Simulation of Oil Production in a Fractured Carbonate Reservoir

Abstract

CO2-EOR is an attractive method because of its potential to increase the oil production from matured oilfields, at the same time reduce the carbon footprint from the industrial sources. The field response to the CO2-EOR technique depends on the petrophysical properties of the reservoir. Carbonate reservoirs are characterized by low permeability and strong heterogeneity, causing significant amounts of water and CO2 to be recycled when CO2 is re-injected into the reservoir. Naturally fractured carbonate reservoirs have low oil production, high water production, early water breakthrough and high water cut. This study focuses on the oil production and the CO2 recycle ratio in naturally fractured carbonate reservoirs, including near-well simulations using the reservoir software Rocx in combination with OLGA. The simulations indicate that closing the fractured zone causes delayed water breakthrough and dramatically reduced water cut, resulting in improved oil recovery as well as lower production and separation costs.