Multiple level preparation of oil shale retort
US4043597A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 1976 |
| Grant date | Aug 23, 1977 |
| Priority date | — |
| Expiry date | Feb 17, 1996 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/248
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A subterranean deposit containing oil shale is prepared for in situ retorting by initially excavating a plurality of vertically spaced apart voids of similar horizontal cross section located one above another within the deposit. A zone of unfragmented deposit temporarily left between each adjacent pair of voids has a thickness greater than the smallest lateral dimension of the voids above and below it. Explosive placed in a lower portion of the unfragmented zone is detonated to expand the lower portion of the unfragmented zone into the lower void, leaving the upper portion of the zone intact and creating a space free of fragmented particles below it. Thereafter, the remaining portion of the unfragmented zone is explosively expanded into the open space below it and into the upper void, forming a subterranean room filled with a fragmented mass of particles having a void volume substantially equal to the total initial volume of the voids. Retorting of the expanded mass is then carried out to recover shale oil from the oil shale.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.