Surfactant oil recovery method for use in high temperature formations containing water having high salinity and hardness

Patent · Tue Apr 12 04:00:00 EST 1977

OSTI ID:6799520

Kalfoglou, G

Surfactant systems employing 2 or more surfactants, one anionic and one or more nonionic surfactants such as polyethoxylated alkylaryl compounds or polyethoxylated alkyl or alkylaryl thiol, are useful in recovering oil from formations which also contain water having high salinities, e.g., salinities greater than about 40,000 ppm, and which also may contain high concentrations of divalent ions such as calcium and/or magnesium, e.g., greater than about 3,000 ppm calcium and magnesium. Polyethoxylated alcohols, alkyl phenols or polyethoxylated alkyl or alkylaryl thiols have well defined cloud points, and as a consequence thereof, if the formation temperature is much above the cloud point of the polyethoxylated compound, the surfactant fluid exhibits phase instability which degrades the oil recovery efficiency. Superior results are obtained if the ethoxylated surfactant is chosen to have a cloud point slightly above the formation temperature, and the concentration of divalent ions in the surfactant systems containing 2 or more surfactants, is maintained at high enough levels to prevent phase instability problems. (19 claims)

• Assignee: Texaco Inc.
• Patent Number(s): US 4016932
• OSTI ID: 6799520
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
36 MATERIALS SCIENCE
360404 -- Materials-- Polymers & Plastics-- Physical Properties-- (-1987)
ALKALINE EARTH METALS
CALCIUM
CATIONS
CHARGED PARTICLES
ELEMENTS
ENGINEERING
ENHANCED RECOVERY
FLUID INJECTION
GROUND WATER
HYDROGEN COMPOUNDS
INTERSTITIAL WATER
IONS
MAGNESIUM
METALS
OIL WELLS
OXYGEN COMPOUNDS
PHASE STABILITY
POLYMERS
RECOVERY
RESERVOIR ENGINEERING
RESERVOIR ROCK
RESERVOIR TEMPERATURE
SALINITY
STABILITY
SURFACTANTS
WATER
WATERFLOODING
WELLS