Method of uniform rubblization for limited void volume blasting
US4333684A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1980 |
| Grant date | Jun 8, 1982 |
| Priority date | — |
| Expiry date | Oct 2, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/248
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
There is provided a method of forming an in situ oil shale retort in a retort site within a subterranean formation containing oil shale. The in situ oil shale retort contains a fragmented permeable mass of formation particles. A first portion of formation is excavated from within the boundaries of the retort being formed to form at least one void. The surface of the formation defining such a void provides at least one free face extending through the formation. The second portion of formation is left within the boundaries of the retort being formed to be explosively expanded toward the void. At least two arrays of explosive charges are formed in the second portion of formation wherein the first array of explosive charges has a first burden distance and the second array of explosive charges has a second burden distance wherein the second burden distance is less than the first burden distance. Explosive is detonated for explosively expanding the second portion of formation toward the void to form a fragmented permeable mass of formation particles containing oil shale in the subterranean formation for forming an in situ oil shale retort.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.