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US 7,125,825 B2Granted
Amidoamine salt-based viscosifying agents and methods of use
AssigneeTomah Products, Inc.
InventorDavid Kelly Moss
Life of this patent
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Abstract
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.
Claims61
A viscoelastic fluid comprising:
- an aqueous medium;
- and
- an amidoamine salt surfactant having the following general structural formula:
- wherein,
- R1 is a branched or straight chained, saturated or unsaturated aliphatic group of from about 17 to about 29 carbon atoms;
- R2 is (a) a divalent alkylene group consisting of from about 2 to about 6 carbon atoms, or (b) R2 together with R3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide;
- R3 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) R3 together with R2 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide, or (c) R3 together with R4 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
- R4 is (a) a branched or straight chained alkyl group or hydroxyalkyl group of from about 1 to about 6 carbon atoms, or (b) R4 together with R3 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.
8 more elements
A viscoelastic fluid comprising:
- about 0.1% to about 10% by weight of an amidoamine salt surfactant having the following general structural formula:
- wherein,
- R1 is a branched or straight chained, saturated or unsaturated aliphatic group of from about 17 to about 29 carbon atoms;
- R2 is (a) a divalent alkylene group consisting of from about 2 to about 6 carbon atoms, or (b) R2 together with R3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide;
- R3 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) R3 together with R2 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide, or (c) R3 together with R4 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
- R4 is (a) a branched or straight chained alkyl group or hydroxyalkyl group of from about 1 to about 6 carbon atoms, or (b) R4 together with R3 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.
8 more elements
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,
- R1 is a branched or straight chained, saturated or unsaturated aliphatic group of from about 17 to about 29 carbon atoms;
- R2 is (a) a divalent alkylene group consisting of from about 2 to about 6 carbon atoms, or (b) R2 together with R3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide;
- R3 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) R3 together with R2 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide, or (c) R3 together with R4 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
- R4 is (a) a branched or straight chained alkyl group or hydroxyalkyl group of from about 1 to about 6 carbon atoms, or (b) R4 together with R3 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.
11 more elements
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,
- R1 is a branched or straight chained, saturated or unsaturated aliphatic group of from about 17 to about 29 carbon atoms;
- R2 is (a) a divalent alkylene group consisting of from about 2 to about 6 carbon atoms, or (b) R2 together with R3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide;
- R3 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) R3 together with R2 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine and the nitrogen of the amide, or (c) R3 together with R4 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
- R4 is (a) a branched or straight chained alkyl group or hydroxyalkyl group of from about 1 to about 6 carbon atoms, or (b) R4 together with R3 form a heterocyclic 5- or 6-membered ring structure which includes the nitrogen of the amine;
- and
- X− is an anion.
7 more elements
Dependencies are inferred from the claim text.