Polymer additives that reduce friction

Abstract

A method for forming a friction-reducing polymer formulation. The method begins with the formation of a friction-reducing polymer. A hydrocarbon additive is then incorporated into the friction-reducing polymer to form a friction-reducing polymer formulation. The friction-reducing polymer formulation is subsequently used as a friction reducer in hydrocarbon pipelines.

Description

Polymer additives that reduce friction FIELD OF INVENTION A method for incorporating a hydrocarbon additive into a polymer that reduces friction. BACKGROUND OF THE INVENTION When fluids are transported through a pipe, a pressure drop typically occurs due to friction between the pipe wall and the fluid. Because of this pressure drop, for a given pipe, the fluid must be transported at sufficient pressure to achieve the desired performance. When higher flow rates are desired through the pipe, more pressure must be applied because, as flow rates increase, the pressure difference caused by the pressure drop also increases. However, limitations in pipe design restrict the pressure drop that can be used. The problems associated with pressure drop are more significant when fluids are transported over long distances. Such pressure drops result in inefficiencies that increase equipment and operating costs. To alleviate problems associated with pressure drop, many in industry use friction reducers in the circulating fluid. When fluid flow in a pipeline is turbulent, high-molecular-weight polymeric friction reducers can be employed to improve flow. A friction reducer is a composition that can substantially reduce the friction loss associated with turbulent fluid flow through a pipeline. The role of a friction reducer is to suppress the growth of turbulent eddies, resulting in a higher flow rate for a constant pumping pressure. Ultra-high-molecular-weight polymers are known to perform well as friction reducers, especially in hydrocarbon pipelines. Generally, the friction reduction depends in part on the molecular weight of the polymeric additive and its ability to dissolve in the turbulent-flowing hydrocarbon.Effective friction reducers have molecular weights exceeding five million or even ten million. Friction reducers are typically injected into a pipeline at the discharge end of a pumping station. A pump capable of operating above the pipeline's pressure line is used to inject the friction reducer into the pipeline. Additives to friction reducers have been shown to improve their effectiveness in injecting into the pipeline. There remains a need for an additive to improve the ability of friction reducers to be injected into the pipeline without negatively affecting the formulation of the friction reducer. BRIEF SUMMARY OF DISCLOSURE The described technology provides a method for forming a friction-reducing polymer formulation that includes the formation of a friction-reducing polymer; and incorporating a hydrocarbon additive into the friction-reducing polymer to form the friction-reducing polymer formulation where the friction-reducing polymer formulation is used as a friction reducer in hydrocarbon pipelines. The technology described further provides a method for forming a friction-reducing polymer where the friction-reducing polymer is a latex friction-reducing polymer. nc Lcnn / zznz / E / YiAi The technology described also provides a method for forming a friction-reducing polymer where the friction-reducing polymer is formed by emulsion polymerization. The technology described also provides a method for forming a friction-reducing polymer where the friction-reducing polymer is formed by emulsion polymerization. The described technology also provides a method for forming a friction-reducing polymer where the hydrocarbon additive is selected from heptane, isooctane, kerosene, kerosene with depleted N-paraffin, and combinations thereof. The technology described also provides a method for forming a friction-reducing polymer where the hydrocarbon additive has a distillation temperature below 275 °C. The technology described also provides a method for forming a friction-reducing polymer where hydrocarbon pipelines are heavy hydrocarbon pipelines. The technology described also provides a method for forming a friction-reducing polymer where the friction reducer suppresses the growth of turbulent eddies in hydrocarbon pipelines. The technology described further provides a method for forming a friction-reducing polymer where the friction-reducing polymer formulation includes at least approximately 25,000 repeating units. The technology described further provides a method for forming a friction-reducing polymer where the friction-reducing polymer formulation has a weight average molecular weight of at least 1 x 106g / mol. The technology described also provides a method for forming a friction-reducing polymer where approximately 3% by weight to approximately 16% by weight of hydrocarbon additive is incorporated into the friction reducer. The technology described also provides a method for forming a friction-reducing polymer where the hydrocarbon