Method for changing coal permeability by using hydrogen-producing acetogenic bacteria

Abstract

The invention discloses a method for changing the permeability of a coal seam by using hydrogen-producing acetogenic bacteria. The method is suitable for being used in a low-permeability coal seam. Firstly, a nutrient solution of the hydrogen-producing acetogenic bacteria is injected into the coal seam in a drilling and hydraulic fracturing mode, then hole sealing operation is carried out, the hydrogen-producing acetogenic bacteria injected into the low-permeability coal seam produce acetic acid and hydrogen, macromolecular organic matter in coal serves as a substrate for life activity of the hydrogen-producing acetogenic bacteria to be converted into the acetic acid, a substrate is provided for methanogens in the coal seam, and the methanogens are promoted to generate methane; waste liquid flows back to the ground through reverse drainage, meanwhile, the permeability of the coal seam is also increased under the corrosion of the acetic acid and the extrusion action of the generated hydrogen and methane gas; and coal bed gas in a coal bed is extracted. The method is easy to implement and low in investment, a single strain is easy to amplify and culture, the reaction process is also controllable, and the influence on the stress distribution condition of a mine is small.

Description

technical field [0001] The invention relates to a method for changing coal permeability, especially a method for changing coal permeability by using hydrogen-producing acetogenic bacteria, which is suitable for use in low-permeability coal seams. Background technique [0002] Coal bed methane (CBM) is a gas that is self-generated and stored in coal seams. Its main component is methane. The development and utilization of coalbed methane has very broad prospects, and the economic benefits brought by this gas are also very considerable. According to statistical analysis, if my country can extract coalbed methane with a buried depth of less than 2,000 meters, as long as the extraction rate reaches About 40%, the utilization rate of 80% can be reached, and the specific coalbed methane that can be used is about 9.6×10 12 m 3 ~11.2×10 12 m 3 , and each cubic meter of coalbed methane resources can generate 3kW·h of electric energy. It can be seen that coalbed methane can bring g...

AI Technical Summary

Problems solved by technology

However, the injection of mixed bacteria is difficult to enlarge and cultivate the flora, and the flora structure is not easy to control, and the injected flora will also interfere with the metabolic methane production of the endogenous flora

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