# US 4,391,719 A · Ethoxylated sulfosuccinate additives for stabilizing solutions of petroleum sulfonates in hard brine

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- Number: US 4,391,719 A
- Document ID: US4391719A
- Status: Granted
- Kind: A
- Application number: 06/212,185
- Filed: 1980-12-02
- Granted: 1983-07-05
- Earliest claimed: 1978-11-28
- Assignees: Phillips Petroleum Company
- Inventors: John J. Meister
- Web page: https://patentgrep.com/patent/US4391719A

## CPC

- G01N 29/27: by moving the material relative to a stationary sensor
- C09K 8/584: characterised by the use of specific surfactants
- Y10S 507/938: with microemulsion
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## 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.++.

## Claims

### Claim 1

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.

### Claim 2 (depends on 1)

A system according to claim 1 wherein the ethoxylated alcohol contains an even number of carbon atoms in the range of C.sub.6 -C.sub.20.

### Claim 3 (depends on 1)

A system according to claim 1 wherein the ethoxylated alcohol is at least one selected from the following:
C.sub.4 H.sub.9 O(CH.sub.2 CH.sub.2 O).sub.12 H
C.sub.6 H.sub.13 O(CH.sub.2 CH.sub.2 O).sub.8 H
C.sub.8 H.sub.17 O(CH.sub.2 CH.sub.2 O).sub.5 H
C.sub.9 H.sub.19 O(CH.sub.2 CH.sub.2 O).sub.4 H
C.sub.10 H.sub.21 O(CH.sub.2 CH.sub.2 O).sub.10 H
C.sub.12 H.sub.25 O(CH.sub.2 CH.sub.2 O).sub.10 H
C.sub.16 H.sub.33 O(CH.sub.2 CH.sub.2 O).sub.6 H
C.sub.18 H.sub.37 O(CH.sub.2 CH.sub.2 O).sub.10 H.

### Claim 4 (depends on 1)

A method of recovering oil from a subterranean formation which comprises injecting a system of claim 1 into the subterranean formation to form a microemulsion suitable to improve tertiary oil recovery and recovering oil from said subterranean formation.

### Claim 5 (depends on 2)

A method of recovering oil from a subterranean formation which comprises injecting a system of claim 2 into the subterranean formation to form a microemulsion suitable to improve tertiary oil recovery and recovering oil from said subterranean formation.

### Claim 6 (depends on 3)

A method of recovering oil from a subterranean formation which comprises injecting a system of claim 3 into the subterranean formation to form a microemulsion suitable to improve tertiary oil recovery and recovering oil from said subterranean formation.