Polymer and its use as a viscosity reducer for hydrocarbons

Abstract

The present invention relates to a polymer and its use as a viscosity reducer for hydrocarbons, in particular heavy hydrocarbons.

Description

Title of the invention: Polymer and its use as a hydrocarbon viscosity reducer Technical field of the invention

[0001] The present invention relates to a polymer and its use as a viscosity reducer for hydrocarbons, in particular heavy and / or extra-heavy hydrocarbons. Prior art

[0002] According to projections by the Organization of the Petroleum Exporting Countries (OPEC), oil demand will reach 111.1 million barrels per day by 2040, an increase of 23.1% compared to current data. Due to this growing global energy demand and the increasingly limited availability of conventional or easily produced crude hydrocarbons, the exploitation of unconventional heavy and extra-heavy hydrocarbons is receiving considerable attention. Of the world's proven hydrocarbon reserves, more than half are heavy or extra-heavy hydrocarbons.

[0003] Hydrocarbons are referred to as "heavy" or "extra-heavy" because their density and apparent viscosity are higher than those of light hydrocarbons (i.e., conventional hydrocarbons). Because of their density, they accumulate at the bottom of reservoirs and / or are very difficult to extract. Once extracted, they remain difficult to transport from the well to storage facilities, refineries, or shipping terminals.

[0004] Various techniques are known to facilitate the movement of hydrocarbons during production, enhanced recovery, or transport to a refinery or storage area. These techniques include, for example, mechanical pumping, mechanical pumping combined with steam or heat injection to maintain low viscosity for pipeline transport. However, prolonged pumping interruptions occur regularly, which cools the hydrocarbons and clogs the pipes and pumps. It is then generally necessary to reheat the hydrocarbons, which results in the expenditure of a large amount of energy and therefore a very significant economic and environmental impact.

[0005] Other methods of hydrocarbon recovery exist, mainly: recovery by mixing with diluents, recovery by emulsification and recovery by adding a viscosity reducer soluble in the hydrocarbons.

[0006] For diluents (e.g., fuel oil or kerosene), it is necessary to use a large quantity and they are generally not readily available in the production areas. Transporting them to the field over long distances involves significant cost and energy expenditure.

[0007] The recovery of hydrocarbons by emulsification requires the injection of water, surfactants and other additives which, once transported, must be separated from the heavy hydrocarbons, the ecological impact being once again significant.

[0008] Various viscosity reducers have also been developed: the document CN110452676 describes lignosulfonate-based polymers, the document CN110484228 describes polyoxyethylene alkylphenols, CN112592430 describes polymers based on acryloyl morpholine and maleic anhydride, US2003135003 describes a copolymer of acrylic ester and N-vinyl pyrrolidone, US20070062101 describes a polyacrylate, and US2005085588 describes an acrylic monomer latex for reducing paraffin crystallization and improving crude oil flow. Although these polymers can reduce the viscosity of hydrocarbons, their effectiveness is limited, especially at low temperatures, for example, at 50°C or below, such as 20°C.

[0009] Despite the development of these techniques, there is a need for products that make it possible to reduce the viscosity of hydrocarbons, particularly at room temperature, in order to reduce the environmental impact of the extraction of said hydrocarbons, particularly heavy or extra-heavy hydrocarbons.

[0010] The Applicant has discovered a new polymer for effectively reducing the viscosity of hydrocarbons, in particular heavy and / or extra-heavy hydrocarbons. The polymer of the invention makes it possible to reduce the amount of energy required to transport the hydrocarbons by being effective at room temperature. This polymer thus makes it possible to reduce the environmental impact of the extraction of hydrocarbons, in particular heavy and / or extra-heavy hydrocarbons. The risks during the handling of said hydrocarbons with a low flash point are also reduced because the use of the polymer according to the invention makes heating the hydrocarbons optional.

[0011] The polymer of the invention and its use for reducing the viscosity of hydrocarbons are part of a principle of environmental awareness and of the impact of industries and humans on the planet. The polymer of the invention not only makes it possible to effectively reduce the viscosity of hydrocarbons, but also to reduce the amount of energy and water required for the extraction of said hydrocarbons, which leads to a reduction in the amount of greenhouse gas emissions such as CO2 associated with hydrocarbon recovery processes and their transport. Statement of the invention

[0012] The subject of the present invention is a polymer comprising: - at least 10 mol% of an acryloyl morpholine monomer A; - at least 20 mol% of a hydrophobic monomer B.

[0013] The present invention also relates to the use as a hydrocarbon viscosity reducer of a polymer comprising: - at least 10 mol% of an acryloyl morpholine monomer A; - at least 20 mol% of a hydrophobic monomer B. Description of the invention

[0014] By "polymer" is meant a polymer comprising at least one monomer A and at least one monomer B, it may optionally comprise at least one monomer C different from A, the monomer C being chosen from hydrophilic anionic monomers, hydrophilic non-ionic monomers, hydrophilic cationic monomers, hydrophilic zwitterionic monomers, and mixtures thereof. The monomer C may be an LCST macromonomer or a UCST macromonomer.

[0015] By “hydrophilic monomer” is meant a monomer which has an octanol / water partition coefficient, Kow, less than or equal to 1, in which the partition coefficient Kow is determined at 25°C in an octanol / water mixture having a volume ratio of 1 / 1, at a pH between 6 and 8.

[0016] By “hydrophobic monomer” is meant a monomer which has an octanol / water partition coefficient, Kow, greater than 1, in which the Kow partition coefficient is determined at 25°C in an octanol / water mixture having a volume ratio of 1 / 1, at a pH between 6 and 8.

[0017] The octanol / water partition coefficient, Kow, represents the ratio of concentrations (g / L) of a monomer between the octanol phase and the aqueous phase. It is defined as follows:

[0018] [Math.l] [monomer] ____ _L ZX. ““ rxi [monomer} f

[0019] By definition, a water-soluble polymer (or block) is a polymer (or block) which gives an aqueous solution when dissolved under stirring at 25°C and with a concentration of 10 gL 1 in water.

[0020] By “X and / or Y” is meant “X”, or “Y”, or “X and Y”.

[0021] Also part of the invention are all possible combinations between the different embodiments disclosed, whether preferred embodiments or given as examples. Furthermore, when ranges of values ​​are indicated, the limits are part of these ranges. The disclosure also includes all combinations between the limits of these ranges of values. For example, the ranges of values ​​"1-20, preferably 5-15", imply the disclosure of the ranges "1-5", “1-15”, “5-20” and “15-20” and values ​​1, 5, 15 and 20.

[0022] By “heavy hydrocarbons” is meant hydrocarbons whose API (American Petroleum Institute) density is less than 31, preferably less than 29, more preferably less than 20, and more preferably less than 16, for example less than 31 to 10.

