Solubilized oil-water solutions suitable for miscible flooding. [99. 9% recovery]
A solubilized slug contained brine which caused oil to be dissolved into the slug but rejected water, resulting in a built-in mobility control through viscosity changes in the slug. Viscosity increased from the leading edge to the trailing edge of the slug after injection into an oil reservoir. The solubilized slug contained Sonneborn Petronate HL (molecular weight 440-470, sodium petroleum mahogany sulfonate), diethylene glycol-mono-n-hexyl ether (cosurfactant), mineral oil, midland Farms Ellenburger crude oil, water, and 0.25 N sodium chloride brine. The ratio of sulfonate to cosurfactant should be in the range of 1:9 to 7:3. The brine should be substantially free of divalent metal ions and contain between 3,000 ppM and 60,000 ppM (IN) sodium chloride. Lower brine concentrations permit higher water content solubilized oil-water solutions. Berea sandstone cores were saturated with the brine, flooded with Midland crude, then injected with the solubilized slug followed by an aqueous polymer (partially hydrolyzed polyacrylamide) flood and driven by the brine. A yield of 99.9 percent of the Midland crude trapped in the core was recovered.
- Assignee:
- Amoco Production Co.
- Patent Number(s):
- US 3698479
- OSTI ID:
- 7093218
- Country of Publication:
- United States
- Language:
- English
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