An additive composition comprising at least one 4-(2-alkoxyethyl)phenol aldehyde resin and at least one alkylphenol-aldehyde resin and use thereof as asphaltene dispersant in petroleum products

Abstract

An additive composition comprising at least one 4-(2- alkoxyethyl)phenol aldehyde resin and at least one alkylphenol- aldehyde resin and use thereof as asphaltene dispersant in petroleum products The present invention deals with a novel additive composition comprising at least a combination of at least two resins as defined hereafter. The instant invention further pertains to the use of such a composition as an additive in a petroleum product such as a crude oil or any product which results therefrom by any refining and / or extraction process. The additive composition of the invention is especially useful for dispersing asphaltenes in petroleum products. In addition, the invention aims at providing a petroleum product comprising such an additive composition, as well as a method for preventing the precipitation of asphaltenes present in a petroleum product, wherein an additive composition as defined herein is added.

Description

[0001] DESCRIPTION

[0002] TITLE : An additive composition comprising at least one 4- (2-alkoxyethyl)phenol aldehyde resin and at least one alkylphenolaldehyde resin and use thereof as asphaltene dispersant in petroleum products

[0003] The present invention deals with a novel additive composition comprising at least a combination of at least two resins as defined hereafter.

[0004] The instant invention further pertains to the use of such a composition as an additive in a petroleum product such as a crude oil or any product which results therefrom by any refining and / or extraction process. The additive composition of the invention is especially useful for dispersing asphaltenes in petroleum products.

[0005] In addition, the invention aims at providing a petroleum product compri sing such an additive composition, as well as a method for preventing the precipitation of asphaltenes present in a petroleum product, wherein an additive composition as defined herein is added.

[0006] PRIOR ART AND BACKGROUND OF THE INVENTION

[0007] Crude oils mainly contain two categories of products : maltenes and asphaltenes. The maltenes mainly contain oils (saturated hydrocarbon compounds and aromatics) and resins. The asphaltenes comprise highly polar entities which have a tendency to combine together to form agglomerates. They constitute the heaviest component of crude oil s. Asphaltenes are composed of molecules comprising fragments of polycycles, polyaromatics, short aliphatic chains, heteroatoms, such as N, O or S, and metals (for example Ni, V or Fe). They are insoluble in alkanes, such as n-pentane or n-heptane, but they are soluble in aromatic solvents, such as toluene or xylene. The interaction of asphaltenes with their environment is a complex phenomenon which is difficult to control .

[0008] The asphaltenes are generally present in crude oils as well as in many products derived from the refining thereof, such as in particular heavy oils and residues . They have a high tendency to precipitate in petroleum production wells, in pipelines and more generally on the surface of any installation in contact with a product containing them.

[0009] The precipitation of asphaltenes shall be avoided all the more that it can lead to problems of clogging of filters and plugging of pipes . This phenomenon results in a loss of productivity and a reduction in the transportation flows . Without a treatment which makes it possible to prevent such precipitations, the frequency of the operations for the maintenance of the production sites of crude oils as well as of the transportation equipment and handling plants represents a major economic burden.

[0010] Several factors can promote the precipitation of asphaltenes in a petroleum product, such as a rise in pressure, a rise in temperature, variations in composition, in particular due to injection of material into the crude oil or into the derived product, for example the arrival of a drilling mud in the reservoir, a mixture of crude oils or an injection of gas or of another fluid.

[0011] The composition of the crude oils and of the derived products also influences the phenomenon of precipitation of the asphaltenes: light oils, exhibiting a low content of asphaltenes, are rich in alkanes in which asphaltenes are not very soluble, and the latter have a tendency to precipitate from this medium. Heavy oils, rich in asphaltenes, comprise high amounts of intermediate compounds which are good solvents for asphaltenes and delay or prevent their precipitation. However, in crude oils, the precipitation of asphaltenes often brings about the coprecipitation of other components, such as resins or waxes.

[0012] In underground formations, the injection of fluids and the application of high pressures result in the adsorption of residues on the rock and a decrease in the permeability which can trigger reservoir blockage. During the refining operations, the rise in temperature applied to the crude oils causes problems of coking and of fouling in the distillation columns and on the heat exchangers, and also deactivation of catalysts . During the transportation of the oil products (crude and refined), the pressure applied to the fluid can lead to the sealing of the pipes. These phenomena are largely attributable to the precipitation of the asphaltenes. The losses in production and the remediable operations which result therefrom represent significant costs .

[0013] Several attempts related in the art have been developed to address this issue. For instance, alkylphenol-based asphaltene inhibitors, especially alkylphenol formaldehyde resins such as nonylphenol formaldehyde resins, octyl phenol formaldehyde resins or decylphenol formaldehyde resins, are commonly and widely used in the oil and gas industry to prevent the precipitation of asphaltenes in crude oil.

[0014] However, the implementation of these alkylphenol-based asphaltene for dispersing asphaltenes and / or for preventing their precipitation in crude oils remains to be improved.

[0015] Accordingly, it remains a real need to provide a novel additive composition which is effective in dispersing asphaltenes in crude oils, including in the long term, as well as in products deriving therefrom and which therefore makes it possible to avoid the drawbacks described above.

[0016] Indeed, one of the purposes of the present invention is to provide novel additives with lasting effectiveness in dispersing the various types of asphaltene compounds which can be present in all kinds of crude oils and products derived therefrom such as heavy oils and residues.

[0017] OBJECT OF THE INVENTION

[0018] The present invention namely results from the unexpected findings, by the inventors, that a specific combination of two different resins, as defined below, was particularly efficient for dispersing asphaltenes and preventing the precipitation thereof in crude oils whatever their origin, as well as in petroleum products derived from such crude oils, even over a long period of time.

[0019] Therefore, the present invention relates to an additive composition comprising:

[0020] (a) at least one resin obtainable by condensation of: at least one 4-(2-alkoxyethyl)phenol compound having the following formula (I): wherein X denotes :

[0021] • a linear or branched, saturated or unsaturated, hydrocarbon group containing from 1 to 24 carbon atoms, optionally interrupted with one or more heteroatoms, especially one or more heteroatoms chosen among oxygen, nitrogen, sulfur and / or phosphorous atoms,

[0022] • a saturated or unsaturated, aromatic or non-aromatic, heterocyclic or cyclic moiety,

[0023] - with at least one aldehyde having from 1 to 8 carbon atoms, preferably from 1 to 4 carbon atoms ; and

[0024] (b) at least one modified alkylphenol-aldehyde resin obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with at least one aldehyde and / or one ketone having from 1 to 8 carbon atoms and at least one hydrocarbon compound having at least one alkylamine group having from 1 to 30 carbon atoms,

[0025] • said alkylphenol-aldehyde condensation resin being itself obtainable by condensation of: o at least one alkylphenol substituted by at least one linear or branched alkyl group having from 1 to 30 carbon atoms with o at least one aldehyde and / or one ketone having from 1 to 8 carbon atoms.

