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:
May. 08, 1979
Filed:
Jun. 30, 1977
Richard D Ridley, 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 contains a fragmented permeable mass of particles containing oil shale. An open base of operation is excavated in the formation above the retort site, and an access drift is excavated to the bottom of the retort site. Formation is explosively expanded to form the fragmented mass between the access drift and an elevation spaced below the bottom of the base of operation, leaving a horizontal sill pillar of unfragmented formation between the top of the fragmented mass and the bottom of the base of operation. The sill pillar provides a safe base of operation above the fragmented mass from which to control retorting operations. A plurality of blasting holes used in explosively expanding the formation extend from the base of operation, through the sill pillar, and open into the top of the fragmented mass. Trenches are formed in the base of operation for collecting ground water which enters the base of operation prior to and during retorting operations, and collected ground water is withdrawn from the base of operation. Casings can be placed in the blasting holes and adapted for controlling gas flow through the fragmented mass during retorting operations. The casings extend above the floor of the base of operation to inhibit flow of ground water through the blasting holes into the fragmented mass, and other blasting holes not having such casings are sealed. After retorting is completed, the floor of the base of operation can be covered with a layer of concrete and/or the blasting holes can be sealed with concrete to inhibit leakage of ground water into treated oil shale particles in the fragmented mass.