A Rapid Method for Determining CO2/Oil MMP and Visual Observations of CO2/Oil Interactions at Reservoir Conditions
The behavior of injected CO2;and its interactions with reservoir fluids has received considerable attention in recent years. Studies include solubility and phase trapping in saline reservoirs, but have not generally considered interactions with oils that are also in the pore space. The presence of an immobile (residual) oil phase in many saline reservoirs has become more widely recognized, and studies will need to include three-phased interactions. CO2;is widely understood to mobilize otherwise immobile oil. The processes involve several mechanisms including hydrocarbon solvation into the CO2;phase, physical displacement, oil swelling, lowered oil viscosity, and the formation of a separate "miscible"CO2/hydrocarbon mixed phase as the CO2;contacts lighter hydrocarbons. This mixed phase is common as reservoir pressures approach 1000 psi and has been simply characterized as a minimum miscibility pressure (MMP) needed for thorough mixing. MMP is a major input variable for models used to optimize enhanced oil recovery (EOR). Long-established methods to determine MMP of crude oil (e.g., slim tube, rising bubble) can be costly, slow, and subject to operational variations. In contrast, newer vanishing interfacial tension (VIT) methods rely on a more fundamental definition of miscibility, i.e., the conditions at which there is no interfacial tension (IFT) between theView/Download Document
Event/Meeting Information
12th International Conference on Greenhouse Gas Control Technologies
10/5/2014
Austin, TX