[0026] The additive composition according to the present invention overcomes the issues raised in the prior art, as this composition is very effective as an asphaltene inhibitor, even over a long period of time, while exhibiting very good ecotoxicological results . Especially, said additive compositions is very effective to prevent and / or reduce the precipitation of asphaltenes .

[0027] Indeed, resin (a) is synthesized from a bio-based compound allowing the preparation of an additive composition having a low impact on environment, including towards aquatic ecosystems, such as marine environment and aquatic life.

[0028] Especially, resin (a) displays the asset of being based on biobased phenols, especially on a renewable compound, namely on Tyrosol which is a natural occurring nontoxic phenol, leading to an additive composition that is more environment friendly than the additives already known in the prior art for dispersing asphaltenes .

[0029] Moreover, resin (a) is biodegradable and reduces CO2 emission allowing the preparation of an additive composition having a low carbon footprint.

[0030] Resin (a) further displays the asset of not releasing any toxic substance during its implementation in the composition of the present invention. Therefore, resin (a) can be widely used in many countries .

[0031] Especially, resin (a) can sustainably be used in marine environment.

[0032] Advantageously, the use of resin (a) makes it possible to lower the quantity of resin (b) necessary to achieve the desired performance in terms of asphaltene dispersing.

[0033] Hence, the additive composition is more environmentally friendly and has a better carbon footprint than the additive compositions already known in the prior art.

[0034] The additive composition has also an excellent solubility in crude oils as well as in petroleum products and is not harmful to human beings and to the environment. It does not give rise to corrosive or other aggressive products, or to solid products which may plug lines or deposit in storage vessels.

[0035] Such additive composition is very effective in keeping asphaltenes dispersed in a hydrocarbon matrix and in avoiding or delaying the phenomena of agglomeration and precipitation of asphaltenes, even over a long period of time. The composition is more effective than many additives already known in the prior art for dispersing asphaltenes . They are effective even when used at low treatment rates and over a great variety of crude oils whatever their compositions .

[0036] The composition of the present invention has the advantage of having a longer asphaltene dispersion activity than each of the resins (a) and (b) taken separately.

[0037] Especially, the composition of the present invention shows 100% asphaltene dispersion activity instantly and even after 168 hours, whereas a drop of between 20 and 25% was recorded with an additive composition comprising one of the two resins only.

[0038] It bespeaks that the combination of the two resins (a) and (b), as previously defined, in the composition of the present invention has a synergistic effect on the dispersion of asphaltenes (and prevention of their precipitation), especially over the long term, which is higher than that obtained with each resin (a) and (b) taken separately.

[0039] In other words, the combination of the two resins (a) and (b) is more effective, especially in the long term, than each of the resins (a) and (b) taken separately.

[0040] In still other words, the effectiveness in terms of preventing asphaltene precipitation during long-term storage of an additive composition according to the present invention far exceeds a composition comprising resin (a) or resin (b) alone.

[0041] The present invention also relates to the use of at least a resin (a) as defined above, in particular 4-(2-alkoxyethyl)phenol - formaldehyde resin as detailed hereafter, to improve the effectiveness of a composition comprising at least one modified alkylphenol-aldehyde resin (b) in terms of preventing asphaltene precipitation, in particular during long-term storage.

[0042] Advantageously, the synergistic effect brought by combination of resin (a) with resin (b) makes it possible to consider the use of reduced quantities of resins to achieve the desired performance as asphaltenes dispersant, and more advantageously a reduced quantity of resin (b), in comparison with the quantity required to achieve the desired performance of asphaltenes dispersing when resin (b) is used alone. The instant invention also pertains to the use of an additive composition of the invention as an additive in a petroleum product, as well as a petroleum product comprising such an additive composition.

[0043] Another subject-matter of the present invention also aims at a method for preventing the precipitation of asphaltenes present in a petroleum product, comprising a step of adding an additive composition as defined herein to said product.

[0044] Other objects, features, aspects and advantages of the invention will become more apparent upon reading the following description and examples .

[0045] In the following, and at least one other indication, the limits of a value range are included within this range, particularly in the expressions "between" and "ranging from ... to ..." .

[0046] Moreover, the expressions "at least one" and "at least" used in the present description are respectively equivalent to the expressions "one or more" and "more than or equal to" .

[0047] Finally, in a manner known per se, Cncompound or group designates a compound or a group containing in its chemical structure n carbon atoms .

[0048] DETAILED DESCRIPTION

[0049] Resin (a)

[0050] As previously mentioned, said resin (a) is obtainable by condensation of at least one 4-(2-alkoxyethyl)phenol compound, as previously defined in formula (I), with at least one aldehyde having from 1 to 8 carbon atoms .

[0051] Said at least one 4-(2-alkoxyethyl)phenol compound has the following formula (I): wherein X denotes :

[0052] • a linear or branched, saturated or unsaturated, hydrocarbon group containing from 1 to 24 carbon atoms optionally interrupted with one or more heteroatoms, especially one or more heteroatoms chosen among oxygen, sulfur, nitrogen and / or phosphorous atoms,

[0053] • a saturated or unsaturated, aromatic or non-aromatic, cyclic or heterocyclic moiety, preferably a saturated or unsaturated, aromatic or non-aromatic, 6- to 24- membered heterocyclic or cyclic moiety.

[0054] According to the present invention, an aromatic or non-aromatic moiety may represent a mono- or polycyclic, fused or not fused, radical comprising 6- to 24-membered groups, especially comprising from 6 to 24 carbon atoms, preferably from 6 to 12 carbon atoms .

[0055] According to one embodiment of the present invention, the cyclic moiety is aromatic and may represent a mono- or polycyclic, fused or not fused, comprising from 6 to 24 carbon atoms, preferably from 6 to 12 carbon atoms.

[0056] Preferably, an aromatic cyclic moiety may be chosen among the group consisting of phenyl, biphenyl or naphthyl, indenyl, anthracenyl, preferably phenyl.

