Abstract
Foaming injected gas has the potential to overcome operational challenges encountered with pure gas injection. A mechanistic population balance model that integrates observed pore level events that are responsible for foam generation and coalescence in porous media was developed. The model is integrated in the AD-GPRS framework (Automatic Differentiation-General Purpose Research Simulator). Based on experimental pore-scale observations that show that the Roof snap-off geometric requirement for foam generation is affected due to the presence of residual oil in the pore, we upscale the pore-scale observations to the macroscale. We use experimental coreflood data from the literature to verify the performance of the model developed. The coreflood data are of two experiments that use the same core to perform a foam flood with and without the presence of oil. Pore-scale observations that show the effect of residual oil on the geometric Roof snap-off requirement translate into less germination sites at the macroscale. The generation constant used in the population balance model in the absence of residual oil reduces to one-fourth its original value when oil is present. The model developed was able to describe experimental data with good agreement both in the presence and absence of oil. In the presence of residual oil, all other foam parameters needed for the population balance model were fixed except the generation constant. The results demonstrate that the "hindered snap-off concept is able to describe foam flow when only residual oil is present.
