Volumetric behaviour of coal due to CO2 and effects of stress

The Kyoto Protocol (1997) committed many countries to reduce their CO2 emissions. Between 2008 and 2012, the Netherlands should reduce its contribution to the total by 6% relative to the level of CO2 in 1990. CO2-emission is coupled to energy demand as satisfied by hydrocarbon consumption. International strategies are therefore to find methods to reduce the consumption of hydrocarbons, or to find a way to dispose the emitted CO2 in the oil and gas extraction process itself. The latter is made possible by ‘Enhanced Coalbed Methane (ECBM) production’, a method where potential new gas plays and CO2-storage in the subsurface are combined. In this method, adsorbed CH4 is driven out by CO2-introduction into underground coal layers. The methane is extracted from the subsurface by a well. A good overview of recent standpoints is given by White et al. (2005).