[0023] By “extra-heavy hydrocarbons” is meant hydrocarbons whose API (American Petroleum Institute) density is less than 10, preferably less than 9, more preferably less than 8, even more preferably less than 7, even more preferably less than 6, and even more preferably less than 5. Polymer composition

[0024] The polymer comprises at least one monomer A (acryloyl morpholine) and one hydrophobic monomer B.

[0025] The amount of monomer A in the polymer is advantageously between 10 and 65 mol% relative to the total amount of monomer in the polymer, preferably between 15 and 60 mol%, more preferably between 20 and 50 mol%, and even more preferably between 20 and 45 mol%.

[0026] The polymer of the invention comprises at least 20 mol% of at least one hydrophobic monomer B.

[0027] Advantageously, the hydrophobic monomer(s) B may be chosen from (meth)acrylic acid esters with an alkyl or arylalkyl group, said group possibly comprising an ethoxylated and / or propoxylated chain; (meth)acrylamide derivatives with an alkyl, arylalkyl or dialkyl group, said group possibly comprising an ethoxylated and / or propoxylated chain; cationic allyl derivatives having an alkyl, arylalkyl or dialkyl group, said group possibly comprising an ethoxylated and / or propoxylated chain; anionic or cationic hydrophobic derivatives of (meth)acryloyl; anionic or cationic monomeric derivatives of (meth)acrylamide carrying a hydrophobic chain; and mixtures thereof. The hydrophobic monomers may comprise halogen atoms, for example chlorine.

[0028] Among these hydrophobic monomers: - the alkyl groups are preferably C4-C2o, more preferably C4-C8. The C6-C2o alkyls are preferably linear alkyls while the C4-C5 alkyls are preferably branched; the dialkyl groups comprise 2 of these alkyl groups, - the arylalkyl groups are preferably C7-C25, more preferably C7-C15, - the ethoxylated chains advantageously comprise between 0 and 100 -CH2 -CH2-O- groups, preferably between 6 and 100, more preferably between 10 and 40, - the propoxylated chains advantageously comprise between 0 and 50 -CH2 -CH2-CH2-O- groups, preferably between 1 and 50, more preferably between 1 and 20.

[0029] Preferred hydrophobic monomers belonging to these classes are, for example: - n-hexyl (meth)acrylate, n-octyl (meth)acrylate, octyl (meth)acrylamide, lauryl (meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate, myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl (meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl (meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl (meth)acrylamide, and mixtures thereof, - cationic allyl derivatives having a formula (I) or (II):

[0030] [Chem.l] (I) (II)

[0031] where, R5: independently an alkyl chain containing 1 to 4 carbons; R6: an alkyl or arylalkyl chain comprising 8 to 30 carbons; X: a halide selected from the group consisting of bromides, chlorides, iodides, fluorides and any negatively charged counterion; and, preferably, hydrophobic cationic derivatives of the methacryloyl type corresponding to formula (III):

[0032] [Chem.2] (III)

[0033] in which A: O or N-R9 (preferably A=N-R9), R7, R8, R9, Rio, Ru: independently a hydrogen atom or an alkyl chain containing 1 to 4 carbons, Q: an alkyl chain comprising 1 to 8 carbons, Rn: an alkyl or arylalkyl chain comprising 8 to 30 carbons, X: a halide chosen from the group consisting of bromides, chlorides, iodides, fluorides, and any negatively charged counterion.

[0034] In a preferred embodiment, the hydrophobic monomer B is chosen from: acrylamide derivatives such as N,N dialkyl acrylamido or N alkyl acrylamido, these derivatives comprising a linear, branched or cyclic hydrocarbon chain, which may comprise one or more unsaturations and / or which may comprise one or more heteroatoms chosen from nitrogen, oxygen, silicon, fluorine and sulfur and / or a sulfonic, sulfonate, phosphoric, phosphate, phosphonic or phosphinate function, the hydrocarbon chain being advantageously C4-C25, preferably C4-C14 and more preferably C4-C8, and mixtures thereof. The hydrophobic monomer B is advantageously chosen from N-tert-butyl acrylamide, N-tert-octyl acrylamide and mixtures thereof.

[0035] The quantity of hydrophobic monomer B in the polymer is advantageously between 35 and 90 mol% relative to the total quantity of monomer in the polymer, preferably between 40 and 85 mol%, more preferably between 50 and 80 mol%, more preferably between 55 and 80 mol%.

[0036] In a preferred embodiment, the amount of hydrophobic monomer B in the polymer is greater than the amount of monomer A (acryloyl morpholine).

[0037] In a preferred embodiment, the polymer consists of monomers A and B, monomer A being acryloyl morpholine and monomer B being a hydrophobic monomer, advantageously chosen from: acrylamide derivatives such as N,N dialkyl acrylamido or N alkyl acrylamido, these derivatives comprising a linear, branched or cyclic hydrocarbon chain, which may comprise one or more unsaturations and / or which may comprise one or more heteroatoms chosen from nitrogen, oxygen, silicon, fluorine and sulfur and / or a sulfonic, sulfonate, phosphoric, phosphate, phosphonic or phosphinate function, the hydrocarbon chains are advantageously C7-C25, preferably C4-C14 and more preferably C4-C8, and mixtures thereof.

[0038] The polymer may optionally comprise one or more monomers C different from A, chosen from hydrophilic anionic monomers, hydrophilic nonionic monomers, hydrophilic cationic monomers, hydrophilic zwitterionic monomers, and mixtures thereof. Monomer C may be an LCST macromonomer or a UCST macromonomer.

[0039] Advantageously, the polymer does not comprise more than 15 mol% of monomer C, preferably not more than 10 mol%, more preferably not more than 5 mol%.

[0040] Advantageously, the hydrophilic anionic monomer(s) are chosen from monomers having vinyl functions (advantageously acrylic, maleic, fumaric, malonic, itaconic, or allylic), and containing a carboxylate, phosphonate, phosphate, sulfate, sulfonate group, or another anionically charged group. Examples of suitable monomers include acrylic acid; methacrylic acid; dimethylacrylic acid; itaconic acid; itaconic acid hemi-ester; itaconic anhydride; itaconamide; crotonic acid; maleic acid; fumaric acid; acrylamido undecanoic acid; 3-acrylamido 3-methylbutanoic acid; acryloyl chloride; maleic anhydride;strong acid monomers having for example a sulfonic acid or phosphonic acid function such as vinylsulfonic acid, vinylphosphonic acid, allylsulfonic acid, methallylsulfonic acid, 2-methylidenepropane-1,3-disulfonic acid, 2-sulfoethylmethacrylate, sulfopropylmethacrylate, sulfopropylacrylate, allylphosphonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (ATBS), 2-acrylamido-2-methylpropane disulfonic acid; the water-soluble salts of these monomers such as their alkali metal, alkaline earth metal, or ammonium salts; and; their mixtures. Preferably, the hydrophilic anionic monomer is acrylic acid.

