Fracture Mechanism on Supercritical Carbon Dioxide Blasting in Low-Permeability Coal Under Various Crustal Stresses

Abstract

The low permeability of coalbed inhabits exploring coalbed methane (CBM) in China. In order to enhance CBM production, supercritical carbon dioxide (SC-CO2) blasting is used as an efficient and promising method. In the paper, the experiments of SC-CO2 blasting were performed for coal and concrete specimens in the large size (1 m × 1 m × 0.5 m) under different crustal stresses, and then the fracture mechanism was analyzed. The results show that Crushing zone, rupture zone, and vibration zone were formed in sequence around the blasting hole, which provide the experimental and theoretical foundation for the field blasting.