LU93040B1 - Additive for improving the flow properties of paraffinic crude oils - Google Patents

Abstract

The invention relates to an additive and its use for improving the flow properties of paraffinic crude oil, a process for preparing a crude oil composition having a pour point lowered from the crude oil, and a crude oil composition comprising the additive. Object of the present invention is therefore to provide a way to favorably influence the pour point of crude oil and thus to improve the flow properties of crude oil. In one aspect, the invention provides an additive for improving the flow properties of paraffinic crude oil, wherein the additive comprises 20-40% by weight of at least one copolymer of at least two comonomers, and wherein the comonomers are selected from groups (a) and ( b) of comonomers, and wherein group (a) consists of comonomers of acrylic acid and methacrylic acid, and group (b) of comonomers consists of styrene and a styrene derivative.

Description

ADDITIVE FOR IMPROVING THE FFIESS PROPERTIES OF

PARAFFINOUS OVEN

DESCRIPTION

The invention relates to an additive and its use for improving the

Flow properties of paraffinic crude oil, a process for producing a crude oil composition having a pour point lowered from the crude oil, and a crude oil composition comprising the additive.

Crude oil is a mixture of substances consisting mainly of hydrocarbons. In addition, crude oil contains oxygen and sulfur containing compounds such as naphthenic acids, phenol, aldehydes, thioesters and various heterocyclic compounds. A majority of the hydrocarbons is a mixture of straight-chain unbranched paraffins having 1 to 30 carbon atoms, wherein gaseous and solid hydrocarbons are dissolved in the liquid hydrocarbons.

At low temperatures prepare the paraffins in the crude oil in terms of flow properties special problems. With pure crude oil, paraffins begin to crystallize and agglomerate at temperatures around 40-50 ° C, which significantly deteriorates the flow properties of the crude oil. The temperature at which crude oil spoils its retaining properties is called the pour point. This leads to deposits on the inner walls of the pipes during transport of the crude oil through pipelines, especially in winter, and in some cases even to their complete blockage (for example when a pipeline is at a standstill).

To restore flowability, there are mechanical, physical and chemical methods such as the following: 1) scraping the crystallized paraffins from the pipe inner wall by using a pig. 2) heating the crude oil to a temperature higher than the

Crystallization temperature of paraffins. 3) Use of different solvents to dissolve heavy paraffins.

In recent years, chemical additives (so-called paraffin inhibitors) have been developed. Such additives are macromolecular substances which by physical interaction with paraffins modify their size, shape and adsorption properties. This leads to the formation of smaller Paraffmkristalle, which no longer aggregate and the

No longer impair the flow properties of crude oil. Paraffin inhibitors have predominantly paraffin-like Auibau and have in the side chains generally on polar groups. One of the tasks of these branches is to counteract the crystal formation of the inhibitor. The additives lead to a lowering of the pour point of crude oil.

Paraffin inhibitors which are known are polymers, copolymers and terpolymers having an average molecular weight of from 3,000 to 100,000 g / mol. The effectiveness of the additives depends on their chemical composition and their concentration. US 3 735 770 discloses a process for improving the flow properties of crude oils. This process involves the addition of copolymers of ethylene with unsaturated carboxylic acid esters or of alkylphenols to the oil. US 3,393,057 discloses a terpolymer as a pour point depressant. This consists of 10 to 90 wt .-% C10-C24 a-olefins, 2.5 to 35 wt .-% butadiene and 2.5 to 35 wt .-% styrene or indene, and has a kinematic viscosity at 210 ° F. from 35 to 600 centistokes. US 3,951,929 discloses a pour point improver comprising an interpolymeric acrylic ester having an average molecular weight of 3,000 to 100,000 g / mole. EP 1 086 964 B2 discloses a pour point improver of (meth) acrylic acid copolymer. The poly (meth) acrylic acid ester copolymer consists of 5 to 60 wt .-% (meth) acrylic acid esters of alcohols having 11 to 15 carbon atoms, and 95 to 40 wt .-% (meth) acrylic acid esters of alcohols having 16 to 30 C. -atoms. DE 2048308 A1 discloses as paraffin inhibitor a mixture of ethylene-vinyl ester copolymer having an average molecular weight of 3,000 and 9,000. From 0.01 to 0.5% by weight of the mixture is added to the crude oil in order to reduce the pour point. EA 012243 B1 discloses a pour point improver consisting of a product

