Seepage mechanism technical practice of hydraulic fracturing of coal seam and auxiliary image simulation technology

摘要

A new method of fracturing hydraulic fracturing is proposed for the characteristics of poor coal permeability and soft coal in coal mine area in China. This method can make the hydraulic pressure concentrated on the coal at one point, and the water pressure is reduced, Effective water pressure increases, the smaller the flow that can get a better fracture effect. Through the numerical simulation, the law of fracture distribution and permeability evolution during segmental hydraulic fracturing is analyzed. Complete sets of anti-reflection equipment for segmented hydraulic fracturing have been developed, which is mainly composed of mobile high-pressure pump station, high-pressure rubber hose, water injector, putters and corresponding connecting parts. It solves the problem of tightness of hydraulic fracturing device, and breaks through the problem of miniaturization of high pressure pumping station, so that the high pressure pumping station can achieve larger working pressure at smaller flow rate. The whole process is simulated and validated by assistant image simulation technology, and applied to Pansidong Coal Mine of Huainan Mining Group. The industrial test of hydraulic directional fracturing of Pan coal mine in Huainan mining group shows that the loose influence range of coal can reach 10 m, and the pressure of underground movable high pressure hydraulic pumping station reaches 25 MPa, and the flow rate is 180 L/min. Compared with non fracturing drilling, drilling, the average gas concentration after fracturing, the average daily average flow rate of mixed gas drainage quantity is improved significantly, the application effect is good, and the equipment is simple, easy to use, can be repeatedly used, and has better economic benefit and application prospect. (C) 2019 Published by Elsevier Inc.