Methods and compositions including associative polymers
Methods and compositions for modifying the rheological properties of non-aqueous fluids for treating subterranean formation are provided. In one or mom embodiment, the compositions comprise a non-aqueous fluid; a weighting agent; and one or more associative polymers that are capable of associating to form one or more supramolecular assemblies. In one or more embodiments, the methods comprise introducing a treatment fluid into a wellbore penetrating at least a portion of a subterranean formation, wherein the treatment fluid comprises a non-aqueous fluid and one or more associative polymers.
1. A method comprising:
introducing a drilling fluid into a wellbore penetrating at least a portion of a subterranean formation, wherein the drilling fluid comprises one or more associative polymers in a non-aqueous fluid, wherein the non-aqueous fluid is an oil-based fluid or the non-aqueous phase of an emulsion;
allowing the one or more associative polymers to form one or more first supramolecular assemblies in the non-aqueous fluid thereby increasing the viscosity of the drilling fluid; and
drilling at least a portion of the wellbore in the subterranean formation using the drilling fluid, wherein drilling at least the portion of the wellbore at least partially breaks the one or more first supramolecular assemblies into one or more polymeric strands thereby reducing the viscosity of the drilling fluid.
2. The method of claim 1 , wherein the one or more associative polymers is present in the drilling fluid in an amount less than 10% by weight of the non-aqueous fluid.
3. The method of claim 1 , wherein the one or more associative polymers each comprises a polymer backbone and one or more functional groups on at least two ends of the polymer backbone.
4. The method of claim 3 , wherein the polymer backbone comprises a polymer selected from the group consisting of: a substituted or unsubstituted polydiene, poly(butadiene), poly(isoprene), a substituted or unsubstituted polyolefin, an ethylene-butene copolymer, polyisobutylene, poly(norbornene), poly(octene), polystyrene, a poly(siloxane), a polyacrylate with one or more alkyl side chains, a polyester, polyurethane, and any combination thereof.
5. The method of claim 3 , wherein the one or more functional groups are selected from the group consisting of: a carboxylic acid, a sulfonic acid, a phosphonic acid, an amine, an alcohol, a nucleotide, a hydrogen atom, diacetamidopyridine, thymine, a Hamilton Receptor, cyanuric acid, and any combination thereof.
6. The method of claim 1 , wherein the one or more associative polymers each has a molecular weight from about 100,000 g/mol to about 1,000,000 g/mol.
7. The method of claim 1 , wherein the non-aqueous fluid comprises at least one fluid selected from the group consisting of: an oil, a hydrocarbon, an organic liquid, and any combination thereof.
8. The method of claim 1 , wherein the drilling fluid further comprises a weighting agent.
9. The method of claim 1 , wherein the drilling fluid further comprises one or more additives selected from the group consisting of: a bridging agent, an emulsifier, a wetting agent, and any combination thereof.
10. The method of claim 1 , wherein the one or more first supramolecular assemblies are reversibly broken into the one or more polymeric strands.
11. The method of claim 10 , wherein the one or more polymeric strands form one or more second supramolecular assemblies in the non-aqueous fluid after drilling at least the portion of the wellbore is slowed or stopped.
12. The method of claim 1 , further comprising adding a chemical breaker to the drilling fluid to at least partially break the one or more first supramolecular assemblies into the one or more polymeric strands.