Polyoxyethylene sorbitan ester condensation with carboxylic acid anhydrides. The additive improves the depressive properties, flow and viscosity of petroleum and petroleum products. The optimum result is achieved with addition of 50 to 5,000 ppm. WO 2001/096503 A2 discloses an additive for improving the flowability of mineral oil. This contains: a) Copolymers of 80 to 96.5 mol% of ethylene and 3.5 to 20 mol%

Venyl esters of carboxylic acids having 1 to 20 carbon atoms and / or (meth) acrylic acid esters of alcohols having 1 to 8 carbon atoms, and homo- or copolymers of C 10 -C 30 -alkyl-bearing esters of ethylenically unsaturated carboxylic acids with up to 20 mol% olefinically unsaturated compounds, b) a poly-α-olefin having a molecular weight of from 250 to 5,000, which is derived from monoolefins having from 3 to 5 carbon atoms, and c) organic acid selected from certain alkylphenol-aldehyde resins and aliphatic and / or or aromatic sulfonic acids. No. 7,790,821 B2 discloses a process for producing a stable latex dispersion consisting of (co) polymers with one or more (meth) acrylic acid ester monomers of alcohols having from 6 to 40 carbon atoms, optionally with one or more monomers, of non-water-soluble (meth) acrylic and / or vinyl type, and optionally one or more polar monomers selected from (meth) acrylamides and their derivatives, and optionally one or more monomers derived from the ethylenically unsaturated mono- and / or dicarboxylic acids or their anhydrides. The latex dispersion inhibits the separation of paraffins in the crude oil.

There is still a need for suitable additives to improve the

Flow properties of crude oil.

Object of the present invention is therefore to provide a way to favorably influence the pour point of crude oil and thus improves the flow properties of crude oil.

In a first aspect, the invention provides an additive for improving the

Flow properties of paraffinic crude oil, said additive comprising 20-40% by weight of at least one copolymer of at least two comonomers, said comonomers being selected from groups (a) and (b) of comonomers, and wherein group (a) of comonomers of acrylic acid and methacrylic acid, and the group (b) of comonomers consists of styrene and a styrene derivative.

It has surprisingly been found that the use of a copolymer of at least two comonomers wherein the comonomers are selected from groups (a) consisting of acrylic acid and methacrylic acid and (b) consisting of styrene and a styrene derivative improves the cold properties of crude oil can. Examples of corresponding copolymers are acrylic acid / styrene, methacrylic acid / styrene or (meth) acrylic acid / styrene derivative, or else mixed polymers of a mixture of acrylic acid and methacrylic acid and styrene or styrene derivative.

By a "paraffin-containing crude oil" is meant a crude oil (crude petroleum) containing hydrocarbons in the form of paraffins. Under "paraffins" here are acyclic, saturated, straight-chain or branched hydrocarbons (alkanes) with 1 to 33

Carbon atoms, in particular with 12-33 carbon atoms or 16-20 carbon atoms understood. A "paraffin-containing crude oil" is used here in particular if the paraffin content amounts to at least 10%.

The term "acrylic acid" (propenoic acid, CAS number 79-10-7) is understood as meaning a compound of the formula CH 2 = CH-COOH.

The term "methacrylic acid" (2-methylpropenoic acid, CAS number 79-41-4) is understood as meaning a compound of the formula CH 2 = C (CH 3) -COOH.

The term "styrene" (phenylethene, CAS number 100-42-5) is understood as meaning a compound of the following formula:

The term "styrene derivative" is understood here to mean a compound according to the following formula:

wherein R 2, R 3, R 4, R 5 and R 6 are each independently H, methyl, or C 2 -C 12 -alkyl, with the proviso that not all of R 2 to R 6 are H. An example of a styrene derivative is 4-methylstyrene (R4 = CEE, R2, R3, R5 and R6 = H). A compound in which all R 2 to R 6 are H would correspond to styrene.

