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:
Jun. 17, 1986
Filed:
Mar. 26, 1984
Raymond L Zahradnik, Grand Junction, CO (US);
Carl L Jacobson, Grand Junction, CO (US);
Jian-Chyun Shen, Houston, TX (US);
Occidental Oil Shale, Inc., Grand Junction, CO (US);
Abstract
A method is provided for operating an in situ oil shale retort in a subterranean formation containing oil shale. The retort contains a fragmented permeable mass of formation particles containing oil shale, within top, bottom and side boundaries of unfragmented formation. A drift is in communication with a lower region of the fragmented mass for withdrawal of liquid products of retorting and an off-gas comprising gaseous products of retorting. A gas-sealing bulkhead is placed across the product withdrawal drift and a water spray is installed in the drift through the bulkhead. An upper region of the fragmented mass is ignited for establishing a combustion zone therein. A retort inlet mixture comprising an oxygen-supplying gas is introduced into the top of the fragmented mass for advancing the combustion zone downwardly through it to thereby establish a retorting zone on the advancing side of the combustion zone for producing the liquid and gaseous products. A retort off-gas comprising such gaseous products is withdrawn from the retort through the product withdrawal drift. The temperature of the off-gas is monitored in the vicinity of the gas-sealing bulkhead. When the off-gas temperature reaches a selected value below the design temperature of the bulkhead, sufficient water is sprayed into the off-gas stream in the drift to maintain the temperature of the off-gas in the vicinity of the bulkhead below its design temperature.