[0041] In a particular embodiment, the hydrophilic anionic monomer(s) may be salified. It may also be a mixture of acid form and salified form, for example a mixture of acrylic acid and acrylate.

[0042] By salified is meant the substitution of a proton of at least one acid function of the type -R(=O)-OH (with R= P, S or C) of the anionic monomer by a metal or ammonium cation to form a salt of the type -R(=O)-OX (X being a metal cation or an organic cation). In other words, the non-salified form corresponds to the acid form of the monomer, for example RC(=O)-OH in the case of the carboxylic acid function, whereas the salified form of the monomer corresponds to the form RC(=O)-0 X+, X+ corresponding to an alkali metal cation or an organic cation. The salification of the acid functions of the polymer may be partial or total.

[0043] The salified form advantageously corresponds to the salts of alkali metals (Li, Na, K, etc.), alkaline earth metals (Ca, Mg, etc.) or ammonium (for example the ammonium ion or a tertiary ammonium). The preferred salts are the sodium salts.

[0044] Salification can be done before, during or after polymerization.

[0045] In a particular embodiment, the polymer advantageously comprises between 10 and 100 mol% of hydrophilic anionic monomer(s) in salified form, preferably between 50 and 100 mol%, relative to the total number of hydrophilic anionic monomer(s).

[0046] In a particular embodiment, 100 mol% of the hydrophilic anionic monomer(s) of the polymer are in salified form.

[0047] Advantageously, the hydrophilic non-ionic monomer(s) are chosen, in particular, from the group comprising water-soluble vinyl monomers, such as acrylamide, methacrylamide, N-alkylacrylamides, N-alkylmethacrylamides, N,N-dialkyl acrylamides (for example N,N-dimethylacrylamide or N,N-diethylacrylamide), N,N-dialkylmethacrylamides, alkoxylated esters of acrylic acid, alkoxylated esters of methacrylic acid, N-vinylpyrrolidone, N-methylolacrylamide, N-vinylformamide (NVF), N-vinyl acetamide, N-vinyl imidazole, N-vinyl suc-cinimide, glycidyl methacrylate, methacrylate glyceryl, diacetone acrylamide, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, hydroxyalkylacrylates, hydroxyalkyl methacrylates, and mixtures thereof. Among these non-ionic monomers, the alkyl groups are advantageously C1-C5, more advantageously C1-C3.These are preferably linear alkyls. Preferably, the hydrophilic non-ionic monomer is acrylamide.

[0048] Advantageously, the hydrophilic cationic monomer(s) are chosen from: monomers derived from vinyl-type units (advantageously acrylamide, acrylic, allyl or maleic), these monomers having a phosphonium, tertiary ammonium or quaternary ammonium function.Mention may be made, in particular and without limitation, of diallyldialkyl ammonium salts such as diallyl dimethyl ammonium chloride (DADMAC); acidified or quaternized salts of dialkylaminoalkylacrylamides; acidified or quaternized salts of dialkylaminoalkylmethacrylamides, such as, for example, methacrylamidopropyltrimethylammonium chloride (MAPTAC), acrylamidopropyltrimethylammonium chloride (APTAC), acidified or quaternized salts of dialkylaminoalkyl acrylate such as quaternized or salified dimethylaminoethyl acrylate (ADAME), acidified or quaternized salts of dialkylaminoalkyl methacrylate such as quaternized or salified dimethylaminoethyl methacrylate (MADAME), vinylamine obtained by the hydrolysis (basic or acidic) of an amide group -N(R2)-CO-R* with R1 and R2 being, independently, a hydrogen atom or an alkylated chain of 1 to 6 carbons, vinylamine obtained by Hofmann degradation and mixtures thereof.Advantageously, the alkyl groups are C1-C3. Preferably, the hydrophilic cationic monomer is quaternized or salified dimethylaminoethyl acrylate (ADAME).

[0049] A person skilled in the art will know how to prepare the quaternized monomers, for example using a quaternizing agent of the RX type, R being an alkyl group and X being a halogen or a sulfate. The quaternizing agent may be chosen from dialkyl sulfates comprising from 1 to 6 carbon atoms or alkyl halides comprising from 1 to 6 carbon atoms. Preferably, the quaternizing agent is chosen from methyl chloride, benzyl chloride, dimethyl sulfate or diethyl sulfate. In addition, the present invention also covers monomers of the DADMAC, APTAC and MAPTAC type whose counterion is a sulfate, a fluoride, a bromide or an iodide instead of the chloride.

[0050] By “quaternizing agent” we mean a molecule capable of alkylating a tertiary amine.

[0051] Advantageously, the hydrophilic zwitterionic monomer(s) may be a derivative of a vinyl-type unit (advantageously acrylamide, acrylic, allylic or maleic), this monomer having an amine, tertiary ammonium or quaternary ammonium function and an acid function of carboxylic (or carboxylate), sulfonic (or sulfonate) or phosphoric (or phosphate) type. Mention may be made, in particular and in a non-limiting manner, of derivatives of dimethylaminoethyl acrylate, such as 2-((2-(acryloyloxy)ethyl) dimethylammonio) ethane-1-sulfonate, 3-((2-(acryloyloxy)ethyl) dimethylammonio) propane-1-sulfonate, 4-((2-(acryloyloxy)ethyl) dimethylammonio) butane-1-sulfonate, [2-(acryloyloxy)ethyl] (dimethylammonio) acetate, derivatives of dimethylaminoethyl methacrylate such as 2-((2-(methacryloyloxy) ethyl) dimethylammonio) ethane-1-sulfonate, 3-((2-(methacryloyloxy) ethyl) dimethylammonio) propane-1-sulfonate, 4-((2-(methacryloyloxy) ethyl) dimethylammonio) butane-1-sulfonate, [2-(methacryloyloxy)ethyl] (dimethylammonio) acetate, derivatives of dimethylaminopropylacrylamide such as 2-((3-acrylamidopropyl) dimethylammonio) ethane-1-sulfonate, 3-((3-acrylamidopropyl) dimethylammonio) propane-1-sulfonate, 4-((3-acrylamidopropyl) dimethylammonio) butane-1-sulfonate, [3-(acryloyloxy) propyl] (dimethylammonio) acetate, dimethylamino propyl methylacrylamide derivatives such as 2-((3-methacrylamidopropyl) dimethylammonio) ethane-1-sulfonate, 3-((3-methacrylamidopropyl) dimethylammonio) propane-1-sulfonate,4-((3-methacrylamidopropyl) dimethylammonio) butane-1-sulfonate and [3-(methacryloyloxy)propyl] (dimethylammonio) acetate and mixtures thereof.

