Emulsifying and viscosity reducing agent composition, preparation method and application thereof, and super heavy oil emulsifying and viscosity reducing method

Abstract

The invention relates to the technical field of thick oil emulsification and viscosity reduction, and discloses an emulsification and viscosity reduction agent composition, a preparation method and application thereof, and a super thick oil emulsification and viscosity reduction method, the composition comprises an anionic sulfate surfactant, an ampholytic surfactant and a solvent; the anionic sulfate surfactant has a structure as shown in a formula (1), # imgabs0 #, wherein R1 is selected from C8-C22 alkyl groups; r3 and R4 are independently selected from H or-SO3M, and at least one of R3 and R4 is-SO3M; each R2 is independently selected from H, 2-hydroxy propyl and methyl; m is selected from any one of Li, Na, K and NH4; m is selected from any integer of 1-10, n is selected from any integer of 1-10, z is selected from any integer of 0-9, and the sum of m, n and z is any integer of 5-11. The super heavy oil emulsifying and viscosity reducing agent composition has excellent emulsifying and viscosity reducing effects and good salt resistance under the condition of weak shearing.

Description

Technical Field

[0001] The invention relates to the technical field of heavy oil emulsification and viscosity reduction, and in particular to an emulsification and viscosity reduction agent composition, a preparation method and application thereof, and a super heavy oil emulsification and viscosity reduction method. Background Art

[0002] Emulsification viscosity reduction technology is a viscosity reduction method that uses an external surfactant to form an "oil-in-water" emulsion between heavy oil and surfactant aqueous solution, thereby reducing the viscosity of crude oil and improving the fluidity of heavy oil. In recent years, the proportion of heavy oil production in overall oil production has gradually increased, and geological conditions have become increasingly complex. The effect of emulsified viscosity reducers is affected by the physical properties of heavy oil and formation conditions. Complex formation conditions increase the amount of emulsifier added, and the viscosity reduction effect becomes worse or even fails, resulting in a significant increase in costs. The main components of existing heavy oil emulsified viscosity reducers are mostly composed of linear anionic surfactants, non-ionic surfactants and co-surfactants, but this type of emulsified viscosity reducer has a poor emulsification effect for deep ultra-heavy oil reservoirs, especially ultra-heavy oil with a viscosity of more than 50,000 mPa.s.

[0003] CN110835522A discloses a heat-resistant and salt-resistant super-heavy oil emulsifying viscosity reducer. The emulsifying viscosity reducer is an amphoteric surfactant formed by the reaction of ethylene oxide and dimethylamine to generate an intermediate, and then reacting with sodium 3-chloro-2-phenylsulfonate. The viscosity reducer has strong emulsification and peeling capabilities for colloids and asphaltene, and has a high viscosity reduction rate, and can reduce the viscosity of super-heavy oil at 50°C by more than 99.0%. However, the dimethylamine and ethylene oxide raw materials used in the preparation are highly dangerous, are gaseous at room temperature, are flammable, and dimethylamine has a strong irritating ammonia odor.

[0004] The ultra-heavy oil viscosity reducers in the prior art are mostly compositions of common surfactants, which have a better emulsification effect under stirring conditions. However, when actually applied to the ultra-heavy oil production process, there is no severe disturbance in the formation or wellbore. How to achieve emulsification and viscosity reduction of ultra-heavy oil with poor fluidity under weak shear is very challenging. It is urgent to develop an ultra-heavy oil emulsification and viscosity reduction system that can enhance the permeability of crude oil and achieve viscosity reduction of ultra-heavy oil under low shear. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems of poor temperature and salt resistance of emulsified viscosity reducers in the prior art and poor emulsification and viscosity reduction effect on super heavy oil under weak shearing, and to provide an emulsified viscosity reducer composition, a preparation method and application thereof, and a super heavy oil emulsification and viscosity reduction method. The emulsified viscosity reducer has good temperature and salt resistance and has good emulsification and viscosity reduction effect on super heavy oil under weak shearing.

