The present disclosure is directed to surfactants (in particular olefin sulfonates), surfactant packages, compositions derived thereof, and uses thereof in hydrocarbon recovery. Methods of making olefin sulfonate surfactants are also described.

A nonionic Gemini surfactant, (octylphenol polyoxyethylene ether disubstituted) dicarboxylic acid diphenyl ether has a structural formula of: ##STR00001##
and is prepared by a two-step reaction: S1, diphenyl ether 4,4′-dicarboxylic acid is subjected to an acyl chlorination reaction to obtain diphenyl ether 4,4′-dicarbonyl dichloride; S2, diphenyl ether 4,4′-dicarbonyl dichloride is subjected to an esterification reaction with octylphenol polyoxyethylene ether (OP-10) to obtain the target product (octylphenol polyoxyethylene ether disubstituted) dicarboxylic acid diphenyl ether. The surfactant is expected to be applied in tertiary oil recovery as an alkali/surfactant, in polymer/surfactant binary composite flooding, in alkali/surfactant/polymer ternary composite flooding, as a microemulsion emulsifier and the like, and it can also be compounded with a common surfactant to reduce the use cost, and thus create conditions for its large-scale application.

The present disclosure is directed to surfactants (in particular olefin sulfonates), surfactant packages, compositions derived thereof, and uses thereof in hydrocarbon recovery. Methods of making olefin sulfonate surfactants are also described.

A slurry comprised of paraffinic or aromatic hydrocarbons, a viscosifier, a dry friction reducer polymer, and a lubricant.

The subject invention provides multi-functional biochemical compositions, as well as their use in enhancing oil recovery from an oil-bearing subterranean formation. Advantageously, the compositions and methods of the subject invention are operationally-friendly, cost-effective, and environmentally-friendly. More specifically, in preferred embodiments, the subject invention provides a multi-functional composition for enhanced oil recovery (EOR) comprising one or more surfactants, one or more chelating agents, and one or more solvents.

Methods of reducing drag in a flowing hydrocarbon include introducing to the flowing hydrocarbon an amount of a solid drag reducing additive effective to improve the flow, the solid drag reducing additive including a polymer particle prepared from at least one polar monomer and a percent by weight (wt %) of liquid of 50 wt % or less. Methods also include producing a solid drag reducing additive that includes forming a polymer from at least one polar monomer by emulsion polymerization; and disrupting the emulsion by adding at least one demulsifier and at least one anti-blocking agent to form the solid drag reducing additive. Compositions include a solid drag reducing additive comprising a polymer prepared from at least one polar monomer and having an average particle size in a range of about 100 μm to about 500 μm, wherein the solid drag reducing additive comprises less than 50 wt % of liquid.

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.

The disclosure is directed to polyelectrolyte complex nanoparticles that can be used to deliver agents deep into hydrocarbon reservoirs. Methods of making and using said polyelectrolyte complex nanoparticles are also provided.

A well treatment additive includes a siloxane surfactant, a solvent and an aqueous phase. The solvent is preferably a terpene hydrocarbon. Also disclosed is a method for using the well treatment additive to form and enhance the properties of terpene solvent based additives useful for the treatment of oil and gas wells. Methods of using the novel well treatment additives include using the additives in a variety of well treatment processes including, but not limited to, acidizing operations, hydraulic fracturing operations, well remediation operations and water removal operations.

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.