An ultra-heavy oil emulsifying viscosity reducer composition and its application, an ultra-heavy oil emulsifying viscosity reducer and its preparation method and application

Abstract

The present invention relates to the technical field of emulsifying viscosity reduction, and discloses a super heavy oil emulsifying viscosity reducer composition and its application, a super heavy oil emulsifying viscosity reducer and its preparation method and application; the viscosity reducer composition contains the following components stored independently or in combination of two or more: anionic surfactant, amphoteric surfactant and water; the anionic surfactant is an anionic oligomeric surfactant based on cyclodextrin modification, and the anionic surfactant has the structure shown in formula (A). The viscosity reducer provided by the present invention has good emulsifying viscosity reduction effect on super heavy oil under weak shear action, and has strong salt resistance, and is suitable for emulsifying viscosity reduction of super heavy oil in formation water containing high calcium and magnesium ions. In addition, the viscosity reducer has good biocompatibility, is easy to biodegradable, does not produce secondary pollution, and has less damage to the formation.

Description

Technical Field

[0001] The present invention relates to the technical field of emulsifying viscosity reduction, and particularly relates to a super heavy oil emulsifying viscosity reducer composition and its application, a super heavy oil emulsifying viscosity reducer and its preparation method and application. Background Art

[0002] The emulsifying viscosity reduction technology is a viscosity reduction method that uses an externally added surfactant to form an "oil-in-water" emulsion of heavy oil and surfactant aqueous solution, thereby reducing the viscosity of crude oil and improving the fluidity of heavy oil. Due to its strong on-site operability, flexible and diverse technologies, and strong environmental adaptability, the emulsifying viscosity reduction technology has become a commonly used technology for heavy oil exploitation at present. This technology mainly reduces the oil-water interfacial tension through the adsorption of the emulsifying viscosity reducer at the oil-water interface, so that the heavy oil changes from the emulsified state of water-in-oil to an oil-in-water emulsion, greatly reducing the viscosity and realizing normal exploitation.

[0003] In recent years, the proportion of heavy oil exploitation in the overall oil exploitation has gradually increased, and the geological conditions have become increasingly complex. The use effect of the emulsifying viscosity reducer is affected by the physical properties of heavy oil and formation conditions. The complex formation conditions increase the dosage of the emulsifier, and the viscosity reduction effect deteriorates or even fails accordingly, resulting in a substantial increase in cost. Most of the existing heavy oil emulsifying viscosity reducers are composed of linear anionic surfactants, non-ionic surfactants and co-surfactants. Such emulsifying viscosity reducers have good viscosity reduction effects for ordinary heavy oil systems, but for deep super heavy oil reservoirs, especially super heavy oil with a viscosity above 50,000 mPa·s, the emulsifying effect is poor, and there are few super heavy oil emulsifying viscosity reducers reported in the current literature.

[0004] CN110835522A discloses a temperature and salt resistant super heavy oil emulsifying viscosity reducer. This emulsifying viscosity reducer is a zwitterionic surfactant formed by reacting ethylene oxide and dimethylamine to generate an intermediate and then reacting with 3-chloro-2-phenylsulfonate. This viscosity reducer has strong emulsifying and stripping ability for resins and asphaltenes, and a high viscosity reduction rate, and can reduce the viscosity of super heavy oil at 50 °C by more than 99.0%. However, the raw materials of dimethylamine and ethylene oxide used in the preparation are highly dangerous, are gaseous at room temperature, flammable, and dimethylamine has a strong irritating ammonia odor.

[0005] CN110423600A discloses an aqueous viscosity reducer for highly efficient viscosity reduction of ultra-heavy crude oil, which is composed of a betaine surfactant, a biological activator, a polyether surfactant and water. The biological activator is a ketone activator extracted from plants. This viscosity reducer has good solubility in formation water with a salinity of about 200,000 mg / L, and can quickly and effectively reduce the viscosity of ultra-heavy crude oil under the action of stirring and mixing to form an oil-in-water emulsion. However, during the actual oil reservoir exploitation process, there is no violent disturbance in the formation or wellbore. Under the weak shear action without stirring, the emulsification viscosity reduction of ultra-heavy crude oil will become difficult.

[0006] Most of the viscosity reducers for ultra-heavy crude oil in the prior art are compositions of ordinary surfactants, and have good emulsification effects under stirring conditions. However, when actually applied to the ultra-heavy crude oil exploitation process, there is no violent disturbance in the formation or wellbore. How to achieve emulsification viscosity reduction of ultra-heavy crude oil with very poor fluidity under weak shear action is highly challenging. There is an urgent need to develop a new ultra-heavy crude oil emulsification viscosity reduction system that can enhance the permeability of crude oil, which can achieve viscosity reduction of ultra-heavy crude oil under lower shear action.

[0007] Cyclodextrin is a natural cyclic polysaccharide obtained by fermenting starch with microorganisms. It has a spatial truncated cone structure and is a commonly used functional host molecule. Cyclodextrin can form host-guest complexes with polycyclic aromatic hydrocarbons through host-guest interactions, which is another effective way to solubilize polycyclic aromatic hydrocarbons besides the solubilization effect of surfactants. Therefore, by introducing cyclodextrin structure into the surfactant molecular structure, the synergistic solubilization of the hydrophobic micro-region of the aggregate and the host-guest complexation can be exerted. At present, the relevant reports in the literature and patents mainly focus on the compound system of surfactants and cyclodextrin, and there are very few reports on the host-guest synergistic surfactant obtained by chemical modification on the cyclodextrin skeleton.

