Leading to more efficient, cleaner coal technologies
Urged by the lack of understanding of the fundamental scientific phenomena of CO2 injection and retention in coal, the ICBM project investigated CO2-CH4 adsorption/desorption, diffusion and flow in coal seams. The knowledge gained contributed to the formulation and development of an improved simulator for CO2-Coalbed Methane (ECBM) recovery and CO2 sequestration. Until now the Coalbed Methane Simulator (METSIM), previously developed by Imperial College, London was used as the industry standard in the UK for primary methane recovery. This tool provides solutions to a set of Darcy equations for the water and gas (methane) phases in the cleats, but it is insufficient to simulate CO2 sequestration/enhanced recovery. Answering this need, an upgraded version the METSIM2 has been designed that solves three new equations for the methane, CO2, and water components, all at the same time. METSIM2 involves a pore bi-disperse diffusion model and a pressure dependent absolute permeability relationship for the coal-bed reservoir during both primary and CO2-enhanced recovery/CO2 storage. Employing a numerical simulator comparison study, the upgraded tool was found to offer results that were in good agreement with other ECBM simulators. METSIM2 has already offered great assistance when used to match the Allison Unit ECBM pilot in the San Juan basin. Academic institutions involved in coal and CO2 sequestration research and industries with reservoir engineering and geological CO2 sequestration field applications are sought for further collaboration.