Coal bed gas thermal production increasing method

Abstract

The invention relates to a coal bed gas thermal production increasing method. The coal bed gas thermal production increasing method comprises the following steps that a drilling hole or a drilling shaft is obtained and drilled to a target coal bed; a coil pipe is arranged in the drilling hole or the drilling shaft, the bottom end of the coil pipe stretches into the target coal bed, a movable spraynozzle and an igniter are arranged at the bottom end of the coil pipe, and the movable spraying nozzle and the igniter face an area to be ignited of the coal bed; and a gasifying agent is sprayed tothe area to be ignited through the movable spray nozzle, the gasifying agent of the area to be ignited is ignited by the igniter, and a coked area or a coked cavity with a certain diameter is formed in the coal bed. By means of the coal bed gas thermal production increasing method, generation of a large amount of coal dust can be avoided, the problems that the permeability of a coal reservoir is low and coal dust blocks a coal bed gas channel are solved, the well yield of coal bed gas is improved, abandoned wells are reduced to the maximum extent, or the abandoned wells can be enabled again ina production increase mode, and the exploitation cost of coal bed gas is reduced.

Description

technical field [0001] The invention relates to the field of coal bed gas exploitation, in particular to a method for increasing production by thermal mining of coal bed gas. Background technique [0002] At present, fracturing technology is the main method of coalbed methane stimulation in my country. Fracturing mainly utilizes the pressure transmission effect of the liquid, injects the fracturing fluid into the well through the surface equipment under the condition of large displacement to open the coal seam cracks, adds proppant, forms a plurality of seepage zones with high conductivity, and communicates the coal seam cracks . Finally, through the process of coal seam drainage-depressurization-desorption, the purpose of normal exhaust is achieved. Because the coal-bearing strata in my country have generally experienced strong tectonic movements after coal formation, the original structure of the coal seam is often greatly damaged, which makes my country's coal reservoir...

AI Technical Summary

Problems solved by technology

Because the coal-bearing strata in my country have generally experienced strong tectonic movements after coal formation, the original structure of the coal seam is often greatly damaged, which makes my country's coal reservoirs characterized by low permeability-ultra-low permeability, low pressure, low water saturation, and fine powder. There are a lot of coal, crushed coal, mylonitic coal and structural coal, which makes it impossible to build a stable coalbed methane channel in the process of coalbed methane drainage of various well types, and it is easy to have the phenomenon of coal powder blocking the channel, resulting in a large amount of coalbed methane gas production. Low

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