Numerical modeling of a subsidence induced by underground coal gasification, including thermal effects
During normal coal extraction roof collapse is controlled, thermal effects are absent and existing data is useless for the formation of numerical models of underground coal gasification(PGU). Thermal deformation occurs during PGU to the extent that rock is deformed, the roof collapses, rock settles, and changes occur in the water-bearing layers, and so forth. As PGU progresses, changes occur in the geometry, size, and other characteristics of the volume of the reaction. Data derived from plastic coal in New Mexico (USA) is used to construct a numerical model. This coal was bedded at a depth of 259 meters where it was stratified throughout a mixture of rock. Core drilling was conducted and a geological column was constructed to induce a PGY combustion front with temperatures of 900 degrees. Temperatures of 600 and 300 degrees were encountered 6.1 and 12.2 meters from the front, respectively. A short distance from the front, in a direction away from the placticized material, the temperature of the rock matched the 27 degree temperature in the surrounding rock. Correlational relationships were obtained for stress in rock under different conditions and these correlations were used to appraise the effect of heat on the rock. It was suggested that the heating of rock did, at times, serve to support the roof rock. Similarly, during periods of cooling, this effect lessened. Comparative and optimal test results are appraised with the aid of the numerical model.
- OSTI ID:
- 7090694
- Journal Information:
- In Situ; (United States), Vol. 7:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COAL
DEFORMATION
THERMAL STRESSES
GROUND SUBSIDENCE
MATHEMATICAL MODELS
IN-SITU GASIFICATION
NEW MEXICO
COAL DEPOSITS
ROCKS
COAL GASIFICATION
COMBUSTION KINETICS
COMBUSTION WAVES
CORRELATIONS
ROCK MECHANICS
TEMPERATURE DISTRIBUTION
TEMPERATURE EFFECTS
THERMAL DEGRADATION
CARBONACEOUS MATERIALS
CHEMICAL REACTION KINETICS
ENERGY SOURCES
FEDERAL REGION VI
FOSSIL FUELS
FUELS
GASIFICATION
GEOLOGIC DEPOSITS
IN-SITU PROCESSING
KINETICS
MATERIALS
MECHANICS
MINERAL RESOURCES
NORTH AMERICA
PROCESSING
REACTION KINETICS
RESOURCES
STRESSES
THERMOCHEMICAL PROCESSES
USA
010404* - Coal
Lignite
& Peat- Gasification