FR3137915A1 - COMPOSITION OF ADDITIVES AND ITS USE TO IMPROVE THE PUMPABILITY OF MIXTURES OF WATER AND CRUDE OIL - Google Patents

Abstract

The subject of the present invention is an additive composition comprising: (1) at least one copolymer of ethylene and vinyl acetate grafted with at least one alkyl (meth)acrylate group whose alkyl chain is saturated and contains 12 to 30 carbon atoms; (2) at least one modified alkylphenol-aldehyde resin capable of being obtained by Mannich reaction of an alkylphenol-aldehyde condensation resin with at least one aldehyde and/or a ketone having from 1 to 8 carbon atoms, and at least one hydrocarbon compound having 1 to 30 carbon atoms and comprising at least one alkylpolyamine group;(3) at least one alkoxylated alkylphenol-aldehyde condensation resin; and; (4) at least one organic solvent The present invention also relates to the use of such a composition of additives to lower the viscosity of a mixture of crude mineral oil and water and/or to improve the pumpability of such a mixture.

Description

COMPOSITION OF ADDITIVES AND ITS USE TO IMPROVE THE PUMPABILITY OF MIXTURES OF WATER AND CRUDE OIL

Technical area
The present invention relates to an additive composition comprising at least one first compound chosen from copolymers of ethylene and vinyl acetate (EVA) grafted with at least one alkyl (meth)acrylate, at least one second compound chosen among alkylphenol-aldehyde resins modified by an alkylpolyamine, at least one third compound chosen from alkoxylated alkylphenol-aldehyde resins and at least one organic solvent.

The invention also relates to the use of this composition to control the viscosity of a mixture of water and crude oil and to improve its pumpability and transport.

The invention further relates to a method for extracting a mixture comprising crude oil and water, comprising a step of introducing the additive composition into said mixture and a step of pumping the mixture comprising said composition .

The invention finally relates to a crude oil composition comprising water and an additive composition as described below.

State of the prior art
Underground formations of crude oil, also commonly referred to as "crude mineral oil" or "crude oil" or "crude oil" have relatively high temperatures. As the crude oil is extracted from the underground formation to the surface, it cools. Its cooling varies depending on the production temperature and storage or transport conditions.

The crude oil extracted mainly includes two classes of products: maltenes and asphaltenes. The main constituents of maltenes are resins and waxes. These so-called waxes are made up of paraffins (saturated hydrocarbon compounds) and aromatics. Paraffins consist of linear or branched alkanes and can be liquid, oily or solid.

Depending on their origin, crude oils have different proportions of waxes, which mainly consist of long-chain n-paraffins. Depending on the type of crude oil, the proportion of these paraffins can typically be from 1 to 30% by weight of the crude oil.

In a manner known per se, when extracting crude oil from a well, the extracted crude oil cools. As a result, the paraffins crystallize, typically in the form of platelets or platelet aggregates, and the viscosity (both dynamic and kinematic) of the oil increases. Platelet-shaped n-paraffin crystals can form a three-dimensional network that encloses the remaining liquid portion of the crude oil, so that the crude oil stops flowing, even if the predominant portion is still liquid. Crystallized paraffins, and therefore very viscous crude oil, can block filters, pumps, pipes/pipelines, clog wells, and other installations or be deposited in tanks, thus requiring a high level of cleaning. The crystallization of these paraffins and thus the increase in viscosity can occur in oil production wells and in pumping installations. These crystallized paraffins considerably harm the fluidity of the oil, they increase its viscosity and make pumping and transport operations more difficult, and more expensive, in particular because they require more energy.

An additional problem arises when the extracted crude oil is mixed with water. This is the case, for example, of a well in production, in which the quantity of water present gradually increases over time. The water comes from natural sources present in the ground or corresponds to water reinjected into the well to maintain a sufficient level of pressure.

This is also the case for underwater wells. In the case of the exploitation of an underwater well, the crude oil is extracted in the form of a mixture, typically an emulsion, of crude oil and more or less salty water with an additional difficulty induced by the low temperatures encountered in the underwater depths (of the order of 4°C): thus, the mixture of water and crude oil is strongly cooled, which promotes an increase in its viscosity.

The presence of water in the crude oil significantly increases the viscosity of the extracted mixture, and further complicates pumping and transport operations. The energy consumed during these operations is greatly increased by the presence of water in the crude oil extracted. This phenomenon also leads to a significant loss of productivity, a substantial increase in production costs and a reduction in the life of the well.

In a manner known per se, it is conventional to add additives to crude oils aimed at reducing the crystallization phenomena of paraffins at low temperature, in particular crystallization modifier additives making it possible to modify the morphology and size of the paraffin crystals and /or to limit the phenomena of agglomeration of paraffin crystals.

Known additives are for example modified alkylphenol-aldehyde resins, obtained by Mannich reaction of an alkylphenol-aldehyde condensation resin with at least one aldehyde and at least one hydrocarbon compound having at least one alkylamine group, in fuel compositions as WASA anti-sedimentation additives (from the English “wax anti settling agents”) (WO2012085865), for resistance to low temperatures (WO2013189868).

However, known additives are not sufficiently effective in the case of extracting a mixture of water and crude oil. As explained above, the presence of water significantly increases the phenomena of increasing the viscosity of the mixture during its cooling, such that the compounds conventionally used to control the formation and growth of paraffin crystals do not are not sufficiently effective.

To remedy this, known solutions consist either of heating the mixture of raw oil and water so as to lower its viscosity, or of increasing the additive contents.