[0057] According to one embodiment of the present invention, the cyclic moiety is non-aromatic and may represent a mono- or polycyclic, fused or not fused, comprising from 6 to 24 carbon atoms, preferably from 6 to 12 carbon atoms, and may comprise one or more unsaturations . According to the present invention, an aromatic or non-aromatic heterocyclic moiety may represent a mono- or polycyclic, fused or not fused, saturated or unsaturated, radical comprising 6- to 24-membered groups, including one or more heteroatoms chosen from nitrogen, oxygen, phosphorous and / or sulfur atoms, preferably chosen from oxygen and / or nitrogen atoms .

[0058] Preferably, the heterocyclic moiety is aromatic and may be chosen among the group consisting of morpholinyl, thiomorpholinyl, piperidinyl, piperazinyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydrothiophenyl, azepanyl, thioazepanyl; preferably pyrrolidinyl and morpholinyl.

[0059] Preferably, X represents a linear or branched, saturated or unsaturated, hydrocarbon group containing from 1 to 24 carbon atoms optionally interrupted with one or more heteroatoms , in particular chosen from nitrogen, oxygen or sulfur atom, especially one or several oxygen atoms .

[0060] Preferably, X represents a linear or branched, saturated or unsaturated, hydrocarbon group containing from 1 to 24 carbon atoms .

[0061] Preferably, X represents a linear or branched, saturated or unsaturated, hydrocarbon group containing 2 to 14 carbon atoms, more preferably from 2 to 12 carbon atoms .

[0062] More preferably, X is a linear or branched saturated hydrocarbon group containing 2 to 14 carbon atoms, even more preferably from 2 to 12 carbon atoms, especially from 2 to 10 carbon atoms .

[0063] Advantageously, the compound of formula (I) is selected among the group constituted of the following compounds : 4-(2- butoxyethyl)phenol; 4-(2-isobutoxyethyl)phenol; 4-(2-

[0064] (pentyloxy)ethyl)phenol; 4-(2-(hexyloxy)ethyl)phenol; 4-(2-((4- methylpentyl)oxy)ethyl)phenol; 4 -(2- ((2- ethylhexyl) oxy ) ethyl / phenol; 4-(2-(octyloxy)ethyl)phenol; 4-(2-(decyloxy)ethyl)phenol; 4- (2- ((2- ethyloctyl)oxy)ethyl)phenol; 4-(2-(dodecyloxy)ethyl)phenol; 4- (2- ((ethyloxy)ethyl)phenol; and mixtures thereof.

[0065] Most preferably, the compound of formula (I) is selected from the group constituted of 4-(2-((ethyloxy)ethyl)phenol, 4-(2- butoxyethyl)phenol, 4-(2-isobutoxyethyl)phenol, 4-(2-((2- ethylhexyl)oxy)ethyl)phenol, 4-(2-(hexyloxy)ethyl)phenol, 4-(2- (octyloxy)ethyl)phenol, 4-(2-(decyloxy)ethyl)phenol, 4-(2- (dodecyloxy)ethyl)phenol or mixture thereof.

[0066] Said at least one aldehyde has from 1 to 8 carbon atoms, especially from 1 to 4 carbon atoms, more preferably from 1 to 2 carbon atoms, specifically 1 carbon atom.

[0067] Said aldehyde is preferably chosen from the group constituted of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2- ethylhexanal, benzaldehyde and mixtures thereof.

[0068] More preferably, said aldehyde is chosen among the group constituted of formaldehyde, acetaldehyde and mixtures thereof.

[0069] Most preferably, said aldehyde is formaldehyde.

[0070] In other words, resin (a) is advantageously a 4-(2- alkoxyethyl)phenol - formaldehyde resin (also named O-alkylated tyrosol formaldehyde resin) .

[0071] In still other words, resin (a) is advantageously a 4-(2- alkoxyethyl)phenol - formaldehyde resin having the following formula (II) :

[0072] (ID wherein X has the same meaning as in formula (I) and n is an integer ranging from 1 to 14, especially ranging from 12 to 14.

[0073] Preferably, X represents a linear or branched, saturated or unsaturated, hydrocarbon group containing 2 to 14 carbon atoms, more preferably from 2 to 12 carbon atoms, even more preferably from 2 to 10 carbon atoms.

[0074] Resin (a) is preferably selected among the group constituted of the following compounds:

[0075] 4-(2-((ethyloxy)ethyl)phenol - formaldehyde resin, 4-(2-butoxyethyl)phenol - formaldehyde resin, 4-(2-isobutoxyethyl)phenol - formaldehyde resin, 4-(2-((2-ethylhexyl)oxy)ethyl)phenol - formaldehyde resin, 4-(2-(hexyloxy)ethyl)phenol - formaldehyde resin, 4-(2-(octyloxy)ethyl)phenol - formaldehyde resin, 4-(2-(decyloxy)ethyl)phenol - formaldehyde resin, 4-(2-(dodecyloxy)ethyl)phenol - formaldehyde resin, or mixtures thereof.

[0076] Advantageously, resin (a) is selected among the group constituted of 4-(2-butoxyethyl)phenol - formaldehyde resin, 4-(2- isobutoxyethyl)phenol - formaldehyde resin, 4-(2- ((ethyloxy)ethyl)phenol - formaldehyde resin, or mixtures thereof.

[0077] Resin (a) is obtainable by condensation of at least one 4-(2- alkoxyethyl)phenol compounds, as previously defined in formula (I), with at least one aldehyde having from 1 to 8 carbon atoms, as previously defined, preferably in the presence of at least one acidic catalyst, such as p-toluenesulfonic acid (pTSA), which may be dissolved in at least one polar solvent, preferably in at least one polar organic solvent such as toluene.

[0078] The condensation may be performed at a temperature ranging from 900°C to 2000°C, preferably from 1000°C to 1800°C.

[0079] The condensation step may be performed one or several times .

[0080] On completion of the condensation, the issued reaction mixture may be cooled and said at least aforementioned polar solvent is removed, preferably under high vacuum.

[0081] Resin (b)

[0082] The modified alkylphenol-aldehyde resin (b) is obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with:

[0083] - at least one aldehyde and / or one ketone having from 1 to 8 carbon atoms ; and

[0084] - at least one hydrocarbon compound having at least one alkylmonoamine or alkylpolyamine (alkylamine) group having between 1 and 30 carbon atoms. Said alkylphenol-aldehyde condensation resin is itself obtainable by condensation of

[0085] - at least one alkylphenol substituted by at least one linear or branched alkyl group having from 1 to 30 carbon atoms, with

[0086] - with at least one aldehyde and / or one ketone having from 1 to

[0087] 8 carbon atoms .

