Amidoamine salt-based viscosifying agents and methods of use
View Patent ↗Viscoelastic surfactants are described for use in aqueous systems to generate thickened fluids. The surfactants are alkyl amidoamine salts of inorganic acids and/or organic acids. The fluids may also contain inorganic salts, organic salts or mixtures thereof. Additionally, the fluids may contain a co-surfactant. These fluids are particularly useful in oilfield applications such as hydraulic fracturing, gravel packing, drilling, completion, etc. Viscoelastic fluids of the invention are also useful in industrial and consumer product fluid applications as rheology control agents.
1. A viscoelastic fluid comprising:
an aqueous medium; and
an amidoamine salt surfactant having the following general structural formula:
wherein,
R 1 is a branched or straight chained, saturated or unsaturated aliphatic group of from about 17 to about 29 carbon atoms;
R 2 is (a) a divalent alkylene group consisting of from about 2 to about 6 carbon atoms, or (b) R 2 together with R 3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide;
R 3 is (a) a branched or straight chained alkyl group of from about 1 to about 6 carbon atoms or a branched or straight chained hydroxyalkyl group, or (b) R 3 together with R 2 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide, or (c) R 3 together with R 4 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
R 4 is (a) a branched or straight chained alkyl group or hydroxyalkyl group of from about 1 to about 6 carbon atoms, or (b) R 4 together with R 3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
X− is an anion; and
the amidoamine salt surfactant is present in a sufficient amount such that the fluid at least partially recovers to an initial state after abatement of an applied stress and has properties of reversible sheer thinning.
2. The viscoelastic fluid of claim 1 wherein R 1 comprises an alkyl group derived from tallow, soybean, rapeseed oil or mixtures thereof.
3. The viscoelastic fluid of claim 1 wherein R 1 comprises about 17 to about 23 carbon atoms.
4. The viscoelastic fluid of claim 1 wherein R 2 is an alkylene group having about 3 carbon atoms.
5. The viscoelastic fluid of claim 1 wherein R 3 and R 4 are each selected from the group consisting of alkyl, alkenyl and hydroxyalkyl groups.
6. The viscoelastic fluid of claim 1 wherein the viscoelastic fluid comprises:
about 0.1% to about 10% by weight of amidoamine salt surfactant; and
the aqueous medium.
7. The viscoelastic fluid of claim 6 wherein the amidoamine salt surfactant comprises about 1% to about 8% by weight of the viscoelastic fluid.
8. The viscoelastic fluid of claim 7 wherein the amidoamine salt surfactant comprises about 2% to about 4% by weight of the viscoelastic fluid.
9. The viscoelastic fluid of claim 1 wherein
X− is an anion dissociated from an acid component selected from the group consisting of inorganic and organic acids.
10. The viscoelastic fluid of claim 9 wherein the acid component is selected from the group consisting of phosphoric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochloric acid, acetic acid, other aliphatic carboxylic acids, perchloric acid, formic acid, salicylic acid, phthalic acid, isophthalic acid, terphthalic acid, lactic acid, malic acid, citric acid, benzoic acid, napthoic acid and mixtures thereof.
11. The viscoelastic fluid of claim 10 wherein the acid component comprises about 0.01% to about 50% by weight of the viscoelastic fluid.
12. The viscoelastic fluid of claim 11 wherein the acid component comprises about 0.01% to about 20% by weight of the viscoelastic fluid.
13. The viscoelastic fluid of claim 1 further including a salt component selected from the group consisting of organic salts, inorganic salts and mixtures thereof.
14. The viscoelastic fluid of claim 13 wherein the salt component comprises an inorganic salt selected from the group consisting of sodium chloride, potassium chloride, ammonium chloride, calcium chloride and mixtures thereof.
15. The viscoelastic fluid of claim 13 wherein the salt component comprises about 0.1 to about 5% by weight of the viscoelastic fluid.
16. The viscoelastic fluid of claim 15 wherein the salt component comprises about 0.1 to about 3% by weight of the viscoelastic fluid.
17. The viscoelastic fluid of claim 16 wherein the salt component comprises about 0.1 to about 2% by weight of the viscoelastic fluid.
18. The viscoelastic fluid of claim 1 further including a co-surfactant selected from the group consisting of cationic, anionic, zwitterionic and amphoteric surfactants and mixtures thereof.
19. The viscoelastic fluid of claim 18 wherein the co-surfactant comprises about 0.01 to about 3% of the viscoelastic fluid.
