UNDERGROUND COAL GASIFICATION AND LINKAGE METHOD

摘要

An underground coal gasification and linkage method comprises the following steps: a) establishing a fire region (4; 21) in a bottom coal layer of a first drill hole (1; 11; 22); b) taking another existing drill hole outside the fire region or a newly drilled drill hole as a second drill hole (2; 13, 14, 15; 23, 24, 25), and mechanically and directionally drilling a nearby coal layer near the bottom of the first drill hole near the fire region through the lower end of the second drill hole, so as to link the nearby coal layer, thereby forming, in the nearby coal layer, a directional passage (5; 17; 27) communicating with the fire region; and c) conveying oxygen-containing gas to the fire region through the second drill hole and the directional passage, and performing hot working on the directional passage, so as to expand the directional passage, thereby forming a gasification passage used for an underground coal gasification furnace.