However, increasing the additive contents is not only expensive but also does not always make it possible to sufficiently lower the viscosity of the mixture. In addition, it is not always possible to heat the mixture during its extraction, particularly in the case of an underwater well. Such heating proves, in practice, complicated to implement and expensive in energy.

The Applicant has now discovered a particular composition of additives, which makes it possible to lower in a very effective and synergistic manner the viscosity of mixtures of crude oils and water, and thus to facilitate the pumping and transport operations of these mixtures.

This composition has proven to be particularly effective when exploiting underwater oil reserves.

Summary of the invention
The subject of the present invention is an additive composition comprising:
(1) at least one first compound chosen from copolymers of ethylene and vinyl acetate grafted with at least one alkyl (meth)acrylate group whose alkyl chain is saturated and contains from 12 to 30 carbon atoms;
(2) at least one second compound chosen from modified alkylphenol-aldehyde resins; said modified alkylphenol-aldehyde resins being capable of being obtained by Mannich reaction of an alkylphenol-aldehyde condensation resin with
- at least one aldehyde and/or a ketone having 1 to 8 carbon atoms, and
- at least one hydrocarbon compound having from 1 to 30 carbon atoms and comprising at least one alkylpolyamine group;
said alkylphenol-aldehyde condensation resin itself being capable of being obtained by condensation:
• at least one alkylphenol substituted by at least one alkyl group, linear or branched, having from 1 to 30 carbon atoms, with
• at least one aldehyde and/or a ketone having 1 to 8 carbon atoms;
(3) at least one third compound chosen from alkoxylated alkylphenol-aldehyde condensation resins; And ;
(4) at least one organic solvent.

The present invention also relates to a composition comprising a crude mineral oil, water and an additive composition as defined above.

The invention also relates to the use of the additive composition to lower the dynamic and/or kinematic viscosity of a mixture of water and crude mineral oil, in particular (but not limited to) at low temperature.

The use according to the invention also aims to improve the pumpability of mixtures of water and crude mineral oil and to facilitate their transport.

The invention finally relates to a process for extracting a mixture of crude mineral oil and water, comprising the injection into said mixture during its pumping of the composition of additives as defined above.

According to a preferred embodiment, the crude mineral oil is extracted from an underwater well.

Other objects, characteristics, aspects and advantages of the invention will appear even more clearly on reading the description and examples which follow.

In what follows, and unless otherwise indicated, the limits of a domain of values are included in this domain, in particular in the expressions: “between… and…”, “included in the range from… to…”, and “ranging from… to…”.

Furthermore, the expressions “at least one” and “at least” used in this description are respectively equivalent to the expressions “one or more” and “greater or equal”.

Finally, in a manner known per se, the term C _N compound means a compound containing N carbon atoms in its chemical structure.

Detailed description of the invention

The graft copolymer (1)
The composition according to the invention comprises a first compound (1) chosen from copolymers of ethylene and vinyl acetate grafted with at least one alkyl (meth)acrylate whose alkyl chain is saturated and contains from 12 to 30 carbon atoms.

In other words, the copolymer comprises a main chain or basic skeleton consisting of a copolymer of ethylene and vinyl acetate onto which are grafted at least one alkyl (meth)acrylate whose alkyl chain is saturated and contains 12 to 30 carbon atoms.

The backbone of ethylene and vinyl acetate
The compound (1) comprises a main chain or basic skeleton consisting of a copolymer of ethylene and vinyl acetate.

Such a copolymer therefore comprises a repeating unit of formula (I) as follows:
(I)
This motif comes from the ethylene monomer.

Preferably, the unit of formula (I) represents from 71 to 94% by moles relative to the total number of moles of units of the grafted copolymer (1), more preferably from 78 to 88% by moles, more preferably still from 80 to 88% in moles, and better still from 82 to 87% in moles.

The copolymer also comprises one or more repeating unit(s) of vinyl acetate corresponding to the following formula (II):
(II)
in which
R ₁ , R ₂ , and R ₃ represent a hydrogen atom, and R ₄ represents a methyl group (CH ₃ ).

The unit(s) of formula (II) preferably represent(s) from 5 to 25% by mole, relative to the total number of moles of units of the graft copolymer (1), more preferably from 10% to 15% by mole.

The units of formula (II) come from monomers of the C2 carboxylic acid ester and vinyl alcohols, that is to say the vinyl acetate ester of formula (IIA) following:
(IIA)
in which R₁,R₂,R₃and R₄are as defined above.

The distribution of the motifs (I) and (II) in the skeleton is preferably of the statistical type.

Preferably, the backbone of the copolymers (1) used in the present invention contains only units of formula (I) and units of formula (II).

Such ethylene and vinyl acetate skeletons can be prepared according to polymerization processes known per se. The different polymerization techniques and conditions are widely described in the literature and fall within the general knowledge of those skilled in the art.

They can in particular be synthesized by conventional radical polymerization as described in document US3627838: we generally proceed by mixing the different monomers in an appropriate solvent, such as benzene, and the copolymerization is initiated by means of a radical polymerization initiator, such as a peroxide such as tert-butyl hydroperoxide. The polymerization conditions are known to those skilled in the art. The reaction temperature can range from 150 to 280°C, and the reaction can be carried out at high pressure (1500 to 2000 bars).