[0052] In a particular embodiment, the polymer may comprise at least one monomer C with an LCST group.

[0053] According to the general knowledge of a person skilled in the art, an LCST group corresponds to a group whose solubility in water for a given concentration is modified beyond a certain temperature and as a function of the salinity. This is a group having a transition temperature upon heating defining its lack of affinity with the solvent medium. The lack of affinity with the solvent results in opacification or a loss of transparency which may be due to precipitation, aggregation, gelation or viscosification of the medium. The minimum transition temperature is called “LCST” (lower critical solubility temperature). For each concentration of LCST group, a transition temperature upon heating is observed. It is higher than the LCST which is the minimum point of the curve.Below this temperature the polymer is soluble in water, above this temperature the polymer loses its solubility in water.

[0054] Advantageously, the polymer does not comprise a monomer C with an LCST group whose transition temperature is less than 100°C, preferably less than 50°C, more preferably less than 30°C, and more preferably less than 25°C.

[0055] In a particular embodiment, the polymer may comprise at least one monomer C with a UCST group.

[0056] According to the general knowledge of a person skilled in the art, a UCST group corresponds to a group whose solubility in water for a given concentration is modified below a certain temperature and as a function of the salinity. This is a group having a cooling transition temperature determinant defining its lack of affinity with the solvent medium. The lack of affinity with the solvent results in opacification or loss of transparency which can be due to precipitation, aggregation, gelation or viscosification of the medium. The maximum transition temperature is called "UCST" (Upper Critical Solution Temperature). For each group concentration at UCST, a cooling transition temperature is observed. It is lower than the UCST which is the maximum point of the curve. Above this temperature, the polymer is soluble in water, below this temperature, the polymer loses its solubility in water.

[0057] The quantities of the different monomer(s) will be adjusted by a person skilled in the art so as not to exceed 100 mol% during the preparation of the polymer according to the invention. Structure of the polymer

[0058] According to the invention, the polymer may have a linear, branched, ramified, star-shaped or comb-shaped structure. This structure may be obtained, according to the general knowledge of a person skilled in the art, for example by selection of the initiator, the transfer agent, the polymerization technique such as reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP) or atom transfer radical polymerization (ATRP), the incorporation of structural monomers, or the concentration.

[0059] The polymer according to the invention may be a random polymer, a block polymer or a gradient polymer. Preferably, it is a block polymer, more advantageously a polymer consisting of blocks of monomers A and blocks of monomers B.

[0060] By "random polymer" is meant a polymer in which the distribution of monomers is random. A random polymer is obtained when all the monomers making up the polymer are present at the start of the polymerization.

[0061] By "block polymer" is meant di-blocks, tri-blocks or multi-blocks, grafted block polymers, branched block polymers (also known as linear star polymers).

[0062] Polymers having a block structure are polymers composed of at least two blocks of different monomers. Di-block polymers have two distinct blocks; tri-block polymers have three, etc. They are advantageously obtained by successively polymerizing different species of monomers.

[0063] In a particular embodiment, the polymer has an XY type structure when it is composed of two different monomers. In other words, the first fraction comprises only as monomer, monomers X. They are polymerized first and when all the monomers X have reacted, the second fraction comprising the monomers Y is then added.

[0064] In a particular embodiment, the polymer has an XYZ type structure when it is composed of three different monomers (A, B and C). In other words, the first fraction comprises only X monomers. They are polymerized initially and when all the X monomers have reacted, the second fraction comprising the Y monomers is then added. When all the Y monomers have reacted, the third fraction comprising the Z monomers is then added.

[0065] This polymerization system can be extended to obtain so-called multiblock polymers having a structure Xi-Yi-...-Xn_i-Yn_i-Xn-Yn, n being an integer greater than or equal to 2 representing the number of blocks.

[0066] In a preferred embodiment, the polymer comprises at least two blocks (advantageously consisting of two blocks): - a water-soluble BA block comprising at least one acryloyl morpholine monomer A; - a hydrophobic BB block comprising at least one hydrophobic B monomer.

[0067] The BA block may optionally comprise one or more monomers C different from A chosen from hydrophilic anionic monomers, hydrophilic non-ionic monomers, hydrophilic cationic monomers and hydrophilic zwitterionic monomers, and mixtures thereof. The monomer C may be an LCST macromonomer or a UCST macromonomer.

[0068] When the water-soluble BA block comprises one or more hydrophobic monomers, it comprises a quantity such that the BA block remains water-soluble.

[0069] The monomers capable of being used to form the BA block are advantageously chosen from the hydrophilic monomers previously described.

[0070] Advantageously, the quantity of monomer A in the block BA is between 25 and 100 mol% relative to the total number of moles of monomers of the polymer, preferably between 40 and 100 mol%, more preferably between 50 and 100 mol%, and more preferably between 85 and 100 mol%.

[0071] A person skilled in the art will know how to adjust the values ​​given for the molar compositions of the BA and BB blocks so as to remain consistent with the values ​​of the molar compositions of the polymer given previously. In other words, even in the case of a block polymer, the molar composition of the entire block polymer complies with the values ​​described previously for the polymer.

[0072] In a particular embodiment, the BA block consists of acryloyl morpholine monomer A and hydrophilic monomers C.

[0073] In a particular embodiment, the BA block mainly comprises monomer A of acryloyl morpholine.

[0074] In a particular embodiment, the BA block consists of acryloyl morpholine monomer A.

[0075] The BA block advantageously has a number-average molecular weight of between 1,000 and 100,000 g / mol, preferably between 2,000 and 50,000 g / mol, more preferably between 2,500 and 25,000 g / mol.

[0076] The hydrophobic BB block may optionally comprise one or more monomers C selected from hydrophilic anionic monomers, hydrophilic nonionic monomers, hydrophilic cationic monomers and hydrophilic zwitterionic monomers, and mixtures thereof. The monomer C may be an LCST macromonomer or a UCST macromonomer.

[0077] The monomers capable of being used to form the BB block are advantageously chosen from the hydrophilic monomers previously described.

[0078] Advantageously, the quantity of monomer B in the block BB is between 25 and 100 mol% relative to the total number of moles of monomers of the polymer, preferably between 40 and 100 mol%, more preferably between 50 and 100 mol%, and more preferably between 85 and 100 mol%.

[0079] When the BB block comprises one or more hydrophilic C monomers, it comprises a quantity such that the BB block is hydrophobic.

[0080] In a particular embodiment, the BB block mainly comprises N-ter-butyl acrylamide.

[0081] In a particular embodiment, the BB block is made up of hydrophobic B monomers.

