Coupled two-component flow in deformable fractured porous media with application to modelling geological carbon storage

摘要

The sequestration of excessive CO_2 emissions from point sources into deep geological formations is a short to mid-term strategy component for mitigating climate change while maintaining the security and stability of the world's energy systems. This storage procedure will result in a series of coupled thermo-hydro-mechanical-chemical processes within the geological formation which may affect its capacity, transmissibility and integrity as a storage medium. This work presents the development of a numerical model, in view of recent carbon storage initiatives, which is to aid potential design, monitoring and legislation. The emphasis of the model formulation is on coupling the driving hydro-mechanical behaviour due to the induced pressure gradients within a fractured reservoir system. It is a Biot-type double-porosity model, coupling immiscible two-component fluid behaviour within a deformable porous medium with a coinciding continuous fracture network. The governing equations are outlined with their constitutive relationships in view of the application. For their solution, the equations are discretised spatially with a Galerkin formulation, and the subsequent non-linearities are solved iteratively through an adaptive temporal discretisation scheme. A simplified benchmark storage scenario is modelled with realistic parameters which is then assessed.