[0088] According to a preferred embodiment, the modified alkylphenol- aldehyde resin is obtainable by a Mannich reaction of an alkylphenol- aldehyde condensation resin with:

[0089] - at least one aldehyde and / or one ketone having from 1 to 4 carbon atoms ; and

[0090] - at least one hydrocarbon compound having at least one alkylmonoamine or alkylpolyamine (alkylamine) group having between 4 and 30 carbon atoms, said alkylphenol-aldehyde condensation resin is itself obtainable by condensation of

[0091] - at least one monoalkylphenol substituted by at least one linear or branched alkyl group having from 1 to 30 carbon atoms, with

[0092] - at least one aldehyde and / or one ketone having from 1 to 4 carbon atoms .

[0093] Said alkylphenol-aldehyde condensation resin can be chosen from any resin of this type already known and in particular those described in EP 31 1 542, EP 857 776 and EP 1 584 673.

[0094] Said alkylphenol-aldehyde condensation resin is advantageously obtained from at least one para-substituted alkylphenol. Use is preferably made of para-nonylphenol.

[0095] The average number of phenol nuclei per molecule of nonylphenol-aldehyde resin is preferably greater than 6 and less than or equal to 25, more preferably from 8 to 17 and more preferably still from

[0096] 9 to 16 phenol nuclei per molecule. The number of phenol nuclei can be determined by nuclear magnetic resonance (NMR) or gel permeation chromatography (GPC).

[0097] According to a preferred embodiment, the modified alkylphenol- aldehyde resin is obtained by employing one and the same aldehyde or one and the same ketone as the aldehyde or ketone used for preparing said alkylphenol-aldehyde condensation resin.

[0098] According to a preferred embodiment, the modified alkylphenol- aldehyde resin is obtained from at least one aldehyde and / or ketone chosen from formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethylhexanal, benzaldehyde or acetone. Preferably, the modified alkylphenol-aldehyde resin is obtained from at least one aldehyde and preferably from formaldehyde.

[0099] According to a specific embodiment, the modified alkylphenol- aldehyde resin is obtained from at least one alkylamine having at least one primary and / or secondary amine group. In particular, the alkylamine is advantageously chosen from primary or secondary amines respectively substituted by one or two alkyl groups preferably comprising from 12 to 24 carbon atoms, more preferably from 12 to 22 carbon atoms .

[0100] According to a preferred embodiment, the modified alkylphenol- aldehyde resin is obtained from at least one alkylmonoamine or from at least one alkylpolyamine having at least one primary amine group. In particular, the modified alkylphenol-aldehyde resin can advantageously be obtained from at least one alkylmonoamine or from at least one alkylpolyamine, all the amine groups of which are primary amines.

[0101] The alkylamine is preferably an alkylmonoamine or an alkylpolyamine comprising a fatty chain having from 12 to 24 carbon atoms, preferably from 12 to 22 carbon atoms. Use is more preferably made of an alkylpolyamine having at least one primary amine group, preferably at least two primary amine groups and more preferably three primary amine groups, and comprising a fatty chain having from 12 to 24 carbon atoms, preferably from 12 to 22 carbon atoms.

[0102] The commercial alkylamines are generally not pure compounds but mixtures . Mention may in particular be made, among the marketed alkylamines which are suitable, of the alkylamines comprising a fatty chain sold under the Noram®, Trinoram®, Duomeen®, Dinoram®, Triameen®, Armeen®, Polyram®, Lilamin® and Cemulcat® names . Mention may be made, as preferred example, of Trinoram® S, which is a tallow dipropylenetriamine, also known under the name N- (tallowalkyl)dipropylenetriamine.

[0103] According to a particularly preferred embodiment, the modified alkylphenol-aldehyde resin is obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with formaldehyde and at least one alkylpolyamine having at least two primary amine groups and comprising a fatty chain having from 12 to 22 carbon atoms; said alkylphenol-aldehyde condensation resin being itself obtainable by condensation of para-nonylphenol and formaldehyde.

[0104] The additive composition

[0105] According to a preferred embodiment, the composition comprises : at least one resin (a) corresponding to 4-(2- alkoxyethyl)phenol - formaldehyde resin as previously defined in formula (II), at least one modified alkylphenol-aldehyde resin (b) obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with formaldehyde and at least one alkylpolyamine having at least two primary amine groups and comprising a fatty chain having from 12 to 22 carbon atoms ;

[0106] • said alkylphenol-aldehyde condensation resin being itself obtainable by condensation of para-nonylphenol and formaldehyde.

[0107] In other words, the composition according to the present invention preferably comprises: at least a 4-(2-alkoxyethyl)phenol - formaldehyde resin as previously defined in formula (II), especially among the group constituted of 4-(2-((ethyloxy)ethyl)phenol - formaldehyde resin, 4-(2-butoxyethyl)phenol - formaldehyde resin, 4-(2-isobutoxyethyl)phenol - formaldehyde resin, 4- (2-((2-ethylhexyl)oxy)ethyl)phenol - formaldehyde resin, 4- (2-(hexyloxy)ethyl)phenol - formaldehyde resin, 4-(2- (octyloxy)ethyl)phenol - formaldehyde resin, 4-(2- (decyloxy)ethyl)phenol - formaldehyde resin, 4-(2- (dodecyloxy)ethyl)phenol - formaldehyde resin, or mixtures thereof, at least one modified alkylphenol-aldehyde resin (b) obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with formaldehyde and at least one alkylpolyamine having at least two primary amine groups and comprising a fatty chain having from 12 to 22 carbon atoms ;

[0108] • said alkylphenol-aldehyde condensation resin being itself obtainable by condensation of para-nonylphenol and formaldehyde.

[0109] Advantageously, the composition according to the present invention comprises: at least a 4-(2-alkoxyethyl)phenol - formaldehyde resin chosen among the group constituted of 4-(2- butoxyethyl)phenol - formaldehyde resin, 4-(2- isobutoxyethyl)phenol - formaldehyde resin, 4-(2- ((ethyloxy)ethyl)phenol - formaldehyde resin, or mixtures thereof, at least one modified alkylphenol-aldehyde resin (b) obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with formaldehyde and at least one alkylpolyamine having at least two primary amine groups and comprising a fatty chain having from 12 to 22 carbon atoms ; • said alkylphenol-aldehyde condensation resin being itself obtainable by condensation of para-nonylphenol and formaldehyde.

[0110] The composition of the invention preferably contains said resins (a) and (b) in a ratio by mass (a): (b) ranging from 5 :95 to 95 : 5, preferably from 80:20 to 20: 80, even more preferably from 70:30 to 30:70.

