BR112017008488B1 - METHOD TO REDUCE PARAFFIN OR WAX DEPOSITION IN A CRUDE OIL STORAGE OR TRANSPORT VESSEL - Google Patents

Abstract

COMPOSITION TO REDUCE DEPOSITION OF PARAFFIN OR WAX ON A VESSEL, AND METHOD FOR REDUCE DEPOSITION OF PARAFFIN OR WAX ON A VESSEL. A composition of copolymers, surfactants and solvents is provided for use in methods of reducing paraffin and wax deposition on crude oil storage and transport vessels.

Description

CROSS-REFERENCE TO RELATED ORDERS

[001] This application claims priority over US Patent Application No. of Serial 14/525,158 filed October 27, 2014, the description of which is hereby incorporated by reference in its entirety.

FIELD OF INVENTION

[002] The present invention generally relates to compositions and methods for reducing paraffin or wax deposits when storing and transporting crude oil. More specifically, the compounds are copolymers derived from maleic anhydride, alpha olefin and specific styrene monomers, which disperse from paraffin or wax deposits of crude oils in storage and transport vessels.

FUNDAMENTALS OF THE INVENTION

[003] Currently, the lack of existing pipeline infrastructure has resulted in increased transportation of some crude petroleum oils, such as Eagle Ford and Bakken crude oils and other compact formation oils or shale oils, by rail. Such crude oils have a tendency to leave residue and build up solids (known as "remains on board") on the walls of storage and transport vessels, such as rail cars. Excessive waste reduces the efficiency of crude oil transport and lead to increased costs related to added downtime for vessel cleaning as well as disposal of waste removed from the vessel which increases the environmental burden. While vessels can be cleaned to remove debris on board, this process generates hazardous waste, takes the ship out of service during the cleaning period, and is expensive.

[004] The addition of compounds to crude oil that are effective in dispersing solids and reducing sludge formation in vessels would be beneficial to the oil and gas industry. Such compounds reduce the formation of solids during storage and transport, therefore mitigating economic losses and reducing the environmental impact.

SUMMARY OF THE INVENTION

em que R1 é hidrogênio ou alquila C12-C30 e R2 é alquila C12 C30. O monômero de alquila de anidrido maleico tem a fórmula (II):

em que R3 é alquila C12-C30 e R4 é hidrogênio ou alquila C12C30.[005] A composition is provided to reduce the deposition of paraffin or wax in a crude oil storage or transport vessel. The composition Contempla is a copolymer which is a product of a polymerization reaction comprising (i) an alpha-olefin monomer and a maleic anhydride monomer, (ii) alpha-olefin monomer and an alkyl maleic anhydride monomer , (iii) the monomer of maleic anhydride and styrene; or (iv) alkyl styrene maleic anhydride monomer; an anionic surfactant; and a solvent. Alpha-olefin monomer has formula (I):

where R1 is hydrogen or C12-C30 alkyl and R2 is C12-C30 alkyl. Maleic anhydride alkyl monomer has formula (II):

wherein R3 is C12-C30 alkyl and R4 is hydrogen or C12C30 alkyl.

[006] A method for reducing paraffin or wax deposition in a crude oil storage or transport container is also provided. The method comprises adding the above-described composition to a crude oil in an amount effective to reduce paraffin or wax deposition in the storage or transport vessel containing the crude oil. Crude oil has an API gravity of at least 33.

[007] Another method is provided to reduce paraffin or wax deposition in a crude oil storage or transport container. The method comprises adding a copolymer as described above to a crude oil in an amount effective to reduce paraffin or wax deposition in the storage or transport vessel containing the crude oil, wherein the crude oil has an API gravity of at least minus 33.

[008] A method for reducing the deposition of paraffin or wax in a storage or transport container used to contain a crude oil is also provided. The method comprises contacting the paraffin or wax deposit in the container with the composition as described above, the amount of the composition being effective to reduce the paraffin or wax deposit in the container; And loading crude oil into the container in such a way that the paraffin or wax is dispersed into the crude oil.

[009] Still another method is provided for reducing the deposition of paraffin or wax in a storage or transport container used to contain a crude oil. The method comprises contacting the paraffin or wax deposition inside the vessel with a copolymer as described above, the amount of the composition being effective to reduce paraffin or wax deposition in the vessel; and charging crude oil into the vessel such that the paraffin or wax is dispersed within the crude oil.

[0010] Other objects and features will be partly apparent and partly indicated below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figures 1 to 6 show the appearance of samples of various Eagle Ford crude oils treated with copolymer additives.

[0012] Figures 7, 8 and 9 depict cold polishers using crude oil blank (Panel A), and cold polishers using crude oil treated with copolymer additives (Panel B).

[0013] Figure 10 shows the temperature viscosity profile of crude oil samples from Eagle Ford treated with copolymer additives.

[0014] Figure 11 depicts the impact of non-esterified AOMA C30 on the stability of Eagle Ford crude oil at room temperature and 10°C.

[0015] Figure 12 represents the adhesion test results of untreated steel (panel A) and treated Bordovsky crude oil (panels B and C).

[0016] Figure 13 illustrates the test results on untreated MEK (panel A) and treated Bordovsky Eagle Ford crude oil (panels B and C).

DESCRIPTION OF THE PREFERRED MODALITY

[0017] Certain copolymers have been found to be effective in reducing paraffin or wax deposits in crude oil storage and shipping containers. Without being bound by any particular theory, these copolymers are believed to disperse paraffin or wax, dissolve paraffin or wax, and provide paraffin or wax slip on metal surfaces in contact with certain crude oils such as compact formation oil or shale, which minimize paraffin or paraffin deposition on such surfaces by up to 50% or more at 6°C. These copolymers also work with anionic surfactants such as alkylbenzene sulfonates to inhibit the adhesion of paraffin or wax deposits to metal surfaces.

[0018] A method is provided to reduce the deposition of paraffin or wax in a crude oil storage or transport container. The method comprises adding a copolymer to a crude oil in an amount effective to reduce paraffin or wax deposition in the storage or shipping vessel containing the crude oil, wherein the crude oil has an API gravity of at least 33. For example, the crude oil may comprise paraffinic crude oil with an API gravity greater than 40. Alternatively, the crude oil may comprise an intermediate crude oil with an API gravity ranging from 33 to 40.

[0019] The copolymer is especially useful when added to a crude oil consisting of shale oil. The shale oil may comprise a tight oil such as an Eagle Ford crude oil or a Bakken crude oil.

