Browsing by Subject "Gas flood"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item A compositional reservoir simulation study to evaluate impacts of captured CO₂ composition, miscibility, and injection strategy on CO₂-EOR and sequestration in a carbonate oil reservoir(2023-08-11) Alsousy, Abdulhamid; Sepehrnoori, Kamy, 1951-; Delshad, MojdehAs the global energy demand rises, concerns regarding the increasing carbon levels deepen. Pushing the international community to pour their time and resources into exploring all avenues that bear potential to aid the decarbonization efforts. The decarbonization efforts attempt to either reduce carbon dioxide emissions or to capture carbon dioxide from the atmosphere. The oil and gas industry’s role falls into the first category. Where captured CO₂ is sequestered into geological stable formations as part of carbon capture, utilization, and storage (CCUS) or carbon capture and storage (CCS) projects. CCUS and CCS technologies hold the keys to decarbonization, possessing a large capacity capable of storing over 8000 GtCO₂, utilizing oil and gas reservoirs, saline aquifers, and coal beds to discard CO₂. In addition, the sequestration in geological structures is long-term, with minimal risk of reintroducing the stored gas back to the surface. This work investigates two scenarios, one in which the reservoir undergoes a tertiary production and another where the reservoir has reached the abandonment stage of its life cycle. The analyses are carried out by employing a historically matched numerical model of a real carbonate reservoir to explore CO₂ storage implications on the reservoir’s performance (EOR) and the efficiency of the injected gas storage in the subsurface. For a holistic evaluation, the numerical model accounts for relative permeability hysteresis, phase trapping, geochemistry, and thermodynamics. Various analyses are conducted to establish the recommended gas blend injected, the importance of miscibility, and the manner of injection (WAG or gas flood). The results showcased how miscible injection outperforms immiscible in CO₂-EOR and sequestration efficiency. Furthermore, gas flood is recommended over WAG, especially when recycling produced gases is possible to store larger volumes of carbon dioxide.Item Gas injection and mobility control in fractured, oil-wet carbonate reservoirs(2018-12) Zhou, Jimin Daniel; Mohanty, Kishore KumarWaterflooding 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.