公开(公告)号：US12134966B2

公开(公告)日：2024-11-05

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.