In the case where the skeleton is prepared by conventional radical polymerization, it may be necessary to carry out, after the polymerization itself, a purification by any appropriate separation technique (in particular by chromatography) so as to isolate a copolymer having the required characteristics in terms of molar mass and dispersity.

According to a preferred embodiment, the ethylene and vinyl acetate skeleton is prepared using controlled radical polymerization (PRC) techniques. Controlled radical polymerization techniques, known per se, have the advantage of being able to lead directly to copolymers having the required molar mass and dispersity characteristics, such that a separative purification may, depending on the conditions used, not be necessary. be necessary.

Among these techniques, we can cite in particular polymerizations governed by reversible termination or by reversible transfer (or degenerative transfer). Among these PRC techniques, those controlled by degenerative transfer are preferred and among these radical polymerization by reversible addition-fragmentation chain transfer (RAFT) is even more preferred.

THE _ ( meth )alkyl acrylate grafts
The basic skeleton consisting of a copolymer of ethylene and vinyl acetate as described above is grafted with at least one alkyl (meth)acrylate whose alkyl chain is saturated and contains from 12 to 30 atoms of carbon.

Such a graft typically corresponds to the following formula (III):
(III)
in which
R ₅ , R _6, identical or different, represent a hydrogen atom or a C ₁ to C ₄ alkyl group; R ₇ represents a hydrogen atom or a methyl group and R ₈ represents a saturated C ₁₂ to C ₃₀ alkyl chain.

In a preferred embodiment, the alkyl (meth)acrylate graft(s) have a saturated alkyl chain comprising from 14 to 26 carbon atoms, and preferably from 18 to 22 carbon atoms.

According to a preferred embodiment, R5, R ₆ , and R _7, identical or different, represent a hydrogen atom or a methyl group. Particularly preferably, R ₅ , R ₆ and R ₇ all represent a hydrogen atom; or R ₅ , R ₆ represent a hydrogen atom and R ₇ represents a methyl group.

According to an also preferred embodiment, R ₈ represents a linear saturated alkyl chain. More preferably, R ₈ is chosen from the groups nC ₁₈ H ₃₇ , nC ₁₉ H ₃₉ , nC ₂₀ H ₄₁ , nC ₂₁ H ₄₃ , and nC ₂₂ H ₄₅ .

According to a particularly preferred embodiment:
- R ₅ , R ₆ , and R ₇ all represent a hydrogen atom, and
- R ₈ is chosen from the groups nC ₁₈ H ₃₇ , nC ₁₉ H ₃₉ , nC ₂₀ H ₄₁ , nC ₂₁ H ₄₃ , and nC ₂₂ H ₄₅ .

Very preferably, R ₈ is chosen from a mixture of the groups nC ₁₈ H ₃₇ , nC ₂₀ H ₄₁ , and nC ₂₂ H ₄₅ , that is to say that the alkyl (meth)acrylate is the acrylate behenyl.

Grafting by the alkyl (meth)acrylate function on the ethylene and vinyl acetate skeleton can be carried out by any grafting process known per se, such as grafting by conventional radical route or controlled radical route, or by ATRP (atom transfer polymerization).

The different grafting techniques and conditions are widely described in the literature and fall within the general knowledge of those skilled in the art.

Grafting by radical route is particularly preferred. Grafting is carried out at the level of the vinyl acetate: either on the methyl group of the acetate, or on the tertiary carbons of the copolymer backbone, depending on the nature of the polymerization initiator.

If the initiating agent is benzoyl peroxide, grafting is instead initiated on the methyl group of the acetate.

If the initiating agent is dicumyl peroxide, grafting is instead initiated on the tertiary carbons of the copolymer backbone, or the methyl group of the acetate.

The graft(s) of formula (III) preferably represent(s) from 1 to 4% by mole, relative to the total number of moles of units of the grafted copolymer (1), more preferably from 1.5 to 3% by mole .

The molar mass in number Mn of the graft copolymers (1) according to the invention, measured by GPC, is preferably in the range going from 5000 to 50,000 g.mol ^-1 , preferably from 10,000 to 40,000 g.mol ^-1 , better from 12,000 to 32,000 g.mol ^-1 .

The molar mass by weight Mw of the graft copolymers (1) according to the invention, measured by GPC, is preferably in the range going from 23,500 to 230,000 g.mol ^-1 , preferably from 46,500 to 190,000 g.mol ^-1 , better from 55,000 to 150,000 g.mol ^-1 .

Preferably, the total content of the grafted ethylene and vinyl acetate copolymer(s) is in the range going from 1 to 15% by mass, preferably from 2 to 10% by mass, and more preferably from 2, 5 to 5% by mass, relative to the total mass of the additive composition.

L has resin alkylphenol -modified aldehyde (2 )
The modified alkylphenol-aldehyde resin(s) used in the present invention is(are) capable of being obtained by Mannich reaction of an alkylphenol-aldehyde condensation resin with
- at least one aldehyde and/or a ketone having 1 to 8 carbon atoms, and
- at least one hydrocarbon compound having from 1 to 30 carbon atoms and comprising at least one alkylpolyamine group.
Said alkylphenol-aldehyde condensation resin is itself capable of being obtained by condensation:
• at least one alkylphenol substituted by at least one alkyl group, linear or branched, having from 1 to 30 carbon atoms, with
• at least one aldehyde and/or ketone having 1 to 8 carbon atoms.