The formulation according to which the comonomers of the at least one copolymer are selected from groups (a) and (b) of comonomers where group (a) consists of comonomers of acrylic acid and methacrylic acid and group (b) of comonomers of styrene and a styrene derivative ", means that the copolymer is in any case composed of at least one type comonomer from group (a) and at least one type comonomer from group (b). Examples of copolymers would therefore be those of two comonomers, e.g. the comonomers acrylic acid (group a) and styrene (group b), acrylic acid (group a) and styrene derivative group b), methacrylic acid (group a) and styrene (group b) or methacrylic acid (group a) and styrene derivative (group b). However, these also include copolymers of more than two comonomers, e.g. those made of acrylic acid,

Methacrylic acid (group a) and styrene (group b), acrylic acid, methacrylic acid (group a), styrene and styrene derivative (group b), acrylic acid (group a), styrene and styrene derivative (group b), or methacrylic acid (group a), styrene and styrene derivative (group b). In principle, mixed polymers of more than four comonomers are also suitable, for example a copolymer of acrylic acid, methacrylic acid (group a), styrene, styrene derivative 1 and styrene derivative 2 (group b). Preference is given to copolymers of acrylic acid and styrene or methacrylic acid and styrene.

The phrase that "the additive comprises 20-40% by weight of at least one copolymer of at least two comonomers" includes, besides additives, a copolymer having a substantially uniform comonomer composition, i. a copolymer of two particular comonomers (e.g., acrylic acid and styrene), also mixtures of copolymers of differing comonomer composition, as long as the copolymers of the copolymer blend have the above specified composition, i. are composed of at least two comonomers selected from comonomers of groups a and b. The copolymer mixture may contain, for example, copolymers of acrylic acid and styrene, methacrylic acid and styrene and / or acrylic acid, methacrylic acid and styrene.

The term "improving the flow properties of paraffin-containing crude oil" is understood to mean a reduction in the pour point of the crude oil. The pour point is the temperature at which crude oil loses its flowing properties. The pour point can be determined, for example, according to ASTM D5853. A crude oil composition containing the additive according to the invention thus has a lower pour point compared to crude oil. For example, a crude oil may have a pour point of 12 ° C while the crude oil composition has a pour point of -5 ° C.

The term "pour point improver", "pour point depressant" or "paraffin inhibitor" is understood herein to mean an additive which lowers the pour point of a crude oil, preferably by at least 1 ° C., particularly preferably by at least 2 ° C., by at least 3 ° C., by at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C.

The term "alkyl" includes saturated and unsaturated aliphatic (non-aromatic) groups, including straight-chain alkyl groups (eg, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl) and branched chain alkyl groups (eg, isopropyl, tert-butyl, isobutyl ). The term "C 2 -C 12 -alkyl" means an alkyl group having 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 C atoms.

If a molecular weight is stated here in relation to a copolymer according to the invention, this means the weight-average molecular weight.

Range indications such as "10000-30000" are here always to be understood that each

Intermediate value is disclosed with. An arbitrary smaller area of the area should also be disclosed, whereby the smaller area also includes areas which do not include any of the limit values of the area. Thus, an indication such as "10000-30000" includes not only areas such as "10000-29000" or "15000-30000", but also ranges of "15000-28000" or "20000-29000" or "12000-27000", where the individual values within the range are expressly included, and not just its limits.

A copolymer used according to the invention has the general structure according to the following formula I:

(I) wherein R 1 is H or methyl, R 2, R 3, R 4, R 5 and R 6 are each independently H, methyl, or C 2 -C 12 -alkyl, and m is the number of comonomers or comonomers of group (a) (Acrylic acid, methacrylic acid) and m indicates the number of comonomer (s) of group (b) (styrene, styrene derivative) in the copolymer. The above formula gives

schematically only to a general structure and in particular is not to be understood that this must be an old-fashioned copolymer. As already indicated, the formula is also not to be understood as meaning that only two comonomers, e.g. Acrylic acid and styrene in which copolymer is present. Rather, mixtures of more than two comonomers are suitable (for example, acrylic acid, methacrylic acid and styrene), but with the proviso that always at least one comonomer from the group a and at least one comonomer from the group b is present.