[0006] In order to achieve the above-mentioned object, the present invention provides an emulsified viscosity reducer composition, which comprises an anionic sulfate surfactant, an amphoteric surfactant and a solvent;

[0007] Wherein, the anionic sulfate surfactant has a structure shown in formula (1),

[0008]

[0009] Wherein R1 is selected from C8-C 22 The alkyl group;

[0010] R3 and R4 are each independently selected from H or -SO3M, and at least one of R3 and R4 is -SO3M;

[0011] Each R2 is independently selected from H, 2-hydroxypropyl, methyl;

[0012] M is selected from any one of Li, Na, K, and NH4;

[0013] m is selected from any integer of 1-10, n is selected from any integer of 1-10, z is selected from any integer of 0-9, and the sum of m, n and z is any integer of 5-11.

[0014] Preferably, the amphoteric surfactant is selected from at least one of alkylpropyl hydroxysulfobetaine, lauramidopropyl hydroxysulfobetaine, cocamidopropyl hydroxysulfobetaine and erucamidopropyl hydroxysulfobetaine.

[0015] The second aspect of the present invention provides a method for preparing the above-mentioned emulsified viscosity reducer composition, comprising: mixing an anionic sulfate surfactant, an amphoteric surfactant and a solvent.

[0016] The third aspect of the present invention provides the use of the emulsified viscosity reducer composition in the exploitation of super heavy oil reservoirs.

[0017] A fourth aspect of the present invention provides a method for reducing the viscosity of super heavy oil by emulsification, the method comprising: mixing the emulsified viscosity reducer composition described in the first aspect with super heavy oil.

[0018] The super-heavy oil emulsified viscosity reducer composition of the present invention contains an anionic sulfate surfactant modified by cyclodextrin, which has a strong aggregation ability, a critical micelle concentration as low as 0.037mM, and a solubilization ability for polycyclic aromatic hydrocarbons that is more than 15 times higher than that of a single-chain surfactant, which can greatly accelerate the penetration and dispersion process of the emulsified viscosity reducer in the heavy oil, so that the super-heavy oil emulsified viscosity reducer composition of the present invention can still effectively reduce the viscosity of the super-heavy oil under weak shear conditions and has good salt resistance. At the same time, the anionic sulfate surfactant modified by cyclodextrin has good oil-water interfacial activity and can reduce the oil-water interfacial tension to 10-2 mN / m order of magnitude, which will further improve the stability of the super-heavy oil emulsion system. Preferably, through the synergistic effect of the anionic sulfate surfactant and the amphoteric surfactant containing a sulfonic group, the temperature resistance of the emulsified viscosity reducer composition can be further improved, and the excellent viscosity reduction effect can be maintained under complex formation conditions. In addition, the emulsified viscosity reducer composition provided by the present invention also has the advantages of good biocompatibility, easy biodegradation, no secondary pollution, and less damage to the formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the MALDI-TOF-MS spectrum of the anionic sulfate surfactant intermediate modified by β-cyclodextrin prepared in Preparation Example 1 of the present invention;

[0020] Figure 2 The anionic sulfate surfactant product based on β-cyclodextrin modification prepared in Preparation Example 1 of the present invention is 1 H NMR spectrum;

[0021] Figure 3 This is the MALDI-TOF-MS spectrum of the anionic sulfate surfactant intermediate modified by α-cyclodextrin prepared in Preparation Example 2 of the present invention;

[0022] Figure 4 The anionic sulfate surfactant product based on α-cyclodextrin modification prepared in Preparation Example 2 of the present invention is 1 H NMR spectrum;

[0023] Figure 5 This is the MALDI-TOF-MS spectrum of the anionic sulfate surfactant intermediate modified by γ-cyclodextrin prepared in Preparation Example 3 of the present invention;

[0024] Figure 6 The anionic sulfate surfactant product based on γ-cyclodextrin modification obtained in Preparation Example 3 of the present invention is 1 H NMR spectrum. DETAILED DESCRIPTION

[0025] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0026] The first aspect of the present invention provides an emulsified viscosity reducer composition, the composition comprising an anionic sulfate surfactant, an amphoteric surfactant and a solvent;

[0027] Wherein, the anionic sulfate surfactant has a structure shown in formula (1),

[0028]

[0029] Wherein R1 is selected from C8-C 22 The alkyl group;

[0030] R3 and R4 are each independently selected from H or -SO3M, and at least one of R3 and R4 is -SO3M;

[0031] Each R2 is independently selected from H, 2-hydroxypropyl, methyl;

[0032] M is selected from any one of Li, Na, K, and NH4;

[0033] m is selected from any integer of 1-10, n is selected from any integer of 1-10, z is selected from any integer of 0-9, and the sum of m, n and z is any integer of 5-11.

