Coal seam advanced fracturing C-shaped furnace method for strengthening the chemical reaction of underground coal gasification

Abstract

A coal seam advance fracturing C-shaped furnace method for strengthening coal underground gasification chemical reaction comprises the steps that a plurality of hydraulic fracturing drill holes in theinclination direction are drilled in a coal seam, and fracturing drill hole protection sleeves are installed in the drill holes; high-pressure water is injected into the fracturing drill holes to carry out coal seam hydraulic fracturing; a row of gas injection drill holes are formed in the interface of the coal seam and a direct bottom in the direction of the trend, gas injection sleeves are installed in the gas injection drill holes, a row of gas exhaust drill holes are formed in the interface of the coal seam and a direct top in the direction of the trend, and gas exhaust sleeves are installed in the gas exhaust drill holes; a hose winding drum A and a hose winding drum B which are respectively used for driving retreating type gas exhaust pipes and retreating type gas injection pipes are arranged on one side outside a gasification furnace area; and the retreating type gas exhaust pipes and the retreating type gas injection pipes are respectively arranged in the gas exhaust sleeves and the gas injection sleeves. According to the method, the gasification heat efficiency can be higher, pore cracks are formed in a gasification furnace, coal seam caving is facilitated, the chemical reaction can be enhanced, and the gasification yield and the coal gas quality are improved.

Description

technical field [0001] The invention relates to the technical field of underground coal mine gasification, in particular to a coal seam advanced fracturing C-shaped furnace method for strengthening the chemical reaction of underground coal gasification. Background technique [0002] Traditional underground coal gasification does not have a good means of strengthening chemical reactions, resulting in low gasification yield and poor gas quality. [0003] Since the traditional underground coal gasification process produces fewer cracks in the coal seam, when the underground gasification is carried out in a gently inclined coal seam or an inclined coal seam with a relatively small inclination angle, it is not easy to cause the coal seam to collapse and the collapsed coal blocks to flow into the gasification channel. Inner filling, leading to gasification is carried out in the dense coal seam with very small pores and fissures under the action of in-situ stress. For the coal sea...

AI Technical Summary

Problems solved by technology

Wellless underground gasification adopts high-pressure gasification method to strengthen chemical reaction, but high-pressure gasification shifts the balance of reduction reaction to the direction that is not conducive to the formation of combustible components, thereby reducing the quality of gas

Secondly, under the condition of insufficient specific surface area of ​​coal seam in high-pressure gasification, the pressed oxygen may not fully react, resulting in excessively high oxygen content in the gas, which will adversely affect subsequent safe production and gas treatment.

Finally, excessive gasifier pressure may cause gas to enter aquifers through fractures and contaminate groundwater

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