Coal mine down-hole drilling hydraulic fracturing anti-reflection mash gas extraction technique

Abstract

The invention relates to a hydraulic fracturing anti-reflection technology for pumping and exploring gas by drilling a hole in a coal mine well, comprising the following steps sequentially: (1) selecting a fracturing location; (2) determining the pressure type according to observed coal type, laneway arrangement and construction development degree, and ways of top soleplate bedding plane borehole hydraulic fracturing, top soleplate translamellar borehole hydraulic fracturing, the coal bed bedding plane borehole hydraulic fracturing or the coal bed translamellar borehole hydraulic fracturing can be adopted; (3) determining borehole parameters for constructing drilling, wherein, the borehole parameters include borehole length, borehole height, aperture, obliquity angle and azimuth angle; (4) designing the hydraulic fracturing, including injected water volume and injection pressure; (5) borehole washing; (6) draining; (7) examining the fracturing effect, if the fracturing effect is in accordance with the requirement, the following step is carried out, if not, turning to step (4); and (8) entering a pipeline for pumping and discharging. The technology enhances the air permeability of the coal bed, reduces the gas emission rate of an excavation working face, and obviously promotes the pumping and exploring capability and the pumping and exploring effect of the single borehole. The pumping and discharging efficiency is improved, the pumping and discharging time is shortened and the damage of the gas is maximally eliminated.

Description

technical field [0001] The invention relates to an underground coal mine borehole hydraulic fracturing antireflection gas extraction process. Background technique [0002] Coal seam gas is a kind of clean energy, but it is also a source of disaster for coal mine production. How to realize the pre-pumping of gas before coal mining, to achieve the dual purpose of resource development and utilization and coal mine disaster reduction has always been the focus of attention. Especially with the increase of mining depth, the increasingly strong demand for resources, and the introduction of a series of national compulsory measures on coal mine gas disaster management and the introduction of incentive policies for the development and utilization of coalbed methane, there is an urgent need to have a set of systematic, complete, ground-to-underground Combined extraction technology. [0003] There are many methods of gas control, such as protection layer mining and ground mining area ...

AI Technical Summary

Problems solved by technology

[0004] In the past, underground gas drainage can be divided into two types in principle: one is the extraction under the original stress state, and the extraction efficiency depends entirely on the original permeability of the coal seam, which is poor in effect and requires a large amount of work.

The current coal seam drainage mostly belongs to this category; the second is mining through mining pressure relief and anti-reflection enhancement, the drainage effect is better, but limited by conditions, it is difficult to solve the problem of rapid excavation

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