[0034] According to the present invention, the anionic sulfate surfactant having the structure shown in the above formula (1) has a strong aggregation ability, and its solubilization ability for polycyclic aromatic hydrocarbons is more than 15 times higher than that of the single-chain surfactant. It can synergize with the amphoteric surfactant to greatly accelerate the penetration and dispersion process of the emulsified viscosity reducer in the heavy oil, so that the super-heavy oil emulsified viscosity reducer composition of the present invention can still effectively reduce the viscosity of the super-heavy oil under weak shear conditions and has good salt resistance.

[0035] Preferably, in formula (I), R1 is selected from C8-C 16 The alkyl group is more preferably C 10 -C 14 In the present invention, "C8-C 22 "Alkyl" means an alkyl group having a total of 8 to 22 carbon atoms, including C8-C 22 Straight chain alkyl, C8-C 22 The branched alkyl group may be, for example, a straight chain alkyl group or a branched alkyl group having a total number of carbon atoms of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22. For example, it may be n-octyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, and the like. 16 Alkyl, C 10 -C 14 The alkyl group has a similar explanation, except that the number of carbon atoms is different.

[0036] In some preferred embodiments of the present invention, the R1 is dodecyl. In the above preferred case, the anionic sulfate surfactant has stronger surface activity, which is further beneficial to improve the penetration and dispersion performance of the emulsified viscosity reducer composition in heavy oil.

[0037] Preferably, M is selected from Na or K.

[0038] Preferably, m is selected from any integer of 1-7, n is selected from any integer of 1-7, z is selected from any integer of 0-6, and the sum of m, n and z is any integer of 6-8. Preferably, m is selected from any integer of 1-6, n is selected from any integer of 1-6, z is selected from any integer of 1-6, and the sum of m, n and z is any integer of 6-8.

[0039] According to some preferred embodiments of the present invention, in formula (1), R1 is selected from C 10 -C 14 alkyl; R3 and R4 are each independently selected from H or -SO3M, and at least one of R3 and R4 is -SO3M; each R2 is each independently selected from H, 2-hydroxypropyl, methyl; M is selected from Na or K; m is selected from any integer from 1 to 6, n is selected from any integer from 1 to 6, z is selected from any integer from 1 to 6, and the sum of m, n and z is any integer from 6 to 8.

[0040] In a further preferred embodiment, the anionic sulfate surfactant has a structure represented by formula (M-1) and / or formula (M-2),

[0041]

[0042] In formula (M-1) and formula (M-2),

[0043] R1 is selected from C8-C 16 The alkyl group is preferably C 10 -C 14 M is selected from Na or K; m is selected from any integer from 1 to 7, n is selected from any integer from 1 to 7, z is selected from any integer from 0 to 6, and the sum of m, n and z is any integer from 6 to 8.

[0044] The use of anionic sulfate surfactants having the above preferred structure is beneficial to further improve the penetration and dispersion performance of the emulsified viscosity reducer composition in heavy oil.

[0045] Through the synergistic effect of the above-mentioned anionic sulfate surfactant and amphoteric surfactant, the penetration and dispersion process of the emulsified viscosity reducer in the heavy oil can be accelerated, thereby effectively reducing the viscosity of the extra-heavy oil and having good salt resistance.

[0046] In the present invention, "amphoteric surfactant" has the conventional definition in the art, and refers to a surfactant containing both anionic hydrophilic groups and cationic hydrophilic groups in the same molecule. The present invention has a wide range of selection for the specific types of the amphoteric surfactant, and all amphoteric surfactants conventionally used in the art can be applied to the present invention. For example, the amphoteric surfactant can be a betaine-type amphoteric surfactant. For example, at least one of alkyl betaine, alkyl amide betaine, sulfo betaine and hydroxy sulfo betaine.

