Multiple zone preparation of oil shale retort
US4043598A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1976 |
| Grant date | Aug 23, 1977 |
| Priority date | — |
| Expiry date | Feb 20, 1996 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21C41/24
- 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 plurality of vertically spaced apart zones of unfragmented deposit are temporarily left between the voids, each unfragmented zone having a thickness of less than about 190 percent of the smallest lateral dimension of the voids above and below it. Explosive placed in each of the unfragmented zones is detonated, preferably in a single round to expand each unfragmented zone into the voids on either side of it and form a subterranean room containing a fragmented mass of particles having a void volume equal to the void violume of the initial 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.