Analysis of suitable development technology of CBM(gas) in Guizhou

In recent years, technical bottlenecks have been encountered in the practice of CBM exploration and development in Guizhou Province, selecting suitable development technology is one of the key issues. Based on the background that CBM exists in thin coal seams and geological structures are complicated in Guizhou, combined with successful development and utilization of CBM, the CBM development and utilization technology suitable for complex geological conditions in Guizhou was put forward. Air drilling is recommended for drilling in Guizhou, according to different distance of thin seams, such as optical casing composite fracturing and salvageable bridge plug fracturing can be used. Com-prehensive utilization of anti-pulverized coal fracturing technology and in-fracture steering technology should be strengthened in soft coal seams; First mining seam should be optimized for soft and low permeability coal seam group, CBM drainage effect is better after mining pressure relief. At the same time, the integral application of the techniques such as directional long borehole, "replacing roadway with hole", casing in whole soft coal seams, fracturing of low permeability coal seams by CO₂ phase transition and hydraulic cutting should be enhanced. It is proved that the effect of gas extraction can be effectively enhanced.