Research on Application of Directional Long Drilling Fracturing Technology in 1930 Coal Mine

Abstract

The solidity coefficient of the main coal seam in Xinjiang Coking Coal Group 1930 Coal Mine is below 0.3, which is a soft outburst coal seam with poor air permeability, a small effective range of gas drainage drilling, low porosity of soft coal seam, low gas drainage rate, and unsatisfactory drainage effect. Using directional drilling equipment to construct directional long drilling, combined with the hydraulic fracturing pump set independently developed by Xi’an Research Institute, directional drilling were constructed in the 1930 coal mine 1600 level 6# coal seam, and hydraulic fracturing was carried out. The results show that after the hydraulic fracturing of the 6# coal seam, the production has been stable for nearly 6 months. During the period, the average gas drainage rate of the drilling was 134.9m3/d (maximum 561.7m3/d), which was 2.10 times that before fracturing, The average drainage concentration is 1.90%, which is 1.45 times that before fracturing. At present, the total amount of gas drainage is 25,900 m3, which is 4 times the original amount. This technology has achieved enhanced permeability of broken soft coal seam, increased drainage volume, extended drainage time, and advanced gas outburst elimination at a long distance. It provides a technical guarantee for the enhanced permeability enhancement of the broken soft low-permeability outburst coal seam and the high-efficiency underground gas drainage.