Horizontal free face blasting for minimizing channeling and mounding in situ retort with cusp at intermediate elevation

Patent · Tue Jul 10 00:00:00 EDT 1984

OSTI ID:6243155

Ricketts, T E

A method is claimed for forming an in situ retort containing a fragmented permeable mass of formation particles in a retort site within a subterranean formation. A void is excavated into the formation and a zone of unfragmented formation is left adjacent the void. A plurality of explosive charges are formed in the zone of unfragmented formation. At least one central explosive charge is in a central portion of the zone of unfragmented formation, and a plurality of outer explosive charges are in the zone of unfragmented formation nearer the side walls of the void than the central explosive charge. The distance from each such outer explosive charge to an adjacent side wall of the void is about equal to the crater radius of the outer explosive charge. The central and outer explosive charges are detonated for explosively expanding the zone of unfragmented formation toward the void for forming a fragmented permeable mass of formation particles in the in situ retort. The retort has a horizontal cross-sectional area at an intermediate elevation which is less than the horizontal cross-sectional area of the retort at elevations above and below the intermediate elevation.

• Assignee: Occidental Oil Shale Inc.
• Patent Number(s): US 4458948
• OSTI ID: 6243155
• 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
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHANNELING
CHEMICAL REACTIONS
CHEMICAL REACTORS
COMMINUTION
DECOMPOSITION
DISTILLATION EQUIPMENT
ENERGY SOURCES
EQUIPMENT
EXCAVATION
EXPLOSIVE FRACTURING
EXPLOSIVES
FOSSIL FUELS
FRACTURING
FRAGMENTATION
FUELS
IN-SITU PROCESSING
IN-SITU RETORTING
LEVELS
MATERIALS
OIL SHALES
PERMEABILITY
PROCESSING
RETORTING
RETORTS