additive comes from a source other than hydrocarbon conduction. The technology described also provides a method for forming a friction-reducing polymer where the addition of the hydrocarbon additive does not affect the stability of the friction-reducing polymer. The described technology further provides a method for forming a friction-reducing polymer formulation that includes forming a latex friction-reducing polymer by emulsion polymerization and incorporating from approximately 3% by weight to approximately 30% by weight of kerosene additive into the latex friction-reducing polymer to form the friction-reducing polymer formulation, where the friction-reducing polymer formulation is used as a friction reducer in heavy hydrocarbon pipelines. The described technology further provides a method for injecting a friction-reducing polymer formulation that includes forming a latex friction-reducing polymer by emulsion polymerization, incorporating from approximately 3% by weight to approximately 30% by weight of kerosene additive into the latex friction-reducing polymer to form the friction-reducing polymer formulation nc Lcnn / zznz / E / YiAi, and injecting the friction-reducing polymer formulation into a heavy hydrocarbon pipeline. The technology described also refers to a method for injecting a friction-reducing polymer formulation where the friction reducer suppresses growth and turbulent eddies in heavy hydrocarbon conveying. The described technology further relates to a method for injecting a friction-reducing polymer formulation where the friction-reducing polymer formulation comprises at least approximately 25,000 repeating units. The described technology further relates to a method for injecting a friction-reducing polymer formulation where the friction-reducing polymer formulation has a weight average molecular weight of at least 1 x 106g / mol. The technology described also refers to a method for injecting a friction-reducing polymer formulation where the kerosene additive comes from a source other than hydrocarbon conveyance. The technology described also refers to a method for forming a friction-reducing polymer where the addition of the hydrocarbon additive does not affect the stability of the friction-reducing polymer. The technology described also refers to a method for injecting a friction-reducing polymer formulation where the hydrocarbon additive has a distillation temperature of 300 °C and below. The technology described also refers to a method for injecting a friction-reducing polymer formulation where approximately 3% by weight to approximately 30% by weight of hydrocarbon additive is incorporated into the friction-reducing polymer. DETAILED DESCRIPTION Turning now to the detailed description of the preferred arrangement(s) of the present invention, it should be understood that the inventive features and concepts may be manifested in other arrangements, and that the scope of the invention is not limited to the embodiments described or illustrated. It is intended that the scope of the invention be limited only by the scope of the following claims. A method for forming a friction-reducing polymer formulation. The method begins with the formation of a friction-reducing polymer. A hydrocarbon additive is then incorporated into the friction-reducing polymer to form a friction-reducing polymer formulation. The friction-reducing polymer formulation is then used as a friction reducer in hydrocarbon pipelines. The friction-reducing polymer formed can be any commonly known friction-reducing polymer. Examples of friction-reducing polymers that can be used include a latex friction-reducing polymer and those formed by emulsion polymerization. Incorporated herein by reference, U.S. Patent 8,022,118 describes several friction-reducing polymers that can be used in the present method. In one embodiment, the friction-reducing polymer may comprise a plurality of repeating units of the residues of one or more of the monomers selected from the group consisting of: nc Lcnn / zznz / E / YiAi (A) R, OHr। ii h2c^=c--c—or2repetitions where Ri is H or a C1-C10 alkyl radical, and R2 is H, a C1-C30 alkyl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, a substituted or unsubstituted C6-C20 aryl radical, a C1-C10 aryl-substituted alkyl radical, a -(CH2CH2O)X-RA radical or a -(CH2CH(CH3)O)X-RA radical where x is in the range of 1 to 50 and Ra is H, a C1-C30 alkyl radical, or a C6-C30 alkylaryl radical; (B) R3-arene-R4 where arene is a phenyl, naphthyl, anthracenyl, or phenanthrenyl, R3 is CH=CH2 or CH3-C=CH2, and R4 is H, a C1-C30 alkyl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, Cl, SO3, ORb, or COORc, where Rb is H, a C1-C30 alkyl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, a substituted or unsubstituted C6-C20 aryl radical, or an aryl-substituted C1-C10 alkyl radical, and where Rb is H, a C1-C30 alkyl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, a substituted or unsubstituted C6-C20 aryl radical, or an aryl-substituted C1-C10 alkyl radical; (C) HO HC I II H2C^=C---O---CR where R5 is H, a C1-C30 alkyl radical, or a substituted or