Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Subterranean in situ oil shale retort and method for making and operating same

Patent ·
OSTI ID:5878200
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 at an elevation above the fragmented mass to be formed, and an access drift is excavated to provide access 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 after it is formed. The fragmented mass is formed by, among other steps, drilling blasting holes from the base of operation down through the sill pillar and then detonating explosive in such holes to form the fragmented mass of particles in the retort below the sill pillar. During retorting, gas is introduced into the fragmented mass through such blasting holes for establishing a combustion zone in the fragmented mass and for advancing the combustion zone through the fragmented mass. The blasting holes have separate valves located in the base of operation for use in controlling gas flow through selected regions of the fragmented mass. 23 claims.
Assignee:
Occidental Oil Shale, Inc.
Patent Number(s):
US 4118070
OSTI ID:
5878200
Country of Publication:
United States
Language:
English