[0111] According to a preferred embodiment, the composition contains said resins (a) and (b) in a ratio by mass (a): (b) of 70: 30, 50:50, or 30:70.

[0112] According to a preferred embodiment, the composition contains : at least one resin (a) chosen among the group constituted of 4-(2-butoxyethyl)phenol - formaldehyde resin, 4-(2- isobutoxyethyl)phenol - formaldehyde resin, 4-(2- ((ethyloxy)ethyl)phenol - formaldehyde resin, or mixtures thereof, at least one modified alkylphenol-aldehyde resin (b) obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with formaldehyde and at least one alkylpolyamine having at least two primary amine groups and comprising a fatty chain having from 12 to 22 carbon atoms ;

[0113] • said alkylphenol-aldehyde condensation resin being itself obtainable by condensation of para-nonylphenol and formaldehyde; wherein resins (a) and (b) are in a ratio by mass (a) :(b) ranging from 5 :95 to 95 :5, preferably from 80:20 to 20: 80, even more preferably from 70:30 to 30:70.

[0114] According to a preferred embodiment, the additive composition of the present invention further contains one or more liquid organic solvent(s) . By liquid, it is meant a solvent which is in liquid form at ambient temperature (20°C) and atmospheric pressure ( 1 ,013. 105Pa) .

[0115] Such solvents may in particular be chosen from poly alkyl ethers, aliphatic hydrocarbons such as alkanes, aromatic solvents such as aromatic hydrocarbons and aromatic hetero-compounds, and mixtures thereof.

[0116] Preferred organic solvents are chosen from aromatic solvents, such as N-methylpyrrolidone, xylene, toluene, benzene; and poly alkyl ethers such as butyl carbitol (diethylene glycol monobutyl ether) ; as well as mixtures thereof.

[0117] Other preferred organic solvents include those derived from biomass, such as oils of vegetable origin. A particularly preferred solvent is cashew nutshell liquid, also known as CSNL, which is a widely available vegetable oil derived from cashew nutshell. CNSL can be used as a mixture with any other solvent such as those described herein. Preferably, the additive composition comprises one or more organic solvent chosen among the group constituted of oils of vegetable origin, especially cashew nutshell liquid.

[0118] The composition of the invention may contain an amount of solvent ranging from 25 to 95% by weight, preferably from 40 to 90%wt of the composition, more preferably from 50 to 80%wt, relative to the total weight of the composition.

[0119] When it contains a solvent, the composition advantageously contains said resins (a) and (b) as previously defined, in a total amount ranging from 5 to 75% by weight, preferably from 10 to 60% by weight, more preferably from 20 to 50% by weight, relative to the total weight of the composition.

[0120] The additive composition may further contain one or more additional additives, different(s) from resins (a) and (b) previously defined.

[0121] Mention may be made, as additional optional additives, of: dispersants / detergents, metal passivators, antioxidants, corrosion inhibitors, biocides, demulsifiers, antifoam agents, paraffin deposition inhibitors, pour point lowering agents, paraffin anti-settling additives, wax inhibitors, scale inhibitors, foamers, anti-foulant, H2S scavengers, organic deposit inhibitors, such as naphthenic acids, mineral deposit inhibitors, heat stabilizers, emulsifiers, friction reducers, surfactants , reodorants and their mixtures.

[0122] Preferred additional additives are: i) antifoam additives, in particular (but non limitatively) chosen from polysiloxanes, oxyalkylated polysiloxanes and amides of fatty acids resulting from vegetable or animal oils ; ii) detergent additives and / or corrosion inhibitors, in particular

[0123] (but non limitatively) chosen from the group consisting of amines, succinimides, alkenylsuccinimides, polyalkylamines, polyalkylpolyamines, polyetheramines and imidazolines; iii) lubricating additives or antiwear agents, in particular (but non limitatively) chosen from the group consisting of fatty acids and their ester or amide derivatives, in particular glycerol monooleate, and derivatives of mono- and polycyclic carboxylic acid; iv) crystallization-modifying additives, additives which inhibit paraffin deposits, additives which lower the pour point; modifiers of the rheology at low temperature, such as ethylene / vinyl acetate (EVA) and / or ethylene / vinyl propionate (EVP) copolymers, ethylene / vinyl acetate / vinyl versatate (E / VA / VeoVA) terpolymers ; ethylene / vinyl acetate / alkyl acrylate terpolymers ; EVA copolymers modified by grafting; polyacrylates; acrylates / 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 of an alkylamine or polyalkylamine having a hydrocarbon chain of 4 to 30 carbon atoms, preferably of 12 to 24 carbon atoms ; amidated a-olefin / maleic anhydride copolymers capable of being obtained by reaction of an a-olefin / maleic anhydride copolymer and of an alkylamine or polyalkylamine, it being possible for the a-olefin to be chosen from C 10-C50 a-olefins, preferably from C 16-C20 a-olefins, and the alkylamine or the polyalkylamine advantageously having a hydrocarbon chain of 4 to 30 carbon atoms, preferably of 12 to 24 carbon atoms. Mention may be made, as examples of terpolymers, of those which are described in EP01692196, W02009 / 106743, W02009 / 106744, U.S . Pat. No . 4,758,365 and U.S . Pat. No. 4, 178,951 ; v) antioxidants, for example of hindered phenolic type or aminated of alkylated para-phenylenediamine type; vi) metal passivators ; vii) acidity neutralizers.

[0124] The use

[0125] The additive composition as described above is particularly useful for dispersing asphaltenes in petroleum products. Said composition can especially be used for preventing or reducing the precipitation of asphaltenes present in a petroleum product.

[0126] According to a preferred embodiment, the composition of invention is used as an additive in a petroleum product which is handled in an equipment chosen from a tank, a refining plant, a pipeline, a drilling well, a storage vessel, a transportation equipment or a filter. The petroleum product may be a crude oil or any product which derives therefrom by any refining and / or extraction process . The petroleum product may also be a bitumen, such as bitumens of natural origin such as those present in natural bitumen or natural asphalt deposits, or bituminous sands, the bitumens originating from the refining of crude oil, in particular from the atmospheric and / or vacuum distillation of oil, it being possible for these bitumens to optionally be blown, visbroken and / or deasphalted and / or mixed.

[0127] The petroleum product is especially selected from crude petroleum oils ; hydrocarbon fractions and residues deriving from the distillation thereof such as in heavy fuel oils, heavy residues; and bitumens .