[0047] In order to further improve the temperature resistance of the emulsified viscosity reducer composition and improve the viscosity reducing effect of the emulsified viscosity reducer composition under complex formation conditions, preferably, the amphoteric surfactant is selected from at least one of alkylpropyl hydroxysulfobetaine, lauramidopropyl hydroxysulfobetaine, cocamidopropyl hydroxysulfobetaine and erucamidopropyl hydroxysulfobetaine.

[0048] Preferably, the number of carbon atoms in the alkyl carbon chain of the alkylpropylhydroxysulfobetaine is 8 to 20, preferably 12 to 18. For example, it may be dodecylpropylhydroxysulfobetaine, hexadecylpropylhydroxysulfobetaine, octadecylpropylhydroxysulfobetaine, and the like.

[0049] According to some preferred embodiments of the present invention, based on the total mass of the composition, the content of the anionic sulfate surfactant is 0.1-2wt%, the content of the amphoteric surfactant is 0.1-2wt%, and the content of the solvent is 96-99.8wt%; preferably, based on the total mass of the composition, the content of the anionic sulfate surfactant is 0.5-1.5wt%, the content of the amphoteric surfactant is 0.5-1.5wt%, and the content of the solvent is 97-99wt%. Under the above preferred composition composition, it is beneficial for the super heavy oil emulsification viscosity reducer to effectively emulsify the super heavy oil under weak shearing conditions, thereby reducing the viscosity of the super heavy oil.

[0050] According to some preferred embodiments of the present invention, the mass ratio of the anionic sulfate surfactant to the amphoteric surfactant is 1:0.3-3, preferably 1:0.7-1.5. Under the above preferred circumstances, it is beneficial to further improve the emulsification and viscosity reduction effect.

[0051] The present invention has a wide range of solvents for the composition, as long as the anionic sulfate surfactant and the amphoteric surfactant can be fully dissolved. From a cost perspective, the solvent can be water, such as deionized water, tap water, mineralized water, etc.

[0052] The second aspect of the present invention provides a method for preparing the above-mentioned emulsified viscosity reducer composition, comprising: mixing an anionic sulfate surfactant, an amphoteric surfactant and a solvent.

[0053] The selection range of the anionic sulfate surfactant and the amphoteric surfactant is the same as that defined in the first aspect and will not be repeated here.

[0054] The present invention has no particular limitation on the manner and conditions of the mixing, and the mixing can be carried out by conventional methods in the art, as long as the anionic sulfate surfactant and the amphoteric surfactant can be fully mixed and dispersed in the solvent.

[0055] Preferably, the mixing is carried out under stirring, preferably magnetic stirring, and the mixing conditions include: temperature of 15-40°C, preferably 20-30°C, stirring speed of 50-600rpm, preferably 100-400rpm, stirring time of 10-80min, preferably 20-50min.

[0056] According to some preferred embodiments of the present invention, the preparation method of the anionic sulfate surfactant comprises:

[0057] (1) in the presence of solvent I and a catalyst, contacting and reacting a 1,2-epoxy compound represented by formula (I-1) with a cyclodextrin compound represented by formula (I-2) to obtain an intermediate;

[0058] (2) in the presence of solvent II, subjecting the intermediate to a sulfonation reaction with a sulfonating agent to obtain a mixture I;

[0059] (3) using an alkaline substance containing the element M to adjust the pH value of the mixture I to be greater than or equal to 7;

[0060]

[0061] In formula (I-1), formula (I-2), and alkaline substances,

[0062] The definitions of R1, R2, m, n, z, and M are the same as those in the first aspect and will not be repeated here.

[0063] According to some preferred embodiments of the present invention, in step (1), the cyclodextrin compound is provided by at least one of cyclodextrin, methyl cyclodextrin, hydroxyethyl cyclodextrin and hydroxypropyl cyclodextrin.

[0064] Preferably, the cyclodextrin is selected from at least one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.

[0065] It should be noted that the cyclodextrin compound, the 1,2-epoxy compound and the sulfonating agent in the present invention can be commercially available chemical reagents, or can be prepared by those skilled in the art according to methods known in the art.

[0066] In the present invention, the method for preparing the anionic sulfonate surfactant is preferably carried out under stirring. There is no particular requirement for the stirring speed, and the method can be carried out using parameters known in the art.

