Citation

Jia J, Ge J, Zhen W, Zhao D. China Saf. Sci. J. 2020; 30(10): 63-68.

Copyright

(Copyright © 2020, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2020.10.009

PMID

unavailable

Abstract

In order to solve problems of low permeability and low gas extraction rate in coal seams, permeability enhancement of hydraulic fracturing was numerically simulated by using discrete element software RFPA2D-flow. Firstly, effect of different water pressure on single-hole fracture propagation was simulated. Secondly, multi-point hydraulic fracturing was simulated, and influence of single fracturing of center hole and simultaneous fracturing of peripheral hole on development state of crack growth was analyzed. Finally, taking Mabao coal mine as working background, anti-reflection effect of hydraulic fracturing was comprehensively evaluated based on theoretical analysis and research and field industrial test. The results show that redistribution of borehole stress can ensure accuracy and reliability of numerical simulation results. Induced stress can affect propagation direction of fracture developed later, making it easier to form a network structure with that developed first, thus verifying anti-reflection mechanism of hydraulic fracturing. In addition, when water pressure is 27 MPa, simulation result of effective radius of fracturing is 2. 8 m, which is basically consistent with actual radius of 3 m. © 2020 China Safety Science Journal. All rights reserved.

Language: zh