Underground gasifier for medium-depth coal seam and gasification method

• Main Authors: YU ZHENGLIAN, WANG JIAN, XU JIAFANG, WANG XIAOPU, KONG LINGFENG, CAO JIE
• Format: Patent
• Language: Chinese; English
• Published: 05.11.2019
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The invention relates to the technical field of underground gasification mining of coal, in particular to an underground gasifier for a medium-depth coal seam and a gasification method. The underground gasifier comprises a gas injection well, a gas recovery well and a plurality of branched horizontal wells which are arranged between the gas injection well and the gas recovery well, are communicated with the gas injection well and the gas recovery well, and are arrayed in parallel; and the gas injection well and the gas recovery well horizontally extend in the coal seam by adopting extended reach horizontal wells and are distributed in an inclined ladder parallel manner. The invention further discloses the gasification method for the gasifier. The gas injection well and the gas recovery well in the underground gasifier disclosed by the invention are distributed in the inclined ladder parallel manner; gasification is performed in each branched horizontal well section; a clustered coiledtubing gasifying agent ca