Pilot geological analysis of indirect fracturing in vertical CBM well

The indirect fracturing approach in coal seam roof and floor has been efficiently used in areas of developed tectonic coal and other coal to enhance the production of single well. The pilot geological analysis of coal reservoir was carried out on the basis of the formation mechanism of pulverized coal and cracks, the mechanism of fracturing fluid leak-off. The results indicated that indirect fracturing was suitable for coal seams with developed fracture system easy to produce pulverized coal and to be out of control of fracture height. Combined with the characteristics of ground stress field, lithological section and stress profile, the paper described in detail how to carry out the design of indirect fracturing. Based on the data of a block in Qinshui basin, Shanxi Province, the fracturing effect of two neighboring wells of similar geological conditions was compared as an example, the yield-increasing effect of the indirect fracturing was better than that of the conventional fracturing, showing that the advantages of indirect fracturing in transformation of coalbed methan desorption and production of gas flow path.