[0008] CN102876309A discloses a viscosity reducer for viscous crude oil, including hydrocarbon oil, β-cyclodextrin, fatty alcohol polyoxyethylene ether and hydrophilic components. The hydrophilic components are selected from one or more of monocarboxylic acids with C1-C4, monohydric alcohols with C1-C4, monoamines with C1-C4 and amides with C1-C4. This viscosity reducer is a solution or microemulsion. However, the viscosity reduction rate of this viscosity reducer for viscous crude oil is only 15.0% - 51.2%, and the viscosity reduction effect needs to be further improved. Moreover, the composition of the viscosity reducer is relatively complex, which not only increases the complexity of the viscosity reduction operation, but also introduces too many foreign substances into the viscous crude oil, increasing the difficulty of subsequent treatment processes. Summary of the Invention

[0009] The purpose of the present invention is to overcome the defect that the viscosity reducer in the prior art has poor emulsification viscosity reduction effect on ultra-heavy crude oil under weak shear action.

[0010] To achieve the above object, a first aspect of the present invention provides an emulsifying viscosity reducer composition for ultra-heavy oil. The viscosity reducer composition contains the following components that are stored independently or in a mixture of two or more: an anionic surfactant, an amphoteric surfactant, and water; the anionic surfactant is an anionic oligomeric surfactant based on cyclodextrin modification, and the anionic surfactant has the structure shown in formula (A):

[0011]

[0012] Wherein, in formula (A),

[0013] M is selected from any one of Li + , Na + , K + , NH 4 + ;

[0014] R is selected from -OH, the group shown in formula (I);

[0015] R 1 is selected from -OH, -OSO 3 M, the group shown in formula (I); and only one of R and R 1 is the group shown in formula (I);

[0016] m and n are each independently selected from any integer from 0 to 12, and the sum of m and n is any integer from 5 to 11; and when m is 0, R 1 is -OSO 3 M;

[0017] In formula (I),

[0018] s is selected from any integer from 0 to 10;

[0019] Each R 2 is independently selected from H, an alkyl group of C 1-22 , an alkenyl group of C 2-22 , an alkynyl group of C 2-22 , an alkyl group of C 2-22 containing at least one oxygen atom;

[0020] R 3 is selected from an alkylene group of C 2-20 , an alkylene group of C 2-20 substituted with at least one heteroatom selected from O, N, S, a cycloalkylene group of C 3-20 , an arylene group of C 6-20 , a heteroarylene group of C 5-20 , a heterocyclic group of C 3-20 , -(C 1-20 alkylene)-Y-(C 1-20-alkylene)-; Y is selected from C 3-20 -cycloalkylene, C 6-20 -arylene, C 5-20 -heteroarylene, C 3-20 -heterocycloalkylene.

[0021] The second aspect of the present invention provides a method for preparing an emulsifying viscosity reducer for ultra-heavy oil, the method comprising: mixing the components in the viscosity reducer composition described in the first aspect.

[0022] The third aspect of the present invention provides an emulsifying viscosity reducer for ultra-heavy oil prepared by the method described in the second aspect.

[0023] The fourth aspect of the present invention provides the application of the viscosity reducer composition described in the first aspect and the emulsifying viscosity reducer for ultra-heavy oil described in the third aspect in the exploitation of ultra-heavy oil reservoirs.

[0024] The emulsifying viscosity reducer for ultra-heavy oil provided by the present invention has a good emulsifying viscosity reduction effect on ultra-heavy oil under weak shear action, and has strong salt resistance, and is suitable for emulsifying viscosity reduction of ultra-heavy oil containing formation water with high calcium and magnesium ions. In addition, the viscosity reducer has good biocompatibility, is easily biodegradable, does not cause secondary pollution, and has less harm to the formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the mass spectrum of the intermediate 3-N-α-CD-2C prepared in Preparation Example 1 of the present invention 12 H 25 ;

[0026] Figure 2 is the mass spectrum of the anionic surfactant 3-N-α-CD-2C prepared in Preparation Example 1 of the present invention 12 -SO 4 Na. DETAILED DESCRIPTION OF THE INVENTION

[0027] The endpoints and any values disclosed in the ranges in this article are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0028] It should be noted that in each aspect of the present invention, for the same components in each aspect, the present invention only describes them once in one aspect without repeating the description, and those skilled in the art should not understand this as a limitation of the present invention.

[0029] The following is an explanation of the terms of the present invention:

[0030] In this text, the wavy line in each group represents the bonding position.

[0031] "An alkyl group of C 1-22 " means an alkyl group with a total of 1 - 22 carbon atoms, including a straight-chain alkyl group of C 1-22 and a branched-chain alkyl group of C 1-22 . The number of carbon atoms can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22. For example, it can be methyl, ethyl, isopropyl, n-pentyl, n-hexyl, n-dodecyl, n-tetradecyl, n-heptadecyl, n-docosyl, etc. For "an alkyl group of C 5-22 " and "an alkyl group of C 10-15 ", there are similar explanations, except that the number of carbon atoms is different.

[0032] "An alkenyl group of C 2-22 " means a hydrocarbon group formed by removing one or several hydrogen atoms from an olefin molecule, and the total number of carbon atoms in this alkenyl group is 2 - 22. The double bond in this group can be at any position. For example, it can be etc. For "an alkenyl group of C 5-22 ", there is a similar explanation, except that the number of carbon atoms is different.

[0033] "An alkynyl group of C 2-22 " means a monovalent hydrocarbon group formed by removing one or several hydrogen atoms from an alkyne molecule, and the total number of carbon atoms in this alkynyl group is 2 - 22. The carbon-carbon triple bond (C≡C) in this group can be at any position. For example, it can be etc. For "an alkynyl group of C 5-22 ", there is a similar explanation, except that the number of carbon atoms is different.