The preparation of copolymers is basically known (see, for example, Ullmanns Enzyklopadie der Technischen Chemie, Vol. 21, pages 305 to 403). In this case, monomers are dissolved in an organic solvent and polymerized in the presence of a radical initiator at temperatures in the range of, for example, 30 to 150 ° C.

The at least one copolymer used in the inventive additive is composed in a preferred embodiment of two comonomers, wherein the comonomer from group (a) of comonomers acrylic acid or methacrylic acid, preferably acrylic acid, and the comonomer from group (b) of comonomers Styrene or a styrene derivative, preferably styrene.

The molecular weight or molecular weight distributions (MWD) of the copolymers used according to the invention can be in a range from 2,000 to 500,000, preferably from 5,000 to 300,000. The molecular weight distribution can be determined, for example, by means of gel permeation chromatography against polystyrene standards. For example, the conversion of acrylic acid can be determined after the reaction by reverse phase high performance liquid chromatography (RP-HPLC). For example, H2O / K2HPO4 (pH = -2.7) can be used as the buffer and acetonitrile as the eluent. The conversions of styrene can e.g. be determined after the reaction by gas chromatography (GC).

The average molecular weight or the molecular weight distribution of the copolymer or of the copolymer mixture in the additive according to the invention is preferably adapted to the crude oil to be treated, in particular the molecular weight distribution of the paraffins contained therein. In a preferred embodiment of the additive according to the invention, the at least one copolymer has an average molecular weight of 2000 to 30,000 g / mol, preferably 5,000 to 30,000 g / mol, more preferably 10,000 to 30,000 g / mol, 10,000 to <30,000 g / mol, 10,000 to 29,000 g / mol, 10,000 to 28,000 g / mol, 10,000 to 27,000 g / mol, 10,000 to 26,000 g / mol or 10,000 to 25,000 g / mol.

In a further preferred embodiment of the additive according to the invention, the proportion of comonomer (a) in the at least one copolymer, based on the comonomer mixture, is 0.6 to <10.0% by weight, preferably 1.0 to <10.0% by weight .-%, more preferably 1.0 to 9.0 wt .-%, 2.0 to 9.0 wt .-%, 3.0 to 9.0 wt .-%, 4.0 to 9.0 wt %, 5.0 to 9.0% by weight or 5.0 to 8.0% by weight.

In a particularly preferred embodiment of the inventive additive, the at least one copolymer has an average molecular weight of 10,000 to 30,000 g / mol, and a proportion of acrylic acid of 1.0 to <10.0 wt .-%, preferably from 2.0 to 9.0 wt .-%, on preferably 3.0 to 9.0% by weight, 4.0 to 9.0% by weight, 5.0 to 9.0% by weight or 5.0 to 8.0% by weight, for example 5 wt .-%, on.

The additive preferably also comprises at least one organic solvent in addition to the at least one copolymer, wherein the organic solvent is preferably an aromatic solvent, and is more preferably selected from aromatic

Hydrocarbons such as toluene, xylene, trimethylbenzene, dimethylnaphthalene or a mixture thereof. The organic solvent is chosen so that they are both readily soluble in crude oil and at the same time solve the erfmdungsgemäße copolymer or copolymer mixture well. The proportion of the solvent in the additive may be, for example, 60-80%

For the preparation of a copolymer, as radical initiators (initiators) e.g. Azo-bis-isobutyronitrile, esters of peroxycarboxylic acid such as t-butyl perprivalate and t-butyl-per-2-ethylxeanoate or dibenzoyl peroxide can be used. The initiators can be added to the comonomer mixture, for example, in an amount of 0.05 to 10 wt .-%. The desired properties of the copolymer can be adjusted, for example, by varying the reaction parameters pressure and temperature and by the ratio of initiator to monomer (s).

In a further aspect, the present invention also relates to a crude oil composition comprising an amount of the inventive additive according to the first aspect of the invention which effects a pour point depression of the crude oil of at least 1 ° C.

