CA2610654A1

CA2610654A1 - Viscoelastic surfactant fluid systems comprising an aromatic sulfonate and methods of using same

Info

Publication number: CA2610654A1
Application number: CA002610654A
Authority: CA
Inventors: Yiyan Chen; Jesse C. Lee; Eric Hanson
Original assignee: Schlumberger Canada Ltd
Current assignee: Schlumberger Canada Ltd
Priority date: 2006-12-07
Filing date: 2007-11-16
Publication date: 2008-06-07
Anticipated expiration: 2027-11-16
Also published as: CA2610654C; US7507693B2; US20090149352A1; US7749944B2; US20080139410A1

Abstract

Methods of improving shear recovery time of viscoelastic surfactant fluid systems are described, one method involving providing a viscoelastic surfactant fluid system comprising a major portion of a surfactant and a rheology enhancer in a concentration sufficient to shorten shear recovery time of the fluid system compared to shear recovery time of the fluid system absent the rheology enhancer, the rheology enhancer selected from aromatic sulfonates having a molecular weight of at least 500; and injecting the fluid system down a well. The rheology enhancer may be a lignosulfonate derived from wood pulping. Viscoelastic surfactant systems including the rheology enhancer are also described.

Claims

1. A method comprising:

(a) providing a viscoelastic surfactant fluid system comprising a major portion of a surfactant selected from cationic, anionic, zwitterionic, and amphoteric surfactants, and mixtures thereof, and a rheology enhancer in a concentration sufficient to shorten shear recovery time of the fluid system compared to shear recovery time of the fluid system absent the rheology enhancer, the rheology enhancer selected from aromatic sulfonates having a molecular weight of at least 500; and (b) injecting the fluid system down a well, wherein the rheology enhancer is present in the fluid at a concentration ranging from 0.0005% to 0.2%.

2. The method of claim 1 wherein the rheology enhancer is present in the fluid at a concentration ranging from 0.001% to 0.05%.

3. The method of claim 1 wherein the aromatic sulfonate comprises one or more lignosulfonates derived from wood pulping.

4. The method of claim 1 wherein the aromatic sulfonate is selected from molecules in which a sulfur atom is bonded directly with a carbon atom in an aromatic ring, molecules in which a sulfur atom is bonded to a carbon atom that itself is not a member of an aromatic ring, and molecules having both of these structures.

5. The method of claim 1 wherein the rheology enhancer has a molecular weight ranging from 500 to 100,000.

6. The method of claim 1 wherein the rheology enhancer further comprises a second rheology enhancer selected from partially hydrolyzed polyvinyl ester and partially hydrolyzed polyacrylate.

7. The method of claim 1 wherein the cationic surfactant is selected from cationic surfactants or mixture of surfactants having the structure:

R1N+ (R2)(R3)(R4) X

in which R1 comprises from 14 to 26 carbon atoms and may be branched or straight chained, aromatic, saturated or unsaturated, and may comprise a carbonyl, an amide, a retroamide, an imide, a urea, or an amine; R2, R3, and R4 are each independently hydrogen or a C1 to C6 aliphatic group which may be the same or different, branched or straight chained, saturated or unsaturated and one or more than one of which is optionally substituted with a group that renders the R2, R3, and R4 group more hydrophilic; the R2, R3 and R4 groups are optionally incorporated into a heterocyclic 5- or 6-member ring structure which includes the nitrogen atom; the R2, R3 and R4 groups may be the same or different; R1, R2, R3 and/or R4 may contain one or more ethylene oxide and/or propylene oxide units; and X- is an anion; and mixtures of these compounds.

8. The method of claim 7 wherein R1 comprises from 18 to 22 carbon atoms and optionally comprises a moiety selected from a carbonyl, an amide, or an amine;
R2, R3, and R4 each comprise from 1 to 3 carbon atoms, and X is a halide.

9. The method of claim 1 wherein the fluid system comprises a zwitterionic surfactant or amphoteric surfactant.

10. The method of claim 9 wherein the zwitterionic surfactant comprises a surfactant or mixture of surfactants having the formula:

RCONH-(CH2)a(CH2CH2O)m(CH2)b-N+(CH3)2-(CH2)a' (CH2CH2O)m'(CH2)b'COO

in which R is an alkyl group comprising from 17 to 23 carbon atoms which may be branched or straight chained and which may be saturated or unsaturated; a, b, a', and b' are independently selected from integers ranging from 0 to 10, m and m' are independently selected from integers ranging from 0 to 13, a and b are each 1 or 2 if m is not 0 and (a + b) is from 2 to 10 if m is 0; a' and b' are each 1 or 2 when m' is not 0 and (a' + b') is from 1 to if m' is 0; (m + m') ranges from 0 to 14; and CH2CH2O may also be OCH2CH2.

11. The method of claim 9 wherein the zwitterionic surfactant has the betaine structure:

wherein R is a hydrocarbyl group that may be branched or straight chained, aromatic, aliphatic or olefinic and has from 14 to 26 carbon atoms and may contain an amine; n ranges from 2 to 4; and p ranges from 1 to 5, and mixtures of these compounds.

12. The method of claim 11 wherein the betaine is oleylamidopropyl betaine or erucylamidopropyl betaine.

13. The method of claim 9 wherein the fluid comprises a co-surfactant.

14. The method of claim 1 wherein the fluid further comprises between 0.01 and percent of a member selected from the group consisting of amines, alcohols, glycols, organic salts, chelating agents, solvents, mutual solvents, organic acids, organic acid salts, inorganic salts, oligomers, polymers, co-polymers, and mixtures of said members.

15. The method of claim 1 wherein the fluid further comprises an acid selected from the group consisting of hydrochloric acid, hydrofluoric acid, formic acid, acetic acid, lactic acid, glycolic acid, sulfamic acid, malic acid, citric acid, tartaric acid, maleic acid, methylsulfamic acid, chloroacetic acid, and mixtures thereof.