[0034] "An alkyl group of C 2-22 containing at least one oxygen atom" means that the carbon atoms in a branched-chain or straight-chain alkyl group with a total of 2 - 22 carbon atoms can be interrupted by at least one oxygen atom. For example, it can be CH 3 OCH 2 OCH 2 -, CH 3 OCH 2 -, CH 3 OCH 2 OCH 2 OCH 2 CH 2 - etc. For "an alkyl group of C 5-22 containing at least one oxygen atom", there is a similar explanation, except that the number of carbon atoms is different.

[0035] When the substituent is a non-terminal substituent or a relevant group loses an H atom, it is a subunit of the corresponding group, usually a divalent group. For example, when an alkyl group loses an H atom, it becomes an alkylene group; a cycloalkyl group corresponds to a cycloalkylene group; an aryl group corresponds to an arylene group; a heterocyclic group corresponds to a heterocycloalkylene group; and a heteroaryl group corresponds to a heteroarylene group.

[0036] "C 1-20 's alkylene group" means a straight-chain or branched-chain alkylene group with a total of 2-20 carbon atoms. For example, the number of carbon atoms can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. For example, this group can be methylene, ethylene, propylene, butylene, etc. For "C 2-20 's alkylene group", "C 2-15 's alkylene group", "C 1-10 's alkylene group", "C 1-5 's alkylene group", there are similar explanations, except that the number of carbon atoms is different.

[0037] "An alkylene group containing at least one heteroatom selected from O, N, and S substituting C 2-20 " means that the carbon atoms in a straight-chain or branched-chain alkylene group with a total of 2-20 carbon atoms can be interrupted by at least one heteroatom selected from O, N, and S. For example, it can be etc.

[0038] "C 3-20 's cycloalkylene group" means a divalent group of a cycloalkyl group with a total of 3-20 carbon atoms. For example, the number of carbon atoms can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 of a monocycloalkylene group. For example, this group can be etc. For "C 3-15 's cycloalkylene group" and "C 3-10 's cycloalkylene group", there are similar explanations, except that the number of carbon atoms is different.

[0039] "C 6-20 's arylene group" means a divalent group of an aryl group with a total of 6-20 carbon atoms. This arylene group can be a monocyclic or fused polycyclic aryl group. For example, it can be etc. For "C 6-15 's arylene group" and "C 6-10 's arylene group", there are similar explanations, except that the number of carbon atoms is different.

[0040] "C 5-20"The divalent group of heteroarylene" refers to a divalent group of a heteroaryl group having a total of 5 to 20 carbon atoms, and one or more heteroatoms are contained in the ring-forming atoms of the heteroaromatic ring, and the heteroatoms are selected from at least one of O, N, and S. For example, it can be etc. "C 5-15 of the divalent heteroarylene group", "C 5-10 of the divalent heteroarylene group" has a similar explanation, except that the number of carbon atoms is different.

[0041] "C 3-20 of the divalent heterocyclic group" refers to a divalent group of a cycloalkyl group having a total of 3 to 20 carbon atoms, and one or more carbon atoms forming the ring are replaced by heteroatoms such as O, N, and S atoms. For example, it can be etc. For "C 3-15 of the divalent heterocyclic group", "C 3-10 of the divalent heterocyclic group" has a similar explanation, except that the number of carbon atoms is different.

[0042] "-(C 1-20 of the alkylene)-Y-(C 1-20 of the alkylene)-" means that any two H in the Y group are replaced by C 1-20 of the alkylene group, and the Y group is selected from any one of C 3-10 of the cycloalkylene group, C 6-10 of the arylene group, C 5-10 of the heteroarylene group, C 3-10 of the divalent heterocyclic group. For example, it can be etc.

[0043] As described above, the first aspect of the present invention provides an emulsifying viscosity reducer composition for ultra-heavy oil. The viscosity reducer composition contains the following components stored independently or in a mixture of two or more: an anionic surfactant, an amphoteric surfactant, and water; the anionic surfactant is an anionic oligomeric surfactant based on cyclodextrin modification, and the anionic surfactant has the structure shown in formula (A):

[0044]

[0045] Among them, in formula (A),

[0046] M is selected from any one of Li + , Na + , K + , NH 4 + ;

[0047] R is selected from -OH and the group shown in formula (I);

[0048] R 1Selected from -OH, -OSO 3 M, the group represented by formula (I); and one of R and R 1 is the group represented by formula (I);

[0049] m and n are each independently selected from any integer from 0 to 12, and the sum of m and n is any integer from 5 to 11; and when m is 0, R 1 is -OSO 3 M;

[0050] In formula (I),

[0051] s is selected from any integer from 0 to 10;

[0052] Each R 2 is independently selected from H, C 1-22 alkyl, C 2-22 alkenyl, C 2-22 alkynyl, C containing at least one oxygen atom 2-22 alkyl;

[0053] R 3 is selected from C 2-20 alkylene, C containing at least one heteroatom selected from O, N, S 2-20 alkylene, C 3-20 cycloalkylene, C 6-20 arylene, C 5-20 heteroarylene, C 3-20 heterocycloalkylene, -(C 1-20 alkylene)-Y-(C 1-20 alkylene)-; Y is selected from C 3-20 cycloalkylene, C 6-20 arylene, C 5-20 heteroarylene, C 3-20 heterocycloalkylene.

