Adjusting salinity to achieve low interfacial tension between aqueous and hydrocarbon phases
To improve oil recovery, the interfacial tension between the waterflood and the reservoir oil can be lowered by the use of a surfactant and a monovalent salt. Surfactants used in this flood are the sodium salts of petroleum sulfonates having a medium molecular weight of about 400 to 430, having molecular weights between 290 and 590, no more than 10 percent by weight having an average molecular weight less than 290, and no more than 15 percent having an average molecular weight greater than 590. The monovalent salt may be sodium chloride. To prevent contamination of the surfactant slug by connate water or the waterflood, slugs of water containing the same concentration of salt as in the surfactant slug can immediately precede and follow the surfactant slug. A test to determine the optimal salt concentration in the surfactant slug was made by measuring, at reservoir temperatures, the interfacial tension between the surfactant slug and crude oil. The crude was obtained from the Upper Upper Loma Novia sand, Loma Novia field, Duval County, Texas. The surfactant slug contained Alconate 80, Pyronate 50, oil field brine, oil field fresh water, and finally sodium carbonate and sodium tripolyphosphate, which reduce adsorption of the surfactants onto reservoir surfaces. The optimum salt concentration was about 0.6 percent by weight.
- Assignee:
- Mobil Oil Corp.
- Patent Number(s):
- US 3467190
- OSTI ID:
- 7301172
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020300* -- Petroleum-- Drilling & Production
ENERGY SOURCES
ENHANCED RECOVERY
ESTERS
FLUID INJECTION
FOSSIL FUELS
FUELS
OIL WELLS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PETROLEUM
PETROLEUM SULFONATES
SULFONATES
SULFONIC ACID ESTERS
SURFACE PROPERTIES
SURFACE TENSION
SURFACTANTS
WATERFLOODING
WELLS