Effects of Reservoir Temperature and Percent Levels of Methane and Ethane on CO2/Oil MMP Values as Determined Using Vanishing Interfacial Tension/Capillary Rise
Geological CO2 storage combined with enhanced oil recovery (EOR) can be a viable approach to storing CO2 while increasing oil recoveries. CO2 mobilizes oil at pressures above the minimum miscibility pressure (MMP) by forming a separate "miscible" CO2/hydrocarbon mixed phase. MMP is a major input variable for models used to optimize EOR efficiencies, but established methods to determine MMP (e.g., the "slim tube") can be costly, slow, and subject to operational variations. In contrast, newer methods rely on a more fundamental definition of miscibility, i.e., the conditions at which there is no interfacial tension (IFT) between the two fluids. EERC's method determines MMP by observing the height of oil in a capillary at increasing pressures, and extrapolating the height vs. pressure plot to zero height (i.e., zero IFT). This innovation greatly decreases the time and cost for determining MMP, thus allowing the effects of various reservoir conditions on MMP to be investigated such as temperature, changing gas composition (e.g., the effect of methane in recycle CO2), and changes in crude oil composition. For example, methane mixed with CO2 increases MMP (which has implications for COView/Download Document
Event/Meeting Information
Carbon Storage R&D Project Review Meeting
8/21/2012
Pittsburgh, PA