Determining the locus of a processing zone in an oil shale retort by effluent water composition

Patent · Tue Sep 23 04:00:00 EDT 1980

OSTI ID:6795835

Cha, C Y

A processing zone advances through a fragmented permeable mass of particles containing oil shale in an in-situ oil shale retort in a subterranean formation containing oil shale. The retort has an effluent water passing therefrom. The effluent water carries a constituent which is formed, by advancement of the processing zone through the fragmented mass, from a precursor contained in the formation. In a first aspect of the invention, the locus of the processing zone is determined by assaying the formation at selected locations in the retort for content of the precursor before processing the selected locations, and effluent water from the retort is monitored for concentration of the selected constituent. For example, the nitrogen content of kerogen can be the precursor and effluent water from the retort can be monitored for the concentration of ammonia and/or ammonium sulfate produced by retorting of kerogen in the oil shale. In the second embodiment of the invention, recognition is made of the correlation between the fischer assay of the oil shale and the amount of water it contains. Core samples of the formation are analyzed prior to processing to determine the water content and the predicted water production rate due to the passage of a processing zone through that location in the formation. Actual water production rate can then be compared with the predicted rate and the locus of the processing zone determined.

• Assignee: Occidental Oil Shale Inc
• Patent Number(s): US 4223726
• OSTI ID: 6795835
• 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
CHEMICAL REACTIONS
DECOMPOSITION
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROGEN COMPOUNDS
IN-SITU PROCESSING
IN-SITU RETORTING
KEROGEN
MATERIALS
MONITORING
OIL SHALES
ORGANIC MATTER
OXYGEN COMPOUNDS
PROCESSING
RETORTING
WATER
ZONES