Abstract
Fractured reservoirs (e.g. Asmari reservoirs in Iran) provide over 20 % of the world oil reserves in our nation. Iran is one of the wold’s leading energy producing countries. Almost 90% of Iranian reservoirs are carbonate and oil production is due to natural fractures. The declining oil production from Iranian fractured reservoirs after several decades of exploitation and the significant amount of oil still remaining in place are of great concern to the Iranian oil company and fully justify its interest in EOR processes. One of the important mechanisms in EOR from fractured reservoirs is miscible fluid injection. Unfortunately, our knowledge about miscible fluid displacement in fractured porous media is limited and there is very little work in the literature on this method. Modeling of miscible displacement in fractured porous media is the subject of this study. In this modeling, mass transfer between matrix and fracture due to diffusion, and crossflow from matrix to fracture and from fracture to matrix are considered. From theoretical aspects, it is concluded that miscible injection in fractured reservoirs can be very efficient. Thus, it is proposed for increasing oil recovery from fractured reservoirs, miscible fluid injection be done in some suitable reservoirs.