[0067] According to the present invention, preferably, the preparation method further comprises: in step (1), filtering and drying the product after the contact reaction between the 1,2-epoxy compound and the cyclodextrin compound. The present invention does not particularly limit the specific method of filtering and drying, and those skilled in the art can perform the filtering and drying according to known methods; as long as an intermediate can be obtained after the solvent is removed and dried to a constant weight.

[0068] Preferably, the method further comprises: removing the solvent from the product obtained in step (3) by rotary evaporation, and drying to obtain an anionic sulfate surfactant. The present invention has no particular limitation on the specific manner of rotary evaporation and drying, and the rotary evaporation and drying can be performed using known technical means in the art.

[0069] According to some preferred embodiments of the present invention, the molar ratio of the cyclodextrin compound to the 1,2-epoxy compound is 1:(1-40). More preferably, the molar ratio of the cyclodextrin compound to the 1,2-epoxy compound is 1:(1-32).

[0070] Preferably, in step (1), the solvent I is water, and the catalyst is an alkali metal hydroxide or 4-dimethylaminopyridine. In the present invention, there is no particular limitation on the water, which may be deionized water, tap water, etc.

[0071] Preferably, the alkali metal hydroxide is selected from at least one of NaOH, KOH and LiOH.

[0072] Preferably, in step (1), the contact reaction conditions at least meet the following conditions: temperature of 30-100°C, time of 1-10 hours. More preferably, the contact reaction conditions at least meet the following conditions: temperature of 60-90°C, time of 3-8 hours.

[0073] Preferably, in step (1), relative to 1 mmol of the cyclodextrin compound, the amount of the solvent I is 0.1-50 mL, and the amount of the catalyst is 0.001-0.1 mmol. More preferably, relative to 1 mmol of the cyclodextrin compound, the amount of the solvent I is 1-10 mL, and the amount of the catalyst is 0.005-0.1 mmol.

[0074] According to a preferred embodiment, in step (2), the sulfonating agent is selected from at least one of sulfur trioxide pyridine complex, fuming sulfuric acid, sulfur trioxide, concentrated sulfuric acid, chlorosulfonic acid, and aminosulfonic acid.

[0075] Preferably, the content of active SO3 in the sulfur trioxide pyridine complex is 45-55wt%.

[0076] According to another preferred embodiment, the mass ratio of the intermediate to the sulfonating agent is 1:0.5-5. More preferably, the mass ratio of the intermediate to the sulfonating agent is 1:1-3.

[0077] Preferably, relative to 1 g of the intermediate, the amount of the solvent II is 5-20 mL.

[0078] Preferably, in step (2), the solvent II is selected from at least one of tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide and pyridine.

[0079] Preferably, in step (2), the conditions of the sulfonation reaction at least meet the following conditions: temperature of 0-90° C. and time of 1-24 h.

[0080] Preferably, in step (3), the alkaline substance is selected from at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide and ammonia water.

[0081] In step (3) of the present invention, the alkaline substance is preferably provided in the form of an aqueous solution, and the concentration of the aqueous solution of the alkaline substance is 0.1wt%-50wt%. More preferably, the concentration of the aqueous solution of the alkaline substance is 5wt%-15wt%.

[0082] Preferably, in step (3), an alkaline substance containing element M is used to adjust the pH value of the mixture I to 7-9.

[0083] The preparation method of the anionic sulfate surfactant provided by the present invention uses cyclodextrin compounds, 1,2-epoxy compounds and sulfonating agents as main raw materials, can be efficiently prepared through three-step reactions, and has the advantages of low cost, simple process, mild reaction conditions, simple post-treatment and high reaction yield.

[0084] The third aspect of the present invention provides the use of the above-mentioned emulsified viscosity reducer composition in the exploitation of super heavy oil reservoirs.

[0085] The emulsified viscosity reducer composition provided by the present invention has good viscosity reduction and emulsification effects on super-heavy oil with a viscosity exceeding 50,000 mPa.s under the simulated weak shearing action of the formation, and the viscosity reducer composition has good temperature resistance and salt resistance, and also has good adaptability to heavy oil containing formation water with high calcium and magnesium ions. In addition, the viscosity reducer has low preparation cost, is easy to biodegrade, does not produce secondary pollution, and has less damage to the formation.

