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:
Oct. 27, 1981
Filed:
Jul. 21, 1980
Applicant:
Inventors:
Shirley C Tsai, Pittsburgh, PA (US);
Richard H Graham, O'Hara Township, Allegheny County, PA (US);
Robin R Oder, Export, PA (US);
Assignee:
Gulf Research & Development Company, Pittsburgh, PA (US);
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; E21C / ;
U.S. Cl.
CPC ...
166259 ; 48210 ; 48DI / ;
Abstract
In the underground gasification of a swelling coal the bulk permeability of the coal proximate to the linkage between the injection and the production holes is increased and the plugging of the linkage during the in situ combustion and gasification procedure is suppressed by subjecting this coal proximate to the linkage between the injection and production holes to a stream of air heated to a temperature below the softening point of the coal prior to the in situ combustion and gasification procedure.