Stress analysis on coal after hydraulic fracturing of coal seam

The law of coal and rock stress distribution after hydraulic fracturing plays a key role in the effect of scour prevention. the theoretical method was used to study the fracture distribution of water area and gas area, methane pressure and analytical solution of stress on coal seam after hydraulic fracturing and water pressure relief. Study shows that the pore pressure of water area changes little along the radial direction after hydraulic fracturing and is close to water injection pressure, gas pressure of gas area showes a decreasing trend along the radial direction. In a certain extent, the gas pressure rise area is formed in the periphery of the water area. The circumferential stress in the water area of the coal body will be reduced until it becoms tensile stress. Radial stress of coal body in gas area shows a decreasing trend along the radial direction. While after the water pressure is relieved, the pore pressure and radial stress of coal body in water and gas area both show a decreasing trend along the radial direction and the value of the radial stress of coal body in gas area is close to primary stress of coal body. The tangential stress and pore pressure of coal body in gas area shows a decreasing trend along the radial direction. All of the studies have provided the theoretical basis for using hydraulic fracturing to prevent rock burst.