A Method for Strengthening Regional Gas Drainage with Hydrothermal Coupled Fracturing

Abstract

The invention discloses a gas drainage method in a hydrothermal coupling fracturing strengthening area. Firstly, the main fracturing hole, branch fracturing holes and guide holes are sequentially constructed on the side of the coal seam, and the main fracturing holes are arranged in the center of an equilateral triangle. position, the opening positions of the branch fracturing holes are respectively arranged at the three vertices of the equilateral triangle, the positions of the final holes meet at the center line of the equilateral triangle, and the leading holes are located at the center of the main fracturing hole, On a circle with a radius of 5-15m; the fracturing equipment includes water injection equipment and a powder injector composed of intelligent water tanks and fracturing pumps. The quicklime powder in the powder injector is injected into the main fracturing hole and the branch fracturing hole through the downhole wind pressure; the main fracturing hole is hydraulically fractured through the water injection equipment, and the quicklime powder enters the fracture under the pressure of high-pressure water. The thermal reaction between powder and water generates a large amount of heat, realizing hydrothermal coupling fracturing; through the implementation of hydrothermal coupling fracturing to strengthen the regional gas drainage method, the area affected by fracturing increases, and the concentration of gas drainage increases. The effect is remarkable, which meets the The needs of coal mine site area gas control and other work.

Description

technical field [0001] The invention relates to a hydrothermal coupling fracturing enhanced regional gas drainage method, which belongs to the technical field of regional gas control in underground coal mines, and is especially suitable for hydrothermal coupling fracturing operations for regional gas control in deep high gas outburst coal seams. Background technique [0002] The Chinese Academy of Engineering's "National Energy Development Strategy 2030-2050" report proposes that the annual output of coal will be controlled at 3 billion tons in 2050, and coal will be the dominant energy source in my country for a long time. However, the geological conditions of my country's coal mines are complex, high-gas coal seams account for 50%-70%, and high-gas low-permeability coal seams account for about 70% of them. The occurrence characteristics of high gassy and low permeability coal seams in my country are microporosity, low permeability and high adsorption, which often lead to a...

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Problems solved by technology

[0003] However, the existing coal seam hydraulic fracturing technology has problems such as unstable technical effect, insufficient pressure relief, and low extraction efficiency.

The main reason is that the traditional hydraulic fracturing technology has insufficient fracture expansion and has not realized the regional fracture network.

Moreover, the existence of water after the implementation of traditional hydraulic fracturing technology blocks the channel of gas flow, which has the effect of inhibiting gas desorption, diffusion and permeation, leading to the gradual limitation of hydraulic fracturing technology

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