[0128] The additive composition is advantageously used in an amount ranging from 1 to 5000 ppm by weight, preferably from 5 to 2000 ppm, more preferably from 10 to 1000 ppm and more preferably still from 15 to 500 ppm, expressed as total weight of said resins (a) and (b) with respect to the total weight of the petroleum product.

[0129] According to a preferred embodiment, the composition of invention is used for dispersing asphaltenes in petroleum products over a long period of time, especially at least 24 hours, preferably at least 48 hours, more preferably at least 168 hours, after the addition of said composition into said petroleum products .

[0130] According to a preferred embodiment, the composition of invention is used for dispersing asphaltenes in petroleum products over a long period of time, especially at least 168 hours, after the addition of said composition into said petroleum products.

[0131] The petroleum product

[0132] The petroleum product contains a crude oil or a product which results therefrom by any refining and / or extraction process, and an additive composition as described above.

[0133] The petroleum product may also contain a bitumen, such as bitumen of natural origin such as those present in natural bitumen or natural asphalt deposits, or bituminous sands, the bitumen originating from the refining of crude oil, in particular from the atmospheric and / or vacuum distillation of oil, it being possible for these bitumen to optionally be blown, visbroken and / or deasphalted and / or mixed.

[0134] The petroleum product preferably contains a crude petroleum oil and / or at least one hydrocarbon fraction or at least one residue deriving from the distillation of crude petroleum oil, such as heavy fuel oils, heavy residues and / or at least one bitumen.

[0135] The petroleum product advantageously contains a total amount of said resins (a) and (b) ranging from 1 to 5000 ppm by weight, preferably from 5 to 2000 ppm, more preferably from 10 to 1000 ppm and more preferably still from 15 to 500 ppm, expressed as total weight of said resins (a) and (b) with respect to the total weight of the petroleum product.

[0136] The method

[0137] The method of the invention for preventing the precipitation of asphaltenes present in a petroleum product comprises a step of adding an additive composition as defined herein to said product.

[0138] The petroleum product is advantageously chosen from those described above.

[0139] The additive composition is preferably added in an amount ranging from 1 to 5000 ppm by weight, preferably from 5 to 2000 ppm, more preferably from 10 to 1000 ppm and more preferably still from 15 to 500 ppm, expressed as total weight of said resins (a) and (b) with respect to the total weight of the petroleum product.

[0140] According to a preferred embodiment, the method of the invention comprises at least two steps :

[0141] ( 1 ) the introduction of an additive composition as described above into the petroleum product, and

[0142] (2) a treatment step chosen from: a rise in pressure, a rise in temperature and a mixing with at least one other fluid.

[0143] According to a most preferred embodiment, steps ( 1 ) and (2) are carried out successively (step 1 and then step 2).

[0144] According to a preferred variant, step (2) is chosen from: an extraction of a crude oil from a reservoir, a stage of refining a crude oil or a derived product, a transportation of a crude oil or of a derived product, a filtration of a crude oil or of a derived product, an injection of gas into a crude oil or into a derived product, a mixing of crude oils or of derived products, and a mixing of a crude oil or of a derived product with a solvent.

[0145] Step (2) can for example correspond to a pressurization, for example in a pipeline or any type of pipe, or through a filter; it can comprise a heating in a refining plant, an injection of a gas or a mixing with another variety of crude oil or with another grade of heavy oil resulting from the refining.

[0146] Conventionally, such treatments result in a precipitation of asphaltenes and a fouling and / or a clogging of the equipment. The method of the invention makes it possible to keep the asphaltenes in dispersion during these treatments and to improve the compatibility of the asphaltenes with the non-asphaltenic part of the petroleum product.

[0147] The method of the invention is advantageously carried out in an equipment chosen from: a tank, a drilling well, a refining plant, a pipeline, a storage vessel, a transportation equipment or a filter.

[0148] The method can be carried out at any stage from the recovery of crude oils from a reservoir up to the refining and the use of the hydrocarbon fractions, via the transportation of the different petroleum products deriving therefrom. The invention is targeted at keeping the asphaltenes in dispersion in the medium, so as to improve the recovery of the crude oils, to stop, prevent, decrease or delay the precipitation of the asphaltenes, the formation of asphaltene deposits, the fouling in the tanks, treatment and transportation plants, such as the extraction or refining equipment, the pipelines, the pipes of all types, the filters, the storage vessels .

[0149] The example hereafter only aims at illustrating the present invention and shall not be interpreted so as to limit its scope.

[0150] EXAMPLES

[0151] Example 1 : Description of resins (a l ), (a2), (a3), (a4) and (b l )

[0152] Resin (al ) : 4-(2-isobutoxyethyl)phenol - formaldehyde resin

[0153] 4-(2-isobutoxyethyl)phenol formaldehyde resin ) was prepared by condensation of 4-(2-isobutoxyethyl)phenol and formaldehyde in the presence of acidic catalyst:

[0154] A three-neck 500ml round bottom flask was equipped with a magnetic stirrer and Dean Stark trap with a reflux condenser along with a Schlenk line for maintaining the nitrogen atmosphere. In the initial step, 100 g (0.514 mol) of 4-(2-isobutoxyethyl)phenol was taken along with acid catalyst i.e., p-TSA (0.215 g, 0.001 1 mol) in 10 mL toluene.

[0155] The mixture was then stirred under a nitrogen blanket at 1200C, and a solution of trioxane 13 g (0.154 mol) in toluene (20 mL) was taken in a syringe and added drop wise over a period of about Ihr by using syringe pump repeatedly for three times .

[0156] After the addition of trioxane, the temperature increased to 1650C, and the reaction continued for lOhrs . Again, the procedure was repeated for l Ohrs using same amount of p-TSA (0.215 g, 0.001 1 mol), trioxane 13 g (0.154 mol) .

[0157] When the collection of water stopped, the reaction mixture was cooled, and the toluene was removed under a high vacuum.

[0158] The crude precipitated by the methanol (approx. 50 mL), DCM (approx. 20 mL) and found the polymer as an insoluble gel. The solvent was evaporated by rotary evaporator. The pure gel was dried under vacuum which afforded 83 g of solid polymer.

[0159] Resin (al ) exhibits a good ecotoxicity profile. Resin (a2) : 4-(2-butoxyethyl)phenol - formaldehyde resin

[0160] 4-(2-butoxyethyl)phenol formaldehyde resin was prepared by condensation of 4-(2-butoxyethyl)phenol and formaldehyde in the presence of at least one acidic catalyst:

[0161] A three-neck 500ml round bottom flask was equipped with a magnetic stirrer and Dean Stark trap with a reflux condenser along with a Schlenk line for maintaining the nitrogen atmosphere. In the initial step, 4-(2-butoxyethyl)phenol was taken along with acid catalyst such p-TSA in 10 mL of toluene.

