Biological permeability-increasing method for coal reservoir

Abstract

The invention discloses a biological permeability-increasing method for a coal reservoir, which comprises the following steps in turn: (1) selecting a middle / low-class coal reservoir; (2) forming a channel for injecting liquid into the coal reservoir in a drilling mode or other mode; (3) selecting and culturing microorganism strains suitable for an anaerobic environment and capable of effectively utilizing coal; (4) injecting the nutrient liquid containing the microorganism strains into the coal reservoir in a hydraulic fracturing mode or other mode; (5) confirming shutdown time of a well according to the difference of the coal rank; (6) organizing the subsequent production according to the conventional coal-bed gas well draining extraction or gas extraction process; and (7) checking an effect. A permeability-increasing technology for the coal reservoir is a key point for the coal bed gas resource development and the coal mine gas treatment. The invention provides the permeability-increasing technology utilizing the biotechnology for the middle / low-class coal reservoir; the coal is degraded by the microorganisms, so that the purpose of increasing the permeability of the coal reservoir is achieved; and the biological permeability-increasing method for the coal reservoir has a significance in promoting the coal bed gas resource development and the coal mine gas extraction.

Description

technical field [0001] The invention belongs to the technical field of coal mine production, and in particular relates to a biological anti-permeability method for coal reservoirs by using microorganisms to improve the permeability of middle and low rank coal reservoirs. Background technique [0002] At present, people have reached a consensus on the use of coal as raw material by some specific microorganisms to convert biogenic methane, that is, in low- and medium-rank coal reservoirs, as long as the temperature, pressure, pH value, Eh value, salinity and nutrient The material meets the growth requirements of microorganisms, and can completely convert coal into methane-based gas, and the conversion of microorganisms to coal will obtain continuous coalbed methane resources. The total amount of coalbed methane currently produced in the Powder River Basin of the United States is much higher than the total amount of resources discovered in the exploration stage, indicating that...

AI Technical Summary

Problems solved by technology

[0003] Coal reservoir permeability is a key parameter for coalbed methane development and coal mine gas control. So far, coal reservoirs have been mainly enhanced by purely physical means, such as hydraulic fracturing, open-hole caves, protection layer mining, local coal seam loosening blasting, hydraulic However, the low permeability of coal reservoirs is still the bottleneck of coalbed methane development and CMM drainage, especially the ultra-low permeability of cracked coal and mylonitic coal still plagues gas drainage and gas extraction. Coal bed methane industry development