According to a preferred embodiment, the modified alkylphenol-aldehyde resin(s) is(are) capable of being obtained by Mannich reaction of an alkylphenol-aldehyde condensation resin with
- at least one aldehyde and/or a ketone having 1 to 4 carbon atoms, and
- at least one hydrocarbon compound having 4 to 30 carbon atoms and comprising at least one alkylpolyamine group,
said alkylphenol-aldehyde condensation resin itself being capable of being obtained by condensation:
• at least one mono-alkylphenol substituted by at least one alkyl group, linear or branched, having from 4 to 30 carbon atoms, with
• at least one aldehyde and/or one ketone having 1 to 4 carbon atoms.

The alkylphenol-aldehyde condensation resin can be chosen from any resin of this type already known and in particular, those described in documents EP857776 and EP1584673.

The modified alkylphenol-aldehyde resin according to the invention can advantageously be obtained from at least one para-substituted alkylphenol. Para-nonylphenol is preferably used.

According to a preferred embodiment, the average number of phenolic nuclei per molecule of nonylphenol-aldehyde resin is between 6 and 25, preferably between 8 and 17, and even more preferably between 9 and 16.

The number of phenolic nuclei can be determined by nuclear magnetic resonance (NMR) or gel permeation chromatography (GPC).

Advantageously, the modified alkylphenol-aldehyde resin is obtained from the same aldehyde or the same ketone as said alkylphenol-aldehyde condensation resin.

According to a preferred embodiment, the modified alkylphenol-aldehyde resin can be obtained from at least one aldehyde and/or at least one ketone chosen from formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde. , 2-ethyl-hexanal, benzaldehyde and/or acetone. Preferably, the modified alkylphenol-aldehyde resin can be obtained from at least one aldehyde, preferably at least formaldehyde (also called methanal).

According to a particular embodiment, the modified alkylphenol-aldehyde resin can be obtained from at least one alkylpolyamine having at least two groups chosen from primary amine and secondary amine groups. In particular, the alkylpolyamine is advantageously chosen from primary and/or secondary polyamines substituted by, respectively, one or two alkyl groups comprising, preferably, from 12 to 24 carbon atoms, more preferably from 12 to 22 carbon atoms.

According to a preferred embodiment, the modified alkylphenol-aldehyde resin can be obtained from at least one alkylpolyamine having at least two amine groups, and preferably at least three amine groups.

According to a preferred embodiment, the modified alkylphenol-aldehyde resin can be obtained from at least one alkylpolyamine comprising a fatty chain having from 12 to 24 carbon atoms, preferably from 12 to 22 carbon atoms.

According to a particularly preferred embodiment, the modified alkylphenol-aldehyde resin can be obtained from at least one alkylpolyamine having at least two amine groups, preferably at least three amine groups, and comprising a fatty chain having 12 to 24 carbon atoms, preferably 12 to 22 carbon atoms.

Commercial alkylpolyamines are generally not pure compounds but mixtures. Among the suitable marketed alkylpolyamines, mention may in particular be made of fatty chain alkylpolyamines marketed under the names Trinoram®, Duomeen®, Dinoram®, Triameen®, Armeen®, Polyram®, Lilamin® and Cemulcat®.

As a preferred example, we can cite Trinoram®S which is a tallow dipropylenetriamine, also known under the name N-(Tallowalkyl)dipropylenetriamine (CAS 61791-57-9).

Preferably, the total content of the modified alkylphenol-aldehyde resin(s) is in the range going from 0.2 to 5% by mass, preferably from 0.5 to 3% by mass, and more preferably from 0.5 to 1.5% by mass, relative to the total mass of the additive composition.

Alkoxylated alkylphenol - aldehyde condensation resin (3)
Said resin consists of an alkylphenol-aldehyde condensation resin onto which (poly)alkoxy groups are grafted.

The alkylphenol-aldehyde condensation resin is advantageously obtained by condensation:
• at least one alkylphenol whose alkyl group, linear or branched, contains from 1 to 30 carbon atoms, preferably from 4 to 18 carbon atoms, and even more preferably from 9 to 12 carbon atoms with
• at least one aldehyde and/or one ketone having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms.

The alkylphenol(s) are advantageously para-substituted.

The resin is preferably obtained from at least one aldehyde and/or at least one ketone chosen from formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethyl-hexanal, benzaldehyde and/or acetone. Preferably, the alkylphenol-aldehyde resin is obtained from at least one aldehyde, preferably at least formaldehyde (also called methanal).

According to a preferred embodiment, said resin is obtained by condensation of formaldehyde with at least one alkylphenol whose alkyl group contains from 4 to 18 carbon atoms, and more preferably from 9 to 12 carbon atoms.

According to a preferred embodiment, the average number of phenolic nuclei per molecule of nonylphenol-aldehyde resin is between 5 and 15.

The number of phenolic nuclei can be determined by nuclear magnetic resonance (NMR) or gel permeation chromatography (GPC).

Said resin is alkoxylated, that is to say it is grafted by (poly)alkoxy groups onto its phenol functions.

Preferably, said resin is polyethoxylated and/or polypropoxylated, and more preferably polyethoxylated.

The average molar percentage of alkoxy groups per mole of alkoxylated resin is preferably in the range from 75% to 95%. Preferably, the average molar percentage of ethoxy groups per mole of polyethoxylated resin is in the range from 75% to 95%.

The molar mass by weight Mw of the alkoxylated alkylphenol-aldehyde condensation resin according to the invention, measured by GPC, is preferably in the range going from 1,000 to 50,000 g.mol ^-1 , preferably from 2,000 to 10,000 g. mol ^-1 and more preferably from 3,000 to 6,000 g.mol ^-1 .