[0020] Preferably, the crude oil consists essentially of crude oil of the specified API gravity such that it does not include any significant amount of a refined petroleum product, such as a distillate (e.g., a flow-braked distillate of a diesel fuel ). More preferably, the crude oil does not comprise any distillate.

em que R1 é hidrogênio ou alquila C12-C30 e R2 é alquila C12 C30. O monômero de anidrido maleico de alquila tem a fórmula (II):

em que R3 é alquila C12-C30 e R4 é hidrogênio ou alquila C12C30.[0021] The copolymer is a product of a polymerization reaction comprising (i) an alpha-olefin monomer and a maleic anhydride monomer, (ii) alpha-olefin monomer and an alkyl maleic anhydride monomer, ( iii) the monomer of maleic anhydride and styrene; or (iv) alkyl styrene maleic anhydride monomer; an anionic surfactant; and a solvent. Alpha-olefin monomer has formula (I):

where R1 is hydrogen or C12-C30 alkyl and R2 is C12-C30 alkyl. Alkyl maleic anhydride monomer has formula (II):

wherein R3 is C12-C30 alkyl and R4 is hydrogen or C12C30 alkyl.

[0022] The copolymer may be a product of a polymerization reaction comprising maleic anhydride and alpha-olefin monomer wherein R1 is hydrogen and R2 is C12-C30 alkyl. Preferably, R2 is C24-C30 alkyl. Such alpha-olefin maleic anhydride (Aoma) copolymers are commercially available as Surfomer™ from several manufacturers, including Hangzhou Prudent Chemical Co., Ltd. from Hangzhou, China. Such polymers can be prepared by radical polymerization using an initiator as described in Example 1.

[0023] The alpha olefin monomer used in the polymerization methods described herein can be a monomer, where R2 is primarily C30 or above, such as AlphaPlus® C30 + alpha-olefin from Chevron Phillips Chemical Company LP (The Woodlands, Texas; 11.42 wt% C24 to C28, 88.59 wt% C30 and above).

[0024] The copolymer which is a product of a polymerization reaction comprising an alpha-olefin monomer may be esterified with a linear C12-C30 alcohol group. Preferably, an esterified copolymer is esterified with a linear C20-C28 alcohol. Such esterified Aoma copolymers are commercially available from Nalco as EC5351A Champion (Houston, Texas). Such polymers can be prepared as described in Example 1.

[0025] The copolymer may be a product of a polymerization reaction comprising alkyl maleic anhydride monomer and alpha-olefin monomer wherein R1 and R3 are hydrogen and R2 and R4 are C12-C30 alkyl. Preferably, R2 is C24-C30 alkyl and R4 is C20-C28 alkyl. These alkyl alpha-olefin maleic anhydride copolymers can be made by a process as described in Example 1, wherein an alkyl maleic anhydride monomer is used as a starting material in place of maleic anhydride. Such esterified AOMA copolymers are commercially available as EC5351A from Nalco Champion (Houston, Texas).

[0026] The copolymer may be a product of a polymerization reaction comprising styrene and the alkyl maleic anhydride monomer wherein R3 is hydrogen and R4 is C12-C30 alkyl. Preferably, R4 is C20-C28 alkyl. Such copolymers are commercially available from Nalco as EC5661A Champion (Houston, Texas). Such styrene-alkyl maleic anhydride copolymers can be made by radical polymerization using an initiator such as an organic peroxide.

[0027] The copolymer may be a product of a polymerization reaction comprising styrene and maleic anhydride monomer. For example, such a copolymer may be a styrene maleic anhydride (i.e., poly(styrene-comaleic anhydride)) copolymer. Such copolymers are commercially available as Xiran™ polymers from Polyscope Polymers (Netherlands) and SMA resins from Sartomer (Exton, SHOVEL ).

[0028] The copolymer can be mixed with a solvent before being added to the crude oil. Preferred solvents include alcohols (e.g. straight chain or branched aliphatic such as methanol, ethanol, propanol, isopropanol, butanol, 2-ethylhexanol, hexanol, octanol, decanol, 2-ethylhexanol, 2-butoxyethanol, etc), aromatic hydrocarbons (e.g. toluene, xylene, heavy aromatic naphtha such as aromatic 150, light aromatic naphtha), hydrocarbons (e.g. pentane, hexane, cyclohexane, methylcyclohexane, heptane, decane, dodecane, gas oil ), ketones (e.g. cyclohexanone, diisobutyl ketone), ethers (e.g. tetrahydrofuran (THF)), amides (e.g. N-methylpyrrolidinone (NMP), N,N-dimethylformamide), nitriles, sulfides (e.g. dimethyl sulfoxide (DMSO)), esters, glycols (e.g. ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol), glycol ethers (e.g. ethylene glycol monobutyl ether ( EGMBE) and diethylene glycol monoethyl ether) or a combination thereof. Heavy aromatic naphtha is most preferred.

[0029] The copolymer can also be mixed with an anionic surfactant. Alternatively, an anionic surfactant can be added to the crude oil. Preferably, the anionic surfactant comprises a C6-C30 linear alkyl benzene sulfonate, a C6-C30 linear alcohol sulfate, a C6-C30 linear alkoxylated alcohol sulfate, an alkyl sulfate, an alkyl ether sulfate , an olefin sulfonate or a combination thereof. A preferred anionic surfactant comprises a C6-C30 linear alkylbenzenesulfonic acid group or a salt thereof. Suitable salts include sodium or ammonium salt forms.

[0030] More particularly, up to about 70.0% by weight of solvent, up to about 15.0% by weight of anionic surfactant, and about 22.5 to 100%% of copolymer are added to the crude oil, based on the total weight of solvent, anionic surfactant and copolymer added to the crude oil.

[0031] When all three components are added to the crude oil, from about 40.0 to about 70.0% by weight of solvent, about 0.1 to about 15.0% by weight of anionic surfactant, and about 22.5 to 60.0% by weight of copolymer are added to the crude oil, based on the total weight of solvent, anionic surfactant, and copolymer added to the crude oil.

[0032] When the solvent and the copolymer are added to the crude oil, from about 40.0 to about 70.0%% Solvent, and about 30.0 to 60.0%% by weight of copolymer are added to crude oil, based on the total weight of solvent, anionic surfactant and copolymer added to the crude oil.

[0033] An effective amount of the copolymer ranges from about 50 to about 1000 ppm in the crude oil.

[0034] The storage or transport container may be any container used to store or transport a crude oil, including but not limited to a storage tank, rail car, tank truck, marine vessel, barge or pipeline. Preferably the composition can be added to a crude oil contained in a storage tank, rail car or tanker.

[0035] Another method is provided for reducing paraffin or wax deposition in a crude oil storage or shipping medium. The method comprises adding a composition containing the copolymer as described herein to a crude oil in an amount effective to reduce paraffin or wax deposition in the storage or shipping vessel containing the crude oil. The crude oil has an API gravity of at least 33. For example, the crude oil can comprise paraffinic petroleum that has an API density of over 40. Alternatively, the crude oil can comprise an intermediate crude oil that has an API density in the range from 33 to 40.

