000 02616nab a2200217 4500
005 20260520003100.0
008 260224s2012 xxu ing
041 _aInglés
245 0 0 _aA poromechanical model for coal seams injected with carbon dioxide
_bFrom an Isotherm of Adsorption to a Swelling of the Reservoir
260 _a
_b
_csept./oct. 2012
270 _a07/05/2013 ; 07/05/2013
300 _a9 p. ; 777-786
520 _aTraducción del resúmen del autor: Injecting carbon dioxide into deep unminable coal seams can enhance the amount of methane recovered from the seam. This process is known as CO2-Enhanced Coal Bed Methane production (CO2-ECBM). The seam is a porous medium whose porous system is made of cleats (small natural fractures) and of coal pores (whose radius can be as small as a few angström). During the injection process, the molecules of CO2 get adsorbed in the coal pores. Such an adsorption makes the coal swell, which, in the confined conditions that prevail underground, induces a closure of the cleat system of the coal bed reservoir and a loss of injectivity. In this work, we develop a poromechanical model which, starting from the knowledge of an adsorption isotherm and combined with reservoir simulations, enables to estimate the variations of injectivity of the coal bed reservoir over time during the process of injection. The model for the coal bed reservoir is based on poromechanical equations that explicitly take into account the effect of adsorption on the mechanical behavior of a microporous medium. We consider the coal bed reservoir as a dual porosity (cleats and coal porosity) medium, for which we derive a set of linear constitutive equations. The model requires as an input the adsorption isotherm on coal of the fluid considered. Reversely, the model provides a way to upscale an adsorption isotherm into a meaningful swelling of the coal bed reservoir at the macroscopic scale. The parameters of the model are calibrated on data on coal samples available in the literature. Reservoir simulations of an injection of carbon dioxide in a coal seam are performed with an in-house finite volume and element code. The variations of injection rate over time during the process of injection are obtained from the simulations. The effect of the compressibility of the coal matrix on those variations is discussed.
581 _a5
773 0 _tOil and Gas Science and Technology
_g67
942 _cARTICULO
100 1 _aNikoosokhan, S.
_953122
100 1 _aVandamme, M.
_953123
100 1 _aDangla, P.
_953124
999 _c187664
_d187664