unsubstituted C6-C20 aryl radical; (D) H H2C^=C---OR where R6 is H, a C1-C30 alkyl radical, or a substituted or unsubstituted C6-C20 aryl radical; (AND) R7 Rg h2c^c—C^CH2where R7 is H or a C1-C18 alkyl radical, and R8 is H, a C1-C18 alkyl radical, or Cl; (F) or III RgO---C. OR10 HH where R9 and R10 are independently H, a C1-C30 alkyl radical, a substituted or unsubstituted C6-C20 aryl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, or heterocyclic radicals; (G) nc Lcnn / zznz / E / YiAi where Rn and R12 are independently H, a C1-C30 alkyl radical, a substituted or unsubstituted C6-C20 aryl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, or heterocyclic radicals; (H) Ri3o or where Rn and Ru are independently H, a C1-C30 alkyl radical, a substituted or unsubstituted C6-C20 aryl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, or heterocyclic radicals; NR15 where R15 is H, a C1-C30 alkyl radical, a substituted or unsubstituted C5-C30 cycloalkyl aryl radical, or heterocyclic radicals; (J) C6-C20 substituted or unsubstituted, a ci ch2(K) radical R16 ch2h2c^ IR16 where Ríe is H, a C1-C30 alkyl radical, or a C6-C20 aryl radical; (L) (EITHER) or nc Lcnn / zznz / E / YiAi where R17 and Ríe are independently H, a C1-C30 alkyl radical, a substituted or unsubstituted C6-C20 aryl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, or heterocyclic radicals; and (P) ch3r19H2cRsoo where Rw and R20 are independently H, a C1-C30 alkyl radical, a substituted or unsubstituted C6-C20 aryl radical, a substituted or unsubstituted C5-C30 cycloalkyl radical, or heterocyclic radicals. In one embodiment, the friction-reducing polymer may comprise repeating units of C4-C20 alkyl moieties, substituted or unsubstituted C6-C20 aryl moieties, or aryl-substituted C1-C10 alkyl esters derived from methacrylic acid or acrylic acid. In another embodiment, the friction-reducing polymer may be a copolymer comprising repeating units of 2-ethylhexyl methacrylate moieties and moieties of at least one other monomer. In a further embodiment, the friction-reducing polymer may be a copolymer comprising repeating units of 2-ethylhexyl methacrylate monomer moieties and butyl acrylate monomers. In yet another embodiment, the friction-reducing polymer may be a homopolymer comprising repeating units of 2-ethylhexyl methacrylate moieties. In one embodiment, the friction-reducing polymer may comprise the residues of at least one monomer having a heteroatom. As stated above, the term heteroatom includes any atom other than a carbon atom or a hydrogen atom. Specific examples of heteroatoms include, but are not limited to, oxygen, nitrogen, sulfur, phosphorus, and / or chlorine atoms. In one embodiment, the friction-reducing polymer may comprise at least approximately 10 percent, at least approximately 25 percent, or at least 50 percent of the monomer residues having at least one heteroatom. In addition, the heteroatom may have a partial charge. As used herein, the term partial charge is defined as an electric charge, either positive or negative, having a value less than 1. The surfactant used in the aforementioned reaction mixture may include at least one anionic or nonionic surfactant with a high HLB value. The term HLB number refers to the hydrophilic-lipophilic balance of a surfactant in an emulsion. The HLB number is determined according to the methods described by W.C. Griffin in J. Soc. Cosmet. Chem., 1, 311 (1949) and J. Soc. Cosmet. Chem., 5, 249 (1954), which are incorporated herein by reference. As used herein, the term high HLB shall denote an HLB number of 7 or higher. The HLB number of the surfactants for use in forming the reaction mixture may be at least approximately 8, at least approximately 10, or at least approximately 12. Illustrative anionic surfactants with high HLB include, but are not limited to, high HLB alkyl sulfates, alkyl ether sulfates, dialkyl sulfosuccinates, alkyl phosphates, alkylaryl sulfonates, and sarcosinates. Suitable examples of commercially available high HLB anionic surfactants include, but are not limited to, sodium lauryl sulfate (available as RHODAPON LSB from Rhodia Incorporated, Cranbury, NJ), sodium dioctyl sulfosuccinate (available as AEROSOL OT from Cytec Industries, Inc., West Paterson, NJ), sodium salt of poly(2-ethylhexyl phosphate) (available from Jarchem Industries Inc., Newark, NJ), sodium dodecylbenzenesulfonate (available as NORFOX 40 from Norman, Fox & Co., Vernon, CA), and sodium lauroylsarcosin (available as HAMPOSYL L-30 from Hampshire Chemical Corp., Lexington, MA). Illustrative high HLB nonionic surfactants include, but are not limited to, high HLB sorbitan esters, fatty acid PEG esters, ethoxylated glycerin esters, ethoxylated fatty amines, ethoxylated sorbitan esters, ethylene oxide / propylene oxide block surfactants, alcohol / fatty acid esters, ethoxylated alcohols, ethoxylated fatty acids, alkoxylated castor oils, glycerin esters, ethoxylated linear alcohols, and ethoxylated alkylphenol. Suitable examples of commercially available high HLB nonionic surfactants include, but are not limited to, nonylphenoxy and octylphenoxy