[0036] A method is also provided for reducing the deposition of paraffin or wax in a storage or transport container used to contain a crude oil. The method comprises contacting the paraffin or wax deposit in the container with a copolymer as described above or a composition as described below, the amount of the copolymer or composition being effective to reduce paraffin or wax deposit in the container; And loading crude oil into the container in such a way that the paraffin or wax is dispersed into the crude oil.

[0037] A composition is provided to reduce the deposition of paraffin or wax in a crude oil storage or shipping medium. The composition yields: a copolymer which is a product of a polymerization reaction comprising (i) an alpha-olefin monomer and a maleic anhydride monomer, (ii) alpha-olefin monomer and an alkyl maleic anhydride monomer, ( iii) maleic anhydride monomer and styrene; or (iv) styrene alkyl maleic anhydride monomer; An anionic surfactant; and a solvent. Such copolymers are described above and in the examples.

[0038] The composition further yields a solvent and an anionic surfactant, both as described above and in the examples.

[0039] The composition may comprise about 40.0 to about 70.0% by weight solvent, about 0.1 to about 15.0% by weight anionic surfactant, and about 22, 5 to about 60.0% by weight copolymer.

[0040] The composition may further comprise one or more additional components including, but not limited to, a corrosion inhibitor, a solvent, an asphaltene inhibitor, an additional paraffin inhibitor, a scale inhibitor, an emulsifier, a dispersant, an emulsion breaker, a gas hydrate inhibitor, a biocide, a pH modifier and a surfactant. A composition of the invention can comprise from 0 to 10 percent by weight of one or more of these additional components, based on the total weight of the composition.

[0041] Suitable corrosion inhibitors for inclusion in the compositions include, but are not limited to, alkyl, hydroxyalkyl, alkylaryl, arylalkyl, or arylamine quaternary salts; Mono- or polycyclic aromatic amine salts; imidazoline derivatives; Mono-, di-, or trialkyl alkyl aryl phosphate esters; Phosphate esters of hydroxylamines; Phosphate esters of polyols; and monomeric or oligomeric fatty acids.

[0042] Suitable alkyl, hydroxyalkyl, alkylaryl arylalkyl or arylamine quaternary salts include those alkylaryl, arylalkyl and arylamine 5a 6a 7a 8a - 5a 6a 7a quaternary salts of the formula [N+R R R R ] [X ] where R , R , R , and R 8a contains from one to 18 carbon atoms, and X is Cl, Br or I. For example, R5a, R6a, R7a, and R8a are each independently selected from the group consisting of alkyl (e.g., C1 alkyl -C18), hydroxyalkyl (e.g. C1-C18 hydroxyalkyl), and arylalkyl (e.g. benzyl). The mono or polycyclic aromatic amine salt with an alkyl or alkylaryl group 5a 6a 7a 8a - 5a 6a halide include salts of the formula [N+R R R R ] [X ] wherein R , R , R7a and R8a contain one to 18 carbon atoms , and X is Cl, Br or I.

[0043] Suitable quaternary ammonium salts include, but are not limited to, tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, tetrahexylammonium chloride, tetraoctylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, chloride of phenyltrimethylammonium, cetyl chloride, benzyl ammonium chloride, hexadecyl trimethyl ammonium chloride, benzyl dimethyl alkyl quaternary ammonium compounds, monomethyl dialkyl benzyl quaternary ammonium compounds, quaternary benzyl trimethyl ammonium compounds, and trialkyl benzyl quaternary ammonium compounds, wherein the alkyl group can contain from about 6 to about 24 carbon atoms, from about 10 to about 18 carbon atoms, or from about 12 to about 16 carbon atoms. Suitable quaternary ammonium compounds (quats) include, but are not limited to, trialkyl, dialkyl, dialkoxy alkyl, monoalkoxy, benzyl and imidazolinium compounds, quaternary ammonium salts, salts thereof, and combinations thereof. The quaternary ammonium salt may be a benzyl alkylamine quaternary ammonium salt, a benzyl triethanolamine quaternary ammonium salt, a benzyl (C12-C18) alkyl dimethylammonium salt, or a benzyl dimethylaminoethanolamine quaternary ammonium salt.

em que R9a é um grupo alquila, um grupo arila ou um grupo arilalquila, onde os referidos grupos alquila possuem de 1 a cerca de 18 átomos de carbono e B é Cl, Br ou I. De entre estes compostos são os sais de piridinio alquila e de alquil-piridínio benzila quats. Exemplos de compostos incluem cloreto de metilpiridinio, cloreto de etilpiridinio, cloreto de propilpiridinio, cloreto de butilpiridinio, cloreto de octilpiridinio, cloreto de decilpiridinio, cloreto de laurilpiridinio, cloreto de cetilpiridinio, benzilpiridinio e um cloreto de alquilbenzilpiridinio, de preferência em que o alquila é um C grupo hidrocarbila C1-C6. O inibidor de corrosão pode incluir cloreto de benzil piridínio.[0044] The corrosion inhibitor may be a quaternary ammonium or alkylpyridinium quaternary salt, such as those represented by the general formula:

wherein R9a is an alkyl group, an aryl group or an arylalkyl group, wherein said alkyl groups have from 1 to about 18 carbon atoms and B is Cl, Br or I. Among these compounds are the alkyl pyridinium salts and alkyl-pyridinium benzyl quats. Examples of compounds include methylpyridinium chloride, ethylpyridinium chloride, propylpyridinium chloride, butylpyridinium chloride, octylpyridinium chloride, decylpyridinium chloride, laurylpyridinium chloride, cetylpyridinium chloride, benzylpyridinium and an alkylbenzylpyridinium chloride, preferably wherein the alkyl is a C1-C6 hydrocarbyl group. The corrosion inhibitor can include benzyl pyridinium chloride.

em que R12a e R13a representam, independentemente um alquila C1-C6 ou hidrogênio, R11a é hidrogênio, alquila C1-C6, C1-C6 hidroxialquila ou C1-C6, arilalquila, e R10a é um grupo alquila C1-C20 ou um grupo alcoxialquila C1-C20C. Por exemplo, R11a, R12a e R13a representam cada um hidrogênio e R10a representa a mistura alquila típico em ácido graxo de óleo de pinho (TOFA).[0045] The corrosion inhibitor may be an imidazoline derived from a diamine, such as ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetraamine (TETA) etc. and a long chain fatty acid such as tall oil fatty acid (TOFA). Suitable imidazolines include those of the formula:

wherein R12a and R13a independently represent a C1-C6 alkyl or hydrogen, R11a is hydrogen, C1-C6 alkyl, C1-C6 hydroxyalkyl or C1-C6 arylalkyl, and R10a is a C1-C20 alkyl group or a C1 alkoxyalkyl group -C20C. For example, R11a, R12a and R13a each represent hydrogen and R10a represents the typical alkyl mixture in pine oil fatty acid (TOFA).

em que R12a e R13a são independentemente um grupo alquila C1-C6 ou hidrogênio, R11a e R14a são independentemente hidrogênio, alquila C1-C6, hidroxialquila C1-C6 ou C1-C6, arilalquila, e R10 é um grupo alquila C1- C20ou um grupo alcoxialquila C1-C20.[0046] The corrosion inhibitor compound may be an imidazolinium compound of the following formula:

wherein R12a and R13a are independently a C1-C6 alkyl group or hydrogen, R11a and R14a are independently hydrogen, C1-C6 alkyl, C1-C6 or C1-C6 hydroxyalkyl, arylalkyl, and R10 is a C1-C20 alkyl group or a C1-C20 alkoxyalkyl.

