A practical Smart-Water flooding simulation model should replicate laboratory and pilot scale observations. An ideal model, however, should also capture the recovery mechanism in play. In the literature, only the conventional straight forward residual oil reduction approach has been suggested and tested to upscale Smart-Water Flood laboratory results. This, consequently, provides a single view of the potential recovery mechanism. Other approaches can be equally successful in matching laboratory results and hence could provide additional insight and understanding of the recovery mechanism in play. In this work, we use the laboratory results of two tertiary Smart-Water corefloods to investigate the various possibilities for modeling Smart-Water flooding—hence, the possible recovery mechanisms.

First, we use a high-accuracy Buckley Leveret solver to study the performance of the two corefloods from a fractional flow perspective. Second, we use a streamline-based simulator to investigate in detail the possible relative permeability sets capable of history matching Smart-Water recoveries and pressures. As a result a new set of relative permeability was generated, and tested through a 3-D synthetic layered reservoir to demonstrate Smart-Water flooding recoveries. The results of this work suggest that recovery enhancement through Smart-Water flooding is best explained based on changes to the curvature of the oil relative permeability curve (i.e. the Corey oil exponent). Incremental recoveries are realized not due to a reduction in the "technical/absolute" residual oil but rather due to improvement in the oil flow capacity (i.e. oil-to-water relative permeability ratio). Based on our results, we postulate that Smart-Water incremental recovery is triggered by the formation of a dual wettability state across the porous medium.

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