. The improved hydraulic fracturing technique and equipment also provide reliable tools for in-situ stress measurement at great depth of other mines.

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