[0047] Mono-, di-, and trialkyl esters, as well as suitable alkylarylphosphate and mono, di, and triethanolamine phosphate esters typically contain between 1 and about 18 carbon atoms. Preferred mono-, di-, and trialkyl phosphate esters, alkylaryl or arylalkyl phosphate esters are those prepared by reacting a C3-C18 aliphatic alcohol with phosphorus pentoxide. The phosphate intermediate intercalates its triethyl phosphate ester groups with triethyl phosphate producing a broader distribution of alkyl phosphate esters.

[0048] Alternatively, the phosphate ester can be prepared by mixing with an alkyl diester, a mixture of low molecular weight alkyl alcohols or diols. Low molecular weight alkyl alcohols or diols preferably include C6 to C10 alcohols or diols. Furthermore, phosphate esters of polyols and their salts containing one or more 2-hydroxyethyl groups and hydroxylamine phosphate esters obtained by reacting polyphosphoric acid or phosphorus pentoxide with hydroxylamines such as diethanolamine or triethanolamine are preferred.

[0049] The corrosion inhibitor compound may also be a monomeric or oligomeric fatty acid. Preferred are C14-C22, saturated and unsaturated fatty acids, as well as dimers, trimers and oligomers products obtained by polymerization of one or more of such fatty acids.

[0050] Suitable asphaltene inhibitors include, but are not limited to, aliphatic sulfonic acids; Alkylarylsulfonic acids; aryl sulfonates; Lignosulfonates; Alkylphenol/aldehyde resins and similar sulphonated resins; Polyolefin esters; Polyolefin imides; Polyolefin esters with alkyl, alkylenephenyl or alkylenepyridyl functional groups; Polyolefin amides; Polyolefin amides having alkyl, alkylenephenyl or alkylenepyridyl functional groups; Polyolefin imide with alkyl, alkylenephenyl or alkylenepyridyl functional groups; Alkenyl/vinylpyrrolidone copolymers; Graft polymers of polyolefins with maleic anhydride or vinyl imidazole; Hyperbranched polyester amides; Polyalkoxylated asphaltenes, amphoteric fatty acids, alkyl succinate salts, sorbitan monooleate and polyisobutylene succinic anhydride.

[0051] Additional paraffin inhibitors include, but are not limited to paraffin crystal modifiers, and dispersant/crystal modifier combinations. Suitable paraffin crystal modifiers include, but are not limited to, alkyl acrylate copolymers, alkyl vinylpyridine acrylate copolymers, ethylene vinyl acetate copolymers, maleic anhydride ester copolymers, branched polyethylenes, naphthalene, anthracene, microcrystalline wax and/or asphaltenes. Suitable dispersants include, but are not limited to, dodecyl benzene sulfonate, oxyalkylated alkylphenols and oxyalkylated alkylpnenol resins.

[0052] Suitable scale inhibitors include, but are not limited to, phosphates, phosphate esters, phosphoric acids, phosphonates, phosphonic acids, polyacrylamides, acrylamido-methylpropanesulfonate/acrylic acid copolymer (AMPS/AA) salts, maleic copolymer phosphinate (PHOS/MA) and salts of a polymaleic acid/acrylic acid/acrylamido-methyl propanesulfonate (PMA/AMPS) terpolymer.

[0053] Suitable emulsifiers include, but are not limited to, salts of carboxylic acids, products of acylation reactions between carboxylic acids or carboxylic anhydrides and amines, and alkyl, acyl and amide derivatives of saccharides (alkyl saccharide emulsifiers).

[0054] Suitable dispersants include, but are not limited to, aliphatic phosphonic acids with 2-50 carbon atoms, such as hydroxyethyl diphosphonic acid and aminoalkylphosphonic acids, eg polyaminoethylene phosphonates with 2-10 nitrogen atoms, for example each having at least one methylene phosphonic acid group; Examples of the latter are tetra ethylenediamine (methylene phosphonate), penta diethylenetriamine (methylene phosphonate), and triamine- and tetrame-mine-polymethylene phosphonates with 2-4 methylene groups between each nitrogen atom, at least 2 of the numbers of methylene groups on each phosphonate Being different. Other suitable dispersing agents include lignin or lignin derivatives such as lignosulfonate and naphthalene sulfonic acid and derivatives.

[0055] Suitable emulsion breakers include, but are not limited to, dodecylbenzylsulfonic acid (DDBSA), the sodium salt of xylenesulfonic acid (NAXSA), epoxylated and propoxylated compounds, cationic and nonionic anionic surfactants, and resins, such as resins phenolics and epoxides.

[0056] Suitable hydrogen sulfide scavengers include, but are not limited to, oxidants (for example, inorganic peroxides such as sodium peroxide or chlorine dioxide), aldehydes (for example, 1-10 carbons such as formaldehyde or glutaraldehyde or (meth)acrolein) (For example, monoethanol amine triazine, monomethylamine triazine and triazines from multiple amines or mixtures thereof) and glyoxal.

[0057] Suitable gas hydrate inhibitors include, but are not limited to, thermodynamic hydrate inhibitors (THI), kinetic hydrate inhibitors (KHI) and anti-caking agents (AA).

[0058] Suitable thermodynamic hydrate inhibitors include, but are not limited to, NaCl salt, KCl salt, CaCl 2 salt, MgCl 2 salt, NaBr 2 salt, formate brines (e.g., potassium formate), polyols (such as glucose, sucrose, fructose, maltose, lactose, gluconate, monoethylene glycol, diethylene glycol, triethylene glycol, monopropylene glycol, dipropylene glycol, tripropylene glycols, tetrapropylene glycol, monobutylene glycol, dibutylene glycol, tributylene glycol, glycerol, diglycerol, triglycerol and sugar alcohols (e.g. sorbitol, mannitol) , Methanol, propanol, ethanol, glycol ethers (such as diethylene glycol monomethyl ether, ethylene glycol monobutyl ether) and alkyl or cyclic esters of alcohols (such as ethyl lactate, butyl lactate, methyl ethyl benzoate).

