The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 10, 1981
Filed:
Jul. 21, 1980
Shirley C Tsai, Pittsburgh, PA (US);
Richard H Graham, O'Hara Township, Allegheny County, PA (US);
Robin R Oder, Export, PA (US);
Gulf Research & Development Company, Pittsburgh, PA (US);
Abstract
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.