Hydraulic Fracturing Technology to Improve Seam Permeability of Driving Belt

Hydraulic fracturing technology has successfully been applied in Datong No.1 Mine to improve driving belt permeability.Borehole for hydraulic fracturing is sealed by grouting 3 times to ensure the fracturing success.The water pressure of fracturing is 19.3 to 39.5 MPa,and water injection volume of each borehole is 120 m³.The fracturing area of coal seam is 50 to 150 m, the average is 100 m. After fracturing and pumping, the gas extraction flow rate and concentration of the single bore can be increased by 3 to 5 times and 3% to 20% respectively. Seam permeability is improved significantly.