[0059] Suitable kinetic hydrate inhibitors and anti-caking agents include, but are not limited to, polymers and copolymers, polysaccharides (such as hydroxyethylcellulose (HEC), carboxymethylcellulose (CMC), starch, starch derivatives and xanthan), lactams ( such as polyvinylcaprolactam, Polyvinyl lactam), pyrrolidones (such as polyvinyl pyrrolidone of various molecular weights), surfactants (such as fatty acid salts, ethoxylated alcohols, propoxylated alcohols, sorbitan esters, ethoxylated sorbitan esters, polyglycerol esters of fatty acids , alkyl glucosides, alkyl sulfonates, alkyl sulfonates, alkyl ester sulfonates, alkyl aromatic sulfonates, alkylbetaine, alkylamidobetaines), hydrocarbon-based dispersants (such as lignosulphonates, iminodisuccinates, polyaspartates), amino acids and proteins.

[0060] Suitable biocides include, but are not limited to, oxidizing and non-oxidizing biocides.

[0061] Suitable non-oxidizing biocides include, for example, aldehydes (for example, formaldehyde, glutaraldehyde and acrolein), amine-type compounds (for example, quaternary amine compounds and cocodiamine), halogenated compounds (for example bronopol and 2- 2-dibromo-3 (eg isothiazolone, carbamates and metronidazole) and quaternary phosphonium salts (eg tetrakis(hydroxymethyl)phosphonium sulfate (THPS)).

[0062] Suitable oxidizing biocides include, for example, sodium hypochlorite, trichloroisocyanuric acids, dichloroisocyanuric acid, calcium hypochlorite, lithium hypochlorite, chlorinated hydantoins, stabilized sodium hypobromite, activated sodium bromide, brominated hydantoins, chlorine dioxide, ozone and peroxides.

[0063] Suitable pH modifiers include, but are not limited to, alkali hydroxides, alkali carbonates, alkali bicarbonates, alkaline earth metal hydroxides, alkaline earth metal carbonates, alkaline earth metal bicarbonates, and mixtures or combinations thereof . Exemplary pH modifiers include NaOH, KOH, Ca(OH)2, CaO, Na2CO3, KHCO3, K2CO3, NaHCO3, MgO and Mg(OH)2.

[0064] Suitable surfactants include, but are not limited to, anionic surfactants, cationic surfactants, zwitterionic surfactants, and nonionic surfactants.

[0065] Additional anionic surfactants include alkyl carboxylates and alkyl ether carboxylates, alkyl and ethoxylated alkyl phosphate esters, and mono and dialkyl sulfosuccinates and sulfosuccinamates.

[0066] Cationic surfactants include alkyl trimethyl ammonium quaternary ammonium salts, alkyl dimethyl benzyl quaternary ammonium salts, dialkyl dimethyl quaternary ammonium salts and imidazolinium salts.

[0067] Non-ionic surfactants include alcohol alkoxylates, alkylphenol alkyloxyphenes, block copolymers of ethylene, propylene and butylene oxides, alkyl dimethylamine oxides, alkyl bis(2-hydroxyethyl) amine oxides, alkyl amidopropyl oxides dimethyl amine, alkylamidopropyl bis(2 hydroxyethyl) amine oxides, alkyl polyglucosides, glycerides, polyalkoxylated sorbitan esters and polyalkoxylated sorbitan esters, polyethylene glycol esters and alcohol diesters, betaines, and sultanes. A mphoteric surfactants such as alkyl amphoacetates and amphodiacetates, alkyl amphopropionates and amphodipropionates, and alkyliminodipropionate can also be used.

[0068] The surfactant may be a quaternary ammonium compound, an amine oxide, an ionic or non-ionic surfactant, or any combination thereof.

[0069] Suitable quaternary amine compounds include, but are not limited to, alkyl benzyl ammonium chloride, benzyl cocoalkyl (C 12 -C 18) dimethylammonium chloride, dicocoalkyl (C 12 -C 18) dimethylammonium chloride, di-tallow dimethylammonium, di(hydrogenated tallow alkyl) dimethyl quaternary ammonium methyl chloride, methyl bis(2-hydroxyethyl cocoalkyl (C 12 -C 18) quaternary ammonium chloride, dimethyl (2-ethyl) tallow sulfate) Methyl ammonia, n-dodecylbenzyldimethylammonium ammonium chloride, n-octadecylbenzyldimethyl chloride, dodecyltrimethylammonium n-sulfate, Soybean alkyltrimethylammonium chloride, and hydrogenated (2-ethylhexyl) dimethyl tallow alkyl quaternary methylammonium sulfate.

[0070] The compositions may further include additional functional agents or additives that provide a beneficial property, such as pH adjusters or other neutralizing agents, emulsifiers, sequestrants, solubilizers, and other lubricants, buffers, detergents, cleaning agents, brighteners, preservatives, binders, Thickeners or other viscosity modifiers, processing aids, foam inhibitors or foam generators, threshold agent or system, aesthetic enhancing agent (i.e. colorant, odorant, perfume and mixtures of these additional agents or additives vary from according to the particular composition to be manufactured and its intended use, as will be appreciated by one skilled in the art.

[0071] Alternatively, the compositions may not contain any of the additional agents or additives.

[0072] The composition is especially useful when added to a crude oil consisting of shale oil. The shale oil may comprise a tight oil such as Eagle Ford crude or a Bakken crude oil.

[0073] An effective amount of the composition ranges from about 50 to about 1000 ppm in the crude oil.

[0074] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

EXAMPLES

[0075] The following non-limiting examples are provided to further illustrate the present invention. Example 1: Polymer synthesis

[0076] Non-esterified alpha-olefin maleic anhydride copolymer (non-esterified AOMA). 80 g of maleic anhydride (0.82 moles) and about 303 g of alpha-olefin (0.65 to 0.82 moles, depending on the weight molecular weight of C12 to C30 alpha-olefin) were heated to 65 to 80°C in a round-bottomed flask with a neck to completely melt reagents while stirring under nitrogen sweep. Once all materials are melted, nitrogen sweeping was continued for an additional 15 minutes, maintaining the temperature at 65 to 80°C. The mixture was then heated further to 140°C with a continuous supply of nitrogen. Tertiary butyl perbenzoate in hydrocarbon solvent 1:1 (by weight) (Exxsol D80) was used as initiator. The initiator solution was prepared by mixing 1.64 g of tert-butyl perbenzoate (0.0084 moles) with equal amounts by weight of the solvent. The initiator solution was introduced into the reaction mixture in five equal doses (about 720 ul per serving) to control the temperature as the initiating reaction is exothermic. The first shot was introduced once the mixture reached the desired temperature of 140°C. Subsequent injections were introduced every 30 minutes to obtain a total reaction time of 2.5 hours. During the course of the polymerization, the reaction temperature was not allowed to exceed 165°C. The reaction gave a light brown to brown (non-esterified AOMA) viscous polymer. The formulated unesterified AOMA was prepared by diluting the polymer with 40-60% heavy aromatic naphtha when hot.

