Numerical and experimental study of strata behavior and land subsidence in an underground coal gasification project
Underground Coal Gasification, with enhanced knowledge of hydrogeological, geomechanical and environmental aspects, can be an alternative technique to exploit the existing unmineable reserves of coal. During the gasification process, petro-physical and geomechanical properties undergo a drastic...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-11-01
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| Series: | Proceedings of the International Association of Hydrological Sciences |
| Online Access: | https://www.proc-iahs.net/372/455/2015/piahs-372-455-2015.pdf |
| Summary: | Underground Coal Gasification, with enhanced knowledge of hydrogeological,
geomechanical and environmental aspects, can be an alternative technique to
exploit the existing unmineable reserves of coal. During the gasification
process, petro-physical and geomechanical properties undergo a drastic
change due to heating to elevated temperatures. These changes, caused due to
the thermal anisotropy of various minerals, result in the generation of
thermal stresses; thereby developing new fracture pattern. These fractures
cause the overhead rock strata to cave and fill the gasification chamber
thereby causing subsidence. The degree of subsidence, change in fluid
transport and geomechanical properties of the rock strata, in and around the
subsidence zone, can affect the groundwater flow. This study aims to predict
the thermo-geomechanical response of the strata during UCG. Petro-physical
and geomechanical properties are incorporated in the numerical modelling
software COMSOL Multiphysics and an analytical strength model is developed
to validate and further study the mechanical response and heat conduction of
the host rock around the gasification chamber. Once the problems are
investigated and solved, the enhanced efficiency and the economic
exploitation of gasification process would help meet country's energy
demand. |
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| ISSN: | 2199-8981 2199-899X |