[0082] In a particular embodiment, the BB block consists of N-ter-butyl acrylamide.

[0083] The BB block advantageously has a number-average molecular weight of between 1,000 and 500,000 g / mol, preferably between 3,000 and 450,000 g / mol, more preferably between 7,500 and 225,000 g / mol.

[0084] The molar mass of the BB block is advantageously greater than the molar mass of the BA block.

[0085] According to a preferred embodiment, the polymer comprises a BA block having a number average molecular weight of between 1,000 and 100,000 g / mol and consisting of acryloyl morpholine monomers A, and a BB block having a number average molecular weight of between 1,000 and 500,000 g / mol and consisting of hydrophobic B monomers.

[0086] By “gradient polymer” is meant a polymer whose monomeric composition and / or structure varies in a controlled manner along the entire polymer chain.

[0087] Polymers having a gradient structure are polymers composed of at least two monomers in which the change in composition of the monomers is gradual, unlike block polymers, which have an abrupt change in composition, and random polymers, which do not have a continuous change in composition. In the gradient polymer, due to the gradual change in composition along the length of the polymer chain, less intra-chain and inter-chain repulsion is observed.

[0088] The gradient can be formed by a spontaneous or forced gradient. Spontaneous gradient polymerization is due to a difference in reactivity of the monomers. Forced gradient polymerization involves varying the composition of monomers introduced throughout the polymerization time.

[0089] A forced gradient process comprises (1) introducing a first fraction of monomers into a reactor, (2) adding at least one additional fraction of monomers, advantageously different from the first, and (3) polymerizing the monomers introduced into the reactor. Polymerization of the monomers is initiated upon introduction of the first fraction.

[0090] The addition of the additional monomer fraction may be carried out in parallel with the introduction of the first monomer fraction into the reactor (the introduction of the fractions may therefore begin and end at the same time). Alternatively, the start of the first monomer feed (first fraction) into the reactor may precede the start of the addition of a second monomer fraction. Alternatively, a first and a second fraction may be introduced simultaneously, but the duration of addition of the second fraction may be greater than the duration of introduction of the first fraction into the reactor. This embodiment is also applicable to processes using at least 3 monomer fractions.

[0091] In the process of the invention, the polymer obtained is formed by the sequenced addition of the monomers, in other words, it is a forced gradient process.

[0092] The polymer may further be structured by a branching agent. By structured polymer is meant a non-linear polymer which has side chains so as to obtain, when this polymer is dissolved in water, a strong state of entanglement leading to high viscosities.

[0093] The branching agent is advantageously chosen from: - structural agents, which may be chosen from the group comprising monomers with polyethylene unsaturation (having at least two unsaturated functions), such as for example vinyl, allylic, acrylic functions and we can cite for example methylene bis acrylamide (MBA), triallyamine, or tetraallylammonium chloride or 1,2 dihydroxyethylene bis-(N-acrylamide), - monomers having at least two epoxy functions, - monomers having at least one unsaturated function and one epoxy function, - macroinitiators such as polyperoxides, polyazos and polytransfer agents such as polymercaptant polymers and polyols, - functionalized polysaccharides.

[0094] The amount of branching agent in the polymer is advantageously less than 40,000 ppm by weight relative to the total weight of the monomers of the polymer, preferably less than 10,000 ppm by weight, more preferably less than 5,000 ppm by weight.

[0095] In a particular embodiment, the amount of branching agent is at least equal to 0.1 ppm by weight relative to the total weight of the monomers of the polymer, preferably at least 1 ppm by weight, more preferably at least 10 ppm by weight, more preferably at least 100 ppm by weight and even more preferably at least 1,000 ppm by weight.

[0096] In a particular embodiment, the polymer does not comprise a branching agent.

[0097] In a particular embodiment, the polymer may comprise a transfer agent.

[0098] The transfer agent is advantageously chosen from methanol; isopropyl alcohol; sodium hypophosphite; calcium hypophosphite; magnesium hypophosphite; potassium hypophosphite; ammonium hypophosphite; 2-mercaptoethanol; 3-mercaptopropanol; dithiopropylene glycol; thioglycerol; thioglycolic acid; thiohydracrylic acid; thiolactic acid; thiomalic acid; cysteine; and aminoethanethiol; thioglycolates; allyl phosphites; allyl mercaptans, such as n-dodecyl mercaptan; sodium methallysulfonate; calcium methallysulfonate; magnesium methallysulfonate; potassium methallysulfonate; ammonium methallylsulfonate;alkyl phosphites such as trialkyl (C12-C15) phosphites, di-oleyl hydrogen phosphites, dibutyl phosphite, dialkyldithiophosphates such as dioctyl phosphonate, tertiary nonyl mercaptan, 2-ethylhexyl thioglycolate, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, isooctylthioglycolate, 2-Ethylhexyl thioglycolate, 2-Ethylhexyl mercaptoacetate, polythiols and mixtures thereof. Preferably, it is sodium hypophosphite. ;

[0099] The amount of transfer agent is advantageously between 0 and 100,000 ppm by weight relative to the total weight of the monomers of the polymer, preferably between 0 and 10,000 ppm by weight, more preferably between 0 and 1,000 ppm by weight, even more preferably between 0 and 100 ppm by weight.

[0100] When present, the transfer agent represents at least 0.1 ppm by weight, relative to the total weight of the monomers of the polymer, preferably at least 1 ppm by weight.

[0101] In a particular embodiment, the polymer does not comprise a transfer agent. Polymerization of the polymer

[0102] Generally speaking, the polymer does not require the development of a particular polymerization process. Indeed, it can be obtained using all the polymerization techniques well known to those skilled in the art. This may in particular involve solution polymerization; gel polymerization; precipitation polymerization; emulsion polymerization (direct or inverse); suspension polymerization; reactive extrusion polymerization; water-in-water polymerization; or semi-cellular polymerization. Preferably, the polymer is obtained by radical polymerization of monomers in solution.

[0103] The polymerization is generally a radical polymerization. By radical polymerization, we include free radical polymerization using UV, azo, redox or thermal initiators as well as controlled radical polymerization (CRP) techniques or matrix polymerization techniques.

[0104] As a controlled radical polymerization technique, mention may be made, in a non-limiting manner, of techniques such as iodine transfer polymerization (ITP), nitroxide-mediated polymerization (NMP), atom transfer (ATRP), reversible addition-fragmentation chain transfer (RAFT), which includes MADIX technology (MAcromolecular Design by Interchange of Xanthates), various variations of polymerizations with organometallic compounds (OMRP), and radical polymerization controlled by heteroatomic compounds. (“OrganoHeteroatom-mediated Radical Polymerization” in English (OHRP)).