[0077] Esterified alpha-olefin maleic anhydride copolymer (esterified AOMA). The unesterified AOMA described above was esterified with fatty alcohol at 125°C, in the absence of any catalyst. After AOMA preparation, linear C12 to C30 fatty alcohol of 0.41 moles (i.e., half the moles of maleic anhydride used in the formation of AOMA; for example, 152 g of C20-C28 alcohols of about 375 g/weight molecular weight mole) were added to the reaction mixture, maintaining the temperature at 125°C. At this time, the nitrogen stream was no longer needed. The reaction was allowed to proceed for an additional 2.5 to 3 hours to give a light brown to brown viscous liquid. The formulated esterified AOMA was prepared by diluting the polymer with 40-60% heavy aromatic naphtha. Example 2: Methyl ethyl ketone test (MEK test)

[0078] A simple test has been developed for rapid screening of candidate copolymers in dispersion wax in crude oils (eg oil from compact formations such as Eagle Ford crude oils). The test involved treating a hot raw sample with the copolymer additive followed by stirring. The sample is then diluted with methyl ethyl ketone (MEK) and allowed to stand at room temperature. Wax is insoluble in MEK and a crude sample (without copolymer additive) gives a wax precipitate instantly. Certain copolymers have a tendency to disperse these precipitates. Copolymer additives that do not show activity give a precipitate similar to that of the raw crude sample. More specifically, the test was conducted as follows.

[0079] Crude oil samples were heated to 52 C in an oven (or to a temperature above the Wax Appearance Temperature (WAT) for the crude sample). 200 µl of 1% copolymer additive solution was pipetted into each graduated centrifuge tube. 500 µl of hot crude sample was added to each centrifuge tube containing the additive and the mixture was vortexed. About 5 ml of MEK was added to each tube and the tubes were stoppered and vortexed for 30 seconds. Tubes were then diluted to label with MEK, capped with a stopper and shaken ten times. After a period of about 20 hours of rest, the dispersibility of each sample is observed.

[0080] Figures 1 to 5 depict the dispersibility of five different Eagle Ford crude oils tested with various copolymer additives. Figure 1 shows the appearance of each sample of a first Eagle Ford crude oil, where, from left to right, #1 is a blank control containing no copolymeric additive, #2 is 1,2-dodecandediol, 3 is dodecane, 12) diyl dioleate, # 4 is an unesterified C30 AOMA, # 5 is an ethoxylated seboamine, # 6 is an ethoxylated oleylamine, and # 7 is an esterified (C20-C28) C 30AOMA.

[0081] Figure 2 shows the appearance of each sample of a second Ford Eagle crude oil, where, from left to right, #1 is a blank control not containing any copolymer additive, #2 is an esterified (C20-C28) styrene AOMA, #3 is an unesterified C 10 AOMA, #4 is an unesterified C 12 AOMA, #5 is an unesterified C 14 AOMA, #6 is an unesterified (C24-C28) AOMA , and #7 is an unesterified AOMA C30, and #8 is an esterified (C 20-C 28) AOMA C30.

[0082] Figure 3 shows the appearance of each sample of a third Ford Eagle crude oil, where, from left to right, #1 is a blank control not containing any copolymer additive, #2 is an esterified (C20-C28) styrene AOMA, #3 is a unesterified C10 AOMA, #4 is a unesterified C12 AOMA, #5 is a unesterified C14 AOMA, #6 is a unesterified (C24-C28) AOMA, and #7 is a non-esterified AOMA C30, and #8 is an esterified (C20-C28) AOMA C30.

[0083] Figure 4 shows the appearance of each fourth Ford Eagle crude oil sample, wherein, from left to right, #1 is a blank control not containing any copolymer additive, #2 is an esterified ( C20-C28) Styrene AOMA, #3 is a non-esterified C10 AOMA, #4 is a non-esterified C12 AOMA, #5 is a non-esterified C14 AOMA, #6 is a non-esterified (C24-C28) AOMA, and #7 is a non-esterified AOMA C30, and #8 is an esterified (C20-C28) AOMA C30.

[0084] Figure 5 shows the appearance of each sample of a fifth Ford eagle oil, where, from left to right, #1 is a blank control containing no copolymer additive, #2 is EC6002A at 500 ppm, # #3 is EC6002A at 1000 ppm, #6 is Surfatron DN 173 at 500 ppm, #7 is Surfatron DN 173 at 100 ppm, #8 is an esterified styrene-maleic anhydride copolymer, and #9 is an esterified styrene-maleic anhydride copolymer (at twice the concentration of #8).

[0085] For all five of Eagle Ford crude oils, the esterified (C20-C28) styrene AOMA, non-esterified (C24-C28) AOMA, non-esterified AOMA C30, and esterified (C20-C28) C30 AOMA, exhibited dispersibility increased compared to the control. Copolymers derived from long chain (C24-C30) alpha-olefins and maleic anhydride, if not esterified or esterified with fatty alcohols (C20-C28) exhibited a tendency to disperse waxes in oil from tight formations. The unesterified copolymer resulted in a more stable dispersion than the esterified counterpart. And while the copolymer derived from shorter alpha-olefins (C10-C14) did not show a tendency to disperse wax in these particular crude oils (Eagle Ford crude oils), we believe it will show dispersibility in other types of paraffinic crude oils containing waxes. shorter chain. Example 3: Bottle Test

[0086] A simple test has been developed for rapid screening of candidate copolymers in dispersion wax in crude oils (eg oil from compact formations such as Eagle Ford crude oils). The test involved treating a hot raw sample with 500 or 1000 ppm of the copolymer additive and allowing the sample to stand for about 20 hours at room temperature without agitation. Certain copolymers have a tendency to disperse wax precipitates. Copolymer additives that do not show activity give a precipitate similar to that of the raw crude sample. Figure 6 depicts the dispersibility of an Eagle Ford tight oil tested with various copolymer additives. Figure 6 shows what each sample looks like, where, from left to right, numbers 1 and 6 are either blank control containing no copolymer additive, #2 is 500 ppm of EC6002A, #3 is 1000 ppm of EC6002A, #4 is 500 ppm EC6003A, #5 is 1000 ppm EC6003A, #7 is 500 ppm Surfatron Dn 173, #8 is 1000 ppm Surfatron DN 173, #9 is 500 ppm Styrene Maleic Anhydride Copolymer esterified and #10 is 1000 ppm esterified styrene-maleic anhydride copolymer. The esterified styrene-maleic anhydride copolymer exhibited increased dispersibility compared to the control. Example 4: Testing Cold Polishers

Depósito de cera wt em branco[0087] The effectiveness of the additive in preventing wax deposition was also evaluated by Cold Finger Test. The test was performed using 100 ml of crude Eagle Ford oil maintained at 40°C in a water bath while stirring at 180 rpm. The Cold Polisher submerged in the sample was 6°C. After 23 hours, the deposit was collected and the % wax inhibition was calculated using the formula below:

blank wt wax deposit

[0088] Figure 7, panel A depicts the Cold Polishers using crude oil blank, and panel B is the Cold Polishers using crude oil treated with a non-esterified AOMA C30. Similarly, Figure 8, panel A depicts the Cold Polishers using a different blank Ford Eagle crude oil and panel B is the Cold Polishers using crude oil treated with esterified (C20-C28) AOMA styrene. The use of non-esterified and esterified AOMA C30 resulted in a 30 to 58% reduction in deposition wax under the above conditions at 400 and 600 ppm treatment rates. Additional wax inhibition results are shown in Table 1: Table 1. Wax inhibition in Eagle Ford crude oil with additive use by Cold Polisher test.