poly(ethyleneoxy)ethanols (available as the IGEPAL CA and CO series, respectively, from Rhodia, Cranbury, NJ), ethoxylated primary C8 to C18 alcohols (such as RHODASURF LA9 from Rhodia Inc., Cranbury, NJ), ethoxylated secondary C11 to C15 alcohols (available as the TERGITOL15S series, including 15-S-7, 15-S-9, 15-S-12, from Dow Chemical Company, Midland, MI), polyoxyethylenated sorbitan fatty acid esters (available as the TWEEN surfactant series from Uniquema, Wilmington, DE), polyethylene oxide nc Lcnn / zznz / E / YiAi (25) oleyl ether (available as SIPONIC Y-500-70 from Americal Alcolac Chemical Co., Baltimore, MD), alkylated polyether alcohols (available as the TRITON X series, including X-100, X-165, X-305, and X-405, from Dow Chemical Company, Midland, MI). In one embodiment, the initiation system for use in the aforementioned reaction mixture can be any system suitable for generating the free radicals necessary to facilitate emulsion polymerization. Possible initiators include, but are not limited to, persulfates (e.g., ammonium persulfate, sodium persulfate, potassium persulfate), peroxypersulfates, and peroxides (e.g., tere-butyl hydroperoxide) used alone or in conjunction with one or more reducing and / or accelerating components. Possible reducing components include, but are not limited to, bisulfites, metabisulfites, ascorbic acid, erythorbic acid, and sodium formaldehyde sulfoxylate. Possible accelerators include, but are not limited to, any composition containing a transition metal having two oxidation states, such as, for example, ferrous sulfate and ferrous ammonium sulfate.Alternatively, known thermal initiation and irradiation techniques can be used to generate the free radicals. In another embodiment, any polymerization method and corresponding initiation, or any catalytic methods known to those skilled in the art, can be used in the present invention. For example, when polymerization is carried out by methods such as addition or condensation polymerization, the polymerization can be initiated or catalyzed by methods such as cationic, anionic, or coordination methods. When water is used to form the aforementioned reaction mixture, the water can be purified water such as distilled or deionized water. However, the continuous phase of the emulsion can also comprise polar organic liquids or aqueous solutions of polar organic liquids, such as those listed below. As previously stated, the reaction mixture may optionally include a buffer. The buffer may comprise any known buffer that is compatible with the initiation system, such as, for example, carbonate, phosphate, and / or borate buffers. As stated above, the reaction mixture may optionally include at least one hydrate inhibitor. The hydrate inhibitor may be a thermodynamic hydrate inhibitor such as, for example, an alcohol and / or a polyol. In one embodiment, the hydrate inhibitor may comprise one or more polyhydrated alcohols and / or one or more polyhydrated alcohol ethers. Suitable polyhydrated alcohols include, but are not limited to, monoethylene glycol, diethylene glycol, triethylene glycol, monopropylene glycol, and / or dipropylene glycol. Suitable polyhydrated alcohol ethers include, but are not limited to, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, and dipropylene glycol monomethyl ether. In general, a hydrate inhibitor can be any composition that, when mixed with distilled water in a 1:1 weight ratio, produces a liquid mixture with hydrate inhibition that has a gaseous hydrate formation temperature at 2,000 psia (13.8 MPa) that is lower than the gaseous hydrate formation temperature of distilled water at 2,000 psia (13.8 MPa) by an amount in the range of about 10 to about 150 °F (-12.22 °C to 65.56 °C), in the range of about 20 to about 80 °F (-6.67 to 26.67 °C), or in the range of 30 to 60 °F (-1.11 to 15.56 °C). For example, monoethylene glycol is suitable as the hydrate inhibitor nc Lcnn / zznz / E / YiAi because the gaseous hydrate formation temperature of distilled water at 2,000 psia (13.8 MPa) is approximately 70 °F (21.11 °C), while the gaseous hydrate formation temperature of a 1:1 mixture of distilled water and monoethylene glycol at 2,000 psia (13.8 MPa) is approximately 70 °F (21.11 °C).The gaseous hydrate formation temperature (GHY) of distilled water at 2,000 psia (13.8 MPa) is approximately 28 °F (-2.22 °F). Thus, monoethylene glycol lowers the GHY formation temperature of distilled water at 2,000 psia (13.8 MPa) by approximately 42 °F (5.56 °F) when added to distilled water at a 1:1 weight ratio. It should be noted that the GHY formation temperature of a particular liquid can vary depending on the conditioning composition of the natural gas used to determine the GHY formation temperature. Therefore, when the GHY formation temperature is used herein to define what constitutes a hydrate inhibitor, it is presumed that such GHY formation temperature is determined using a natural gas composition containing 90 mol percent methane, 5 mol percent ethane, and 3 mol percent propane. In the formation of the reaction mixture, the monomer, water, at least one surfactant, and