Coal Engineering ›› 2023, Vol. 55 ›› Issue (3): 127-132.doi: 10.11799/ce202303023

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Study on Layout Parameters of Long Directional Boreholes in Roof Based on COMSOL

  

  • Received:2022-06-21 Revised:2022-10-19 Online:2023-03-20 Published:2023-04-11

Abstract: In view of the deficiency that the current research on the hole layout parameters of roof directional long drilling is only to determine the drilling layout horizon and horizontal range, taking the 21215 working face of Dongpang mine as the engineering background, the vas pumping model of roof long drilling under five different layout modes is established by using COMSOL numerical simulation software, and the drilling layout mode of "normal spacing of 2 m and horizontal spacing of 3 m" is determined according to the simulation results. According to the height of fracture zone in 21215 working face, the layout parameters of drilling holes are designed, and the feasibility of hole layout parameters is verified by using the formula determined by the horizontal position theory of drilling holes. The field application results show that in the mining process of the working face, there are stable stage and attenuation stage in the roof directional long drilling drainage. In the attenuation stage, the drilling drainage effect decreases and the gas concentration in the upper corner increases. The analysis is due to the reduction of the drilling height and the destruction of the drilling integrity. On the whole, the gas concentration in the upper corner during mining is 0.3% ~ 0.4%, which is at a low level, indicating that the drainage effect of roof directional drilling is good. This arrangement effectively solves the problem of gas concentration overrun in the upper corner.

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