A preferred crude oil composition according to the invention comprises an amount of the additive according to the invention which has a pour point depression of the crude oil of at least 2 ° C, preferably at least 3 ° C, at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C causes.

In a further preferred embodiment, the inventive

Crude oil composition, for example 50 to 1000 ppmw of an additive according to the invention.

In a further aspect, the present invention also relates to a process for producing a crude oil composition having a pour point lowered from the crude oil, comprising adding an additive according to the invention of the first aspect of the invention to the crude oil in an amount which causes a lowering of the pour point.

In a preferred embodiment of the method according to the invention, an amount of the inventive additive according to the first aspect of the invention is added to the crude oil, which is a lowering of the pour point by at least 1 ° C, preferably at least 2 ° C, at least 3 ° C, at least 4 ° C. , at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C.

In a further preferred embodiment of the process according to the invention, 50 to 1000 ppmw of an inventive additive are added to the crude oil.

In a still further aspect, the present invention relates to the use of a copolymer or mixture of copolymers of at least two comonomers wherein the comonomers are selected from groups (a) and (b) of comonomers, and wherein group (a) comprises comonomers Acrylic acid and methacrylic acid, and the group (b) consists of comonomers of styrene or a styrene derivative as an additive for improving the flow properties of paraffin-containing crude oil.

In a preferred embodiment, a copolymer or copolymer mixture is used, which is dissolved in an organic solvent, wherein the copolymer or copolymer mixture 2% by weight of the solution of copolymer or copolymer mixture and organic solvent.

The copolymer or copolymer mixture is preferably present in an aromatic solvent, preferably in a solvent of one or more aromatic hydrocarbons, for example toluene, xylene, trimethylbenzene, dimethylnaphthalene or a mixture thereof.

The invention is described below purely by way of illustration with reference to FIG

Embodiments described in more detail.

Production of an inventive additive.

A mixture of acrylic acid, styrene (or a styrene derivative) and hydrocarbon solvent is heated with stirring at a temperature of 95 ° C with N 2 flow. The amount of the comonomer mixture in the formulation is from 20.0 to 40.0% by weight.

The amount of acrylic acid is from 0.6 to 10.0 wt .-%, based on the

Comonomer. Thereafter, initiator (dibenzoyl peroxide) in an amount of 0.1 to 3.0 wt .-%, based on the comonomer mixture used. The metering of the initiator takes place at intervals of 40 minutes (4-6 times) (ratio of initiator to monomers: 0.1 to 3.0% by weight) up to full conversion after about 160-240 minutes. Solubility of copolymers according to the invention with different acrylic acid content.

It has been studied how different acrylic acid moieties in the copolymer affect its solubility in hydrocarbons. It became a diesel fraction for the

Investigations used since the solubility / insolubility here can be easily observed with the naked eye. The result is shown in Tab.

Tab. 1: Influence of the amount of acrylic acid in the formulation on the solubility of the copolymer in hydrocarbons (diesel fraction).

Amount of acrylic acid in the recipe based on the comonomer mixture [wt.%] 0.0 2.0 3.0 5.0 7.0 9.0 10.0 Soluble (yes / no) yes yes yes yes yes yes no

Copolymers, which were prepared with a mass fraction of 10% of acrylic acid, do not dissolve in hydrocarbons.

The effectiveness of the prepared copolymers of the invention as a paraffin inhibitor (pour point depressant) was determined by measuring the pour point, determined according to ASTM D5853. The "Sahara" (Saharan Blend) crude oil grade was used with a pour point of +12.0 ° C (see Table 2).

Tab. 2: Influence of the amount of acrylic acid in the recipe on the pour point of Rohôl of the variety "Sahara".