[0162] The mixture was then stirred under a nitrogen blanket at 120°C, and a solution of trioxane in toluene (20 mL) was taken in a syringe and added drop wise over a period of about Ihr by using syringe pump repeatedly for three times .

[0163] After the addition of trioxane, the temperature increased to 165 °C, and the reaction continued for 10 hours. The procedure was then repeated for lOhrs using same amount of p-TSA, trioxane. When the collection of water stopped, the reaction mixture was cooled, and the toluene was removed under a high vacuum. The crude precipitated by the methanol (approx. 50 mL), DCM (approx. 20 mL) and found the polymer as an insoluble gel. The solvent was evaporated by rotary evaporator.

[0164] The pure gel was dried under vacuum which afforded a solid polymer.

[0165] Resin (a2) exhibits a good ecotoxicity profile. Resin (a3) : 4-(2-(ethyloxy)ethyl)r)henol formaldehyde resin

[0166] Resin (a3) was synthesized using the same protocols as those previously described for resins (al ) and (a2) by using 4-(2- (ethyloxy)ethylphenol (tyrosol 2-ethyl ether) and ethanol as starting materials .

[0167] Resin (a3) exhibits a good ecotoxicity profile.

[0168] Resin (a4) : 4-(2-octyloxy)ethyl)phenol formaldehyde resin

[0169] Resin (a4) was synthesized using the same protocols as those previously described for resins (al ) and (a2) by using 4-(2- (octyloxy)ethylphenol (tyrosol 2-octyl ether) and octanol as starting materials . Resin (a4) exhibits a good ecotoxicity profile.

[0170] Resin (b l )

[0171] A modified alkylphenol-aldehyde was synthetised using the protocol described below. Stage 1 : In a first stage, an alkylphenol-aldehyde condensation resin was prepared by condensation of para-nonylphenol and formaldehyde (for example according to the procedure described in EP 857 776), with a viscosity at 50° C. of between 1800 and 4800 mPa- s (viscosity measured at 50° C. using a dynamic rheometer with a shear rate of 10 s'1on the resin diluted with 30% by weight of aromatic solvent (Solvesso 150 ®)) .

[0172] Stage 2: In a second stage, the alkylphenol-aldehyde condensation resin resulting from the first stage was modified by a Mannich reaction by addition of 2 molar equivalents of formaldehyde and 2 molar equivalents of tallow dipropylenetriamine, known under the name N-(tallowalkyl)dipropylenetriamine and sold under the name Trinoram S®.

[0173] The features of the modified alkylphenol-aldehyde resin obtained at the end of stage 2 are detailed in Table 1 below.

[0174] Table 1

[0175] (*) Viscosity at 50° C: measured on the resin diluted with 70% by weight of Solvesso 150®, shear rate of 10 s'1, using a Haake RheoWin ® rheometer.

[0176] (**) Evaluation of the mean number of phenol nuclei per resin molecule or Nphe: measured by proton nuclear magnetic resonance.

[0177] Example 2:

[0178] Preparation of comparative additive compositions (C l ) - (C5)

[0179] A comparative additive composition (C l ) was prepared by dissolving resin (al ) with xylene as a solvent. The amount of resin in composition (C l ) is 50% by weight relative to the total weight of the composition.

[0180] A comparative additive composition (C2) was prepared by dissolving resin (a2) with xylene as a solvent. The amount of resin in composition (C2) is 50% by weight relative to the total weight of the composition.

[0181] A comparative additive composition (C3) was prepared by dissolving resin (a3) with xylene as a solvent. The amount of resin in composition (C3) is 50% by weight relative to the total weight of the composition.

[0182] A comparative additive composition (C4) was prepared by dissolving resin (a4) with xylene as a solvent. The amount of resin in composition (C4) is 50% by weight relative to the total weight of the composition.

[0183] A comparative additive composition (C5) was prepared by dissolving resin (b l ) with xylene as a solvent. The amount of resin in composition (C5) is 50% by weight relative to the total weight of the composition.

[0184] The resins used for each composition (C l ) to (C5) is detailed in Table 2 below.

[0185] Table 2

[0186] Preparation of additive compositions (A l ) - (A 12)

[0187] Additive compositions (A l ) to (A3) according to the invention were prepared by dissolving resin (al ) and resin (b l ) with xylene as solvent. For each composition, the total amount of resin including (al ) and (b l ) was 50% by weight.

[0188] Additive compositions (A4) to (A6) according to the invention were prepared by dissolving resin (a2) and resin (b l ) with xylene as solvent. For each composition, the total amount of resin including (al) and (bl) was 50% by weight.

[0189] Additive compositions (A7) to (A9) according to the invention were prepared by dissolving resin (a3) and resin (bl) with xylene as solvent. For each composition, the total amount of resin including (a3) and (bl) was 50% by weight.

[0190] Additive compositions (A10) to (A12) according to the invention were prepared by dissolving resin (a4) and resin (bl) with xylene as solvent. For each composition, the total amount of resin including (a4) and (bl) was 50% by weight.

[0191] The resins used for each composition is detailed in Table 3 below.

[0192] Table 3

[0193] Assessment of efficiency of said additive compositions (Cl) - (C5) and (Al) - (A12)

[0194] The efficiency in terms of preventing asphaltene precipitation on long term storage of compositions (Cl) - (C5) and (Al) - (A12) above was assessed by mixing thoroughly each composition in the Varandey crude oil, at respective treatment rates (total amount of active matter) of 10 ppm by weight, 25 ppm by weight, 50 ppm by weight and 100 ppm by weight.

[0195] The presence of sediments was assessed by visual observation of the samples, immediately after preparation and after storage thereof at room temperature for a duration detailed in the table below.

[0196] The results obtained are detailed in Table 4 below, in terms of percentage of asphaltene dispersion.

[0197] Table 4

[0198] The above results show that additive compositions Al to A12 provide an effective prevention of asphaltene precipitation on long term-storage, typically when tested for 168 hours test duration, as all compositions (Al) to (A12) remained fully dispersed without any apparition of sediments contrary to the comparative compositions (Cl) to (C5). These results illustrate the synergistic effect provided by the combination of the two resins of the present invention.

