Abstract:

Abstract: Aim at the problem of high gas content and low permeability at work face S1206, yuwu coal mine, pulsating hydraulic fracturing experiment was carried out to get a better effect on gas drainage. The principle of pulsating hydraulic fracturing is analyzed, fracturing borehole parameters, borehole sealing process and fracturing parameters are designed. Results indicate that for fracturing boreholes, concentration and flux of extraction gas are boosted by as much as 4.7 times and 6.3 times respectively compared with a normal borehole, for directional boreholes, concentration and flux of extraction gas are increased by 3.7 times and 3.9 times respectively. This technology provides a way of pressure relief and permeability promotion for coal seam.

Key words: hydraulic fracturing, gas drainage, pressure relief and permeability promotion