Fracturing of pillars for enhancing recovery of oil from in situ oil shale retort
US4045085A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 14, 1975 |
| Grant date | Aug 30, 1977 |
| Priority date | — |
| Expiry date | Apr 14, 1995 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21C41/24
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An underground in situ oil shale retort, having predetermined boundaries, contains a bed of fragmented oil shale particles having an appreciable void volume distributed therethrough. Air passed through this bed of fragmented oil shale supports combustion of some of the carbonaceous material in the oil shale and provides heat for retorting oil therefrom. A number of such retorts may be formed in an area and pillars are left to support the overburden. Pillars forming walls between adjacent retorts also prevent gas leakage. Oil recovery from intact oil shale pillars is enhanced by fracturing the pillars as well as fragmenting the shale in the retort. The pillars are fractured by hydraulic fracturing, electrical fracturing, liquid explosive fissuring, or the like. The fractures are propagated from access holes in the vicinity of the pillars, typically between similar holes adjacent the next retort volume when the pillars are between retorts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.