Liquid-liquid phase behavior in CO/sub 2/-hydrocarbon systems

Conference · Sun Feb 01 00:00:00 EST 1981 · Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States)

OSTI ID:6525078

Orr, Jr, F M; Lien, C L; Pelletier, M T

This paper reports results of phase behavior experiments with two CO/sub 2/-hydrocarbon systems: CO/sub 2/ plus methane (C/sub 1/) and hexadecane (C/sub 16/), and CO/sub 2/ mixed with a synthetic oil containing pentane (C/sub 5/), decane (C/sub 10/), hexadecane (C/sub 16/) and squalane (C/sub 30/). Results of those experiments are compared with the phase behavior of CO/sub 2/-crude oil systems and with qualitative predictions of the Peng-Robinson equation of state. Results of phase behavior measurements for CO/sub 2/ and two well characterized hydrocarbon systems indicate that: (1) high pressure samples can be obtained reliably by flushing samples trapped at system temperature and pressure from a liquid sampling valve into a pressure tight syringe; (2) at temperatures below about 50/sup 0/C, L/sub 1/-L/sub 2/-V phase behavior occurs for CO/sub 2/-hydrocarbon mixtures at pressures near the vapor pressure of CO/sub 2/; (3) the second liquid phase is predominantly CO/sub 2/ with some hydrocarbons dissolved in it. The L/sub 2/ phase extracts hydrocarbons from the oil more efficiently than the vapor phase; (4) at temperatures below 50/sup 0/C, the range of pressures within which L/sub 1/-L/sub 2/-V occurs is bounded above by the vapor pressure of CO/sub 2/ if methane is not present. If it is, the pressure required to eliminate the vapor phase is somewhat higher than the vapor pressure of CO/sub 2/ (extrapolated if necessary). A reasonable estimate of the pressure required to produce L/sub 1/-L/sub 2/ behavior in CO/sub 2/-crude oil systems is the vapor pressure plus 1750 kPa; and (5) conclusions about CO/sub 2/-crude oil displacement mechanisms should be drawn with caution from CO/sub 2/-synthetic oil displacement studies.

• Research Organization: New Mexico Inst. of Mining and Tech., Socorro
• OSTI ID: 6525078
• Report Number(s): CONF-810308-(Vol.1)
• Journal Information: Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States), Vol. 26:1; Conference: American Chemical Society symposium on the chemistry of engine combustion deposits, Atlanta, GA, USA, 29 Mar 1981
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
CARBON DIOXIDE
PHASE STUDIES
HEXADECANE
PETROLEUM
METHANE
DECANE
PENTANE
SQUALANE
SYNTHETIC PETROLEUM
CARBON DIOXIDE INJECTION
ENHANCED RECOVERY
PRESSURE DEPENDENCE
TEMPERATURE EFFECTS
ALKANES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
ENERGY SOURCES
FLUID INJECTION
FOSSIL FUELS
FUELS
HYDROCARBONS
MISCIBLE-PHASE DISPLACEMENT
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RECOVERY
SYNTHETIC FUELS
020300* - Petroleum- Drilling & Production
023000 - Petroleum- Properties & Composition