Preferably, the total content of the alkoxylated alkylphenol resin(s) is in the range going from 1 to 20% by mass, preferably from 2 to 15% by mass, and more preferably from 3 to 10 % by mass, relative to the total mass of the additive composition.

The solvent (4)
The additive composition according to the invention further comprises at least one organic solvent.

For example, the organic solvent is chosen from aliphatic and/or aromatic hydrocarbons, and/or chosen from mixtures of hydrocarbons, for example gasoline, diesel, kerosene fractions, decane, pentadecane. , toluene, xylene, ethylbenzene, polyethers.

Preferably, the solvent is chosen from aromatic hydrocarbons and more preferably from xylenes and mixtures of aromatic solvents comprising aromatic compounds having 9 and/or 10 carbon atoms.

As non-limiting examples of aromatic solvents, the following commercial products can be used: Solvarex 10®, Solvarex 10 LN®, Solvent Naphta®, Shellsol AB ®, Shellsol D ®, Solvesso 150 ®, Solvesso 150 ND®.

The content of the organic solvent(s) is advantageously at least 30% by mass, preferably at least 40% by mass, relative to the total mass of the additive composition. Preferably, this content is included in the range going from 40 to 95% by mass, preferably from 50 to 90% by mass, more preferably from 60 to 85% by mass, relative to the total mass of the composition of additives.

The composition of additives
The composition according to the invention is such that the mass ratio of the quantity of the first compound (1) to the quantity of the second compound (2) is advantageously included in the range going from 2 to 10, preferably from 2 to 5, plus preferably from 2.5 to 4.

Other additives in the composition
The additive composition may also comprise one or more additional additive(s), different from the compounds (1), (2) and (3) described above.

According to a preferred embodiment, the composition further comprises at least one copolymer with ethylene oxide (EO) and propylene oxide (PO) blocks.

The average molar ratio between the number of EO groups and the number of PO groups in the block copolymer can typically be in the range of 40:60 to 60:40.

The molar mass by weight Mw of the EO/PO block copolymers useful in the invention, measured by GPC, is preferably in the range from 6,000 to 26,000 g.mol ^-1 .

Preferably, the total content of the ethylene oxide and propylene oxide block copolymer(s) is in the range going from 0.5 to 10% by mass, preferably from 1 to 5% by mass, relative to the total mass of the additive composition.

According to a preferred embodiment, the composition further comprises at least one polyoxyalkylenated polyethyleneimine, and preferably at least one polyoxyethylenated polyethyleneimine.

Preferably, the total content of the polyoxyethylenated polyethyleneimine(s) is in the range going from 0.5 to 10% by mass, preferably from 1 to 5% by mass, relative to the total mass of the composition of additives.

Additional additives that may also be incorporated into the composition are, without limitation: dispersants, corrosion inhibitors, biocides, demulsifiers or anti-foam agents, paraffin deposit inhibitors; pour point depressants, paraffin anti-sedimentation additives; H ₂ S scavengers, organic deposit inhibitors such as naphthenic acids, mineral deposit inhibitors, markers, thermal stabilizers, emulsifiers, friction reducing agents, surfactants, and mixtures thereof.

Among the other additional additives, we can cite more particularly:
a) anti-foam additives, in particular (but not limited to) chosen from polysiloxanes, oxyalkylated polysiloxanes, and fatty acid amides derived from vegetable or animal oils;
b) dispersing and/or anti-corrosion additives, in particular (but not limited to) chosen from the group consisting of amines, succinimides, alkenylsuccinimides, polyalkylamines, polyalkyl polyamines, polyetheramines; imidazolines; quaternary ammonium salts derived from the above-mentioned compounds; fatty acids and their ester or amide derivatives, in particular glycerol monooleate, and mono- and polycyclic carboxylic acid derivatives;
c) crystallization modifier additives, paraffin deposit inhibitor additives, pour point depressant additives; low temperature rheology modifiers such as ethylene/vinyl propionate (EVP) copolymers, ethylene/vinyl acetate/vinyl versatate (EA/AA/EOVA) terpolymers; ethylene/vinyl acetate/alkyl acrylate terpolymers; polyacrylates; acrylate/vinyl acetate/maleic anhydride terpolymers; amidated maleic anhydride/alkyl(meth)acrylate copolymers capable of being obtained by reaction of a maleic anhydride/alkyl(meth)acrylate copolymer and an alkylamine or polyalkylamine having a hydrocarbon chain of 4 and 30 carbon atoms, preferably, from 12 to 24 carbon atoms; the amidated alpha-olefin/maleic anhydride copolymers capable of being obtained by reaction of an alpha-olefin/maleic anhydride copolymer and an alkylamine or polyalkylamine, the alpha-olefin being able to be chosen from alpha- C10-C50 olefin, preferably C16-C20 and the alkylamine or polyalkylamine having, advantageously, a hydrocarbon chain of 4 and 30 carbon atoms, preferably of 12 to 24 carbon atoms. As examples of terpolymers, mention may be made of those described in EP01692196, WO2009106743, WO2009106744, US4758365 and US4178951,
d) acidity neutralizers.

According to a preferred embodiment, the additive composition comprises a dispersing agent. For example, the dispersant is chosen from surfactants, sulfonates, sulfonic acids (naphthalene, dodecylbenzene, etc.)...

The composition of crude oil
This composition comprises at least one crude mineral oil (or crude oil), water and an additive composition as described above.

