Compositions for stimulating hydrocarbon production from a subterranean formation are generally disclosed. In some embodiments, such compositions include olefinic ester compounds, such as alkyl esters of C10-18 unsaturated fatty acids. In some embodiments, the olefinic ester compounds are derived from a natural oil or a natural oil derivative, for example, by catalytic olefin metathesis. Uses of such compounds, such as in oil- and gas-production methods are also generally disclosed.

Methods for selecting a surfactant for treating a subterranean formation based on the performance of the surfactant and the characteristics of the subterranean formation and the treatment fluids that may be used to treat that formation are provided. In one embodiment, the method may comprise providing a treatment fluid, formation materials, hydrocarbon, and a plurality of surfactants, wherein the hydrocarbon is acquired from a subterranean formation; selecting at least two surfactants from the plurality of surfactants by determining whether each of the plurality of surfactants separates a mixture of the treatment fluid and the hydrocarbon; and selecting at least one surfactant from the at least two surfactants by determining whether the hydrocarbon displaces the treatment fluid from the formation materials in the presence of each of the at least two surfactants.

Methods for selecting a surfactant for treating a subterranean formation based on the performance of the surfactant and the characteristics of the subterranean formation and the treatment fluids that may be used to treat that formation are provided. In one embodiment, the method may comprise providing a treatment fluid, formation materials, hydrocarbon, and a plurality of surfactants, wherein the hydrocarbon is acquired from a subterranean formation; selecting at least two surfactants from the plurality of surfactants by determining whether each of the plurality of surfactants separates a mixture of the treatment fluid and the hydrocarbon; and selecting at least one surfactant from the at least two surfactants by determining whether the hydrocarbon displaces the treatment fluid from the formation materials in the presence of each of the at least two surfactants.

A novel surfactant composition that comprises of two surfactant components, a solvent, and water. The surfactant composition is added to a fracturing fluid, which is then pumped downhole into a subterranean formation where the novel characteristics of the fracturing fluid lend to improved oil production over the fracturing fluid without the surfactant composition.

A friction reducing treatment solution that includes water, from 100 to 500,000 ppm of total dissolved solids, and from 0.5 to 3 gallons per thousand gallons of a water-in-oil emulsion containing a water soluble polymer. The total dissolved solids include at least 10 weight percent of a multivalent cation. The water-in-oil emulsion includes an oil phase and an aqueous phase, where the oil phase is a continuous phase containing an inert hydrophobic liquid and the aqueous phase is present as dispersed distinct particles in the oil phase and contains water, the water soluble polymer, and surfactants and an inverting surfactant. The water soluble polymer is made up of 30 to 60 weight percent of a non-ionic monomer, 5 to 50 weight percent of a sulfonic acid containing monomer, and 10 to 60 weight percent of a cationic monomer and makes up from 5 to 40 weight percent of the water-in-oil emulsion.

A friction reducing treatment solution that includes water, from 100 to 500,000 ppm of total dissolved solids, and from 0.5 to 3 gallons per thousand gallons of a water-in-oil emulsion containing a water soluble polymer. The total dissolved solids include at least 10 weight percent of a multivalent cation. The water-in-oil emulsion includes an oil phase and an aqueous phase, where the oil phase is a continuous phase containing an inert hydrophobic liquid and the aqueous phase is present as dispersed distinct particles in the oil phase and contains water, the water soluble polymer, and surfactants and an inverting surfactant. The water soluble polymer is made up of 30 to 60 weight percent of a non-ionic monomer, 5 to 50 weight percent of a sulfonic acid containing monomer, and 10 to 60 weight percent of a cationic monomer and makes up from 5 to 40 weight percent of the water-in-oil emulsion.

A method of treating a bottom hole region of a formation (BRF) with an estimated frequency for performing the stages, wherein the second and each stage is carried out when the factor and/or the daily crude oil flow rate of a well has decreased by 25% or more over the preceding 6 months of well operation. In the first and second stages, the BRF is treated with an emulsion system containing silicon dioxide nanoparticles, an acid composition, and an aqueous solution of potassium or calcium chloride. In the third stages, the BRF is treated with an emulsion system containing silicon dioxide nanoparticles, a composition of surfactants and alcohols, and an aqueous solution of potassium chloride or calcium chloride. The thermal stability of the emulsion system, increase the rate of development of an oil and gas bearing layer, increase the duration of a positive effect and enhance oil production.

Compositions and methods are provided for delayed breaking of viscoelastic surfactant gels inside subterranean formations. Breaking is accomplished without mechanical intervention or use of a second fluid. The delayed breaking agent is a hydrophobically modified alkali swellable emulsion polymer, which can be a copolymer comprising acidic monomers, nonionic monomers, and associative monomers. The viscoelastic surfactant can be a zwitterionic surfactant, and can be selected from the group consisting of sultaines, betaines, and amidoamine oxides.

The present invention relates to a new Winsor type IV microemulsion system for faster return of well service fluid and enhanced production of hydrocarbon-containing fluids in fractured tight subterranean formations, where the microemulsion system includes a surfactant subsystem including at least one glucamide sugar surfactant, a solvent subsystem and a co-solvent subsystem and to methods for making and using same.

A synthetic acid composition for use in oil industry activities, said composition comprising: urea and hydrogen chloride in a molar ratio of not less than 0.1:1; and an alcohol or derivative thereof optionally, it may further comprise a phosphonic acid derivative.