Enhanced oil recovery methods cause more ultimate oil recovery from reservoirs. One of which is solvent injection that is known as a proper method for chemical enhanced oil recovery from reservoirs. Solvent injection affects mass transfer mechanism at system and many factors affects reservoir ultimate oil recovery in this mechanism. For examples: permeability of reservoir rock, Density difference between oil and solvent, viscosities and etc. In this study, the effect of these factors on ultimate oil recovery were investigated. Some experiments were done for investigating mass transfer rate between matrix and fracture. In soak and saturation experiment, a porous medium that consists of oil, was submerged in bottle which contains solvent and at this way matrix network and fracture simulated. In experiments, the weight of core that is submerged versus time was recorded and oil recovery from core was calculated. Experimental data were compared with simulated model built with the software and good matching was observed. Influence of different parameters related to rock and fluid properties on the amount of oil recovery were studied and it was concluded that the rate of mass transfer depends on permeability of rock and oil and solvent densities. With increasing density difference between oil and solvent, oil recovery from core increased and with increasing permeability of core, the rate of mass transfer and so oil recovery from core were enhanced and with changing the solvent type, according to oil properties, more and faster oil recovery can be achieved.
