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. 03, 1978
Filed:
Apr. 25, 1977
Ned M Hutchins, Grand Junction, CO (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. The retort with top, bottom and side boundaries contains a fragmented permeable mass of particles containing oil shale. A base of operation is excavated at a working level in the formation. Means are excavated through the formation for access to a location underlying the base of operation. In one embodiment, a void in the form of a vertical slot is excavated in the site between the means for access and an elevation below the bottom of the base of operation, leaving a remaining portion which is to be expanded toward the void. This is designed to leave a horizontal sill pillar of intact formation between the top of the void and the bottom of the base of operation with a vertical thickness sufficient to maintain a safe base of operation after explosive expansion of formation to form the fragmented permeable mass of particles. The void provides at least one free face extending vertically through the formation within the boundaries of the in situ oil shale retort site. This remaining portion is explosively expanded toward the void with a single round of explosions.