Research On Hydraulic Technology For Increase The Permeability Prevention In High-gas-permeability And Low-air-permeability Coalsearn

In the process of coal mine safety production, gas has always been one of the main threats to coal mine safety production. Currently, through gas extraction, reducing gas content in coal seam is an important measure to prevent gas disasters. However, with the increasing depth of coal mining, coal seam permeability drastically reduced, which makes the extraction of gas seriously affected. Therefore, how to improve the permeability of coal seam becomes the task of the safety production in coal mines.The paper from mechanics theory mechanics, computer simulation, field test three aspects, research and analysis of high gas and low permeability coal seam hydraulic fracturing AR technology.Firstly, introduces the process of development and research status of high gas and low permeability coal seam hydraulic fracturing method and some AR technology. Introduces the basic theory of fracture mechanics, mainly introduces the basic theory of crack and its classification, J integral principle and the basic theory of brittle fracture. for hydraulic fracturing, discusses the rock characteristics discussed before drilling fracturing, it is concluded that the stress redistribution after drilling surrounding rock is divided into crushing zone, plastic zone, elastic zone and the original rock stress areas. Fracturing is divided into along-layer and trans-layer two kinds of circumstances, and then respectively discusses the stress and fracture initiation position and other issues surrounding hydraulic fracturing drilling in both cases.Secondly, using software RFPA2D-Flow establish three model simulations to study Li Zuizi mine A1coal seam, fracturing radius of A1coal seam was simulated, analyzed several paths and fracturing process under different stress conditions, analyses the stress and permeability change during the process of hydraulic fracturing.Finally, in the Li Zuizi coal mine32321bottom lanes for hydraulic fracturing AR technology field test. By comparing permeability coefficient drainage radius and comparison of moisture content before and after hydraulic fracturing, fully demonstrates hydraulic fracturing AR technology feasibility and effectiveness. Hydraulic fracturing AR technology is an important measure to improve the gas extraction rate of high gas and low permeability coal seam permeability.