Embodiments of the present disclosure include a method of separating an oil-in-water emulsion formed during crude oil production into a water phase and an oil phase that includes adding 1 part-per-million (ppm) to 10000 ppm of an N-vinylpyrrolidone based cationic copolymer to the oil-in-water emulsion, based on the total volume of the oil-in-water emulsion, to form a water phase and an oil phase, and separating the water phase from the oil phase.

Disclosed herein is a method for inhibiting scale comprising adding to a fluid that causes scale formation a polycarboxylic acid having a polymer backbone and a plurality of branches from the polymer backbone.

Disclosed herein is a method for inhibiting scale comprising adding to a fluid that causes scale formation a polycarboxylic acid having a polymer backbone and a plurality of branches from the polymer backbone.

Various embodiments disclosed relate to compositions including a viscosifier polymer and a polyamine viscosity modifier and methods of using the same for treatment of subterranean formations. In various embodiments, the present invention provides a method of treating a subterranean formation. The method includes placing in a subterranean formation a composition including a viscosifier polymer and a polyamine viscosity modifier.

The invention is directed to polymers that self-crosslink at acidic pH or can be crosslinked by phenolic agents in brine. Such polymers have lower viscosity and can be pumped deep into reservoirs, where they will cross link in situ, thus increasing their viscosity and/or form a gel and blocking thief zones. Methods of making and using such polymers are also provided.

The invention is directed to polymers that self-crosslink at acidic pH or can be crosslinked by phenolic agents in brine. Such polymers have lower viscosity and can be pumped deep into reservoirs, where they will cross link in situ, thus increasing their viscosity and/or form a gel and blocking thief zones. Methods of making and using such polymers are also provided.

The instant application relates to nanogels or compositions that hold multivalent metal ions until some level of nanogel degradation has occurred, then slowly release the multivalent metal ions for gelation with carboxylate containing polymers. Compositions comprising such nanogels, together with polymers that can be crosslinked with multivalent metal ions, allow the deployment of such mixtures in various applications, and greatly increased gelation times.

The instant application relates to nanogels or compositions that hold multivalent metal ions until some level of nanogel degradation has occurred, then slowly release the multivalent metal ions for gelation with carboxylate containing polymers. Compositions comprising such nanogels, together with polymers that can be crosslinked with multivalent metal ions, allow the deployment of such mixtures in various applications, and greatly increased gelation times.

Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The viscosity reducer is buffered at a pH of 7 or less (e.g., at a pH of from 2 to 7, such as at a pH of from 3.5 to 7, or at a pH of from 5 to 7). The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.

Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The viscosity reducer is buffered at a pH of 7 or less (e.g., at a pH of from 2 to 7, such as at a pH of from 3.5 to 7, or at a pH of from 5 to 7). The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.