公开(公告)号：US20230008988A1

公开(公告)日：2023-01-12

申请号：US17786596

申请日：2020-11-26

Applicant: SHANDONG UNIVERSITY OF SCIENCE AND TECHNOLOGY

Inventor： Zhijie WEN ,  Jing HUANG ,  Peng XIAO ,  Jingkai ZHANG ,  Hengzhong ZHU

IPC: E21B43/295

Abstract: An underground gasifier pre-control structure includes a flame retardant injection system. The flame retardant injection system includes a flame retardant injection shaft pipe channel drilled from ground to a coal seam and a flame retardant injection channel located in the coal seam. The flame retardant injection channel includes a first flame retardant injection channel and a second flame retardant injection channel at both sides of each gasifier and a third flame retardant injection channel located in a horizontal direction of an adjacent gasifier. The first flame retardant injection channel includes a horizontal section along a strike of the coal seam and a bypass section offset toward the gasifier. The flame retardant injection system forms a wet coal wall in the coal seam to achieve pre-control for the gasifier. The pre-control structure wets the coal masses at both sides of the gasifier and the gasifier does not spread toward both sides.