Chemical composition of acidified solution for improving permeability of coal seam

Abstract

The invention provides a chemical composition of an acidified solution for improving permeability of a coal seam. The chemical composition is prepared from, by weight, 12%-15% of hydrochloric acid, 2%-2.5% of hydrofluoric acid, 2.5%-3% of acidification retarding agent, 1.5%-1.8% of acidification corrosion inhibitor, 0.3%-0.5% of ferric ion stabilizer, 2%-2.2% of anti-swelling agent and the balance water. The permeability of the coal seam is improved by adopting a chemical method, the chemical composition mainly aims at calcite, dolomite, silicate and other mineral components contained in the coal seam, the mineral components are dissolved by the acidified solution and flow from the coal seam with the acidified solution, cracks in the coal seam and the connectivity of the cracks are increased, the permeability of the coal seam is improved, and accordingly a coalbed methane (mine gas) extraction effect is improved.

Description

technical field [0001] The invention relates to the field of coal bed gas (mine gas) and the field of chemical application, in particular to a chemical formula of an acidification solution for improving the permeability of coal seams. Background technique [0002] The coal seam permeability directly determines the extraction effect of coal bed methane (mine gas). Due to the generally poor permeability of coal seams in my country, with the increase of coal mine mining depth in my country, the mining conditions become more complex, and high ground stress, high gas, The characteristics of high heterogeneity, low permeability, and low strength coal body, the primary fracture and porosity of coal body gradually become smaller, and the permeability of coal seam decreases accordingly. The effective range of impact of a single drainage borehole is small, the pre-drainage borehole requires a large amount of work, and the extraction efficiency is low. The conventional coalbed methane (...

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Problems solved by technology

[0003] In view of the rare problem of underground coalbed methane (mine gas) extraction in low-permeability coal seams, Chinese coal mine researchers have adopted hydraulic fracturing, hydraulic punching, hole reaming technology, hydraulic slotting, N 2 Foam fracturing, CO 2 Physical methods such as foam fracturing to transform the coal seam and change the conductivity of the coal seam consume a lot of manpower, material resources, and financial resources. Some effects have been achieved in some areas, but the transformation effect in some areas is not satisfactory

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