[0054] According to a preferred specific embodiment, in formula (A),

[0055] M is selected from any one of Li + , Na + , K + , NH 4 + ;

[0056] R is selected from -OH, the group represented by formula (I);

[0057] R 1 is selected from -OH, -OSO 3 M, the group represented by formula (I), and one of R and R 1 is the group represented by formula (I);

[0058] m and n are each independently selected from any integer from 0 to 7, and the sum of m and n is any integer from 5 to 7; and when m is 0, R 1 is -OSO 3 M;

[0059] In formula (I),

[0060] s is selected from any integer from 0 to 5;

[0061] Each R 2 is independently selected from H, C 5-22 alkyl, C 5-22 alkenyl, C 5-22 alkynyl, C containing at least one oxygen atom 5-22 alkyl;

[0062] R 3 is selected from C 2-15 alkylene, C containing at least one heteroatom selected from O, N, S substituted 2-20 alkylene, C 3-15 subcycloalkyl, C 6-15 arylene, C 5-15 heteroarylene, C 3-15 heterocycloalkylene, -(C 1-10 alkylene)-Y-(C 1-10 alkylene)-; Y is selected from C 3-15 subcycloalkyl, C 6-15 arylene, C 5-15 heteroarylene, C 3-15 heterocycloalkylene.

[0063] According to another preferred embodiment, wherein, in formula (A),

[0064] M is selected from Li + 、Na + 、K + 、NH 4 + any one of;

[0065] R is selected from -OH, the group shown in formula (I);

[0066] R 1 is selected from -OH, -OSO 3 M, the group shown in formula (I), and there is and only one of R and R 1 is the group shown in formula (I);

[0067] m and n are each independently selected from any integer from 0 to 7, and the sum of m and n is any integer from 5 to 7; and when m is 0, R1 -OSO 3 M;

[0068] In formula (I),

[0069] s is selected from any integer from 0 to 5;

[0070] Each R 2 is independently selected from H, C 5-22 alkyl, C 5-22 alkenyl, C 5-22 alkynyl, C containing at least one oxygen atom 5-22 alkyl;

[0071] R 3 is selected from C 2-15 alkylene, C containing at least one heteroatom selected from O, N, S 2-20 alkylene, C 3-15 subcycloalkyl, C 6-15 arylene, C 5-15 heteroarylene, C 3-15 heterocycloalkylene, -(C 1-5 alkylene)-Y-(C 1-5 alkylene)-; Y is selected from C 3-10 subcycloalkyl, C 6-10 arylene, C 5-10 heteroarylene, C 3-10 heterocycloalkylene.

[0072] Preferably, M is selected from any one of Na + , K + .

[0073] Preferably, s is 0.

[0074] Preferably, each R 2 is independently selected from any one of , each a is independently selected from any integer from 1 to 15, b is selected from any integer from 1 to 7, and d is selected from any integer from 1 to 5. Preferably, each R 2 is independently selected from C 10-15 alkyl; More preferably, each R 2 is independently selected from C 10-15 linear alkyl.

[0075] Preferably, R 3 is selected from C 2-15 alkylene,

[0076] The present invention has no particular limitation on the method for preparing the anionic surfactant. However, in order to obtain better effects, the present invention preferably provides the method for preparing the anionic surfactant as described below.

[0077] A method for preparing an anionic surfactant, the surfactant being selected from at least one of the compounds having the structure shown in formula (A); the method comprising:

[0078] (1) In the presence of solvent I, subjecting the amino-functionalized cyclodextrin shown in formula (B) to a first contact with 1,2-epoxyalkane shown in formula (C) to obtain intermediate I;

[0079] (2) In the presence of solvent II, subjecting the intermediate I and a sulfonating agent to a second contact to obtain intermediate II;

[0080] (3) Adjusting the pH value of the intermediate II to 7-10 with a basic substance containing M element;

[0081]

[0082] Wherein, in formula (B), one of R 4 , R 5 is -OH, and the other is s, and the definition of R 3 is the same as the definition in the previous text;

[0083] In formula (A), formula (B), formula (C) and the basic substance, the definitions of m, n, R 1 , R 2 , M are the same as the definitions in the previous text.

[0084] Preferably, in step (1), the amino-functionalized cyclodextrin is selected from one of aminoated α-cyclodextrin, aminoated β-cyclodextrin, and aminoated γ-cyclodextrin.

[0085] It should be noted that in the amino-functionalized cyclodextrin, the position of the amino-functionalized cyclodextrin can be at the 3-hydroxy position of the cyclodextrin or at the 6-hydroxy position.

[0086] More preferably, formula (B) is the structure shown in formula (II) or formula (III):

[0087]

[0088] Preferably, in step (1), the 1,2-epoxyalkane is selected from one of the following; each a is independently selected from any integer from 1 to 15, b is selected from any integer from 1 to 7, and d is selected from any integer from 1 to 5.

[0089] In the preparation method of the present invention, the amino-functionalized cyclodextrin and the 1,2-epoxyalkane can be prepared by methods known in the art or obtained by purchase.

[0090] In the foregoing method for preparing an anionic surfactant of the present invention, various post-treatment operations known in the art may also be involved, such as rotary evaporation, extraction, washing, filtration, recrystallization, column chromatography, etc. The present invention has no special limitation on this, and those skilled in the art should not understand it as a limitation of the present invention.

[0091] Exemplarily, after the first contact reaction is completed, the solvent in the reaction system is removed by rotary evaporation, and then purified by recrystallization or column separation to obtain the intermediate I. The mixed solvent used for recrystallization is one of methanol-ethyl acetate, methanol-acetone, ethanol-ethyl acetate, and ethanol-acetone; the eluent used for column separation is dichloromethane and ethanol with a volume ratio of 5-20:1.

[0092] Exemplarily, after adjusting the pH value of the intermediate II to 7-10, insoluble substances are removed by filtration, and then the solvent in the system is removed by rotary evaporation to obtain the surfactant.

[0093] Preferably, the molar ratio of the amount of the 1,2-epoxyalkane to the amino-functionalized cyclodextrin in terms of N-H bonds is (0.2-10):1; more preferably, the molar ratio of the amount of the 1,2-epoxyalkane to the amino-functionalized cyclodextrin in terms of N-H bonds is (1-5):1.