20. A viscoelastic fluid comprising:
about 0.1% to about 10% by weight of an amidoamine salt surfactant having the following general structural formula:
wherein,
R 1 is a branched or straight chained, saturated or unsaturated aliphatic group of from about 17 to about 29 carbon atoms;
R 2 is (a) a divalent alkylene group consisting of from about 2 to about 6 carbon atoms, or (b) R 2 together with R 3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide;
R 3 is (a) a branched or straight chained alkyl group of from about 1 to about 6 carbon atoms or a branched or straight chained hydroxyalkyl group, or (b) R 3 together with R 2 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide, or (c) R 3 together with R 4 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
R 4 is (a) a branched or straight chained alkyl group or hydroxyalkyl group of from about 1 to about 6 carbon atoms, or (b) R 4 together with R 3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine; and
X− is an anion; and
the balance comprises an aqueous medium;
wherein, the fluid at least partially recovers to an initial state after abatement of an applied stress and has properties of reversible sheer thinning.
21. The viscoelastic fluid of claim 20 wherein R 1 comprises an alkyl group derived from tallow, soybean, rapeseed oil or mixtures thereof.
22. The viscoelastic fluid of claim 20 wherein R 1 comprises about 17 to about 23 carbon atoms.
23. The viscoelastic fluid of claim 20 wherein R 1 comprises erucylalkyl.
24. The viscoelastic fluid of claim 20 wherein R 2 is an alkylene group having about 3 carbon atoms.
25. The viscoelastic fluid of claim 20 wherein R 3 and R 4 are each methyl groups.
26. The viscoelastic fluid of claim 20 wherein R 2 together with R 3 comprise a heterocyclic 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide and R 4 comprises a methyl group.
27. The viscoelastic fluid of claim 20 wherein X− is selected from the group consisting of oxo ions of phosphorus, sulfur or chloride, chlorides, bromides, iodides, oxides of phosphorus, hypochlorides, phosphates, oxides of sulfur, sulfates, sulfites, sulfonates, phosphates, acetates, other aliphatic carboxylates, chlorates, formates, perchlorates, salicylates, phthalates, isophthalates, terphthalates, lactates, maleates, glycinates, citrates, benzoates and napthoates.
28. The viscoelastic fluid of claim 20 further including a salt component selected from the group consisting of sodium chloride, potassium chloride, ammonium chloride, calcium chloride and mixtures thereof.
29. The viscoelastic fluid of claim 20 further including a co-surfactant selected from the group consisting of cationic, anionic, zwitterionic and amphoteric surfactants and mixtures thereof.
30. The viscoelastic fluid of claim 29 wherein the co-surfactant comprises about 0.01 to about 3% by weight of the viscoelastic fluid.
31. A method of fracturing a subterranean formation comprising the steps of:
providing a surfactant-based aqueous viscoelastic hydraulic fracturing fluid comprising:
an aqueous medium; and
an amidoamine salt surfactant having the following general structural formula:
wherein,
R 1 is a branched or straight chained, saturated or unsaturated aliphatic group of from about 17 to about 29 carbon atoms;
R 2 is (a) a divalent alkylene group consisting of from about 2 to about 6 carbon atoms, or (b) R 2 together with R 3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide;
R 3 is (a) a branched or straight chained alkyl group of from about 1 to about 6 carbon atoms or a branched or straight chained hydroxyalkyl group, or (b) R 3 together with R 2 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide, or (c) R 3 together with R 4 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
R 4 is (a) a branched or straight chained alkyl group or hydroxyalkyl group of from about 1 to about 6 carbon atoms, or (b) R 4 together with R 3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
X− is an anion; and
the amidoamine salt surfactant is present in a sufficient amount such that the fluid at least partially recovers to an initial state after abatement of an applied stress and has properties of reversible sheer thinning; and
pumping the surfactant-based aqueous viscoelastic hydraulic fracturing fluid through a wellbore and into a subterranean formation at sufficient pressures to fracture the formation.
32. The fracturing method of claim 31 wherein R 1 comprises an alkyl group derived from tallow, soybean, rapeseed oil or mixtures thereof.
33. The fracturing method of claim 31 wherein R 1 comprises about 17 to about 23 carbon atoms.
34. The fracturing method of claim 31 wherein R 2 is an alkylene group having about 3 carbon atoms.
35. The fracturing method of claim 31 wherein R 3 and R 4 are each selected from the group consisting of alkyl, alkenyl, hydroxyalkyl groups.
36. The fracturing method of claim 31 wherein the viscoelastic hydraulic fracturing fluid comprises:
about 0.1% to about 10% by weight of the amidoamine salt surfactant; and
the balance, aqueous medium.
37. The fracturing method of claim 31 wherein
X− is an anion dissociated from an acid component selected from the group consisting of inorganic and organic acids.
38. The fracturing method of claim 37 wherein the acid component is selected from the group consisting of phosphoric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochloric acid, acetic acid, other aliphatic carboxylic acids, perchloric acid, formic acid, salicylic acid, phthalic acid, isophthalic acid, terphthalic acid, lactic acid, malic acid, citric acid, benzoic acid, napthoic acid and mixtures thereof.
