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:
Dec. 16, 1980
Filed:
Jun. 20, 1979
Gordon B French, Bakersfield, CA (US);
Occidental Oil Shale, Inc., Grand Junction, CO (US);
Abstract
An in situ oil shale retort is formed in a subterranean formation containing oil shale and including underground workings by excavating a means for access to a retort site in the formation, excavating a void in the retort site at least in part from the means for access, leaving a remaining portion of the unfragmented formation in the retort site adjacent the void, placing explosive in the remaining portion of formation, and detonating the explosive in such unfragmented formation in a single round to explosively expand formation toward the void for forming a fragmented permeable mass of formation particles containing oil shale in an in situ retort. A permeable barrier is provided between the void and the underground workings which provide means for access to such a void. The permeable barrier has a cross-section for gas flow which is substantially smaller than the transverse cross-section of such means for access, and the cross-section of such permeable barrier temporarily confines gas from such explosive expansion and limits flow of such gas to such means for access to attentuate airblast in underground workings. A fragmented permeable mass of formation particles produced during excavation of the void can provide such a permeable barrier.