[0094] Preferably, with respect to 1 mmol of amino-functionalized cyclodextrin, the volume of the solvent I used is 10-30 mL.

[0095] Preferably, in step (1), the solvent I is selected from at least one of methanol, ethanol, isopropanol, n-butanol, water, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and ethylene glycol.

[0096] Preferably, in step (1), the conditions of the first contact at least satisfy: the temperature is 60-90 °C and the time is 2-5 days.

[0097] Preferably, the conditions of the second contact in step (2) at least satisfy: the temperature is -5 °C to 80 °C and the time is 0.5-48 h.

[0098] The method for preparing the anionic surfactant is preferably carried out under stirring, and there is no particular requirement for the stirring speed, and parameters known in the art can be adopted.

[0099] Preferably, in step (2), the solvent II is selected from at least one of N,N-dimethylformamide, pyridine, N,N-dimethylacetamide, dioxane, tetrahydrofuran, dichloromethane, chloroform, dimethyl sulfoxide.

[0100] Preferably, the mass ratio of the intermediate I to the solvent II is 1:8 - 12.

[0101] Preferably, in step (2), the molar ratio of the sulfonating agent to the intermediate I is 1:(0.1 - 20); more preferably 1:(1 - 10).

[0102] Preferably, the sulfonating agent in step (2) is selected from at least one of a complex of sulfur trioxide and an organic compound, chlorosulfonic acid, concentrated sulfuric acid, fuming sulfuric acid, sulfur trioxide, sulfamic acid; the organic compound is selected from at least one of amine compounds, amide compounds, ether compounds.

[0103] More preferably, the complex of sulfur trioxide and an organic compound is selected from at least one of sulfur trioxide pyridine complex, sulfur trioxide dimethylformamide complex, sulfur trioxide dioxane complex.

[0104] Preferably, in step (2), the basic substance is at least one of a hydroxide containing M element, an aqueous solution of a hydroxide containing M element, an alcoholic solution of a hydroxide containing M element.

[0105] The method for preparing the anionic surfactant provided by the present invention is simple and efficient.

[0106] Preferably, the amphoteric surfactant is selected from at least one of alkyl dimethyl betaine, alkyl hydroxypropyl sulfobetaine, coconut oil amide propyl betaine.

[0107] Preferably, the number of carbon atoms of the alkyl carbon chain in the alkyl dimethyl betaine and alkyl hydroxypropyl sulfobetaine is independently selected from any integer of 8 - 20.

[0108] More preferably, the number of carbon atoms of the alkyl carbon chain in the alkyl dimethyl betaine and alkyl hydroxypropyl sulfobetaine is independently selected from any integer of 12 - 18. The inventors of the present invention have found that in this preferred case, the obtained viscosity reducer composition has better effect when used for emulsifying and reducing the viscosity of ultra-heavy oil.

[0109] Preferably, based on the total weight of the viscosity reducer composition, the content of the anionic surfactant is 0.1-2 wt%, the content of the amphoteric surfactant is 0.1-2 wt%, and the content of water is 96.0-99.8 wt%.

[0110] More preferably, based on the total weight of the viscosity reducer composition, the content of the anionic surfactant is 0.5-1.5 wt%, the content of the amphoteric surfactant is 0.5-1.5 wt%, and the content of water is 97-99 wt%. The inventors of the present invention have found that in this preferred case, the obtained viscosity reducer composition has better effect when used for reducing the viscosity of ultra-heavy oil by emulsification.

[0111] It should be noted that the present invention has no special requirements for the water in the viscosity reducer composition, and those skilled in the art can select according to needs. In the following text of the present invention, in order to test the salt tolerance of the heavy oil emulsifying viscosity reducer, the water is preferably mineralized water with a salinity of 50000-200000 mg / L when preparing the viscosity reducer.

[0112] As described above, the second aspect of the present invention provides a method for preparing an ultra-heavy oil emulsifying viscosity reducer, which is characterized in that the method includes: mixing the components in the viscosity reducer composition described in the first aspect.

[0113] The dosages and types of the components involved in the second aspect of the present invention are the same as the contents and types of the corresponding components described in the first aspect of the present invention, and will not be elaborated here. Those skilled in the art should not understand this as a limitation of the present invention.

[0114] Preferably, the conditions of the mixing at least satisfy: the temperature is 15-40 °C, the stirring speed is 50-600 rpm, and the stirring time is 10-80 min.

[0115] When the viscosity reducer prepared by the present invention is used for reducing the viscosity of ultra-heavy oil, relative to 100 parts by weight of the heavy oil, the dosage of the viscosity reducer is more than 40 wt% of the weight of the heavy oil; more preferably, the dosage of the viscosity reducer is 40 wt% - 100 wt% of the weight of the heavy oil.

[0116] As described above, the third aspect of the present invention provides an ultra-heavy oil emulsifying viscosity reducer prepared by the method described in the second aspect.

[0117] As described above, the fourth aspect of the present invention provides the application of the viscosity reducer composition described in the first aspect and the ultra-heavy oil emulsifying viscosity reducer described in the third aspect in the exploitation of ultra-heavy oil reservoirs.

[0118] Preferably, the viscosity of the ultra-heavy oil is 50000-300000 mPa·s.

[0119] Under the weak shear action of the simulated formation, the ultra-heavy oil emulsifying viscosity reducer prepared by the present invention has good viscosity reduction and emulsifying effects on ultra-heavy oil with a viscosity exceeding 50,000 mPa·s. Moreover, the viscosity reducer has good salt resistance and good adaptability to heavy oil in formation water containing high calcium and magnesium ions. In addition, the viscosity reducer has good biocompatibility, is easily biodegradable, does not cause secondary pollution, and has less damage to the formation.

