Invention Grant
- Patent Title: Fracturing relief method for stress concentration of remaining ore pillars in overlying goaf
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Application No.: US16768889Application Date: 2018-11-02
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Publication No.: US11299954B2Publication Date: 2022-04-12
- Inventor: Bingxiang Huang , Luying Shao , Xinglong Zhao , Shuliang Chen
- Applicant: China University of Mining and Technology , XUZHOU USURE MINING TECHNOLOGY CO., LTD
- Applicant Address: CN Jiangsu; CN Jiangsu
- Assignee: China University of Mining and Technology,XUZHOU USURE MINING TECHNOLOGY CO., LTD
- Current Assignee: China University of Mining and Technology,XUZHOU USURE MINING TECHNOLOGY CO., LTD
- Current Assignee Address: CN Jiangsu; CN Jiangsu
- Agency: JCIPRNET
- Priority: CN201810549872.1 20180531
- International Application: PCT/CN2018/113595 WO 20181102
- International Announcement: WO2019/227852 WO 20191205
- Main IPC: E21B43/26
- IPC: E21B43/26 ; E21B33/12 ; E21B4/02 ; E21B23/06

Abstract:
Provided is a fracturing relief method for stress concentration of remaining ore pillars in an overlying goaf, including first, performing directional fracturing on a roof to optimize the stress of the roof and reduce the source of force; secondly, performing pulse fracturing on a coal pillar to produce a crack network, weaken the stiffness of the coal pillar and reduce the bearing capacity of the coal pillar; and finally, performing pulse fracturing on a floor strata of the coal pillar to reduce the ability of transferring stress concentration thereof. A drilling machine is used for separately constructing fracturing drill holes in a roadway to a set depth at an interval in a direction oblique to the coal pillar in an upper goaf. The roof, the coal pillar and the floor can be fractured by an oblique fracturing hole in a sublevel retreating manner. The position of the directional fracturing of the roof is approximately 1 m above the middle of a main roof above the coal pillar. The method reduces the width of the lower coal pillar, improves the coal mining rate, reduces the deformation of the lower coal roadway, effectively solves the problems of mine pressure passing through the coal pillar on the working face of the lower coal seam, rock burst, and coal and gas outburst in the mining of the lower coal seam, and simultaneously has the advantages of high safety factor, simple method, convenient construction and low cost.
Public/Granted literature
- US20210348471A1 FRACTURING RELIEF METHOD FOR STRESS CONCENTRATION OF REMAINING ORE PILLARS IN OVERLYING GOAF Public/Granted day:2021-11-11
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