Multi-scale simulation of multiphase multi-component flow in porous media using the Lattice Boltzmann Method

Abstract

This thesis consists of work mainly performed within the Qatar Carbonates and Carbon Storage Research Centre (QCCSRC) project, focusing on the prediction of flow and transport properties in porous media. The direct pore scale simulation of complex fluid flow on reservoir rocks is the main topic of this work. A simulation package based on the lattice Boltzmann method has been developed to study single and multiphase flow as well as thermal and solute dispersion in porous media. The simulator has been extensively validated by comparing simulation results to reference solutions. Various numerical experiments have been performed to study the single/multiphase/solute dispersion flow in reservoir rocks. The simulator successfully predicts various transport properties including single phase and relative permeability, capillary pressure, initial-residual saturation, residual cluster size distribution and dispersion coefficient. The prediction has been compared to available experimental data and was generally found to be in good agreement. The simulator is also ready for exploring the two-phase dynamic problem with coupled and nonlinear physical processes including the effect of wettability, surface tension and hysteresis. To improve the efficiency of the lattice Boltzmann simulations, an optimised collision model and corresponding parallel operation are proposed and implemented. A sparse storage scheme which significantly reduces the memory requirement has been designed and implemented for complex porous media. Due to the application of these optimisation schemes, it is possible to perform simulations on large scale samples (Size >1024x512x512). The optimised code shows very good and promising performance, and nearly ideal scalability was achieved.