optionally the hydrate inhibitor, can be combined in a substantially oxygen-free atmosphere maintained at less than approximately 1,000 ppmp of oxygen or less than approximately 100 ppmp of oxygen. The oxygen-free atmosphere can be maintained by continuously purging the reaction vessel with an inert gas such as nitrogen and / or argon. The system temperature can be maintained at a level from the freezing point of the continuous phase to approximately 60 °C, in the range of approximately 0 to approximately 45 °C, or in the range of 0 to 30 °C. The system pressure can be maintained in the range of approximately 5 psia (34.5 kPa) to approximately 100 psia (689.5 kPa), in the range of approximately 10 psia (68.95 kPa) to approximately 25 psia (172.4 kPa), or approximately atmospheric pressure.However, higher pressures of up to 300 psia (2.1 MPa) may be necessary to polymerize some monomers, such as diolefins. A buffer can then be added, if necessary, followed by the addition of the initiation system, either all at once or gradually. The polymerization reaction is carried out for a sufficient amount of time to achieve a conversion of at least approximately 90 percent by weight of the monomers. Typically, this time ranges from approximately 1 to approximately 10 hours, or from 3 to 5 hours. During polymerization, the reaction mixture can be stirred continuously. The following table establishes approximate wide and narrow ranges for the amounts of ingredients present in the reaction mixture. nc Lcnn / zznz / E / YiAi Ingredient Wide Range Narrow Range Monomer (% by weight of reaction mixture) 10-60% 30-50% Water (% by weight of reaction mixture) 20-80% 50-70% Surfactant (% by weight of the reaction mixture) 0.1-10% 0.25 - 6% Initiation system Monomer:Initiator (molar ratio) 1x103:1 - 5x106:1 5x103:1 - 2x106:1 Monomer:Comp. Reducer (molar ratio) 1x103:1 - 5x106:1 1x104:1 - 2x106:1 Accelerator: Initiator (molar ratio) 0.001:1 -10:1 0.005:1 -1:1 Buffer 0 to the amount required to achieve the starting pH (dependent on the initiator, normally between approximately 6.5-10) Initiation system Optional hydrate inhibitor If present, the hydrate inhibitor may have a weight ratio between hydrate inhibitor and water of approximately 1:10 to approximately 10:1, approximately 1:1 to approximately 5:5, or 2:3 to 3:2. The emulsion polymerization reaction yields a latex composition comprising a dispersed phase of solid particles and a continuous liquid phase. The latex may be a stable colloidal dispersion comprising a dispersed phase of high molecular weight polymer particles and a continuous phase comprising water. The colloidal particles may comprise approximately 10 to approximately 60 percent by weight of the latex, or approximately 40 to 50 percent by weight of the latex. The continuous phase may comprise water, a high HLB surfactant, a hydrate inhibitor (if present), and a buffer as required. The water may be present in the range of approximately 20 to approximately 80 percent by weight of the latex, or approximately 40 to approximately 60 percent by weight of the latex.The HLB-high surfactant may range from approximately 0.1 to approximately 10 percent by weight of the latex, or from 0.25 to 6 percent by weight of the latex. As indicated in the table above, the buffer may be present in an amount necessary to achieve the pH required to initiate the polymerization reaction and is dependent on the initiator. Typically, the pH required to initiate a reaction is in the range of 6.5 to 10. When a hydrate inhibitor is used in the reaction mixture, it may be present in the resulting latex in an amount that provides a weight ratio of hydrate inhibitor to water in the range of approximately 1:10 to approximately 10:1, in the range of approximately 1:5 to approximately 5:1, or in the range of approximately 2:5 to approximately 3:2. Alternatively, all or part of the hydrate inhibitor may be added to the latex after polymerization to provide the desired amount of hydrate inhibitor in the continuous phase of the latex. In one embodiment, the friction-reducing polymer of the dispersed latex phase may have a weight-average molecular weight (Mw) of at least approximately 1 x 10⁶ g / mol, at least approximately 2 x 10⁶ g / mol, or at least 5 x 10⁶ g / mol. The colloidal particles of the friction-reducing polymer may have an average particle size of less than approximately 10 micrometers, less than approximately 1,000 nm (1 micrometer), in the range of approximately 10 to approximately 500 nm, or in the range of 50 to 250 nm. At least approximately 95 percent by weight of the colloidal particles may be larger than approximately 10 nm and smaller than approximately 500 nm. At least approximately 95 percent by weight of the particles may be larger than approximately 25 nm and smaller than approximately 250 nm.The continuous phase may have a pH in the range of approximately 4 to approximately 10, or in the range of approximately 6 to approximately 8, and contains few, if any, multivalent cations. In one embodiment, the friction-reducing polymer may comprise at least approximately 10,000, at