Coupled Simulation of Underground Coal Gasification (UCG) Using CMG STARS

Underground Coal Gasification transforms coal into energy underground, but doing so safely and efficiently requires understanding one of the most complex coupled subsurface processes in energy engineering. 

It is an in-situ process that converts coal into syngas by injecting oxidants into a coal seam and producing combustible gases through a network of high-temperature chemical reactions.

In this study, CMG STARS was used to develop a fully coupled thermal-hydro-mechanical-chemical (THMC) model of UCG, capturing the evolution of the gasification cavity, chemical reactions, composition of produced syngas, production behavior, and subsidence.

Outcome: The model demonstrates how coupled simulation can predict cavity growth, gas production, and geomechanical deformation, providing critical insights for safe and efficient UCG operations.