Amount of acrylic acid concentration Concentration point based on the comonomer mixture of the additive [° C] (dibenzoyl peroxide wt. 2.0%) [ppmw] [wt.%] 0.0 500 +10.0 2.0 500 +7.0 4 , 0 500 -2.0 5.0 500 -12.0 7.0 500 +1.0 10.0 500 + 12.0

Examples of the preparation of inventive paraffin inhibitors comprising copolymers of styrene / acrylic acid (S / AA) with different molecular weights (acrylate content in each case 5%) are described below:

Example 1 1.50 g of acrylic acid (acrylic acid 5.0% by weight of the comonomer mixture), 28.50 g of styrene and 69.85 g of toluene are placed in a 500 ml beaker under a draft (N 2 flow). The mixture is heated to a temperature of 95 ° C with constant stirring. Over a period of 40 minutes, a total of 0.075 g of dibenzoyl peroxide (dibenzoyl peroxide 0.25% by weight of the comonomer mixture) is added to the mixture at a constant temperature. The addition is carried out with a dosage of 5 x 0.015 g of dibenzoyl peroxide at intervals of about 8 minutes until the full conversion of 0.075 g is reached. The resulting copolymer had a molecular weight of 30043.2 g / mol.

Example 2 1.50 g of acrylic acid (acrylic acid 5.0% by weight of the comonomer mixture), 28.50 g of styrene and 69.85 g of toluene are placed in a 500 ml beaker under a draw (N 2 flow). The mixture is heated to a temperature of 95 ° C with constant stirring. Over a period of 40 minutes, a total of 0.15 g of dibenzoyl peroxide (dibenzoyl peroxide 0.50% by weight of the comonomer mixture) was added to the mixture at the same temperature. The addition is carried out with a dosage of 5 x 0.03 g of dibenzoyl peroxide at intervals of about 8 minutes until the full conversion of 0.15 g is reached. The resulting copolymer had a molecular weight 21,747.3 g / mol.

Example 3 1.50 g of acrylic acid (acrylic acid 5.0% by weight of the comonomer mixture), 28.50 g of styrene and 69.85 g of toluene are placed in a 500 ml beaker under a draft (N 2 flow). The mixture is heated to a temperature of 95 ° C with constant stirring. About one

For a period of 40 minutes, a total of 0.30 g of dibenzoyl peroxide (dibenzoyl peroxide 1.00% by weight of the comonomer mixture) is added to the mixture at the same temperature. The addition is carried out with a dosage of 5 x 0.06 g of dibenzoyl peroxide at intervals of about 8 minutes until the full conversion of 0.30 g is reached. The resulting copolymer had a molecular weight of 17986.7 g / mol.

Examples 4, 5

Two further paraffin inhibitors were prepared according to the pattern described in Examples 1-3, the amount of dibenzoyl peroxide being 2.0 and 2.5% by weight, respectively. The copolymers produced had molecular weights of 11583.0 and 10512.5, respectively.

The additives according to the invention prepared in Examples 1-5 were added to "Sahara" crude oil and the pour point of the crude oil compositions thus prepared was determined (see Table 4).

Tab. 3: Influence of the molecular weight of the copolymer on the pour point of "Sahara" crude oil.

Example No. Amount of dibenzoyl peroxide M w concentration Concentration point with respect to the comonomer mixture [g / mol] of the additive [° C] (acrylic acid, wt.% 5.0%) [ppmw] [wt.%]

Ex. 1 0.25 30043.2 500 + 12.0

Ex. 2 0.5 21747.3 500 -20.0

Ex. 3 1.0 17986.7 500 -21.0

Ex. 4 2.0 11583.0 500 -12.0

Ex. 5 2.5 10512.5 500 -10.0

The additive prepared in Example 3 was added to "Sibir" (pour point +17.0 ° C) and "Sahara" (pour point +12.0 ° C) crude at different concentrations, and the pour point of the resulting crude oil compositions was determined (see Tab. 4, 5).

