Method for increasing coalbed methane by waste heat in underground coal gasification process

Abstract

The invention discloses a method for increasing coalbed methane by waste heat in underground coal gasification process. The method comprises the following steps that S1, a gas injection well and a gasproduction well are driven to a target coal seam of underground coal gasification from the ground, so that a U-shaped well is formed; S2, a horizontal well section of a coalbed methane well and the space of a gasification channel of underground coal gasification form an X-shape intersection; S3, an auxiliary device of underground coal gasification is installed at the tail end of the gas injectionwell; S4, nearby coal can be heated by the high temperature produced by the combustion of the coal; S5, an air pumping device is installed at the ground end of the gas production well; S6, the heat is transferred to a coalbed gas production coal seam for heating by high-temperature airflow in a radiation and heat conduction mode, and the desorption rate of the coalbed gas is improved; and S7, thecoalbed gas is discharged from the coalbed gas well. According to the using method, heat generated in the underground coal gasification process can be reasonably utilized, and a large amount of energy consumption in the coalbed gas heat injection development process is reduced.

Description

technical field [0001] The invention relates to the technical field of coalbed methane injection heat production increase, in particular to a method for increasing coalbed methane production with waste heat in an underground coal gasification process. Background technique [0002] Underground coal gasification (Underground Coal Gasification, UCG) is a special coal development method that does not mine coal to the surface, but directly processes coal underground. The coal is ignited in the in-situ space of the formation through drilling or roadway, so that the coal undergoes a series of thermal and chemical actions, and the solid coal is transformed into a gas state and transported to the surface. However, a large amount of energy contained in the high-temperature output gas produced after underground coal gasification is wasted in gasification channels and formations. At the same time, in order to increase the production of coalbed methane, injecting heat into the coalbed t...

AI Technical Summary

Problems solved by technology

However, a large amount of energy contained in the high-temperature output gas produced after underground coal gasification is wasted in gasification channels and formations.

At the same time, in order to increase the production of coalbed methane, inj

Images