[0105] The activation-deactivation process linked to controlled radical polymerization allows the chains to grow at the same speed until the total consumption of the monomer, making it possible to control the molecular weights of the polymers and to obtain narrow molecular weight distributions. This will also make it possible to minimize the heterogeneity of the composition. The reversible deactivation of the growing chains is at the origin of the minimization of irreversible termination reactions. The vast majority of the polymer chains remain in dormant form and are therefore reactivatable. It is then possible to functionalize the chain ends in order to initiate other polymerization modes or to make chain extensions. This makes it possible to control the molecular weight, the composition and the architecture of the polymer.

[0106] Controlled radical polymerization therefore has the following distinctive aspects: 1- The number of polymer chains is fixed throughout the duration of the reaction, 2- The polymer chains all grow at the same speed, which results in: * a linear increase in molecular weights, * a tight distribution of average molecular weights, 3- The average molecular weight is controlled by the monomer / control agent molar ratio.

[0107] The controlled nature is all the more marked as the rate of reactivation of the radical chains is clearly higher than the rate of growth of the chains (propagation). However, in certain cases, the rate of reactivation of the radical chains is higher than or equal to the rate of propagation. In these cases, conditions 1 and 2 are not observed and, consequently, control of the molecular weights is not possible.

[0108] In a preferred embodiment, the polymer is obtained by reversible addition-fragmentation chain transfer polymerization.

[0109] Reversible addition-fragmentation chain transfer polymerization requires the presence of at least one control agent, advantageously of formula (IV):

[0110] [Chem.3] (IV) [YES] in which - Z= O, S or N; - Ri and R2, identical or different, represent: * an optionally substituted alkyl, acyl, alkenyl or alkynyl group (i), or * a carbon cycle (ii), saturated or not, possibly substituted or aromatic, or * a heterocycle (iii), saturated or unsaturated, optionally substituted or aromatic, these groups and cycles (i), (ii) and (iii) being able to be substituted by substituted aromatic groups or by alkoxycarbonyl or aryloxycarbonyl (-COOR), carboxy (-COOH), acyloxy (-O2CR), carbamoyl (-CON(R)2), cyano (-CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidimo, hydroxy (-OH), amino (-N(R)2), halogen, allyl, epoxy, alkoxy (-OR), S-alkyl, S-aryl, groups having a hydrophilic or ionic character such as alkali salts of carboxylic acids, alkali salts of sulfonic acid, polyalkylene oxide chains (POE, POP), cationic substituents (quaternary ammonium salts); R representing a C1-C2o alkyl or aryl group; - Q is a linear or structured polymer chain comprising n identical or different monomers comprising at least one ethylenic function; - n is an integer between 0 and 500, advantageously between 1 and 500, more advantageously between 1 and 100. When n = 0, Q is a single bond between the sulfur atom and the R2 group.

[0112] The monomer(s) used to form Q are advantageously chosen from the same hydrophilic monomers as those described to form the polymer (monomers A and C). These may in particular be acrylamide, acrylic acid and mixtures thereof.

[0113] In NR2 functions, the two R groups can be the same or different from each other.

[0114] In a preferred embodiment, the control agent is of formula (IV) in which Z = O.

[0115] In another preferred embodiment, the control agent is of formula (IV) in which: -Z = O, - Q is a linear or structured polymer chain obtained from 1 to 100 monomers comprising at least one hydrophilic non-ionic monomer and / or at least one hydrophilic anionic monomer and / or at least one hydrophilic cationic monomer.

[0116] In another preferred embodiment, the control agent is of formula (V):

[0117] [Chem.4]

[0118] in which n is an integer between 0 and 100, preferably between 1 and 50.

[0119] In another preferred embodiment, the control agent is of formula (IV) in which Z = S.

[0120] In another preferred embodiment, the control agent is of formula (VI):

[0121] [Chem. 5] (VI)

[0122]

[0123]

[0124] in which - The R3 groups are identical or different, independently represent an H or a CH3 or a cation, the cation being advantageously chosen from cations of alkali metals (Li, Na, K...), alkaline earth metals (Ca, Mg...) or ammonium (for example the ammonium ion or a tertiary ammonium), preferably sodium. In another preferred embodiment, the control agent is of formula (VII): COORs (VII)

[0125]

[0126]

[0127] In which - The R3 groups are identical or different, independently represent an H or a CH3 or a cation, the cation being advantageously chosen from cations of alkali metals (Li, Na, K...), alkaline earth metals (Ca, Mg...) or ammonium (for example the ammonium ion or a tertiary ammonium), preferably sodium; and n and n' are whole numbers independent of each other, between 0 and 100, preferably between 1 and 50. In another preferred embodiment, the control agent is of formula (VIII): [Chem. 7] FLOOC HORN (VIII)

[0128]

[0129]

[0130] in which - The R3 are identical or different, independently represent an H or a CH3 or a cation, the cation being advantageously chosen from cations of alkali metals (Li, Na, K...), alkaline earth metals (Ca, Mg...) or ammonium (for example the ammonium ion or a tertiary ammonium), preferably sodium. In another preferred embodiment, the control agent is of formula (IX): [Chem. 8]

[0131]

[0132]

[0133]

[0134]

[0135] (IX) in which - The R3 groups are identical or different, independently represent an H or a CH3 or a cation, the cation being advantageously chosen from cations of alkali metals (Li, Na, K...), alkaline earth metals (Ca, Mg...) or ammonium (for example the ammonium ion or a tertiary ammonium), preferably sodium; and n is an equal integer, between 0 and 100, preferably between 1 and 50. According to the invention, the quantity of control agent is advantageously between 5.10 7% and 10% by weight, relative to the total weight of the reaction medium, preferably between 5.10 4 and 5% by weight. The molar ratio of monomer A to control agent in the aqueous phase is advantageously between 12,500:1 and 300,000:1, preferably between 27,500:1 and 250,000:1, more preferably between 27,500:1 and 10,000:1. The polymer can be partially or completely post hydrolyzed. Post-hydrolysis is the hydrolysis reaction of the polymer after its formation by polymerization of monomer(s). This step consists of the reaction of hydrolyzable functional groups of advantageously non-ionic monomers C, more advantageously the amide or ester functions, with a hydrolysis agent. This hydrolysis agent may, for example, be an enzyme, an ion exchange resin, or a Brpnsted acid (for example a hydrohalic acid) or a Brpnsted base (for example an alkali hydroxide or an alkaline earth hydroxide). Preferably, the hydrolysis agent is a Brpnsted base. During this post-hydrolysis step of the polymer, the number of carboxylic acid (or carboxylate) functions increases. Indeed, the reaction between the base and the amide or ester functions present in the polymer produces carboxylic acid or carboxylate groups.