Crude mineral oil comes from a natural reserve or rock formation, preferably underground, underwater, and more preferably underwater. It is extracted via a well or “wellbore”, which corresponds to a hole or well penetrating the rock formation containing the oil.

The raw mineral oil(s) can be alone or mixed with other components, such as gas, or other additives used during drilling (anti-limescale, etc.).

This composition comprises water, which may contain salts in particular sodium chloride (brine).

The water content of the composition is typically in the range from 1 to 80% by mass, preferably from 5 to 60% by mass, and better still from 8 to 50% by mass.

Preferably, the content of the additive composition is in the range going from 20 to 1500 ppm by mass, preferably from 50 to 1000 ppm, more preferably from 75 to 500 ppm, and better still from 100 to 300 ppm in mass, relative to the total mass of the crude oil and water composition.

Uses
The invention also relates to the use of the composition of additives described above to lower the dynamic and/or kinematic viscosity of a mixture of water and raw mineral oil, preferably at lower or equal temperature. at 30°C, more preferably less than or equal to 25°C, more preferably less than or equal to 20°C, more preferentially less than or equal to 15°C, more preferentially less than or equal to 10°C, more preferentially less than or equal to 5°C, more preferably even less than or equal to 0°C.

In a manner known per se, dynamic viscosity characterizes the resistance to laminar flow of an incompressible fluid.

The viscosity is measured with a rheometer, for example of the Anton Paar MCR 302 type, 27mm coaxial cylinder geometry, CSR (controlled shear rate) control: the flow curves are determined and the viscosity. This determination method is well known to those skilled in the art.

Another object of the invention is the use of the additive composition to improve the pumpability of mixtures of water and crude mineral oil.

The additive composition according to the invention is also used to lower the pour point of a mixture of crude mineral oil and water. The pour point is the minimum temperature at which a substance (crude oil) will still flow. It is measured according to ASTM D5853.

The additive composition according to the invention is also used to reduce the shear stress, the flow threshold and/or the viscosity (kinematic and/or dynamic) during the flow of the mixture, preferably at a lower temperature or equal to 85°C, more preferably less than or equal 75°C, more preferably still less than or equal 65°C, better still less than or equal 55°C, more preferably less than or equal 45°C, more preferably less than or equal 35°C , more preferably less than or equal to 25°C, more preferably less than or equal to 10°C, more preferably less than or equal to 5°C, more preferably still less than or equal to 0°C.

Shear stress is the ratio of a tangential force applied to a surface to the cross-sectional area tangential to the force. The shear stress is measured with an Anton Paar MCR 302 rheometer, 27mm coaxial cylinder geometry, CSR control. The flow curves make it possible to deduce the shear stress.

The mixture of crude mineral oil and water typically contains from 1 to 80% by weight of water, preferably from 5 to 60% by weight, and better still from 8 to 50% by weight of water, relative to the mass of said mixture.

Preferably, the additive composition is used at a content in the range from 20 to 1500 ppm by mass, preferably from 50 to 1000 ppm, more preferably from 75 to 500 ppm, and even better from 100 to 300 ppm. by mass, relative to the total mass of the composition of crude mineral oil and water.

The process of reducing the viscosity of a liquid petroleum product
The invention also relates to a process for extracting a mixture of crude mineral oil and water comprising a step of pumping said mixture, characterized in that a composition of additives as described above is injected into said mixture.

The additive composition is injected during pumping of the mixture, preferably at the outlet of the well (or wellhead).

The flow rate of injected composition is preferably regulated proportionally to the pumping flow rate of the mixture of crude oil and water, so as to obtain the desired concentration.

According to the process of the invention, the additive composition is injected into the mixture at a content in the range from 20 to 1500 ppm by mass, preferably from 50 to 1000 ppm, more preferably from 75 to 500 ppm, and more preferably 100 to 300 ppm by mass, based on the total mass of the crude oil and water composition.

According to a preferred embodiment, the mixture of raw mineral oil and water is extracted from an underwater well.

The examples below are intended solely to illustrate the invention, and should not be interpreted as limiting its scope.

EXAMPLES

Example 1 : preparation of an additive composition according to the invention
The examples use the following additives:
As first compound (1): a grafted copolymer of ethylene and vinyl acetate (EVA), comprising 5% by mass of vinyl acetate and 74% by mass of behenyl acrylate, and whose molar masses are Mn=24,471 g/mol, Mw=118,528 g/mol (polydispersity index Ip=4.8). The number average molar masses (M _n ) and mass averages (M _w ) were determined on a size exclusion chromatographic chain by permeation of AGILENT PL-GPC50-Plus gel. The elution solvent is tetrahydrofuran and the standards consist of polystyrenes.

As second compound (2): a modified alkylphenol-aldehyde resin, the synthesis method of which is detailed below.

As third compound (3): an alkylphenol-aldehyde resin modified by polyethoxylation.

s protocol synthesis of the resin alkylphenol -modified aldehyde 2 :
In a first step, an alkylphenol-aldehyde condensation resin was prepared by condensation of para-nonylphenol and formaldehyde (for example according to the procedure described in EP857776). This resin has a viscosity at 50°C of between 1800 and 4800 mPa.s (viscosity measured at 50°C using a dynamic rheometer with a shear speed of 10 s^-1on the resin diluted with 30% by weight of aromatic solvent (Solvesso 150 ®)).
In a second step, the alkylphenol-aldehyde resin resulting from the first step was modified by Mannich reaction by adding 2 molar equivalents of formaldehyde and 2 molar equivalents of tallow dipropylenetriamine, known under the name N-(Tallowalkyl)dipropylenetriamine and marketed for example under the name Trinoram S®, compared to the alkylphenol-aldehyde resin resulting from the first stage.

