Method for enhancing permeability and promoting drainage by combining hydraulic hole making and hole drilling heat injection in mining-coal bed

Abstract

The invention provides a method for enhancing permeability and promoting drainage by combining hydraulic hole making and hole drilling heat injection in a mining-coal bed. The method comprises the following steps that crossheading drilling is carried out on a working face crossheading, wherein the distance between every two adjacent drill holes is 7-10m, and any two adjacent drill holes are namedas a heat injection hole and a drainage hole respectively; drainage pipes are arranged in the drill holes, and a special hole packer is sent into the second drainage pipe for hole sealing; high-temperature and high-pressure nitrogen is injected into the heat injection holes through the special hole packer, the adjacent drainage holes are always in normal gas drainage, and gas escaping from heatedcoal is pumped away in time; the drainage pipes in the heat injection holes are connected with a drainage system for gas drainage work, and the gas drainage effect is further enhanced. In conclusion,the method is scientific in principle, tight in hole sealing, safe and reliable, the heat injection improving drainage promoting effect is greatly enhanced by combining hydraulic punching; and the method can be widely applied to rock cross-cut coal uncovering, fault crossing, permeability enhancement and drainage promotion of excavation working faces, enhanced gas drainage and other work and is wide in application prospect.

Description

technical field [0001] The invention belongs to the technical field of coal mine safety production, and in particular relates to a method for hydraulic cavitation in the coal seam combined with heat injection in drilling holes to enhance permeability and promote pumping. Background technique [0002] Most coal seams in my country have the characteristics of "three lows and one high" (low permeability, low saturation, low reservoir pressure, and high degree of metamorphism). The low permeability of the coal seam makes it difficult to extract gas, resulting in the imbalance of "pumping-excavation-mining" in the mine, forming a major safety hazard, and laying hidden dangers for the occurrence of coal mine gas accidents. Therefore, scholars at home and abroad have proposed hydraulic cutting, protective layer mining, deep hole blasting, CO 2 Phase change fracturing and other technical measures to increase permeability of coal seam and promote drainage. However, due to various r...

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Problems solved by technology

[0010] In order to solve the deficiencies in the prior art, the present invention provides a coal seam hydraulic hole creation method combined with drilling heat injection to enhance permeability and promote pumping, covering safe and efficient nitrogen heating, coal seam drilling, heat injection, enhanced pumping and special hole sealing device , Combined with hydraulic cavitation, the heat-injection enhanced pumping method solves the low heating efficiency and unsafeness of the heat-injection medium, the conventional hole sealer is not suitable for high temperature conditions, the sealing effect is poor, and the pumping is caused by solely relying on hydraulic cavitation Insufficient effect and other problems, to achieve the purpose of strengthening the sealing effect under high temperature and normal temperature conditions, improving the degree of coal heat injection to enhance drainage, and improving the effect of coal seam gas drainage

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