[0120] The present invention will be described in detail below through preparation examples and examples. In the following preparation examples and examples, the instruments, reagents, materials, etc. involved, unless otherwise specified, are all conventional instruments, reagents, materials, etc. existing in the prior art and can be obtained through regular commercial channels. The experimental methods, detection methods, etc. involved in the following examples, unless otherwise specified, are all conventional experimental methods and detection methods existing in the prior art. In the following preparation examples and examples, room temperature means the temperature is 25 ± 5 °C.

[0121] In the following examples of preparing the ultra-heavy oil emulsifying viscosity reducer, the water is water with a salinity of 150,000 mg / L, in which the concentration of Ca 2+ is 5,000 mg / L, and the concentration of Mg 2+ is 5,000 mg / L.

[0122] The main raw materials used in the preparation examples, examples, and comparative examples are shown in Table 1.

[0123] Table 1

[0124]

[0125] Preparation Example 1

[0126] Based on amino-functionalized α-cyclodextrin, an anionic surfactant 3-N-α-CD-2C 12 -SO 4 Na:

[0127] The intermediate 3-N-α-CD-2C 12 H 25 has a structure as shown in formula (Y1), and the compound with the structure shown in formula (A1) is the main product of the surfactant 3-N-α-CD-2C 12 -SO 4 Na.

[0128]

[0129] In formulas (Y1) and (A1), -C 12 H 25 represents n-dodecyl.

[0130] Weigh 0.972 g of 3A-amino-3A-deoxy-(2AS,3AS)-α-cyclodextrin hydrate and 0.85 g of 1,2-epoxytetradecane into a reaction flask, then add 20 ml of absolute ethanol, stir evenly, stir and react at 75 °C for 3 days, stop the reaction, and rotary evaporate to remove the solvent. The residue is recrystallized with ethanol / acetone to obtain the intermediate 3-N-α-CD-2C 12 H 25 , with a yield of 95%. The intermediate 3-N-α-CD-2C 12 H 25 was characterized by MALDI-TOF-MS. As Figure 1 shown, the peak at 1396.76721 ((M+H) + ) in the product spectrum is the highest, which is the molecular ion peak of the intermediate 3-N-α-CD-2C 12 H 25 , proving that the intermediate 3-N-α-CD-2C 12 H 25 was successfully prepared.

[0131] Weigh 1 g of the intermediate 3-N-α-CD-2C 12 H 25 and 1.2 g of sulfur trioxide pyridine complex into a single-necked flask, add 10 g of pyridine, stir tightly at room temperature for 24 hours, then dropwise add a methanol solution of 1 mol / L NaOH to adjust the pH of the system to 8. Then filter to remove the insoluble matter, and rotary evaporate the organic solvent in the obtained filtrate to obtain the anionic surfactant, denoted as 3-N-α-CD-2C 12 -SO 4 Na, with a yield of 95%.

[0132] The anionic surfactant was characterized by MALDI-TOF-MS, and the results are as Figure 2 shown. The primary hydroxyl groups on the cyclodextrin skeleton of this product were sulfonated to form sulfate anions, and the mass spectrometry showed that the main product was the compound formed by sulfonation of 5 primary hydroxyl groups. The peak at 357.5000 in the product spectrum corresponds to the main product, which is the [(M-5Na) 5- / 5 peak. The peak at 343.5304 is the highest and also corresponds to the main product of pentasulfonation, which is the [(M-5Na-4H 2 O) 5- / 5 peak. This proves that the anionic surfactant was successfully prepared.

[0133] Preparation Example 2

[0134] Preparation of anionic surfactant 6-N-β-CD-2C 12 -SO 4 Na based on amino-functionalized β-cyclodextrin:

[0135] Intermediate 6-N-β-CD-2C 12 H 25 has the structure shown in formula (Y2), and the compound with the structure shown in formula (A2) is surfactant 6-N-β-CD-2C 12 -SO 4 the main product of Na.

[0136]

[0137] In formulas (Y2) and (A2), -C 12 H 25 represents n-dodecyl.

[0138] Weigh 1.134 g of mono-(6-amino-6-deoxy)-β-cyclodextrin and 0.85 g of 1,2-epoxytetradecane into a reaction flask, then add 20 ml of absolute ethanol, stir evenly, stir and react at 75 °C for 3 days, then stop the reaction, and rotary evaporate to remove the solvent. The residue is recrystallized with ethanol / acetone to obtain intermediate 6-N-β-CD-2C 12 H 25 , with a yield of 97%. Characterize intermediate 6-N-β-CD-2C 12 H 25 by MALDI-TOF-MS. The MALDI-TOF-MS characterization result: 1558.580 ((M+H) + ).

[0139] Weigh 1 g of intermediate 6-N-β-CD-2C 12 H 25 , 0.2 g of chlorosulfonic acid into a single-necked flask, add 10 g of N,N-dimethylformamide, stir tightly at room temperature for 24 hours, then dropwise add 1 mol / L NaOH ethanol solution to adjust the pH of the system to 8. Then filter to remove the insoluble matter, rotary evaporate the organic solvent in the obtained filtrate to obtain anionic surfactant 6-N-β-CD-2C 12 -SO 4 Na, with a yield of 94%. Characterize anionic surfactant 6-N-β-CD-2C 12 -SO 4 Na by MALDI-TOF-MS. The MALDI-TOF-MS characterization result: 856.8 [(M-2Na) 2- / 2.