[0089] The effectiveness of some additives in preventing wax deposits was also evaluated by a Cold Polisher Test. The test was carried out using 100 ml of crude Eagle Ford oil maintained at 25°C in a water bath while stirring at 180 rpm. The Cold Polisher submerged in the sample was at 0°C. After 22 hours, the deposit was collected and the % wax inhibition was calculated using the formula above: Figure 9, Panel A depicts the Cold polishers using blank crude oil, and Panel B is the Cold polishers using oil crude treated with an esterified styrene-maleic anhydride copolymer. The use of esterified styrene-maleic anhydride resulted in a 14 to 48% reduction in wax deposition under the conditions indicated above at 25 to 500 ppm treatment rates. Example 5: Pour Point Test

1 Uma cera Temperatura Aparência (WAT), conforme medido por DSC. Exemplo 6: Temperatura - Perfil de Viscosidade[0090] The treatment of crude Eagle Ford oils with esterified and non-esterified AOMA also resulted in lower pouring point. The pour point of three different Eagle Ford crude oils (AC samples) was improved by 9 to 12°C after treatment with the copolymer additive as shown in Table 2. Table 2. Impact of esterified and non-esterified AOMA on pour point of crude oil samples from Eagle Ford.

1 A Wax Temperature Appearance (WAT) as measured by DSC. Example 6: Temperature - Viscosity Profile

[0091] The temperature-viscosity profile of the untreated and treated Eagle Ford crude was recorded using a Brookfield viscometer. The impact of unesterified and esterified AOMA is shown in Figure 10. The temperature viscosity profile of Eagle Ford crude oil samples was significantly improved when treated with these copolymer additives, resulting in better pumpability at lower temperatures. Example 7: Suspended solids

[0092] The amount of suspended solids in raw untreated and treated Ford Eagle was measured by Turbiscan at room temperature (RT) and at 10°C. The untreated crude product showed only up to 70% suspended solids after 8 hours at 10°C and 40% suspended solids after 4 hours at room temperature. With the addition of esterified (data not shown) and non-esterified AOMA C30, solid settling was minimized to achieve 100% suspended solids for the entire duration of the test. The impact of unesterified AOMA C30 on the stability of Eagle Ford crude oil at room temperature and 10°C is shown in Figure 11. Example 8: Composition Testing

[0093] Steel adhesion test. A procedure was developed to demonstrate the effectiveness of a copolymer additive to promote skidding of crude oil over metallic surfaces at low temperatures. The combination of non-esterified AOMA C30 with sodium alkylbenzene anionic surfactant sulfonate (and its other forms eg ammonium salt or acid form) showed better performance compared to the untreated slip on Bordovsky Ford Eagle crude. More specifically, the desired amount of copolymer additive was weighed out and placed in a 20 mL vial. 5 mL of crude oil was added to each vial and tightly sealed. The sealed vials were placed in an oven at 140F for 15 minutes. The vials were then removed from the oven and shaken very gently. The steel coupon was inserted into each sample and the vials were placed in a freezer for 2 hours. The vials were removed from the freezer and slowly inverted. After thirty minutes of allowing the vials to warm to room temperature, each vial was carefully opened upside down over a receptacle. The steel coupon was removed and observed for the amount of adherent deposit on the metal surface. Figure 12 represents the adhesion test results of untreated steel and treated Bordovsky crude oil (A: untreated sample; B: treated with non-esterified AOMA C30; C: treated with AOMA C30 + sodium alkylbenzene sulfonate).

[0094] MEK test. A combination of unesterified AOMA C30 and sodium alkylbenzenesulfonate also increased the effectiveness of the former in minimizing deposits in Bordovsky Ford Eagle crude oil. In Example 2, both unesterified and esterified AOMA help to disperse wax in oil from compact formations such as Eagle Ford. When combined with an anionic surfactant (alkylbenzenesulfonic acid or a salt thereof (eg sodium or ammonium)), the MEK test showed increased solubility of the wax. Figure 13 represents MEK test results on crude oil from Bordovsky Eagle Ford. (A: untreated; B: non-esterified C30 AOMA treated; C: non-esterified C30 AOMA treated + sodium alkylbenzene sulfonate; surfactant copolymer weight ratio 4:1). When fully formulated, the combined active ingredients (copolymer + surfactant) should make up 40-60% of the final formulation, with the remainder being solvent such as heavy aromatic naphtha.

[0095] When introducing elements of the present invention or its preferred embodiment(s), the articles "a", "a", "the" and "said" mean that there is one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements in addition to the elements listed. The present disclosure also contemplates other embodiments "comprising", "consisting of" and "consisting essentially of", the embodiments or elements presented herein, whether explicitly stated or not.

[0096] The term "suitable substituent", as used herein, is intended to mean a chemically acceptable functional group, preferably a moiety that does not abrogate the activity of the compounds of the invention. Such suitable substituents include, but are not limited to, halo groups, perfluoroalkyl groups, perfluoroalkoxy groups, alkyl groups, alkenyl groups, alkynyl groups, hydroxyl groups, oxo groups, mercapto groups, alkylthio groups, alkoxy groups, aryl or heteroaryl groups, arylaxy or Heteroarylaxyl groups, aralkyl or heteroaralkyl groups, aralkoxy or heteroaralkoxy groups, HO-(C=O)- groups, heterocyclic groups, cycloalkyl groups, amino groups, alkyl- and dialkylamino groups, carbamoyl groups, alkylcarbonyl groups, alkoxycarbonyl groups, alkylaminocarbonyl groups, dialkylaminocarbonyl groups, arylcarbonyl groups, aryloxycarbonyl groups, alkylsulfonyl groups and arylsulfonyl groups. Those skilled in the art will understand that many substituents can be replaced by additional substituents.

