Inverse emulsion compositions

1. An inverse emulsion composition comprising:

one or more hydrophobic liquids having a boiling point at least about 100° C.;

up to about 38% by weight of one or more acrylamide-(co)polymers;

water in an amount greater than about 12% by weight based on the total amount of all components of the composition;

one or more emulsifier surfactants; and

one or more inverting surfactants;

wherein, when the composition is inverted in an aqueous solution, it provides an inverted polymer solution having a filter ratio using a 1.2 micron filter (FR 1.2) at 15 psi of about 1.5 or less, and a viscosity of at least 10 cP at 40° C., for a solution comprising about 2000 ppm active polymer; and

wherein each of the one or more acrylamide-(co) polymers comprises one or more of monomers selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, monomers comprising sulfonic acid groups, vinylsulfonic acid, allylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, 2-acrylamidobutanesulfonic acid, 3-acrylamido-3-methylbutanesulfonic acid, 2-acrylamido-2,4,4-trimethylpentanesulfonic acid, or monomers comprising phosphonic acid groups, vinylphosphonic acid, allylphosphonic acid, N-(meth)acrylamidoalkylphosphonic acids, (meth)acryloyloxyalkylphosphonic acids, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, allyl alcohol, hydroxyvinyl ethyl ether, hydroxyl vinyl propyl ether, hydroxyvinyl butyl ether or polyethyleneoxide(meth)acrylates, monomers which may cause hydrophobic association of the (co)polymers, N-alkyl acrylamides, N-alkyl quaternary acrylamides, salts of the foregoing, mixtures or combinations of the foregoing.

2. The composition of claim 1 , wherein the aqueous solution comprises produced water, fresh water, salt water, brine, sea water, or a combination thereof.

3. The composition of claim 1 , wherein when the composition is inverted in an aqueous solution to provide an inverted polymer solution comprising about 2000 ppm active polymer, the inverted polymer solution has a viscosity of at least 20 cP at 40° C.

4. The composition of claim 1 , wherein when the composition is inverted in an aqueous solution, the inverted polymer solution has a FR 1.2 of about 1.0 to about 1.3.

5. The composition of claim 1 , wherein when the composition is inverted in an aqueous solution, the inverted polymer solution has a FR 1.2 of about 1.2 or less.

6. The composition of claim 1 wherein when the composition is inverted in an aqueous solution, the inverted polymer solution has a filter ratio using a 5 micron filter (FR5) of about 1.5 or less.

7. The composition of claim 1 , wherein the one or more hydrophobic liquids having a boiling point at least about 100° C. is selected from the group consisting of paraffin hydrocarbons, naphthene hydrocarbons, aromatic hydrocarbons, olefins, oils, stabilizing surfactants, and mixtures or combinations of the foregoing.

8. The composition of claim 1 , wherein the one or more emulsifier surfactants are selected from the group consisting of sorbitan esters, ethoxylated fatty alcohols with 1 to 4 ethyleneoxy groups, phthalic esters, fatty acid glycerides, glycerine esters, sorbitan monooleate, the reaction product of oleic acid with isopropanolamide, hexadecyl sodium phthalate, decyl sodium phthalate, sorbitan stearate, ricinoleic acid, hydrogenated ricinoleic acid, glyceride monoester of lauric acid, glyceride monoester of stearic acid, glycerol diester of oleic acid, glycerol triester of 12-hydroxystearic acid, glycerol triester of ricinoleic acid, and the ethoxylated versions of the foregoing containing 1 to 10 moles of ethylene oxide per mole of the basic emulsifier, modified polyester surfactants, anhydride substituted ethylene copolymers, N,N-dialkanol substituted fatty amides, tallow amine ethoxylates, and mixtures or combinations of the foregoing.

9. The composition of claim 1 , wherein the one or more inverting surfactants are selected from the group consisting of ethoxylated alcohols, alcohol ethoxylates, ethoxylated esters of sorbitan, ethoxylated esters of fatty acids, ethoxylated fatty acid esters, ethoxylatedesters of sorbitol and fatty acids, nonionic surfactants comprising a hydrocarbon group and a polyalkylenoxy group of sufficient hydrophilic nature, nonionic surfactants of the general formula R 1 —O—(CH(R 2 )—CH 2 —O) n H (I), wherein R 1 is a C 8 -C 22 -hydrocarbon group, n is a number of >4, and R 2 is H, methyl or ethyl, and at least 50% of the groups R 2 are H, polyethoxylates based on C 10 -C 18 -alcohols, tridecylalcohol ethoxylates comprising from 4 to 14 ethylenoxy groups, tridecyalcohol·8 EO, or C 12/14 fatty alcohol ethoxylates, C 12/14 8 EO, modified polyester surfactants, anhydride substituted ethylene copolymers, N,N-dialkanol substituted fatty amides, tallow amine ethoxylates, and mixtures or combinations of the foregoing.

10. The composition of claim 1 , wherein each of the one or more acrylamide-(co)polymers comprises at least 30% by weight of acrylamide monomer units with respect to the total amount of all monomeric units in the (co)polymer and that each of the one or more acrylamide-(co)polymers comprises at least one additional ethylenically unsaturated monomer.

11. The composition of claim 1 , wherein at least one of the one or more acrylamide-(co) polymers comprises 2-acrylamido-2-methylpropanesulfonic acid or salts thereof.

12. The composition of claim 1 , wherein the composition may be inverted in the aqueous solution in less than 30 minutes.

13. The composition of claim 1 , wherein the one or more acrylamide-(co)polymers have a weight average molecular weight (M w ) of greater than about 5,000,000 Dalton.