Jetting out weak areas for forming an in situ oil shale retort
An in situ oil shale retort is formed in a subterranean formation containing oil shale. A void can be formed in formation within the retort site by directing fluid under pressure against a zone of relatively weakened formation, such as tuffs, gravel beds, or fractured oil shale, to erode such weakened formation into particle form, leaving a void space adjacent a remaining zone of unfragmented formation within the retort site. The void space can be formed by drilling a bore hole into the zone of weakened formation, placing a jet nozzle in the bore hole, and forcing a fluid such as water through the nozzle against the weakened formation for eroding it to form the void space. Eroded formation particles are passed to the bottom of the bore hole. Such water jetting techniques can be used to form voids in zones of weakened formation interspersed throughout the retort site. Remaining formation within the retort site is explosively expanded toward such a void space for forming a fragmented permeable mass of formation particles containing oil shale in an in situ oil shale retort. The amount of eroded formation particles jetted from the retort site can be measured prior to explosive expansion for providing a selected void fraction in the resulting fragmented mass. Explosive also can be placed in voids excavated by such jetting for such explosive expansion.
- Assignee:
- Occidental Oil Shale Inc
- Patent Number(s):
- US 4279444
- OSTI ID:
- 6260125
- Resource Relation:
- Patent File Date: Filed date 7 Jan 1980
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
OIL SHALES
FRAGMENTATION
IN-SITU RETORTING
BOREHOLES
EXPLOSIVE FRACTURING
FLUID INJECTION
NOZZLES
VOIDS
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CAVITIES
CHEMICAL REACTIONS
COMMINUTION
DECOMPOSITION
ENERGY SOURCES
FOSSIL FUELS
FRACTURING
FUELS
IN-SITU PROCESSING
MATERIALS
PROCESSING
RETORTING
040300* - Oil Shales & Tar Sands- Drilling
Fracturing & Mining
040401 - Oil Shales & Tar Sands- In Situ Methods
True & Modified