[0140] Preparation Example 3

[0141] Preparation of anionic surfactant 3-N-β-CD-2C 12 -SO4 Na:

[0142] Intermediate 3-N-β-CD-2C 12 H 25 The structure of is shown in formula (Y3), and the compound with the structure shown in formula (A3) is surfactant 3-N-β-CD-2C 12 -SO 4 The main product of Na.

[0143]

[0144] In formulas (Y3) and (A3), -C 12 H 25 represents n-dodecyl.

[0145] Weigh 1.134 g of 3A-amino-3A-deoxy-(2AS,3AS)-β-cyclodextrin hydrate and 0.85 g of 1,2-epoxytetradecane into a reaction flask, then add 20 ml of absolute ethanol, stir evenly, stir and react at 75 °C for 3 days, then stop the reaction, and rotary evaporate to remove the solvent. The residue is recrystallized with ethanol / acetone to obtain intermediate 3-N-β-CD-2C 12 H 25 , with a yield of 98%. Characterize intermediate 3-N-β-CD-2C 12 H 25 by MALDI-TOF-MS. The MALDI-TOF-MS characterization result: 1558.8942 ((M + H) + ).

[0146] Weigh 1 g of intermediate 3-N-β-CD-2C 12 H 25 , 0.5 g of sulfamic acid into a single-necked flask, add 10 g of N,N-dimethylformamide, stir tightly at 25 °C for 12 hours, then add 1 mol / L NaOH aqueous solution to adjust the pH of the system to 8. Then filter to remove the insoluble matter, and rotary evaporate the organic solvent in the obtained filtrate to obtain anionic surfactant 3-N-β-CD-2C 12 -SO 4 Na, with a yield of 92%. Characterize anionic surfactant 3-N-β-CD-2C 12 -SO 4 Na by MALDI-TOF-MS. The MALDI-TOF-MS characterization result: 598.8 ([(M - 3Na) 3- / 3).

[0147] Example 1

[0148] Add 1.0 g of the anionic surfactant 3-N-α-CD-2C in Preparation Example 1 12 -SO 4 Na and 1.0 g of tetradecyldimethylbetaine to 98.0 g of water, and stir for 30 min under the conditions of magnetic stirring at 20 °C and 300 rpm to obtain a super-viscous oil emulsifying viscosity reducer, numbered YA1.

[0149] Example 2

[0150] Add 1.2 g of the anionic surfactant 6-N-β-CD-2C in Preparation Example 2 12 -SO 4 Na and 1.3 g of octadecylpropylhydroxysulfobetaine to 97.5 g of water, and stir for 40 min under the conditions of magnetic stirring at 25 °C and 200 rpm to obtain a super-viscous oil emulsifying viscosity reducer, numbered YA2.

[0151] Example 3

[0152] Add 0.8 g of the anionic surfactant 3-N-β-CD-2C in Preparation Example 3 12 -SO 4 Na and 0.8 g of cocoamidopropyl betaine to 98.4 g of water, and stir for 20 min under the conditions of magnetic stirring at 30 °C and 400 rpm to obtain a super-viscous oil emulsifying viscosity reducer, numbered YA3.

[0153] Example 4

[0154] Add 0.5 g of the anionic surfactant 3-N-α-CD-2C in Preparation Example 1 12 -SO 4 Na and 1.5 g of tetradecyldimethylbetaine to 98.0 g of water, and stir for 30 min under the conditions of magnetic stirring at 20 °C and 300 rpm to obtain a super-viscous oil emulsifying viscosity reducer, numbered YA4.

[0155] Example 5

[0156] Add 1.5 g of the anionic surfactant 3-N-α-CD-2C in Preparation Example 1 12 -SO 4 Na and 0.5 g of tetradecyldimethylbetaine to 98.0 g of water, and stir for 30 min under the conditions of magnetic stirring at 20 °C and 300 rpm to obtain a super-viscous oil emulsifying viscosity reducer, numbered YA5.

[0157] Comparative Example 1

[0158] Add 1.0 g of SDS and 1.0 g of tetradecyldimethylbetaine to 98.0 g of water, and stir for 30 min under the conditions of magnetic stirring at 20 °C and 300 rpm to obtain an ultra-heavy oil emulsifying viscosity reducer, numbered YA6.

[0159] Comparative Example 2

[0160] Add 2.0 g of the anionic surfactant 3-N-α-CD-2C 12 -SO 4 Na in Example 1 to 98.0 g of water, and stir for 30 min under the conditions of magnetic stirring at 20 °C and 300 rpm to obtain an ultra-heavy oil emulsifying viscosity reducer, numbered YA7.

[0161] Comparative Example 3

[0162] Add 2.0 g of tetradecyldimethylbetaine to 98.0 g of water, and stir for 30 min under the conditions of magnetic stirring at 20 °C and 300 rpm to obtain an ultra-heavy oil emulsifying viscosity reducer, numbered YA8.

[0163] Comparative Example 4

[0164] Add 1.0 g of β-cyclodextrin and 1.0 g of tetradecyldimethylbetaine to 98.0 g of water, and stir for 30 min under the conditions of magnetic stirring at 20 °C and 300 rpm to obtain an ultra-heavy oil emulsifying viscosity reducer, numbered YA9.

[0165] Test Example

[0166] Ultra-heavy oil emulsifying viscosity reduction test

[0167] The ultra-heavy oil from Shengli Oilfield (the viscosity of the heavy oil at 50 °C is 125300 mPa·s) was selected for the determination of the emulsifying viscosity and viscosity reduction rate of the ultra-heavy oil. The dosage of the ultra-heavy oil emulsifying viscosity reducer was uniformly 50 wt% of the weight of the heavy oil.

