Method for pumping coalbed gas by heating coal bed

Abstract

Provided is a method for heating coal seam and extracting coal seam gas. Firstly, a plurality of vertical wells are drilled from the ground to the coal seam, after the drilled well reached to the coal seam, the coal seam is inserted with a screen tube casing (4), the section above the coal seam is inserted with a heat insulation casing (31) and the well is correspondingly fixed. At least one well of the wells is selected to be a heat source injection well (1) and other wells are gas production wells (2), steam with high temperature and high pressure is injected into the heat source injection well (1) to perform fracturing to communicate all the wells in the network. Drainage and pressure reduction are performed to the gas production wells (2) to extract the mixed gas of the coal seam gas and steam. The mixed gas of the coal seam gas and steam is cooled by known cooling method so as to obtain gaseous coal seam gas and liquid distilled water to realize the separation of the mixed gas. According to the change of the coal seam temperature, the heat source injection well (1) and the gas production wells (2) are allocated to control the heated coal seam and extract coal seam gas. The method of he invention can effectively perform the extraction of the coal seam gas, accelerate the coal seam extraction speed, and improve the extraction rate.

Description

technical field [0001] The invention relates to an underground coal-bed gas mining method, in particular to a method for extracting coal-bed gas by using group wells to connect and heat coal seams. Background technique [0002] Coalbed methane is an associated gas of coal, the main component is methane, commonly known as "gas" in coal mines. Because coalbed methane can be burned, it is exploited and utilized as a clean energy. Known main drainage methods at present include: the underground coal seam drilling drainage method in the coal mine roadway and the multi-branch horizontal well drainage technology implemented on the ground. The underground coal seam drilling and drainage technology is a technology for drilling from the underground roadway of the coal mine to the coal seam and performing drainage. The technology is mainly to reduce the coalbed gas content in the coal seam and ensure the safe production of the coal mine. The multi-branch horizontal well drainage tech...

AI Technical Summary

Problems solved by technology

At present, due to the immaturity of rapid and efficient gas separation technology, especially the difficulty of separation technology for carbon dioxide and methane gas, it is difficult to realize the application of this technology in industrial production

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