A thermodynamics-based simulation framework for modelling of geological CO2 sequestration

Abstract

In an attempt to decarbonize industries and support the transition to a sustainable energy supply, subsurface technologies will play a vital role. Security and responsible use of the subsurface for a wide range of decarbonizing technologies require proper understanding and management of all activities. In order to understand the dynamics of all processes involved while having only limited information about underground conditions, numerical simulation presents a pivotal tool for any subsurface operation. Numerical simulation of CO2 sequestration operations, in particular, aims to model complex multiphase, multiphysics dynamics and demands advanced simulation technology. The conditions for CO2 injection for storage expose a range of physical phenomena that require careful thermodynamic and physical modelling. The interaction of CO2 and impurities with brines and residual hydrocarbons, combined with the rather different operational conditions from conventional hydrocarbon production, give rise to complex physical interactions at different scales. To make predictions of subsurface processes whilst having highly limited physical and geological information, reservoir simulation becomes a useful tool only if it addresses the uncertainties and representativeness of the inputs. Despite the availability of more computational efficiency, however, the accuracy of prediction from simulation models is only as good as the physical representation of fluid flow. Accordingly, a greatly improved understanding of subsurface processes can be achieved by means of advanced fluid modelling. This entails an efficient coupling of thermodynamics and fluid flow, an advanced computational framework that enables modelling of complex physics whilst handling nonlinearities appropriately....