Bias gas-liquid two-phase jet-flow slotting permeability-increasing device and method

A bias gas-liquid two-phase jet-flow slotting permeability-increasing device comprises a gas-liquid two-phase fluid generating system and a drilling and slotting integrated system, wherein the gas-liquid two-phase fluid generating system is composed of a high pressure water pump, a high pressure resistant hose, a pressure regulating valve, a check valve, a gas-liquid mixer, a pressure regulating valve, a high pressure air pump, a drilling rig, a drill pipe, a pressure control drill and a side nozzle. The side nozzle is used for spraying high-pressure bias gas-liquid two-phase jet flow to slot different sections of drilling walls. Two-beam gas-liquid two-phase jet flow acts on coal through impulses at a certain angle under the interaction of washout and cavitation erosion, 'water fight' in the slotting process is effectively avoided, the coal breakage threshold pressure is effectively reduced, the effective length of a slot in single slotting is enlarged, the coal disturbance range is increased obviously, the air permeability of the coal can be improved by about 250-400 times, and the gas extraction effect is improved substantially. Backflow gas can dilute the gushed gas density and operation safety is improved. The method is simple, the operation is easy, practicability is high, and time and labor are saved.