Extension of the single-phase flow solver to accommodate multiphase flow is under development, aiming at extending the applicability of ParaGeo to modelling C02 sequestration and storage. The advanced geomechanical constitutive and contact models of ParaGeo are particularly suited to the hysteretic nature of the stress field in this class of problem, so the addition of multiphase flow modelling will provide a very powerful coupled analysis tool.
The goal is to simulate the transport of multiple fluid phases in porous, fractured and faulted media when coupling with temperature and geomechanical stress fields. The implementation and validation of non-isothermal two-phase immiscible and miscible flow have been completed. Importantly, this phase also includes the full implementation of a tightly coupled framework for multiphase flow, thermal and geomechanical fields. Test case results below include the Buckley-Leverett problem, buoyancy-driven flow, and a simple water-flood reservoir simulation.
Extension to multiphase flow across/along discrete contact surfaces, e.g. for faults and fractures, is currently being undertaken and is expected to be completed in Q4 2022. In this implementation, all fields are treated within the same contact framework by optimizing the availability of the state variables and enhancing accuracy when updating field-dependent variables.