The characteristics of the resin obtained at the end of the second stage are listed in table 1 below:

Alkylpolyamine used Dry matter
(1g/ 30 mins/ 200°C) Viscosity (mPa.s) (*) NOT_Phe (**) Trinoram S® 70.10% 4855 14.1

(*) Viscosity at 50°C: measured on a resin diluted with 30% by weight of Solvesso 150® solvent, shear speed 10 s^-1, using a Haake RheoWin® rheometer.
(**) Evaluation of the average number of phenolic nuclei per resin molecule or N_Phe : measured by proton nuclear magnetic resonance.

A composition of additives C according to the invention was prepared, from the following components, the contents of which are indicated as a percentage by mass of active material, relative to the total mass of composition C:
- copolymer of ethylene and grafted vinyl acetate (1): 2.8% by mass;
- modified alkylphenol-aldehyde resin (2): 0.95% by mass;
- ethoxylated alkylphenol aldehyde resin (3): 4.8% by mass;
- aromatic solvents: Qs 100% by mass

Example 2: dynamic viscosity measurements
Viscosity measurements were carried out on a crude oil alone, then on the same crude oil with added water and finally on the mixture of crude oil, water and the additive composition C of Example 1.

The crude oil used is an oil of Brazilian origin having a density at 15°C of 0.911 g.cm ^-3 , a pour point (ASTM D5853) of +15°C, a wax content of 9.5% by mass and an asphaltene content of 2.11% by mass.

The above crude oil was added with 10% by mass of water, and the viscosity of this mixture was measured.

To the above mixture of crude oil and water, 200 ppm by weight of composition C was added, and the viscosity of the mixture was measured.

The dynamic viscosity measurements were carried out at 23°C and 18°C, using an Anton Paar MCR 302 rheometer, 27mm coaxial cylinder geometry, CSR control at a shear rate of 38 s ^-1 .

The viscosity values obtained (expressed in mPa.s) are summarized in Table 2 below.

Viscosity at 23°C
(mPa.s) Viscosity at 18°C
(mPa.s) Crude oil alone 950 2000 Crude oil + 10% water 1500 3150 Invention: crude oil + 10% water + 200 ppm C 1150 2450

The above results show that the dynamic viscosity of crude oil increases very sharply when mixed with water.

The addition of the additive composition C according to the invention makes it possible to effectively reduce the viscosity of the mixture of water and crude oil, including at a low treatment rate of 200 ppm.

Example 3 comparative :
The crude oil used is an oil of Brazilian origin with a density at 15°C of 0.911 g.cm^-3, a pour point (ASTM D5853) of +12°C, and a wax content of 10.2% by mass.

The above crude oil was added with 15% by weight of water.

The three compositions of additives C, C1 and C2, the composition of which is detailed in Table 3 below, were compared. In the table below, the contents of each compound are indicated as a percentage by mass of active ingredient, relative to the total mass of the composition.

Ingredients VS
invention C1
comparative C2
comparative EVA graft copolymer (1) 2.8% 2.8% - modified alkylphenol-aldehyde resin (2) 0.95% 0.95% - ethoxylated alkylphenol aldehyde resin (3) 4.8% - 4.8% aromatic solvents Qs 100% Qs 100% Qs 100%

To the mixture of crude oil and water above, 200 ppm by mass of each of compositions C, C1 and C2 were added, and the viscosity of the mixture was measured.

The dynamic viscosity measurements were carried out at 23°C and 18°C, using an Anton Paar MCR 302 rheometer, 27mm coaxial cylinder geometry, CSR control at a shear rate of 38 s ^-1 .

The viscosity values obtained (expressed in mPa.s) are summarized in Table 4 below.

Viscosity 23°C
(mPa.s)
Viscosity 18°C
(mPa.s)
Crude oil alone 1100 2250 Crude oil + 15% water 1500 3000 Invention: crude oil + 15% water + 200 ppm C 1300 2800 Comparison: crude oil + 15% water + 200 ppm C1 1634 3250 Comparison: crude oil + 15% water + 200 ppm C2 1550 3150

The above results show that the dynamic viscosity of crude oil increases very sharply when mixed with water.

The addition of the additive composition C according to the invention makes it possible to effectively reduce the viscosity of the mixture of water and crude oil, including at a low treatment rate of 200 ppm. The reduction in viscosity obtained is 13.3% at 23°C and 6.7% at 18°C.

Comparative compositions C1 and C2, which respectively contain either compounds (1) and (2) or compound (3), on the contrary degrade the viscosity of the mixture of water and crude oil. With composition C1, the increase in viscosity is 8.9% at 23°C and 8.3% at 18°C. With composition C2, the increase in viscosity is 3.3% at 23°C and 5% at 18°C.

These results are brought together in Table 5 below.

Viscosity reduction at 23°C
Viscosity reduction at 18°C
Invention: crude oil + 15% water + 200 ppm C 13.3% 6.7% Comparison: crude oil + 15% water + 200 ppm C1 -8.9% -8.3% Comparison: crude oil + 15% water + 200 ppm C2 -3.3% -5%

These results illustrate the unexpected synergistic effect provided by the composition of additives according to the invention.

