Research on the Permeability Damage Caused by the Hydraulic Fracturing for Coalbed Methane Wells

The generation of hydraulic fracture will inevitably have an impact on the permeability of the coal nearby in the fracturing process. For the problem of coal bed permeability damage caused by fracturing,the equation between the induced stress and permeability was established. By calculation example,the characteristics of permeability damage caused by hydraulic fracturing were analyzed. Studies suggest that: the distribution of induced stress and permeability damage caused by hydraulic fracturing are symmetrical on the both sides of fracture. Hydraulic fracturing has a direct impact on the permeability of coalbed near the fracture,and the permeability damage phenomenon is very obvious. Permeability damage caused by hydraulic fracturing may be one of the reasons that the stimulation effect of some coalbed methane wells is not satisfactory.