Postburn roof stability analysis for the TONO CRIP UCG burn
During the Ninth Annual Underground Coal Gasification Symposium, Sutherland, Hommert, Taylor, and Benzley presented a preburn prediction for the burn, roof fall and surface subsidence for the TONO CRIP UCG site in Washington state. That burn has now been completed and postburn measurements of cavity sizes have become available. In this manuscript we show that the preburn predictions are, in general, in good agreement with the postburn examination of the burn site. Discrepancies between the predictions and the measurements are shown to arise for two reasons. The first is that the burn sequence analyzed in the prediction was not followed during the course of the experiment due to experimental difficulties. The second reason is that the stratigraphic section analyzed in the preburn predictions is slightly different from that observed above the burn. To clarify the discrepancies, the roof stability of the measured burn cavity is analyzed using the two analysis schemes that were used in the preburn analysis. The first technique is the Rubble model. It uses a continuum description of the rubblization process that occurs as roof material fails and falls into the cavity below it. This technique is based on a standard finite element numerical analysis scheme. The second technique is the BLOCKS model. This technique divides the geologic strata into a collection of discrete, individual blocks and monitors all the collisions which occur between them. Both techniques yield very good descriptions of the roof stability for the measured burn cavity. 10 refs., 7 figs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5401677
- Report Number(s):
- SAND-85-0879C; CONF-8508101-1; ON: DE85017159
- Country of Publication:
- United States
- Language:
- English
Similar Records
Subsidence prediction for the forthcoming TONO UCG project. [Rubble model and block model]
Underground Coal Gasification Program: FY85 annual report
Related Subjects
010404* -- Coal
Lignite
& Peat-- Gasification
010900 -- Coal
Lignite
& Peat-- Environmental Aspects
CAVITIES
COAL GASIFICATION
DATA
EXPERIMENTAL DATA
FEDERAL REGION X
FIELD TESTS
FINITE ELEMENT METHOD
GASIFICATION
GEOLOGY
GROUND SUBSIDENCE
IN-SITU GASIFICATION
IN-SITU PROCESSING
INFORMATION
NORTH AMERICA
NUMERICAL DATA
NUMERICAL SOLUTION
PROCESSING
ROOFS
STABILITY
STRATIGRAPHY
TESTING
THERMOCHEMICAL PROCESSES
USA
WASHINGTON