Formation of an in situ oil shale retort with control of mounding
A method for forming a fragmented permeable mass of oil shale particles in an in situ oil shale retort in a subterranean formation containing oil shale is provided. At least one void is excavated within the retort site in the subterranean formation while zones of unfragmented formation are left adjacent such a void. The zones of unfragmented formation are then explosively expanded toward the void for forming the fragmented permeable mass of formation particles in the retort. To provide a fragmented mass with a flat top surface and reasonably uniform void fraction distribution, at least one of the zones of unfragmented formation is explosively expanded toward the void in a plurality of contiguous regions. Each such contiguous region has a free face adjacent the void and is expanded by first explosively expanding a first portion of that region toward the void. The free face of the first portion expanded is near the center of its respective region. Thereafter, a second portion of each region is expanded toward the void. The free face of the second portion is adjacent the free face of the first portion and surrounds the free face of the first portion. Remaining portions of each region are then expanded toward the void in sequence radially outwardly from the next previously expanded portion.
- Assignee:
- Occidental Oil Shale, Inc., Grand Junction, Colo.
- Patent Number(s):
- US 4423908
- OSTI ID:
- 6839773
- Resource Relation:
- Patent File Date: Filed date 26 Jun 1981; Other Information: PAT-APPL-277852
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHEMICAL EXPLOSIVES
EMPLACEMENT
OIL SHALES
EXPLOSIVE FRACTURING
IN-SITU RETORTING
BOREHOLES
ENGINEERING GEOLOGY
EXCAVATION
OIL SHALE DEPOSITS
OIL SHALE MINING
RETORTS
UNDERGROUND MINING
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CAVITIES
CHEMICAL REACTIONS
CHEMICAL REACTORS
COMMINUTION
DECOMPOSITION
DISTILLATION EQUIPMENT
ENERGY SOURCES
EQUIPMENT
EXPLOSIVES
FOSSIL FUELS
FRACTURING
FUELS
GEOLOGIC DEPOSITS
GEOLOGY
IN-SITU PROCESSING
MATERIALS
MINERAL RESOURCES
MINING
PROCESSING
RESOURCES
RETORTING
040401* - Oil Shales & Tar Sands- In Situ Methods
True & Modified
040300 - Oil Shales & Tar Sands- Drilling
Fracturing & Mining