Laboratory study of immiscrible CO2 drive in the Great Palogue Oilfield in Republic of Sudan

Samma formation in Great Palogue Oilfield,Block 3/7 of Republic of the Sudan was high porosity and high permeability heavy oil reservoir.The CO2 immiscible drive mechanism,injection mode and injection volume were studied by using the high-temperature high-pressure experimental system,and the recovery efficiency,injection pressure,gas consumption and CO2 recycling usage were analyzed.The result shows that CO2 continuous drive can get a considerable effect with a ultimate recovery rate of 70.2%.The single CO2 slug injection can get higher oil recovery rate than continuous injection,and the best injection volume is 0.625 PV with a recovery rate of 89.4%.It is suitable to develop the reservoir by CO2 immiscible drive with single slug injection.At the same time,formation pressure should be maintained rationally.