Technology of CBM extraction in the crushed and soft coal seam in Luling coal mine

The horizontal drilling is inclined to collapse in crushed and soft coal seam, and it is difficult to extract coalbed methane(CBM) on the surface. Based on the advanced development technology for shale gas and tight sand gas, enhanced CBM extraction technology by stimulated horizontal well drilled in the roof of crushed and soft coal is studied, and the procedure of horizontal drilling in roof, oriented perforating and staged fracturing is optimized. Using the technology, horizontal well LG01 was completed in Luling coal field, Anhui Province. The testing shows that the daily CBM production from this well is more than 1.0×10⁴ m³, the production is beyond four times of that from local vertical wells, and it is a successful and brand-new method to extract CBM from crushed and soft coal seam.