Fracturing of pillars for enhancing recovery of oil from in situ oil shale retort

Patent · Tue Aug 30 04:00:00 EDT 1977

OSTI ID:5362323

Garrett, D E

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. 26 claims, 4 figures.

• Assignee: Occidental Oil Shale, Inc.
• Patent Number(s): US 4045085
• OSTI ID: 5362323
• Country of Publication: United States
• Language: English

Related Subjects

04 OIL SHALES AND TAR SANDS
040401* -- Oil Shales & Tar Sands-- In Situ Methods
True & Modified
AIR
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COMBUSTION
ENERGY SOURCES
EXPLOSIVE FRACTURING
FLUIDS
FOSSIL FUELS
FRACTURING
FUELS
GASES
HYDRAULIC FRACTURING
IN-SITU PROCESSING
IN-SITU RETORTING
MINING
OIL SHALES
OXIDATION
PROCESSING
RETORTING
ROOM AND PILLAR MINING
UNDERGROUND MINING