[0168] The steps of the viscosity reduction test are as follows: Add 50 g of the test oil to a beaker, and then add 25 g of the ultra-heavy oil emulsifying viscosity reducer in the example or comparative example, which accounts for 50 wt% of the weight of the ultra-heavy oil. Place the beaker in a 70 °C water bath and keep it standing at a constant temperature for 1 h. Use a biological shaker to simulate the emulsifying viscosity reduction process under weak shear conditions. The oscillation level is 1 (oscillation frequency 50 r / min, amplitude 25 mm), and the oscillation time is 30 min. Observe the emulsified form of the heavy oil; then use a Brookfield DV-II viscometer at 50 °C and at a shear rate of 7.34 s -1 to measure the viscosity.

[0169] Calculate the viscosity reduction rate, and the viscosity reduction rate = (viscosity of the heavy oil before viscosity reduction - viscosity of the heavy oil after viscosity reduction) / viscosity of the heavy oil before viscosity reduction × 100%; the experimental results are shown in Table 2.

[0170] Table 2 Emulsification effect, viscosity of emulsified heavy oil and viscosity reduction rate of different heavy oil emulsifying viscosity reducers

[0171] Viscosity reducer Emulsification effect Viscosity of emulsified heavy oil (mPa.s) Viscosity reduction rate (%) YA1 Uniform fine-dispersed emulsion 25.6 99.98 YA2 Uniform fine-dispersed emulsion 48.4 99.96 YA3 Uniform fine-dispersed emulsion 98.6 99.92 YA4 Uniform fine-dispersed emulsion 427.2 99.66 YA5 Uniform fine-dispersed emulsion 618.5 99.51 YA6 Unable to disperse uniformly 16400 86.91 YA7 Unable to disperse uniformly 45300 63.85 YA8 Unable to disperse uniformly 30800 75.42 YA9 Unable to disperse uniformly 38400 69.35

[0172] The results in Table 2 show that in the presence of water, by using a composite of an anion oligomeric surfactant modified based on cyclodextrin and an amphoteric surfactant to prepare a heavy oil emulsifying viscosity reducer (YA1 - YA5), it is possible to achieve emulsification and viscosity reduction of heavy oil with a viscosity of 125300 mPa·s under simulated weak shear action, and the viscosity reduction rate reaches over 99.51%. Moreover, this viscosity reducer has good salt resistance and also has good adaptability to heavy oil in formation water containing high calcium and magnesium ions.

[0173] As a comparison, when using a conventional anionic surfactant (SDS) or replacing the anionic surfactant shown in formula (A) with β - cyclodextrin and compounding it with an amphoteric surfactant to prepare a heavy oil emulsifying viscosity reducer (YA6, YA9), it is impossible to achieve uniform emulsification and dispersion of heavy oil under weak shear force, and its viscosity reduction effect is poor.

[0174] By comparing YA1 with YA7 and YA8, it is found that when using only the anionic surfactant shown in formula (A) or only the amphoteric surfactant alone, it is impossible to achieve uniform emulsification and dispersion of heavy oil under weak shear force, and the viscosity reduction effect is poor. Therefore, for the emulsification and viscosity reduction of heavy oil by the viscosity reducer under weak shear action, neither the anionic surfactant nor the amphoteric surfactant component shown in formula (A) can be missing.

[0175] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including combining each technical feature in any other suitable way. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A super heavy oil emulsifying viscosity reducer composition, characterized in that, the viscosity reducer composition contains the following components stored independently or in combination of two or more: anionic surfactant, amphoteric surfactant and water; the anionic surfactant is a cyclodextrin-modified anionic oligomeric surfactant, and the anionic surfactant has the structure shown in formula (A): wherein, in formula (A), M is selected from Li + , Na + , K + , NH 4 + ; any one of them R is selected from -OH, the group shown in formula (I); R 1 Selected from -OH, -OSO 3 M, the group represented by formula (I), and only one of R and R 1 is the group represented by formula (I); m and n are each independently selected from any integer from 0 to 7, and the sum of m and n is any integer from 5 to 7; and when m is 0, R 1 is -OSO 3 M; in formula (I), S is 0; Each R 2 is independently selected from C 10-15 alkyl; the amphoteric surfactant is selected from at least one of alkyl dimethyl betaine, alkyl hydroxypropyl sulfobetaine, and coconut oil amide propyl betaine; based on the total weight of the viscosity reducer composition, the content of the anionic surfactant is 0.1-2 wt%, the content of the amphoteric surfactant is 0.1-2 wt%, and the content of water is 96.0-99.8 wt%.

2. The viscosity reducer composition according to claim 1, wherein, the alkyl carbon chain of the alkyl dimethyl betaine and alkyl hydroxypropyl sulfobetaine is independently selected from any integer of 8-20.

3. The viscosity reducer composition according to claim 2, wherein, the alkyl carbon chain of the alkyl dimethyl betaine and alkyl hydroxypropyl sulfobetaine is independently selected from any integer of 12-18.

4. The viscosity reducer composition according to any one of claims 1-3, wherein, based on the total weight of the viscosity reducer composition, the content of the anionic surfactant is 0.5-1.5 wt%, the content of the amphoteric surfactant is 0.5-1.5 wt%, and the content of water is 97-99 wt%.

5. A method for preparing a super heavy oil emulsifying viscosity reducer, characterized in that, the method includes: mixing the components in the viscosity reducer composition according to any one of claims 1-4.

6. The method according to claim 5, wherein, the conditions for the mixing at least satisfy: the temperature is 15-40 °C, the stirring speed is 50-600 rpm, and the stirring time is 10-80 min.

7. A super heavy oil emulsifying viscosity reducer prepared by the method according to claim 5 or 6.

8. The application of the viscosity reducer composition according to any one of claims 1-4 and the super heavy oil emulsifying viscosity reducer according to claim 7 in the exploitation of super heavy oil reservoirs.

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