04299285 is referenced by 227 patents and cites 8 patents.

In the underground gasification of a swelling coal the high gas-flow link between the injection and the production wells is produced by introducing hot air into the injection well at a pressure sufficient to fracture the coal. The bulk permeability of the coal proximate to the link is increased and the plugging of the link during the subsequent in situ combustion and gasification procedure is suppressed by continuing the injection of the hot air, heated to a temperature below the softening point of the coal, into the injection well, through the link to the production well without combustion of the coal.

Title
Underground gasification of bituminous coal
Application Number
6/170707
Publication Number
4299285
Application Date
July 21, 1980
Publication Date
November 10, 1981
Inventor
Robin R Oder
Export
PA, US
Richard H Graham
O'Hara Township, Allegheny County
PA, US
Shirley C Tsai
Pittsburgh
PA, US
Agent
Donald L Rose
Forrest D Stine
Deane E Keith
Assignee
Gulf Research & Development Company
PA, US
IPC
E21C 43/00
E21B 43/247
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