Simulation study of wettability alteration enhanced oil recovery during co-current spontaneous imbibition

Naturally fractured reservoirs are highly dependent on capillary forces to recover hydrocarbons during water injection. Water can spontaneously imbibe and expel oil if positive exist; purely counter-current all sides of the matrix blocks exposed water; predominantly co-current with some production simultaneously. The latter is referred as a spontaneous imbibition (SI) setup. Wettability alteration (WA) has been identified key mechanism improve recovery from naturally reservoirs, however almost experimental modeling studies WA SI have focused SI. Our review indicates limited systematic work using nonzero initial saturation, mixed wettability or processes This study will investigate enhanced by where brine general component imbibes causes system become more water-wet. We model 1D oil-saturated core at one end (inlet) other (outlet), thus facilitating initially preferentially (not strongly) oil-wet low potential. both transported imbibing diffuses towards front. Adsorption assumed water-wetness porous medium hence parameterized consistent pressure relative permeabilities previous history matching brine-dependent disc experiments. behavior mixed-wet state examined compared that literature strongly water-wet behavior. Both secondary tertiary then considered in simulations. Important parameters such mobility ratio (as via viscosity), back pressure, concentration, adsorption time exposure investigated. Under conditions, favorable unfavorable ratios do not limit be case for wetted media ratio. due preserving obtained saturations. A third total was counter-current, which high media. It shown half could produced counter-currently an upper limit. High preserved twophase region near inlet found ensure minimum fraction production. Twice much incremental co-currently, explained increased permeability affected region. Sensitivity analysis revealed opposite shift would reduce despite raised local forces. Capillary resists without limiting imbibing. As result, had significant impact simulations fixed changing wettability. trends discovered this study, alternating systems, hoped inspire future measurements.