TY - GEN

T1 - Screening of EOR Potential on the Pore Scale - Application of Microfluidics to Alkaline Flooding

AU - Ott, Holger

AU - Kharrat, Ahmad

AU - Borji, Mostafa

AU - Clemens, Torsten

AU - Arnold, Pit

PY - 2019/5

Y1 - 2019/5

N2 - Complex chemical EOR processes, such as in alkaline or surfactant flooding, are typically optimized on theirphase behavior and by core flood experiments. However, the information from classical experiments arerather limited, because they do not directly give insight the details of oil mobilization and displacements – incore floods, typically oil production and differential pressure are measured, which are both 1D data sets. Thephase behavior is typically measured in test tubes and not under realistic flow (mixing) conditions in porousmedia flow.Chemical EOR is changing interactions between fluids and the porous medium and is therefore manifested onthe pore scale, where fluids are actually displaced. However, pore scale observations are typically sufferingfrom a limited field of view especially for multiphase flow effects, which may not be representative for theoverall system or the displacement.In the frame of this study, we investigate displacements of crude oil by water and alkali solutions in order tooptimize injection-water compositions for tertiary recovery. The study takes advantage of the high spatial andtemporal resolution of microfluidics in order to observe fluid phases in the pore space, their distribution anddisplacements. Changes of the wetting state, breaking of oil clusters and the formation of emulsion phases ascharacteristic for the displacements have been observed. In order to overcome the limitation of the relativelysmall field of view, oil clusters have been analyzed by statistical and topological means showing a systematicchange form water flooding to EOR.The study shows that (a) cluster analysis can be used for EOR screening and – in the present case – is moreindicative with respect to EOR performance than production data from the same experiment. The study mightbe a first step towards statistical fingerprinting for optimizing EOR processes. (b) classical phase behaviorexperiments do not reflect (or just partly) the phase behavior in the porous medium under flow conditions. (c)the formation of (micro) emulsions in the pore space leads to pinning effects and is therefore of disadvantagefor the displacement

AB - Complex chemical EOR processes, such as in alkaline or surfactant flooding, are typically optimized on theirphase behavior and by core flood experiments. However, the information from classical experiments arerather limited, because they do not directly give insight the details of oil mobilization and displacements – incore floods, typically oil production and differential pressure are measured, which are both 1D data sets. Thephase behavior is typically measured in test tubes and not under realistic flow (mixing) conditions in porousmedia flow.Chemical EOR is changing interactions between fluids and the porous medium and is therefore manifested onthe pore scale, where fluids are actually displaced. However, pore scale observations are typically sufferingfrom a limited field of view especially for multiphase flow effects, which may not be representative for theoverall system or the displacement.In the frame of this study, we investigate displacements of crude oil by water and alkali solutions in order tooptimize injection-water compositions for tertiary recovery. The study takes advantage of the high spatial andtemporal resolution of microfluidics in order to observe fluid phases in the pore space, their distribution anddisplacements. Changes of the wetting state, breaking of oil clusters and the formation of emulsion phases ascharacteristic for the displacements have been observed. In order to overcome the limitation of the relativelysmall field of view, oil clusters have been analyzed by statistical and topological means showing a systematicchange form water flooding to EOR.The study shows that (a) cluster analysis can be used for EOR screening and – in the present case – is moreindicative with respect to EOR performance than production data from the same experiment. The study mightbe a first step towards statistical fingerprinting for optimizing EOR processes. (b) classical phase behaviorexperiments do not reflect (or just partly) the phase behavior in the porous medium under flow conditions. (c)the formation of (micro) emulsions in the pore space leads to pinning effects and is therefore of disadvantagefor the displacement

KW - Multiphase Flows

KW - Fluid Dynamics

M3 - Conference contribution

BT - InterPore 2019

ER -