Method for forming an in situ oil shale retort with horizontal free faces
US4366987A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1980 |
| Grant date | Jan 4, 1983 |
| Priority date | — |
| Expiry date | Nov 21, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/305
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for forming a fragmented permeable mass of formation particles in an in situ oil shale retort is provided. A horizontally extending void is excavated in unfragmented formation containing oil shale and a zone of unfragmented formation is left adjacent the void. An array of explosive charges is formed in the zone of unfragmented formation. The array of explosive charges comprises rows of central explosive charges surrounded by a band of outer explosive charges which are adjacent side boundaries of the retort being formed. The powder factor of each outer explosive charge is made about equal to the powder factor of each central explosive charge. The explosive charges are detonated for explosively expanding the zone of unfragmented formation toward the void for forming the fragmented permeable mass of formation particles having a reasonably uniformly distributed void fraction in the in situ oil shale retort.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.