[0097] The term "alkyl", as used herein, refers to a linear or branched hydrocarbon radical having primarily the specified number of carbon atoms and preferably having primarily from 1 to 30 carbon atoms (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 39 or 30 carbons), unless otherwise stated. Alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl and tertiary butyl. Alkyl groups can be unsubstituted or substituted by one or more suitable substituents, as defined above. For example, an alkyl group is C30 alkyl if it contains a range of carbon atoms (for example, C24-C66), but most of the range by weight is C30. More specifically, an alkyl group consisting of 5% by weight of C28, 25% by weight of C30, 20% by weight of C32, 15% by weight of C34, 10% by weight of C36 and each of C40-C66 to less than 5% by weight represents a C30 alkyl group, as used herein since most are C30.

[0098] In view of the foregoing, it will be seen that the various objects of the invention are achieved and other advantageous results are achieved.

[0099] Since various changes can be made to the above compositions and processes without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense .

Claims (13)

1. Method for reducing paraffin or wax deposition in a crude oil storage or transport vessel, the method characterized in that it comprises adding from 50 to 1000 ppm of a copolymer or a composition comprising the copolymer, an anionic surfactant and a solvent to a crude oil to reduce paraffin or wax deposits in the storage or transport vessel containing the crude oil, wherein the crude oil has an API degree of at least 33; and the copolymer is a polymerization reaction product comprising (i) an alpha-olefin monomer and a maleic anhydride monomer, (ii) the alpha-olefin monomer and an alkyl maleic anhydride monomer, (iii) the maleic anhydride and styrene monomer; or (iv) the styrene alkyl maleic anhydride monomer, the alpha-olefin monomer having formula (I):

wherein R1 is hydrogen or C12-C30 alkyl and R2 is C12C30 alkyl, and the alkyl maleic anhydride monomer having the formula (II):

wherein R3 is C12-C30 alkyl and R4 is hydrogen or C12-C30 alkyl. 2. Method according to claim 1, characterized in that: the copolymer is a product of a polymerization reaction comprising maleic anhydride and alpha-olefin monomer in which R1 is hydrogen and R2 is C12-C30 alkyl, or the copolymer is a polymerization reaction product comprising maleic anhydride and the alpha-olefin monomer wherein R1 is hydrogen and R2 is C24-C30 alkyl, or the copolymer is a polymerization reaction product comprising styrene and the monomer of maleic anhydride, or the copolymer is a product of a polymerization reaction comprising maleic anhydride and alpha-olefin monomer wherein R1 is hydrogen and R2 is C12-C30 alkyl and the copolymer is esterified with a linear C12-C30 alcohol; or the copolymer is a product of a polymerization reaction comprising maleic anhydride and the alpha-olefin monomer wherein R1 is hydrogen and R2 is C24-C30 alkyl and the copolymer is esterified with a linear C12-C30 alcohol; or the copolymer is a product of a polymerization reaction comprising styrene and maleic anhydride monomer and is esterified with a linear C12-C30 alcohol; or the copolymer is a polymerization reaction product comprising alkyl maleic anhydride monomer and alpha-olefin monomer wherein R1 and R3 are hydrogen and R2 and R4 are C12-C30 alkyl; or the copolymer is a polymerization reaction product comprising alkyl maleic anhydride monomer and alpha-olefin monomer wherein R1 and R3 are hydrogen, R2 is C24-C30 alkyl, and R4 is C20-C28 alkyl; or the copolymer is a polymerization reaction product comprising styrene and alkyl maleic anhydride monomer wherein R3 is hydrogen and R4 is C12-C30 alkyl; or the copolymer is a product of a polymerization reaction comprising styrene and the alkyl maleic anhydride monomer wherein R3 is hydrogen and R4 is C20-C28 alkyl. 3. Method according to claim 2, characterized in that the copolymer is a product of a polymerization reaction comprising maleic anhydride and alpha-olefin monomer in which R1 is hydrogen and R2 is C12-C30 alkyl and is esterified with a linear C20-C28 alcohol; or the copolymer is a product of a polymerization reaction comprising maleic anhydride and the alpha-olefin monomer wherein R1 is hydrogen and R2 is C24-C30 alkyl and is esterified with a linear C20-C28 alcohol; or the copolymer is a product of a polymerization reaction comprising styrene and maleic anhydride monomer and is esterified with a linear C20-C28 alcohol. 4. Method according to claim 2, characterized in that the copolymer is a product of a polymerization reaction comprising maleic anhydride and alpha-olefin monomer in which R1 is hydrogen and R2 is C24-C30 alkyl. 5. Method according to any one of claims 1 to 4, characterized in that the copolymer is mixed with a solvent before being added to the crude oil. 6. Method according to any one of claims 1 to 4, characterized in that the solvent comprises methanol, heavy aromatic naphtha, light aromatic naphtha, 2-ethylhexanol or a combination thereof. 7. Method according to claim 6, characterized in that the solvent comprises heavy aromatic naphtha. 8. Method according to any one of claims 1 to 7, characterized in that the copolymer is added to the crude oil, and further comprises adding an anionic surfactant to the crude oil. 9. Method according to any one of claims 1 to 8, characterized in that the anionic surfactant comprises C6-C30 linear alkyl benzene sulfonic acid, a C6-C30 linear alkyl benzene sulfonate, a C6-C30 alcohol sulfate linear, a linear C6-C30 alkoxylated alcohol sulfate, an alkyl sulfate, an alkyl ether sulfate, an olefin sulfonate or a combination thereof. 10. Method according to claim 9, characterized in that the anionic surfactant comprises a C6-C30 linear alkyl benzene sulfonic acid or a salt thereof. 11. Method according to any one of claims 1 to 10, characterized in that: the copolymer is added to the crude oil, and from 0 to 70.0% by weight of solvent, from 0 to 15.0% by weight of anionic surfactant, and 22.5 to 100% by weight of copolymer are added to the crude oil, based on the total weight of solvent, anionic surfactant and copolymer added to the crude oil; or the copolymer is added to the crude oil, and from 40.0 to 70.0% by weight of solvent, 0.1 to 15.0% by weight of anionic surfactant and 22.5 to 60.0% by weight of copolymer are added to the crude oil, based on the total weight of solvent, anionic surfactant and copolymer added to the crude oil; or the composition is added to the crude oil, and the composition comprises from 40.0 to 70.0% by weight of solvent, 0.1 to 15.0% by weight of anionic surfactant and 22.5 to 60.0% of copolymer weight. 12. Method according to any one of claims 1 to 11, characterized in that: the crude oil comprises a paraffinic crude oil having an API degree above 40; or the crude oil comprises an intermediate crude oil having an API degree ranging from 33 to 40; or the crude oil comprises a shale oil. 13. Method according to any one of claims 1 to 12, characterized in that the storage or transport vessel comprises a storage tank, wagon, tank truck, marine vessel, barge or pipeline.

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