Download or read book Gas Injection and Mobility Control in Fractured, Oil-wet Carbonate Reservoirs written by Jimin Daniel Zhou and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Waterflooding in low permeability, fractured and oil-wet carbonate reservoirs yields extremely low oil recovery due to bypassing through fractures and little imbibition into the matrix resulting in a large amount of oil remaining in the reservoir. Gravity-aided gas injection is studied at the lab-scale in this work to enhance oil recovery from fractured reservoirs. The miscibility of the gas with a model oil (decane with naphthenic acid) is varied by enriching the methane with ethane. Mobility of the gas is decreased by incorporating the gas in foam or glycerol-alternating-gas floods. As the miscibility increases, the oil recovery increases, but reaches a plateau above the near-miscible conditions. The foam flood improves oil recovery by diverting gas into the matrix, if the gas is sufficiently soluble in the oil and the gas-oil capillary pressure is sufficiently low. The pressure gradient generated in the fracture by foam helps in the diversion of the gas into the matrix. Glycerol-alternating-gas floods result in minor additional oil recovery over foam floods because the pressure gradients are about the same as those observed in foam floods. Secondary foam flooding achieves similar ultimate oil recovery values as tertiary foam flooding, but at faster rates. Simulations of gas floods show the presence of three different gas fronts during the experiments. Miscible and near-miscible foam floods increased the oil recovery to high values (about 85% OOIP) in core floods and their scale-up to field-scale warrants further study