Characteristics and effect evaluation of hydraulic fracturing of CBM well with thick coal seam

In order to make full use of the CBM resources in thick coal seams, it is necessary to improve the fracturing effect of thick coal seams and establish a complex fracture network in the thick coal seams. Taking the CBM wells of different thickness in Lanhua Block of Qinshui Basin as an example, the influence of fracturing construction parameters on the fracturing effect and gas production effect under different thickness conditions was studied. The results show that the fracture network length and reconstruction effect of thick coal seams in the study area are significantly affected by the total amount of fracturing fluid. The average length of fracturing fractures is 192 m, and the fracturing fractures extend longer to the shallower buried area. The horizontal principal stress direction of No.3 coal seam of Shanxi Formation in the study area is north-east-east, and the fracturing fractures deviate from the horizontal principal stress direction, and the difference in the length of the fractures on both sides of the shaft increases. The thicker the coal seam, the higher the resource abundance, the greater the contribution to the average daily gas production per meter of coal thickness and the cumulative gas production per meter of coal thickness. Through the optimization of multi-parameter geological sweet spot of coal reservoir and the optimization of development engineering parameters, the development risk of CBM in thick coal seam is reduced and the gas production effect is improved.