Research on the technology of pressure relief and outburst prevention in the seam area of high pressure water jet cutting

Abstract

In view of the problems of coal and gas dynamic disasters in deep coal seams, which tend to be complex, fuzzy and common, this paper theoretically analyzes the distribution law of original stress around the borehole, reveals the mechanism of pressure relief and permeability enhancement of high-pressure hydraulic slotting, and uses FLAC3D numerical software to analyze the borehole circumference under different slotting pressures, different slotting spacing, different drilling spacing and different slotting methods. The displacement of the surrounding coal body and the distribution of the plastic zone reveal the law of the pressure relief of the coal body around the borehole after the high pressure hydraulic slotting. Through field test, the average extraction concentration of slotted borehole is 1.75 times that of common borehole, and the average extraction purity is 3.25 times that of common borehole. The research shows that the high pressure water jet slotting technology can be used as a new way of pressure relief and outburst prevention in deep coal seam area.