Tab. 4: Cold properties of "Sibir" crude oil when using 50-500 ppm of copolymer S / AA

Example No. Concentration of additive pour point [ppmw] [° C]

Example 3 50 +15.0

Example 3 75 -4.0

Example 3 100 -21.0

Example 3 200 -21.0

Ex. 3 500 -21.0

Tab. 5: Cold properties of "Sahara" crude oil when using 50-500 ppm of copolymer S / AA

Examples No Concentration of Additive pour point [ppmw] [° C]

Example 3 50 +12.0

Example 3 100 -10.0

Example 3 250 -20.0

Ex. 3 500 -21.0

Example 3 750 -21.0

Claims (14)

An additive for improving the flow properties of paraffinic crude oil, comprising 20-40% by weight of at least one copolymer of at least two comonomers, the comonomers being selected from groups (a) and (b) of comonomers, and wherein the group ( a) consists of comonomers of acrylic acid and methacrylic acid, and the group (b) consists of comonomers of styrene and a styrene derivative. 2. An additive according to claim 1, wherein the at least one copolymer has a molecular weight of 2000 to 30,000 g / mol, preferably 5,000 to 30,000 g / mol, more preferably 10,000 to <30,000 g / mol, 10,000 to 30,000 g / mol, 10,000 to 29,000 g / mol, 10,000 to 28,000 g / mol, 10,000 to 27,000 g / mol, 10,000 to 26,000 g / mol or 10,000 to 25,000 g / mol or 10,000 to 25,000 g / mol. 3. Additive according to claim 1 or 2, wherein the Anted of the comonomer of group (a) to the at least one copolymer, based on the comonomer mixture, 0.6 to <10.0 wt .-%, preferably 1.0 to <10 , 0 wt .-%, more preferably 1.0 to 9.0 wt .-%, 2.0 to 9.0 wt .-%, 3.0 to 9.0 wt .-%, 4.0 to 9 , 0 wt .-%, 5.0 to 9.0 wt .-% or 5.0 to 8.0 wt .-% is. 4. Additive according to one of the preceding claims, wherein the at least one copolymer is composed of two comonomers, and wherein the comonomer from the group (a) of comonomers is acrylic acid or methacrylic acid, preferably acrylic acid, and the comonomer from the group (b) of comonomers is styrene or a styrene derivative, preferably styrene. 5. Additive according to one of the preceding claims, further comprising at least one organic solvent, wherein the organic solvent is preferably an aromatic solvent, more preferably an aromatic hydrocarbon, and is more preferably selected from toluene, xylene, trimethylbenzene, dimethylnaphthalene or a mixture thereof. A crude oil composition comprising an amount of the additive according to any one of claims 1 to 5, which causes a lowering of the pour point of the crude oil of at least 1 ° C. A crude oil composition according to claim 6, comprising an amount of the additive according to any one of claims 1 to 5, which is a lowering of the pour point of the crude oil of at least 2 ° C, preferably at least 3 ° C, at least 4 ° C, at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C causes. 8. Crude oil composition according to one of claims 6 to 7, comprising 50 to 1000 ppmw of an additive according to one of claims 1 to 5. A process for producing a crude oil composition having a pour point lowered from the crude oil, comprising adding an additive according to any one of claims 1 to 5 to the crude oil in an amount effective to lower the pour point. 10. The method of claim 9, wherein the crude oil, an amount of the additive according to any one of claims 1 to 5 is added, a lowering of the pour point by at least 1 ° C, preferably at least 2 ° C, at least 3 ° C, at least 4 ° C. , at least 5 ° C, at least 6 ° C, at least 7 ° C, at least 8 ° C, at least 9 ° C or at least 10 ° C. 11. The method according to any one of claims 9 or 10, wherein the crude oil 50 to 1000 ppmw of an additive according to any one of claims 1 to 5 are added. Use of a copolymer or mixture of copolymers of at least two comonomers, wherein the comonomers are selected from groups (a) and (b) of comonomers, and wherein group (a) consists of comonomers of acrylic acid and methacrylic acid, and the group (b) Comonomers of styrene or a styrene derivative, as an additive for improving the flow properties of paraffinic crude oil. 13. Use according to claim 12, wherein the copolymer or copolymer mixture is dissolved in an organic solvent, and wherein the copolymer or copolymer mixture constitutes 20-40 wt .-% of the solution of copolymer or copolymer mixture and organic solvent. 14. Use according to claim 13, wherein the copolymer or copolymer mixture is present in an aromatic solvent, preferably in an aromatic solvent which is selected from toluene, xylene, trimethylbenzene, dimethylnaphthalene or a mixture thereof.