Performed surfactant-optimized aqueous alkaline flood

Patent · Tue Nov 26 04:00:00 EST 1991

OSTI ID:5540908

Thigpen, D R; Lawson, J B; Nelson, R C

This paper describes improvement in a process for recovering oil from an acidic oil reservoir by injecting an aqueous alkaline solution comprising water, sodium chloride, and alkaline material for reacting with the reservoir oil forming a petroleum acid soap to form an in-situ surfactant system. The improvement comprises: selecting a preformed cosurfactant which is soluble in both the aqueous solution and the reservoir oil and has a solubility ratio which is grater than the solubility ratio of the petroleum acid soap where the solubility ratio is the ratio of solubility in the aqueous alkaline solution to the solubility in the reservoir oil; combining with the alkaline solution an amount of the preformed cosurfactant which will result in the in-situ surfacant system having a salinity about equal to a salinity which results in minimal interfacial tension between the oil in the reservoir and the in-situ surfactant system at reservoir temperature, wherein the amount of the preformed cosurfactant is about 0.3 percent by weight in the aqueous alkaline solution; and injecting the cosurfactant-aqueous alkaline solution mixture into the reservoir to displace oil toward a fluid production location.

• Assignee: Shell Oil Co., Houston, TX (United States)
• Patent Number(s): A; US 5068043
• Application Number: PPN: US 7-391004
• OSTI ID: 5540908
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
AQUEOUS SOLUTIONS
CAUSTIC FLOODING
DISPERSIONS
DRILLING
DRILLING FLUIDS
ENERGY SOURCES
ENHANCED RECOVERY
FLUID INJECTION
FLUIDS
FOSSIL FUELS
FUELS
MIXTURES
OIL WELLS
OPTIMIZATION
PETROLEUM
RECOVERY
RESERVOIR ROCK
SOLUTIONS
STIMULATION
SURFACTANTS
WATERFLOODING
WELL DRILLING
WELL STIMULATION
WELLS