39. The fracturing method claim 38 wherein the acid component comprises about 0.01% to about 50% by weight of the viscoelastic hydraulic fracturing fluid.
40. The fracturing method of claim 39 wherein the acid component comprises about 0.01% to about 20% by weight of the viscoelastic hydraulic fracturing fluid.
41. The fracturing method of claim 31 further including a salt component selected from the group consisting of organic salts, inorganic salts and mixtures thereof.
42. The fracturing method of claim 41 wherein the salt component comprises an inorganic salt selected from the group consisting of sodium chloride, potassium chloride, ammonium chloride, calcium chloride and mixtures thereof.
43. The fracturing method of claim 41 wherein the salt component comprises about 0.1 to about 5% of the viscoelastic hydraulic fracturing fluid.
44. The fracturing method of claim 31 further including a co-surfactant selected from the group consisting of cationic, anionic, zwitterionic and amphoteric surfactants and mixtures thereof.
45. The fracturing method of claim 44 wherein the co-surfactant comprises about 0.01 to about 3% of the viscoelastic hydraulic fracturing fluid.
46. The fracturing method of claim 31 wherein the viscoelastic hydraulic fracturing fluid further comprises a suspended particulate proppant.
47. The fracturing method of claim 46 wherein the fracturing fluid proppant is selected from the group consisting of sand, glass beads and polystyrene beads.
48. A method for controlling the rheology of an aqueous medium comprising the steps of:
providing an aqueous medium; and
providing an amidoamine salt surfactant in the aqueous medium to control rheology of the aqueous medium such that the aqueous medium has a viscosity in excess of about 50 centipoise, said amidoamine salt surfactant comprising about 0.1% to about 10% of the total weight of the aqueous medium and having the general structural formula:
wherein,
R 1 is a branched or straight chained, saturated or unsaturated aliphatic group of from about 17 to about 29 carbon atoms;
R 2 is (a) a divalent alkylene group consisting of from about 2 to about 6 carbon atoms, or (b) R 2 together with R 3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide;
R 3 is (a) a branched or straight chained alkyl group of from about 1 to about 6 carbon atoms or a branched or straight chained hydroxyalkyl group, or (b) R 3 together with R 2 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide, or (c) R 3 together with R 4 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
R 4 is (a) a branched or straight chained alkyl group or hydroxyalkyl group of from about 1 to about 6 carbon atoms, or (b) R 4 together with R 3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine; and
X− is an anion.
49. The method of claim 48 wherein R 1 comprises an alkyl group derived from tallow, soybean, rapeseed oil or mixtures thereof.
50. The method of claim 48 wherein R 1 comprises about 17 to about 23 carbon atoms.
51. The method of claim 48 wherein R 2 is an alkylene group having about 3 carbon atoms.
52. The method of claim 48 further comprising, at any time, the step of providing an acid component in the aqueous medium, said acid component being selected from the group consisting of inorganic and organic acids and X− is an anion dissociated from the acid component.
53. The method of claim 52 wherein the acid component is selected from the group consisting of phosphoric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochloric acid, acetic acid, other aliphatic carboxylic acids, perchloric acid, formic acid, salicylic acid, phthalic acid, isophthalic acid, terphthalic acid, lactic acid, malic acid, citric acid, benzoic acid, napthoic acid and mixtures thereof.
54. The method of claim 53 wherein the step of providing the acid component comprises providing said acid component in an amount of about 0.01% to about 50% by weight of the aqueous medium.
55. The method of claim 54 wherein the acid component comprises about 0.01% to about 20% by weight of the aqueous medium.
56. The method of claim 48 further comprising, at any time, the step of providing a salt component in the aqueous medium, said salt component being selected from the group consisting of organic salts, inorganic salts and mixtures thereof.
57. The method of claim 56 wherein the salt component comprises an inorganic salt selected from the group consisting of sodium chloride, potassium chloride, ammonium chloride, calcium chloride and mixtures thereof.
58. The method of claim 56 wherein the step of providing the salt component comprises providing said salt component in an amount of about 0.1 to about 5% by weight of the aqueous medium.
59. The method of claim 48 further comprising, at any time, the step of providing a co-surfactant in the aqueous medium, said co-surfactant being selected from the group consisting of cationic, anionic, zwitterionic and amphoteric surfactants and mixtures thereof.
60. The method of claim 59 wherein the step of providing the co-surfactant comprises providing said co-surfactant in an amount of about 0.01 to about 3% by weight of the aqueous medium.
61. The method of claim 48 wherein R 3 and R 4 are each selected from the group consisting of alkyl, alkenyl, hydroxyalkyl groups.