Claims (16)

Composition of additives comprising:
(1) at least one first compound chosen from copolymers of ethylene and vinyl acetate grafted with at least one alkyl (meth)acrylate group whose alkyl chain is saturated and contains from 12 to 30 carbon atoms;
(2) at least one second compound chosen from modified alkylphenol-aldehyde resins; said modified alkylphenol-aldehyde resins being capable of being obtained by Mannich reaction of an alkylphenol-aldehyde condensation resin with
- at least one aldehyde and/or a ketone having 1 to 8 carbon atoms, and
- at least one hydrocarbon compound having from 1 to 30 carbon atoms and comprising at least one alkylpolyamine group;
said alkylphenol-aldehyde condensation resin itself being capable of being obtained by condensation:
• at least one alkylphenol substituted by at least one alkyl group, linear or branched, having from 1 to 30 carbon atoms, with
• at least one aldehyde and/or a ketone having 1 to 8 carbon atoms;
(3) at least one third compound chosen from alkoxylated alkylphenol-aldehyde condensation resins; And ;
(4) at least one organic solvent. Composition according to the preceding claim, characterized in that the copolymers of ethylene and vinyl acetate are grafted with at least one alkyl (meth)acrylate group whose alkyl chain is saturated and comprises from 14 to 26 carbon atoms , and preferably from 18 to 22 carbon atoms. Composition according to any one of the preceding claims, characterized in that the total content of the grafted ethylene and vinyl acetate copolymer(s) is included in the range going from 1 to 15% by mass, preferably from 2 to 10% by mass, and more preferably 2.5 to 5% by mass, relative to the total mass of the additive composition. Composition according to any one of the preceding claims, characterized in that the modified alkylphenol-aldehyde resin(s) is(are) capable of being obtained by Mannich reaction of a alkylphenol-aldehyde condensation resin with at least one aldehyde and/or a ketone having from 1 to 4 carbon atoms and at least one hydrocarbon compound having from 4 to 30 carbon atoms and comprising at least one alkylpolyamine group,
said alkylphenol-aldehyde condensation resin itself being capable of being obtained by condensation:
• at least one mono-alkylphenol substituted by at least one alkyl group, linear or branched, having from 4 to 30 carbon atoms, with
• at least one aldehyde and/or a ketone having 1 to 4 carbon atoms, preferably chosen from formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethyl-hexanal, benzaldehyde and/or acetone, preferably formaldehyde. Composition according to any one of the preceding claims, characterized in that the modified alkylphenol-aldehyde resin can be obtained from at least one para-substituted alkylphenol, preferably para-nonylphenol. Composition according to any one of the preceding claims, characterized in that the modified alkylphenol-aldehyde resin can be obtained from at least one alkylpolyamine having at least two amine groups, preferably at least three amine groups, and comprising a fatty chain having from 12 to 24 carbon atoms, preferably from 12 to 22 carbon atoms. Composition according to any one of the preceding claims, characterized in that the total content of the modified alkylphenol-aldehyde resin(s) is included in the range going from 0.2 to 5% by mass, preferably from 0.5 to 3% by mass, and more preferably from 0.5 to 1.5% by mass, relative to the total mass of the additive composition. Composition according to any one of the preceding claims, characterized in that the alkylphenol-aldehyde condensation resin (3) is obtained by condensation:
• at least one alkylphenol whose alkyl group, linear or branched, contains from 1 to 30 carbon atoms, preferably from 4 to 18 carbon atoms, and even more preferably from 9 to 12 carbon atoms with
• at least one aldehyde and/or one ketone having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, preferably chosen from formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethyl -hexanal, benzaldehyde and/or acetone, and more preferably formaldehyde. Composition according to any one of the preceding claims, characterized in that the alkylphenol-aldehyde condensation resin (3) is polyethoxylated and/or polypropoxylated, preferably polyethoxylated. Composition according to any one of the preceding claims, characterized in that the total content of the alkoxylated alkylphenol resin(s) is in the range going from 1 to 20% by mass, preferably from 2 to 15 % by mass, and more preferably from 3 to 10% by mass, relative to the total mass of the additive composition. Composition according to any one of the preceding claims, characterized in that the organic solvent is chosen from aliphatic and/or aromatic hydrocarbons, preferably from aromatic hydrocarbons and more preferably from xylenes and mixtures of aromatic solvents comprising aromatic compounds having 9 and/or 10 carbon atoms. Composition according to any one of the preceding claims, characterized in that it further comprises at least one ethylene oxide and/or propylene oxide block copolymer, at a content preferably in the range of 0.5 at 10% by mass, more preferably from 1 to 5% by mass, relative to the total mass of the additive composition. Composition according to any one of the preceding claims, characterized in that it further comprises at least one polyoxyalkylenated polyethyleneimine, and preferably at least one polyoxyethylenated polyethyleneimine, at a content preferably in the range from 0 .5 to 10% by mass, more preferably 1 to 5% by mass, relative to the total mass of the additive composition Composition comprising at least one crude mineral oil, water and an additive composition as defined in any one of claims 1 to 13. Use of the additive composition as defined in any one of claims 1 to 13 for lowering the dynamic and/or kinematic viscosity of a mixture of crude mineral oil and water and/or for improving the pumpability of 'a mixture of raw mineral oil and water. Process for extracting a mixture of crude mineral oil and water comprising a step of pumping said mixture, characterized in that a composition of additives as defined in any one of claims 1 to 13 is injected in said mixture.