The role of coal seam properties on coupled processes during CO2sequestration: A parametric study

Abstract

AbstractIt has been proposed that a considerable amount of CO2can be safely sequestered from the atmosphere in geological formations such as coalbeds. In spite of promising evidence of the economic and technical viability of CO2sequestration in coal seams, many of its hydro‐geomechanical aspects are not fully understood. This paper presents a coupled hydro‐mechanical model that is used to assess the reservoir performance of a coalbed and the induced surface and subsurface deformations. A series of numerical simulations has been performed to study the effects of different parameters on the reservoir and geomechanical behaviors associated with CO2injection. A single‐phase dual‐porosity model is coupled to a one‐dimensional poroelastic model and an analytical model for the ground surface movements. Through these simulations, the role of three sets of parameters at different scales is investigated: fracture characteristics, matrix characteristics, and geomechanical/geometrical characteristics. The comparative impacts of these parameters on reservoir permeability, volume of the stored CO2, and deformations of the coalbed and the ground surface, are quantitatively assessed, in order to identify the most important parameters influencing the hydro‐mechanical response of the ground.