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. 15, 1984
Filed:
Jun. 18, 1982
Frederick M Gragg, Seabrook, TX (US);
Jian C Shen, Santa Ana, CA (US);
Carl L Jacobson, Rifle, CO (US);
Occidental Research Corporation, Irvine, CA (US);
Abstract
A method for recovering liquid and gaseous products from an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale is provided. A hot ignition gas comprising oxygen at a first selected concentration is introduced into the fragmented mass for heating the fragmented mass top surface. The percentage of the fragmented mass surface that is at a temperature no less than the ignition temperature of oil shale is determined. Thereafter, the concentration of oxygen in the ignition gas is increased by an amount proportional to the determined percentage. Such heating of the fragmented mass top surface establishes a combustion zone in the retort. After the combustion zone has spread horizontally across the retort, introduction of the hot ignition gas is discontinued. Thereafter, an oxygen-supplying gas is introduced into the retort for advancing the combustion zone downwardly through the fragmented mass. Liquid and gaseous products are produced in a retorting zone on the advancing side of the combustion zone and are recovered.