The disclosure relates to the oil and gas production industry, and more particularly to technologies for redistributing filter flows in the bottom-hole formation zone of an injection well. A method involves pumping into the bottom-hole formation zone a blocking agent in the form of an emulsion system containing nanoparticles of silicon dioxide and being comprised of: 5-12 vol % diesel fuel or processed oil from an oil processing and pumping station, 2-3 vol % emulsifier, 0.25-1.0 vol % colloidal nanoparticles of silicon dioxide, with the remainder being an aqueous solution of calcium chloride or potassium chloride. The emulsifier is in the form of a composition comprising: 40-42 vol % esters of higher unsaturated fatty acids and resin acids, 0.7-1 vol % amine-N-oxide, 0.5-1 vol % high-molecular-weight organic thermostabilizer, with the remainder being diesel fuel.

A single well chemical tracer composition comprising core/shell tracer particles and an aqueous fluid is provided. The core/shell tracer particles have a core and a polymer shell. At least two tracer chemicals are encapsulated in the core/shell tracer particles. A method of determining residual oil in a reservoir is also provided. The method includes introducing a tracer fluid having the core/shell tracer particles into a wellbore. The reservoir is then maintained for a period of time such that the core/shell particle is ruptured, and the tracer chemicals are released into the reservoir. Then, the method includes producing a produced fluid from the reservoir, measuring the quantity of the tracer chemicals in the produced fluid, and determining a residual oil content of the reservoir based on the measured quantity of the tracer chemicals in the produced fluid.

Aqueous suspensions are presented that are stable against settling without additional mixing in which the suspensions comprise a water soluble polymer that is anionic or non-ionic comprising a blend of water with at least about 32 weight percent chloride salt with a counter ion A.sup.+a with 2≤a, from about 1 wt % to about 10 wt % particulate polyethylene glycol having an average molecular weight from about 1600 g/mol to about 50,000 g/mol, and from about 10 wt % to about 50 wt % of the water soluble polymer that is not a poly ether. The suspension has chlorides in a sufficient amount to inhibit hydration of the suspended water soluble polymer and the particulate polyethylene glycol. The aqueous suspension can be formed by adding a powder of polyethylene glycol to a high salt solution and then adding the high molecular weight polymer. The aqueous suspensions can be useful as friction reducing agents in flowing liquids, such as for hydraulic fracture.

Aqueous suspensions are presented that are stable against settling without additional mixing in which the suspensions comprise a water soluble polymer that is anionic or non-ionic comprising a blend of water with at least about 32 weight percent chloride salt with a counter ion A.sup.+a with 2≤a, from about 1 wt % to about 10 wt % particulate polyethylene glycol having an average molecular weight from about 1600 g/mol to about 50,000 g/mol, and from about 10 wt % to about 50 wt % of the water soluble polymer that is not a poly ether. The suspension has chlorides in a sufficient amount to inhibit hydration of the suspended water soluble polymer and the particulate polyethylene glycol. The aqueous suspension can be formed by adding a powder of polyethylene glycol to a high salt solution and then adding the high molecular weight polymer. The aqueous suspensions can be useful as friction reducing agents in flowing liquids, such as for hydraulic fracture.

Aqueous suspensions are presented that are stable against settling without additional mixing in which the suspensions comprise a water soluble polymer that is anionic or non-ionic comprising a blend of water with at least about 32 wt % chloride salt with a counter ion A.sup.+a with 2≤a, from about 1 wt % to about 10 wt % particulate polyethylene glycol having an average molecular weight from about 1600 g/mol to about 50,000 g/mol, and from about 10 wt % to about 50 wt % of the water soluble polymer that is not a polyether. The suspensions have chlorides in a sufficient amount to inhibit hydration of the suspended water soluble polymer and the particulate polyethylene glycol. The aqueous suspension can be formed by adding a powder of polyethylene glycol to a high salt solution and then adding the high molecular weight polymer. The aqueous suspensions can be useful as friction reducing agents in flowing liquids, such as for hydraulic fracture.

Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the manufacturing steps are allocated to two different locations A and B and the process comprises the step of transporting an aqueous polyacrylamide gel hold in a transportable polymerization unit from a location A to a location B. The transportable polymerization unit comprises a cylindrical upper part, a conical part at its lower end, feeds for the aqueous monomer solution, a closable bottom opening, and means allowing to deploy the polymerization unit in a vertical manner.

Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the manufacturing steps are allocated to two different locations A and B and the process comprises the step of transporting an aqueous polyacrylamide gel hold in a transportable polymerization unit from a location A to a location B. The transportable polymerization unit comprises a cylindrical upper part, a conical part at its lower end, feeds for the aqueous monomer solution, a closable bottom opening, and means allowing to deploy the polymerization unit in a vertical manner.

Compositions and methods comprising certain microemulsions and certain clay control additives for enhancing clay swelling protection and persistency in treating swelling clay of a subterranean formation of oil and/or gas wells are generally provided. The combination of certain microemulsions and certain clay control additives exhibit synergistic effects by enhancing clay swelling protection and persistency in treating swelling clay. The well treatment composition may use up to four times less concentration of clay control additive compared to using the same clay control additive alone, while still providing the same, similar, or higher degree of clay swelling protection and enhanced persistency. The microemulsion and the clay control additive may be added to a carrier fluid to form the well treatment composition, which is injected into the subterranean formation to provide enhanced clay swelling protection and persistency of continuing to provide clay swelling protection for a longer period of time during flowback.

Compositions and methods comprising certain microemulsions and certain clay control additives for enhancing clay swelling protection and persistency in treating swelling clay of a subterranean formation of oil and/or gas wells are generally provided. The combination of certain microemulsions and certain clay control additives exhibit synergistic effects by enhancing clay swelling protection and persistency in treating swelling clay. The well treatment composition may use up to four times less concentration of clay control additive compared to using the same clay control additive alone, while still providing the same, similar, or higher degree of clay swelling protection and enhanced persistency. The microemulsion and the clay control additive may be added to a carrier fluid to form the well treatment composition, which is injected into the subterranean formation to provide enhanced clay swelling protection and persistency of continuing to provide clay swelling protection for a longer period of time during flowback.

In an embodiment, a hydrocarbon recovery material includes an organic acid and a water material, the organic acid including a naphthenic acid, L-proline, or combinations thereof. In another embodiment, an oil recovery method includes injecting a treatment fluid into a reservoir under reservoir conditions, the reservoir containing hydrocarbons, and the treatment fluid includes an organic acid and a water material. In another embodiment, an oil recovery method includes injecting a treatment fluid into a reservoir containing hydrocarbons, the treatment fluid comprising an organic acid in one or more of an oil-in-water emulsion, a resin dispersion, or a polymer capsule.