Coal Engineering ›› 2021, Vol. 53 ›› Issue (5): 80-84.doi: 10.11799/ce202105015

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Application of Directional Hydraulic Fracturing and Pressure Relief Technology for Overhang at Shallow Depth

  

  • Received:2020-09-04 Revised:2021-03-19 Online:2021-05-20 Published:2021-05-17

Abstract: The strong dynamic pressure on the shallow working face in the Shenfu mining area often causes coal wall slicing and support accidents. At present, the top slab is treated by drilling or blasting along the slot. However, pyrotechnic products have greater safety risks. This article is based on the analysis of the roof lithology of Yanghuupan Coal Mine and the reasons for the shallow overhang. It is proposed to use directional hydraulic fracturing technology to destroy the integrity of the roof. Combined with the monitoring curve of the water pressure recorder, the pump pressure is adjusted in time and the degree of rock cracking and expansion is judged. Transfer the high stress on the working surface support away from the roof. Analysis of mining practice and mine pressure monitoring data show that. After directional hydraulic fracturing is used to treat the roof of the working face. The mine pressure at the working end appears to be significantly eased. The proportion of high resistance areas is significantly reduced. The resistance of the stent in the range of 5000~7000kN was reduced from 36% to 29%. After the pressure is relieved, the load on the support is basically normally distributed. It can be seen that the directional hydraulic fracturing technology is an effective means to control the environment of strong dynamic pressure stress at shallow depth and has broad application prospects.