Controlled release of surfactants for enhanced oil recovery
A sparingly soluble sulfonate-metal salt particle includes the metal ion salt of an alkyl aryl sulfonate, the metal ion salt of a petroleum sulfonate and a hydrophobically modified hydrophilic polymer, and has an average particle size diameter in a range of from about 50 nm to about 450 nm and is sparingly soluble in water at room temperature. A method of producing a sparingly soluble sulfonate-metal salt particle includes the steps of introducing an aqueous solution containing a metal ion salt into a reactor, introducing an aqueous solution containing a sulfonate surfactant and a polymer into the reactor, and operating the reactor such that the sparingly soluble sulfonate-metal salt particle forms from the interaction of the metal ion from the salt, the sulfonate surfactant and the polymer.
1. A method of producing a sparingly soluble sulfonate-metal salt particle comprising the steps of:
introducing an aqueous solution containing a metal ion salt into a reactor;
introducing a non-aqueous solution containing a sulfonate surfactant and a polymer into the reactor, where the non-aqueous solution is introduced to the reactor with vigorous stirring of the aqueous solution; and
operating the reactor such that the sparingly soluble sulfonate-metal salt particle forms from the interaction of the metal ion from the salt, the sulfonate surfactant and the polymer in an aqueous solution;
where the sparingly soluble sulfonate-metal salt particle has an average particle size diameter in a range of from about 50 nm to about 450 nm, and
where the sparingly soluble sulfonate-metal salt particle is sparingly soluble in water at room temperature.
2. The method of claim 1 where the metal ion of the metal ion salt is selected from the group consisting of cobalt, zinc, aluminum, copper, and combinations thereof.
3. The method of claim 1 where the metal ion salt concentration is in a range of from about 0.1 to about 20 wt. % of the aqueous solution containing the metal ion salt.
4. The method of claim 1 where the reactor has a fixed volume and where the solution containing the metal ion salt is introduced such that the metal ion salt containing solution has a residence time in a range of from about 0.33 minutes to about 3 minutes in the reactor.
5. The method of claim 1 where the sulfonate surfactant is selected from the group consisting of an alkyl sulfonate, an alkyl aryl sulfonate, and combinations thereof.
6. The method of claim 5 where the alkyl aryl sulfonate comprises dodecyl benzene sulfonate.
7. The method of claim 1 where the sulfonate surfactant comprises a mixture of a petroleum sulfonate and dodecyl benzene sulfonate.
8. The method of claim 1 where the sulfonate surfactant concentration is in a range of from about 0.1 to about 20 wt. % of the aqueous solution containing the sulfonate surfactant and the polymer.
9. The method of claim 1 where the polymer is selected from the group consisting of polyacrylamide, polyvinyl acetate, polyvinyl alcohol, xanthan gum, gelatins, a hydrophobically modified hydrophilic polymer, and combinations thereof.
10. The method of claim 1 where the polymer concentration is in a range of from about 0.1 to about 20 wt. % of the aqueous solution containing the sulfonate surfactant and the polymer.
11. The method of claim 1 where the reactor has a fixed volume and where the solution containing the sulfonate surfactant and the polymer is introduced such that the sulfonate surfactant and the polymer solution has have a residence time in a range of from about 0.17 minutes to about 1.5 minutes in the reactor.
12. The method of claim 1 where the sparingly soluble sulfonate-metal salt particle comprises a metal ion salt of dodecyl benzene sulfonate, a metal ion salt of a sulfonated petroleum and a hydrophobically modified hydrophilic polymer.
13. The method of claim 1 where the sulfonated surfactant salt particle has an average particle size diameter in a range of from about 50 nm to about 200 nm.