least approximately 25,000, or at least 50,000 repeating units selected from the aforementioned monomer residues. In one embodiment, the friction-reducing polymer may comprise less than one branched unit per monomer residue in the repeating unit. Furthermore, the friction-reducing polymer may comprise less than one linkage group per monomer residue in the repeating unit. Additionally, the friction-reducing polymer may exhibit little or no branching or crosslinking. Furthermore, the friction-reducing polymer may comprise perfluoroalkyl groups in an amount ranging from approximately 0 to approximately 1 percent based on the total number of monomer residues in the repeating units of the friction-reducing polymer. The hydrocarbon additive added after the formation of the friction-reducing polymer can be any conventionally known hydrocarbon additive. In one embodiment, the hydrocarbon additive can be selected from hydrocarbons such as heptane, isooctane, kerosene, kerosene with depleted N-paraffin, and combinations thereof. In an alternative embodiment, the hydrocarbon additive is derived from a source other than hydrocarbon pipelines. Any amount of the hydrocarbon additive can be added to the friction-reducing polymer, provided it does not affect the stability of the friction-reducing polymer. In one embodiment, from approximately 3 wt% to approximately 16 wt% of hydrocarbon additive is incorporated into the friction reducer. In one embodiment, from approximately 3% by weight to approximately 30% by weight of hydrocarbon additive is incorporated into the friction reducer. In an alternative embodiment, the hydrocarbon additive may have a distillation temperature of approximately 300 °C and below. In other embodiments, the distillation temperature may be approximately 275 °C and below, 250 °C and below, 258 °C and below, 225 °C and below, 200 °C and below, 175 °C and below, 150 °C and below, 126 °C and below, or even 100 °C and below. The following examples of certain embodiments of the invention are provided. Each example is provided as one way of explaining the invention, one of several embodiments of the invention, and the following examples should not be considered as limiting or defining the scope of the invention. Sample preparation Hydrocarbon additives were then added in various concentrations to the prefabricated friction-reducing formulations. The resulting samples were rolled to ensure uniform distribution before testing. LMI pump test Milton Roy LMI B7 series pumps were also used to screen the pumping behavior of the product formulations in the laboratory. Approximately 1 liter of sample was added to a container with a feed port and a return port and continuously recirculated by the pump at a rate of approximately 180 g / min. After a period of time, depending on the test protocol, the pump was stopped, and the pump head, made of clear acrylic, was removed. The inner surface of the head and the diaphragm were lightly rinsed with water to remove any residual latex before collecting any adherent film that had formed. The film was collected in a tared tin container and allowed to dry at room temperature for 24 hours before weighing. Table 1. Results of the test with the LMI pump for five hours of the friction reducer with hydrocarbon additives. nc Lcnn / zznz / E / YiAi Additive Test duration (h) Mass on diaphragm (g) Toluene (8%) 5 0.000 Kerosene (12%) 5 0.0109 1-Decene (8%) 5 0.027 1-Decene (4%) 5 0.149 No additive 5 0.292 No additive 5 0.121 Table 2. Results of the test with the LMI pump for three hours of the friction reducer with hydrocarbon additives. Additive Test duration (h) Mass on diaphragm (g) Heptane (12%) 3 0.000 Isooctane (12%) 3 0.000 Kerosene (12%) 3 0.000 Molex Refined (12%) 3 0.001 Hexane (6%) 3 0.024 Kerosene (6%) 3 0.0421 Isooctane (6%) 3 0.043 Kerosene (10%) 3 0.061 No additive 3 0.0768 No additive 3 0.08 No additive 3 0.0973 nc Lcnn / zznz / E / YiAi Finally, it should be noted that the discussion of any reference does not constitute an admission that it is prior art with respect to the present invention, especially any reference that may have a publication date later than the priority date of this application. At the same time, each and every one of the following claims is hereby incorporated into this detailed description or specification as a further embodiment of the present invention. Although the systems and processes described herein have been detailed, it should be understood that various changes, substitutions, and alterations may be made without departing from the spirit and scope of the invention as defined in the following claims. Those skilled in the art may be able to study preferred embodiments and identify other ways of implementing the invention that are not exactly as described herein. It is the inventors' intention that variations and equivalents of the invention be included within the scope of the claims, while the description, abstract, and drawings should not be taken as limiting the scope of the invention. The invention is specifically intended to be as broad as the following claims and their equivalents.

