Development of Unsteady-State Continuum Scale Solver for Core Scale Simulations

DEVELOPMENT OF UNSTEADY-STATE CONTINUUM SCALE SOLVER FOR CORE SCALE SIMULATIONS
Hani Akbari (University of Queensland), Stephan Matthai

This project develops a parallelised tensor-property hybrid finite element – finite volume solver for the upscaling of pore-network modelling derived saturation functions from the micro plug to the whole-core scale. The development is based on the software API CSMP++. The first step is the verification of this solver with classical CO2 migration benchmarks, including analytical solutions and verification cases from the literature: A) Pruess et al. (2004) Problem 3: 1D radial flow salt precipitation problem; B) Pruess et al. (2004) Problem 4: migration up a fault zone; C) Pruess et al. (2004) Problem 7: layered system brine displacement; D) Class et al. (2009) Problem 1.2: leakage through an abandoned well.

The new CSMP++ unsteady state solver will facilitate the computation of equivalent relative permeabilities, in the presence of combined gravitational, capillary and viscous forces on the cm-scale (hybrid FEM-FVM pressure-saturation formulation including capillary pressure in global pressure equation). By contrast with standard tools, it will be suitable for computations between the capillary- and the viscous limits, and the algorithms will handle saturation functions in an effective manner for media with full tensor permeabilities. The methodology for unstructured mesh generation and quality will also be improved.

The project also includes A) the validation of the USS solver by comparing measured and observed CO2 : brine fluid distributions. B) An initial demonstration of the impact of incorporating realistic bedding structure and geometries on equivalent relative permeability functions at the near wellbore and single geo-cell scale.