Research and field practice of integrated pressure relief technology of low-pressure abrasive jet slotting and fracturing in deep roadway

Abstract In order to control the large deformation of deep roadway, this paper analyzes the initiation conditions of abrasive jet slotting and fracturing, uses Fluent and UDEC to simulate and analyze the effect of low-pressure abrasive jet and the effect of slotting-fracturing integrated roof cutting and pressure relief, and conducts experiments in the field. The results show that the purpose of abrasive jet is to form prefabricated cracks and crack damage zones on the hole wall, providing an advantageous channel for hydraulic fracturing. In a certain range, with the increase of incident pressure, abrasive particle diameter and nozzle diameter, the effect of abrasive jet is improved, and the influence of incident pressure is the most significant. After the application of low-pressure abrasive jet slotting-fracturing integration technology in the field, the displacement of the roadway on the side of the goaf is significantly reduced, and the pressure relief effect of the roadway is good. The numerical simulation results also show that after the slotting fracturing pressure relief, the peak value and concentration coefficient of the bearing stress inside the retained coal pillar are reduced, and the damage zone around the roadway is relatively reduced.