Claims

1. A friction-reducing polymer formulation comprising: a mixture comprising: a friction-reducing polymer; a surfactant selected from the group consisting of a non-ionic surfactant, an anionic surfactant, and combinations thereof; and a hydrocarbon additive selected from the group consisting of: heptane, isooctane, kerosene, kerosene with depleted N-paraffin, and combinations thereof, wherein the weight percentage of the hydrocarbon additive in the friction-reducing polymer formulation ranges from 3% to 16% by weight.

2. The friction-reducing polymer formulation according to claim 1, wherein the hydrocarbon additive is kerosene.

3. The friction-reducing polymer formulation according to claim 1 or 2, wherein the friction-reducing polymer is formed by emulsion polymerization.

4. The friction-reducing polymer formulation according to any of claims 1 to 3, wherein the hydrocarbon additive has a distillation temperature below 300°C.

5. The friction-reducing polymer formulation according to any of claims 1 to 4, wherein the friction-reducing polymer comprises at least 25,000 repeating units.

6. The friction-reducing polymer formulation according to any of claims 1 to 5, wherein the friction-reducing polymer has a weight average molecular weight of at least 1 x 106 g / mol.

7. The friction-reducing polymer formulation according to any one of claims 1 to 6, wherein the anionic surfactant is selected from the group consisting of alkyl sulfates, alkyl ether sulfates, dialkyl sulfosuccinates, alkyl phosphates, alkylaryl sulfonates, and sarcosinates.

8. The friction-reducing polymer formulation according to any one of claims 1 to 7, wherein the nonionic surfactant is selected from the group consisting of sorbitan esters, fatty acid PEG esters, ethoxylated glycerin esters, ethoxylated fatty amines, ethoxylated sorbitan esters, ethylene oxide / propylene oxide block surfactants, alcohol / fatty acid esters, ethoxylated alcohols, ethoxylated fatty acids, alkoxylated castor oils, glycerin esters, ethoxylated linear alcohols, and ethoxylated alkylphenol.