Claims

CLAIMS1. An additive composition comprising:(a) at least one resin obtainable by condensation of: at least one 4-(2-alkoxyethyl)phenol compound having the following formulawherein X denotes :• a linear or branched, saturated or unsaturated, hydrocarbon group containing from 1 to 24 carbon atoms, optionally interrupted with one or more heteroatoms, especially one or more heteroatoms chosen among oxygen, nitrogen, sulfur and / or phosphorous atoms,• a saturated or unsaturated, aromatic or non-aromatic, heterocyclic or cyclic moiety, with at least one aldehyde having from 1 to 8 carbon atoms, preferably from 1 to 4 carbon atoms; and(b) at least one modified alkylphenol-aldehyde resin obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with at least one aldehyde and / or one ketone having from 1 to 8 carbon atoms and at least one hydrocarbon compound having at least one alkylamine group having from 1 to 30 carbon atoms,• said alkylphenol-aldehyde condensation resin being itself obtainable by condensation of:o at least one alkylphenol substituted by at least one linear or branched alkyl group having from 1 to 30 carbon atoms with o at least one aldehyde and / or one ketone having from 1 to 8 carbon atoms.

2. The composition as defined in claim 1 , wherein, in said formula (I), X denotes a linear or branched, saturated or unsaturated, hydrocarbon group containing from 2 to 14 carbon atoms, more preferably from 2 to 12 carbon atoms, more preferably a linear or branched saturated hydrocarbon group containing from 2 to 14 carbon atoms, even more preferably from 2 to 12 carbon atoms.

3. The composition as defined in claim 1 or claim 2, wherein said 4-(2-alkoxyethyl)phenol compound, corresponding to formula (I), is selected among the group consisted of 4-(2-butoxyethyl)phenol; 4-(2- isobutoxyethyl)phenol; 4-(2-(pentyloxy)ethyl)phenol; 4-(2- (hexyloxy)ethyl)phenol; 4- (2 -((4- methylpentyl) oxy )e thy l)phenol; 4- (2- ((2- ethylhexyl) oxy) ethyl )phenol; 4-(2-(octyloxy)ethyl)phenol; 4- (2- (decyloxy)ethyl)phenol; 4 -(2- ((2- ethyloctyl) oxy ) ethyl) phenol; 4- (2- (dodecyloxy)ethyl)phenol; 4-(2-((ethyloxy)ethyl)phenol, and mixtures thereof.

4. The composition as defined in any of the preceding claims, wherein the aldehyde used for obtaining said resin (a) contains from 1 to 4 carbon atoms, preferably said aldehyde is chosen among the group constituted of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethylhexanal, benzaldehyde and mixtures thereof, and more preferably said aldehyde is formaldehyde.

5. The composition as defined in any of the preceding claims, wherein said resin (a) is a 4-(2-(alkoxy)ethyl)phenol formaldehyde resin having the following formula (II) :wherein X has the same meaning as in formula (I) and n is an integer ranging from 1 to 14.

6. The composition as defined in any of the preceding claims, wherein said resin (a) is selected among the group constituted of:4-(2-butoxyethyl)phenol - formaldehyde resin, 4-(2-isobutoxyethyl)phenol - formaldehyde resin, 4-(2-((ethyloxy)ethyl)phenol - formaldehyde resin, 4-(2-((2-ethylhexyl)oxy)ethyl)phenol - formaldehyde resin, 4-(2-(hexyloxy)ethyl)phenol - formaldehyde resin, 4-(2-(octyloxy)ethyl)phenol - formaldehyde resin, 4-(2-(decyloxy)ethyl)phenol - formaldehyde resin, 4-(2-(dodecyloxy)ethyl)phenol - formaldehyde resin, or mixtures thereof.

7. The composition as defined in any of the preceding claims, wherein said resin (a) is obtainable by condensation of at least one 4- (2-(alkoxy)ethyl)phenol compound, as defined in any of claims 1 to 3, with at least one aldehyde having from 1 to 8 carbon atoms, as defined in any of claims 1 and 4, in the presence of at least one acidic catalyst.

8. The composition as defined in any of the preceding claims, wherein said modified alkylphenol-aldehyde resin (b) is obtainable by a Mannich reaction of an alkylphenol-aldehyde condensation resin with at least one aldehyde and / or one ketone having from 1 to 4 carbon atoms and at least one hydrocarbon compound having at least one alkylmonoamine or alkylpolyamine group having between 4 and 30 carbon atoms, said alkylphenol-aldehyde condensation resin is itself obtainable by condensation of:- at least one monoalkylphenol substituted by at least one linear or branched alkyl group having from 1 to 30 carbon atoms, with- at least one aldehyde and / or one ketone having from 1 to 4 carbon atoms.

9. The composition as defined in any of the preceding claims, wherein said modified alkylphenol-aldehyde resin (b) is obtained by employing one and the same aldehyde or one and the same ketone as thealdehyde or ketone used for preparing said alkylphenol-aldehyde condensation resin.

10. The composition as defined in any preceding claim, wherein said alkylphenol is para-substituted, and preferably said alkyl-phenol is para-nonylphenol.1 1. The composition as defined in any of the preceding claims, wherein said at least one aldehyde and / or ketone, in said resin (b), is chosen from formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethylhexanal, benzaldehyde or acetone, and preferably formaldehyde.

12. The composition as defined in any of the preceding claims, wherein said at least one hydrocarbon compound having at least one alkylamine group is chosen from alkylpolyamines having at least one primary amine group, preferably at least two primary amine groups and more preferably three primary amine groups, and comprising a fatty chain having from 12 to 24 carbon atoms, preferably from 12 to 22 carbon atoms .

13. The composition as defined in any of the preceding claims, wherein said resins (a) and (b) are in a ratio by mass (a) :(b) ranging from 5 :95 to 95 :5, preferably from 80:20 to 20: 80.

14. The composition as defined in any of the preceding claims, wherein it further comprises one or more liquid organic solvent(s) chosen in the group constituted of: poly alkyl ethers, aliphatic hydrocarbons such as alkanes, aromatic solvents such as aromatic hydrocarbons and aromatic hetero-compounds, organic solvents derived from biomass, in particular oils of vegetable origin and more preferably cashew nutshell liquid, and mixtures thereof15. A petroleum product containing:- a crude oil and / or at least one hydrocarbon fraction or at least one residue deriving from the distillation of a crude petroleum oil, and / or at least one bitumen; and- an additive composition as defined in any of the preceding claims.

16. Use of a composition as defined in any of the preceding claims 1 to 13 as an additive in a petroleum product, preferably for preventing or reducing the precipitation of asphaltenes .

17. A method for preventing the precipitation of asphaltenes present in a petroleum product, comprising a step of adding to said product an additive composition as defined in any of the preceding claims 1 to 13.

Images