A method for improving coalbed methane recovery by self-generated multi-component gas displacement in coal seams

Abstract

The invention discloses a method for increasing the coalbed methane recovery ratio through coalbed self-generated multicomponent gas displacement. The method comprises the following steps that S1, a target area is selected; S2, coalification microorganism species suitable for the area are selected and cultivated according to the coal component and the coalbed water environment in the target area; S3, the cultivated coalification microorganism species are injected into a coalbed, and coal powder in coalbed fractures and hole channels is dissolved, so that a coal solution is formed; S4, coal solution degrading bacteria are injected into the coalbed so that the coal solution and undissolved substances left in the coalbed fractures can be subjected to decomposition processing; S5, a gas generation substance water solution is poured into the coalbed processed through the step S4; S6, the mouth of a well is sealed, and set-in-well treatment is conducted; and S7, after set-in-well treatment, air is injected into the coalbed for displacement. According to the method, the microbial conversion technology and an ammonium bicarbonate water solution are adopted for production increasing, and the method has the advantages of being simple in process, low in energy consumption, free of pollution and the like which are incomparable to common treatment technologies.

Description

technical field The invention relates to the field of coal bed methane exploitation, in particular to a method for increasing the recovery rate of coal bed methane by alternately injecting gas and liquid into coal seam self-generated multi-component gas for displacement. Background technique Coalbed methane is an efficient and clean energy, a national strategic resource, and an important unconventional oil and gas resource. my country is rich in coalbed methane resources, with huge reserves and wide distribution. As a special oil and gas resource, coalbed methane is distributed in coal seams. At present, coalbed methane has been developed in many coal blocks in China, but the mining effect in most of the research areas is not ideal, mainly due to geological factors such as low pressure, low porosity and low permeability of coal seams. Decision, followed by imperfect mining methods and inadequate mining measures. The cementation degree of the coal seam is low, and the pore...

AI Technical Summary

Problems solved by technology

Another purpose of the present invention is to solve the problem that in the prior art, the microbial plugging removal method cannot accelerate the desorption rate of the adsorbed gas, and the metabolites produced after microbial coalification have no subsequent treatment, and some metabolites may cause secondary blockage of the coal seam At the same time, the gas huff and puff method will disturb the continuous drainage system of the coal seam, which will have a certain impact on the stability of pulverized coal particles and the continuous drainage of coalbed methane wells and other technical problems

Images