Thermomechanical impact of underground coal gasification exploitation

Farid Laouafa (1)

1 INERIS - Institut National de l'Environnement Industriel et des Risques

Underground mining by coal combustion (Underground Coal Gasification - UCG) raises questions regarding the mechanical behavior of the site and the stability of the overburden rock layers. By studying the underground reactor, its inlet and outlet, we confirmed the key roles played by mechanical damage and thermo-mechanical phenomena. Deformation or collapse above the cavity may cause a collapse in the overlying layers or a subsidence at the surface level. These phenomena highly depend on the thermo-poro-mechanical behavior of the surrounding rock (host rocks). The numerical results presented in this paper were derived from models based on different assumptions describing a raw geological background. Both 3D and 2D nonlinear finite element modeling was conducted based on two different approaches. Based on the analysis of the numerical results, we were able to highlight the main factors influencing the behavior and mechanical stability of the overburden, and consequently the UCG process evolution.

Keywords: Underground; coal; combustion; mining; thermomechanic; modelling

Domains: Earth Sciences

Farid Laouafa. Thermomechanical impact of underground coal gasification exploitation. 3. International Symposium on Mine Safety Science and Engineering (ISMS 2016), Aug 2016, Montreal, Canada. pp.170-175. ⟨ineris-01854255⟩