MODELING OF MACRO-EMULSION FLOODING WITH CAPILLARY-DRIVEN EFFECTS

Ranena V. Ponce Flores¹; Márcio S. Carvalho¹; Vladimir Alvarado²

¹ PUC-Rio; ² University of Wyoming

doi:10.20906/CPS/COB-2015-2602

Resumo

Capillary forces play a significant role during multiphase fluid flow in porous media as multiphase fluid interfaces control fluid distribution equilibria at the myriad of interconnected or isolated menisci. Capillary number is a key parameter in emulsion designs for EOR purposes. Pore-scale displacement of an emulsion dispersed phase results from the competition of viscous forces, which drives the drops transport through the pores, and capillary forces, responsible for drops entrapment in pore throats. In this work we incorporate capillary-driven effects in two known mechanism observed in water-alternated-emulsion (WAE) injection, namely a microscopic increased pore-level efficiency and a macroscopic mobility control. To properly parametrize relative permeability curves as functions of the capillary number along with the emulsion dispersed phase concentration, a Matlab open source code was modified. A parametric analysis of a ¼ five-spot geometry used on the first layer of the Tabert formation shows that capillary number significantly impacts mobility control potential of the emulsion shown to be responsible for the extra oil recovery. Emulsions with suited drop-to-pore size distribution and interfacial properties optimize emulsion mobility control and sweep efficiency, since heterogeneities in capillary pressure impact emulsion performance and not only flow rate. Results show that mitigation of high injection pressure is possible during cyclic WAE injection without oil recovery impairment.

Palavras-chave: Emulsion; Capillary number; Mobility control; Enhanced oil recovery; Two-phase flow