9. A method comprising: injecting a friction-reducing polymer formulation into a conduit containing a first hydrocarbon, wherein the friction-reducing polymer formulation comprises: a mixture comprising: a friction-reducing polymer; a surfactant selected from the group consisting of a non-ionic surfactant, an anionic surfactant, and combinations thereof; and a second hydrocarbon selected from the group consisting of: heptane, isooctane, kerosene, depleted N-paraffin kerosene, and combinations thereof, wherein the weight percentage of the second hydrocarbon in the friction-reducing polymer formulation ranges from 3% to 16% by weight.

10. The method according to claim 9, wherein the second hydrocarbon is kerosene.

11. The method according to claim 9 or 10, wherein the first hydrocarbon is heavy oil.

12. The method according to any of claims 9 to 11, wherein the friction-reducing polymer is a latex friction-reducing polymer.

13. The method according to any of claims 9 to 12, wherein the friction-reducing polymer is formed by emulsion polymerization.

14. The method according to any of claims 9 to 13, wherein the second hydrocarbon has a distillation temperature of less than 300°C.

15. The method according to any of claims 9 to 14, wherein the friction-reducing polymer comprises at least 25,000 repeating units and has a weight-average molecular weight of at least 1 x 10⁶ g / mol.

16. The method according to any of claims 9 to 15, wherein the second hydrocarbon comes from a source other than the pipeline.

17. The method according to any of claims 9 to 16, wherein the second hydrocarbon does not affect the stability of the friction-reducing polymer in the mixture.

18. The method according to any one of claims 9 to 17, wherein the anionic surfactant is selected from the group consisting of alkyl sulfates, alkyl ether sulfates, dialkylsulfosuccinates, alkyl phosphates, alkylaryl sulfonates, and sarcosinates.

19. The method according to any one of claims 9 to 18, wherein the nonionic surfactant is selected from the group consisting of sorbitan esters, fatty acid PEG esters, ethoxylated glycerin esters, ethoxylated fatty amines, ethoxylated sorbitan esters, ethylene oxide / propylene oxide block surfactants, alcohol / fatty acid esters, ethoxylated alcohols, ethoxylated fatty acids, alkoxylated castor oils, glycerin esters, ethoxylated linear alcohols, and ethoxylated alkylphenol.

20. A method for forming a friction-reducing polymer formulation comprising: forming a friction-reducing polymer using a reaction mixture comprising: a monomer; water; and a surfactant selected from the group consisting of a nonionic surfactant, an anionic surfactant, and combinations thereof; and incorporating a hydrocarbon additive with the friction-reducing polymer to form the friction-reducing polymer formulation, wherein the hydrocarbon additive is selected from the group consisting of: heptane, isooctane, kerosene, depleted N-paraffin kerosene, and combinations thereof, wherein from 3 wt% to 16 wt% of the hydrocarbon additive is incorporated into the friction-reducing polymer.

21. The method according to claim 20, wherein the hydrocarbon additive is kerosene.

22. The method according to claim 20 or 21, wherein the anionic surfactant is selected from the group consisting of alkyl sulfates, alkyl ether sulfates, dialkylsulfosuccinates, alkyl phosphates, alkylaryl sulfonates, and sarcosinates.

23. The method according to any one of claims 20 to 22, wherein the nonionic surfactant is selected from the group consisting of sorbitan esters, fatty acid PEG esters, ethoxylated glycerin esters, ethoxylated fatty amines, ethoxylated sorbitan esters, ethylene oxide / propylene oxide block surfactants, alcohol / fatty acid esters, ethoxylated alcohols, ethoxylated fatty acids, alkoxylated castor oils, glycerin esters, ethoxylated linear alcohols, and ethoxylated alkylphenol.

24. The method according to any of claims 20 to 23, wherein the friction-reducing polymer comprises at least 25,000 repeating units and has a weight-average molecular weight of at least 1 x 10⁶ g / mol.

25. The method according to any of claims 20 to 24, wherein the hydrocarbon additive has a distillation temperature of less than 300°C.