Abstract
Experiments investigating the flow of two fluids in an approximately 2D heterogeneous porous medium are combined with 1D mathematical analysis with a view to understanding the dissolution of CO2 in reservoir brines in an enhanced oil recovery (EOR) geometry. The model adequately describes many aspects of the flow observed in experiments when gravity can be ignored, and can explain some aspects of the flow developed when gravity is important. The growth and retreat of pore scale viscous fingers was observed, driven by significant cross-layer pressure differences predicted by the model. These fingers significantly increase the interfacial area between fluids with a viscosity contrast in a heterogeneous medium, and are thought to enhance CO2 dissolution in reservoir brines. Two flow regimes are observed when gravity acts perpendicular to the principal direction of flow, one in which flow is controlled by density differences and a second in which flow is focused along high permeability layers. The second regime is predicted to allow the most mixing between fluids, and is calculated to occur in typical EOR situations.
Original language | English |
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Publication date | 2012 |
Publisher | University of Cambridge |
Number of pages | 56 |
Publication status | Published - 2012 |