[0136] The polymer may be in liquid, gel or solid form when its preparation includes a drying step such as spray drying, drum drying, radiation drying such as microwave drying, or even fluidized bed drying.

[0137] The polymer advantageously has a number-average molecular weight of between 2,000 and 600,000 g / mol, preferably between 5,000 and 500,000 g / mol, more preferably between 10,000 and 250,000 g / mol.

[0138] The polydispersity index (Ip) of the polymer obtained according to the invention is advantageously equal to 3 or less (<3), preferably less than or equal to 2 (<2), preferably less than or equal to 1.5 (<1.5), even more preferably equal to 1. The polydispersity index is determined according to the following formula: Ip = Mw / Mn Mw is the weight average molecular weight Mn is the number average molecular weight.

[0139] Use as a hydrocarbon viscosity reducer

[0140] As already indicated, the present invention also relates to the use as viscosity reducer of hydrocarbons, advantageously heavy hydrocarbons, of the polymer comprising: - at least 10 mol% of an acryloyl morpholine monomer A; - at least 20 mol% of a hydrophobic monomer B.

[0141] The polymer can be used to reduce the viscosity of any type of hydrocarbon, preferably heavy hydrocarbons (API < 31).

[0142] The polymer can be used to reduce the viscosity of any type of hydrocarbon, preferably extra-heavy hydrocarbons (API < 10).

[0143] The quantity of polymer added to the hydrocarbons is advantageously between 10 and 10,000 ppm by weight of polymer relative to the weight of hydrocarbons, preferably between 50 and 5,000 ppm, more preferably between 100 and 2,000 ppm.

[0144] The polymer works in all applications related to the reduction of viscosity of hydrocarbons (for example in an underground reservoir, in a pipeline, a production facility, a mixture of heavy hydrocarbons, a refinery). The use of the polymer does not require any special treatment, the viscosity reduction is done by contacting the described polymer with hydrocarbons. The polymers of the invention can be added at any point in the flow line, advantageously upstream of the point where a reduced viscosity is desired.

[0145] The contact between the hydrocarbons and the polymer can be done by any means known to those skilled in the art, for example a pump, a static mixer, a dynamic mixer. EXAMPLES

[0146] List of abbreviations: AM = Acrylamide AA = Acrylic Acid ACMO = 4-Acryloylmorpholine TBA = N-tert-butyl acrylamide DMA = Dimethylacrylamide NIPAM = N-isopropylacrylamide Characterization of polymers

[0147] The polymers were analyzed by size exclusion chromatography (SEC) to determine the number average molar masses (Mn) and the polydispersity index (Ip). The analytical conditions are: - Detector: refractive index; - Chromatographic columns: PL Aquagel, PL Aquagel OH 20, PL Aquagel OH 40; - Solvent: NaCl, NaH2PO4, NaN3. Example 1: Synthesis of control agents

[0148] In a synthesis reactor, the following are introduced at room temperature: - 4.53 g of O-ethyl-S-(l-methoxycarbonyl) ethyl dithiocarbonate; - 22.66 g of acrylamide; - 27.19 g of deionized water; - 45.31 g of acetic acid; - 0.32 g of azo initiator (VA 044). The reaction mixture is degassed and then heated to 60°C. The reaction lasts 3 hours with stirring. Control agent XI is thus obtained.

[0149] Other control agents (XI, X2, X3, X5 and X6) were synthesized according to the same method. They are characterized by Q groups of different chemical nature summarized in Table 1.

[0150] [Tables 1] Reference XT p AM / AA (70 / 30 moi%) 1230 X5 HOOC-C2H5 CH(CH3)-COOH s —

[0151] Table 1: Control agents Example 2: Synthesis of PI polymers

[0152] 2-1 Synthesis of Block A of the polymer In a reactor equipped with a stirring and vapor condensation system, the following are mixed at room temperature: - 75.7 g of deionized water; - 2.23 g of XI; - 30 g of 4-Acryloylmorpholine.

[0153] The reaction medium is stirred, degassed at room temperature for 30 minutes, then heated to 60°C. The polymerization is initiated with 0.173 g of 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (V-50). The reaction time is 120 minutes. The Al-1 block is then obtained.

[0154] Other A blocks were also synthesized using the same experimental protocol, adjusting the quantities and using different control agents. The characteristics are summarized in Table 2.

[0155] [Tables2] Tests Synthesis block A Reference block A Monomer block A Control Agent Mn (g / mol) block A ' 1 ALI ACMO XI 1530 2 AL2 ACMO XI 2550 3 AL3 ACMO XI 10110 4 Al-4 ACMO XI 45230 8 AL8 ACMO X2 10320 9 AL9 ACMO X5 13350 10 AL10 ACMO X6 11200

[0156] Table 2: Characteristics of blocks A

[0157] 2-2 Synthesis of Block B of the polymer The synthesis of block B is carried out by extension of block A. In a reactor equipped with a stirring and vapor condensation system, the following are mixed at room temperature: - 21.7 g of deionized water; - 2.29 g of block A1-2; - 1.86 g of N-tert-butyl acrylamide; - 3.92 g of acrylamide.

[0158] The reaction medium is stirred, degassed at room temperature for 30 minutes, then heated to 60°C. The polymerization is initiated with 0.006 g of 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (V-50). The reaction time is 240 minutes. The final active material of the block polymer Pl-1 obtained is 21.5% by weight.

[0159] Other block polymers were also synthesized using this experimental protocol, using different A blocks and adjusting the amounts of initiators. The characteristics are summarized in Table 3.

[0160] [Tables3] reference Chemical composition of block polymers Characterization Block A Block B Mn Block A (mol) Mn Block B (g / mol) reference monomer mol % monomer 1 mol % monomer 2 mol % Pl-1 Al-3 ACMO 5 TBA 20 AM 75 10110 194230 Pl-2 Al-3 ACMO 10 TBA 15 AM 75 10110 80990 Pl-3 Al-5 ACMO 50 NIPAM 50 - 0 13950 11120 P1-4 Af-3 ACMO 30 TBA 70 - 0 10110 20650 Pl-5 Al-4 ACMO 35 TBA 65 - 0 12540 24280 IT-6 Al-4 ACMO 30 TBA 70 - 0 12540 28260 Pl-7 Al-3 ACMO 30 TBA 35 DMA 35 10110 21590

[0161] Table 3: Synthesis of PI block polymers Example 3: Synthesis of P2 polymers

[0162] The random polymer P2-1 was synthesized following protocol 2-1 above, but adding all of the polymer monomers to the polymerization feedstock. Polymer P2-2 was synthesized in the same way as polymer P2-1, but the control agent was replaced by a combination of V-50 and sodium hypophosphite to obtain the characteristics shown in Table 4.

