Ethoxylated sulfosuccinate additives for stabilizing solutions of petroleum sulfonates in hard brine
AssigneePhillips Petroleum Company
InventorJohn J. Meister
Life of this patent
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Abstract
Ethoxylated sulfosuccinate derivatives, e.g., diesters and half-esters of alpha-sulfosuccinic acid and ethoxylated alcohols are added as phase stabilizing agents to aqueous saline solutions of petroleum sulfonates to substantially prevent or to eliminate phase separation and/or precipitation of surfactant and/or cosurfactant in such solutions on contacting them with hard brines containing high concentrations of divalent ions such as CA.sup.++ and Mg.sup.++.
Claims6
An aqueous saline surfactant system suitable for use in tertiary oil recovery operations consisting essentially of brine, a petroleum sulfonate present in an amount in a range of about 0.01 to about 15 weight percent, an ethoxylated sulfosuccinate present in an amount in a range of about 0.01 to about 15 weight percent and a cosurfactant chosen from among the group consisting of C.sub.3 to C.sub.6 aliphatic alcohols and present in an amount in a range of about 1 to about 7 weight percent with each weight percent based on the weight of water in the surfactant system and wherein the ethoxylated sulfosuccinate derivative is a diester of alpha-sulfosuccinic acid and an ethoxylated alcohol, the diester having the formula ##STR3## wherein R.sub.1 and R.sub.2 represent alkyl radicals, which can be different, containing 3-18 carbon atoms and M is selected from the group consisting of sodium, lithium, potassium, ammonium and substituted ammonium;
- and the ethoxylated alcohol has the formula
- R(OCH.sub.2 CH.sub.2).sub.x OH
- wherein R corresponds to R.sub.1 or R.sub.2, x encompasses all the values of m and n, and m+n is in the general range of from 4 to 100, m or n being at least 1.
Dependencies are inferred from the claim text.