Method for improving permeability and promoting drainage by cooperation of hydraulic punching, freezing fracturing and heat injection excitation

• Main Authors: WANG YAO, YUAN JUNWEI, JIANG XIAOGAI, XU YANPENG, XIA JINGYI, ZHI GUANGHUI, CHEN LIWEI, YUE GAOWEI, LI HUAIZHEN, AN FENGHUA
• Format: Patent
• Language: Chinese; English
• Published: 26.02.2021
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The invention provides a method for improving permeability and promoting drainage by cooperation of hydraulic punching, freezing fracturing and heat injection excitation. The method comprises the following steps of: constructing cross-layer drill holes in a coal body in a bottom plate rock roadway, wherein any two adjacent drill holes are respectively named as a measure hole and an extraction hole, and the two adjacent drill holes are respectively named as a measure hole and an extraction hole; installing extraction pipes in the drill holes for hole sealing, and connecting the extraction holeswith an extraction system; injecting water into the measure holes at high pressure; performing hole sealing on the extraction pipes in the measure holes by using a special hole sealing device; injecting liquid nitrogen into the measure holes to freeze the coal body, wherein the liquid nitrogen is slowly sublimated into nitrogen under the action of ground temperature, and the nitrogen can effectively replace and displace