[0163] [Tables4] Reference Polymer P2 Monomer A Monomer B Control Agent Mn (g / mol) Nature mot % Nature mol % P2-1 ACMO 30 TBA 70 XI 34950 P2-2 ACMO 30 TBA 70 - 37730

[0164] Table 4: Characteristics of P2 polymers

[0165] Example 4: Bulk Viscosity Reduction Tests - API 13 Crude Oil

[0166] The polymers were mixed at different dosages in a hydrocarbon of the type crude oil which is characterized by an API degree equal to 13. For each test, the Brookfield viscosity before and after addition was measured (LV3 module, 60 rpm). The percentages of reduction in bulk viscosity before and after addition of the polymer are deduced with the following formula: % Reduction = 100 x (1 - (final VB / initial VB)) in which final VB = final Brookfield viscosity; Initial VB = initial Brookfield viscosity. The results are collected in Table 5.

[0167] [Tables5] Polymer Test Percentage reduction in bulk viscosity 20°C 50°C Polymer mass concentration 200 ppm 1000 ppm 1500 ppm 1000 ppm 1 Pl-1 <0.5% < 0.5% < 0.5% 7% 2 Pl-2 < 0.8% < 0.8% <0.8% 4% 3 Pl-3 1% 3% 5% 9% 5 Pl-4 20% 29% 33% 28% 6 Pl-6 21% 26% 30% 24% 7 P2-1 10% 15% 22% 17% 8 P2-2 7% 12% 18% 14%

[0168] Table 5: Bulk viscosity reduction test

[0169] The best results were obtained for tests 5 and 6 using the block polymers P1-4 and P1-6 in API 13 crude oil. Tests 7 and 8 show that, for the same monomeric molar composition, the polymer having a block structure makes it possible to obtain better results than the statistical polymer obtained from a control agent and than a statistical polymer obtained without a control agent.

[0170] Tests 5, 6 and 7 show that the performance of polymers Pl-4, Pl-6 and P2-1 is not temperature dependent. They perform as well at room temperature as at 50°C.

[0171] In the control tests Pl-1 to Pl-3 demonstrate that, when the monomer proportions are not according to the invention, there is little or no reduction in viscosity, more so at room temperature.

[0172] Example 5: Bulk viscosity reduction tests in an API 28 crude oil

[0173] The following tests aim to evaluate the performance of certain polymers in a crude oil type hydrocarbon characterized by an API degree equal to 28. The implementation of the tests is identical to that of the tests of example 4. The reduction percentages are calculated according to the calculation formula of example 4. The results are gathered in Table 6. Polymer Test Percentage reduction in bulk viscosity 20°C Polymer mass concentration 200 ppm 1000 ppm 1500 ppm 9 Pl-1 < 0.5% < 0.5% 3% 12 Pl-2 < 0.8% < 0.8% 2% 11 Pl-3 1% 3% 5% 12 Pl-4 20% 29% 33% 13 Pl-6 21% 26% 30% 14 P2-1 10% 15% 22% 15 P2-2 7% 12% 18%

[0175] Table 6: Bulk viscosity reduction test

[0176] This new series of tests shows that polymers Pl-4, Pl-6, P2-1 and P2-2 are also effective in higher API crude oil.

Claims

Claims

1. Polymer comprising: - at least 10 mol% of an acryloyl morpholine monomer A; - at least 20 mol% of a hydrophobic monomer B.

2. Polymer according to claim 1, characterized in that the polymer comprises between 10 and 65 mol% of acryloyl morpholine monomer A, relative to the total quantity of monomer.

3. Polymer according to claim 1 or 2, characterized in that the hydrophobic monomer B is chosen from: N,N dialkyl acrylamido acrylamide derivatives and N alkyl acrylamido acrylamide derivatives, and mixtures thereof; these derivatives comprising a C4-C14 alkyl chain, preferably C4-C8.

4. Polymer according to one of claims 1 to 3, characterized in that the polymer comprises between 35 and 90 mol% of hydrophobic monomer B, relative to the total quantity of monomer.

5. Polymer according to one of claims 1 to 4, characterized in that the polymer is a block polymer.

6. Polymer according to one of claims 1 to 5, characterized in that the polymer is composed of at least two blocks: - a water-soluble BA block comprising at least one acryloyl morpholine monomer A; - a hydrophobic BB block comprising at least one hydrophobic B monomer.

7. Polymer according to one of claims 1 to 6, characterized in that the polymer comprises a BA block consisting of acryloyl morpholine monomer A and a BB block consisting of hydrophobic B monomers.

8. Polymer according to one of claims 1 to 7, characterized in that the polymer comprises a BA block having a number average molecular weight of between 1,000 and 100,000 g / mol and consisting of acryloyl morpholine monomers A, and a BB block having a number average molecular weight of between 1,000 and 500,000 g / mol and consisting of hydrophobic B monomers.

9. Polymer according to one of claims 1 to 8, characterized in that the polymer is obtained by radical polymerization of monomers in solution.

10. Polymer according to one of claims 1 to 9, characterized in that the polymer is obtained by chain transfer polymerization by reversible addition-fragmentation in the presence of at least one control agent of formula (IV): [Chem.9] (IV) in which - Z= O, S or N, - R1 and R2, identical or different, represent a group chosen from groups (i), (ii) and (iii): (i) an optionally substituted alkyl, acyl, alkenyl or alkynyl group, or (ii) a carbon ring, saturated or unsaturated, optionally substituted or aromatic, or (iii) a heterocycle, saturated or unsaturated, optionally substituted or aromatic, these groups (i), (ii) and (iii) may be substituted by substituted aromatic groups or by alkoxycarbonyl or aryloxy-carbonyl groups -COOR, carboxy -COOH, acyloxy -O2CR, carbamoyl -CONR2, cyano -CN, alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidimo, hydroxy (-OH), amino (-NR2), halogen, allyl, epoxy, alkoxy (-OR), S-alkyl, S-aryl, alkali salts of carboxylic acids, alkali salts of sulfonic acid, polyalkylene oxide chains, cationic substituents, - R representing a C2-C20 alkyl or aryl group; - Q is a linear or structured polymer chain comprising n identical or different monomers comprising at least one ethylenic function, - n is an integer between 0 and 500.

11. Polymer according to one of claims 1 to 10, characterized in that the polymer has a molecular weight of between 2,000 and 600,000 g / mol.

12. Use as a hydrocarbon viscosity reducer of the polymer according to one of claims 1 to 11.

13. Use according to claim 12, characterized in that the hydrocarbons are heavy hydrocarbons having an API density of less than 31.

14. Use according to claim 12, characterized in that the hydrocarbons are heavy hydrocarbons having an API density of less than 20.

15. Use according to claim 12, characterized in that the hydrocarbons are extra-heavy hydrocarbons having an API density of less than 10.