[0086] A fourth aspect of the present invention provides a method for reducing the viscosity of super heavy oil by emulsification, the method comprising: mixing the emulsified viscosity reducer composition described in the first aspect with super heavy oil.

[0087] The ultra-heavy oil viscosity reducers in the prior art are mostly compositions of common surfactants, which have a better emulsification effect under stirring conditions. However, when actually applied to the ultra-heavy oil production process, there is no severe disturbance in the formation or wellbore. In this case, the emulsification viscosity reduction effect is not ideal. The emulsified viscosity reducer composition provided by the present invention can achieve viscosity reduction of ultra-heavy oil under low shear action.

[0088] According to some preferred embodiments of the present invention, the mixing conditions include: a temperature of 60-90°C, preferably 65-80°C, a mixing rate of 1-10rpm, preferably 4-8rpm, and a mixing time of 10-80min, preferably 20-50min. For ultra-heavy oil viscosity reduction, the conventional emulsified viscosity reducer in the prior art usually requires a higher shearing effect in order to achieve a viscosity reduction rate of more than 99%, and the mixing rate is generally not less than 100rpm. The ultra-heavy oil emulsified viscosity reduction method provided by the present invention can achieve a viscosity reduction rate of more than 99% at a lower mixing rate.

[0089] According to some preferred embodiments of the present invention, the amount of the emulsified viscosity reducer composition is 25-400 parts by weight relative to 100 parts by weight of the super heavy oil; preferably, the amount of the emulsified viscosity reducer composition is 40-100 parts by weight relative to 100 parts by weight of the super heavy oil.

[0090] Preferably, the viscosity of the super heavy oil at 50° C. is not less than 50,000 mPa·s, preferably 50,000-300,000 mPa·s.

[0091] The present invention will be described in detail below through examples.

[0092] The main raw materials used in the preparation examples, embodiments and comparative examples are shown in Table 1.

[0093] Table 1

[0094] Product Name factory purity α-Cyclodextrin Innochem 98％ β-Cyclodextrin Innochem 99％ γ-Cyclodextrin Innochem 98％ 1,2-Epoxytetradecane TCI 95％ Sulfur trioxide pyridine complex Innochem Industrial Grade Sodium hydroxide Innochem Analytical grade Chlorosulfonic acid TCI 99％ Concentrated sulfuric acid Sinopharm Group Analytical grade Dodecylpropyl hydroxysulfobetaine Shanghai Chuxing Chemical 35±2％ Lauramidopropyl Hydroxysulfobetaine Shanghai Chuxing Chemical 40±2％ Cocamidopropyl Hydroxysulfonate Betaine Shanghai Chuxing Chemical 40±2％ Erucamidopropyl Hydroxysulfobetaine Shanghai Chuxing Chemical 40±2％ Dodecyl dimethyl betaine Shanghai Chuxing Chemical 35±2％ Sodium dodecyl sulfate (SDS) Innochem 99％

[0095] The following preparation examples are used to illustrate the preparation of anionic sulfate surfactants in the present invention.

[0096] Preparation Example 1

[0097] Preparation of anionic sulfate surfactant T1 based on β-cyclodextrin:

[0098]

[0099] The structures shown in formula (1) and formula (2) are the structures of intermediate I and anionic sulfate surfactant T1, respectively. In formula (1) and formula (2), m is 2, n+z is 5, the sum of m, n, and z is 7, -C 12 H 25 represents n-dodecyl.

[0100] Weigh 10 mmol of β-cyclodextrin and 70 mmol of 1,2-epoxytetradecane into a reaction bottle, then add 20 mL of water, 0.05 mmol of 4-dimethylaminopyridine and a magnet. Stir the reaction at 85°C for 7 hours, stop the reaction, filter and dry to obtain intermediate I as a white solid.

[0101] The structure of intermediate I was characterized by MALDI-TOF-MS. Figure 1 As shown, the peaks at mass-to-charge ratios of 1369.350, 1581.509, 1793.666, 2005.817, 2217.964, 2430.107, and 2642.248 correspond to the molecular ion peaks of the intermediate represented by formula (1) obtained after 1-7 primary hydroxyl groups and 1,2-epoxytetradecane are contacted and reacted; this result proves that intermediate I is prepared. Figure 1 From the intensity of MALDI-TOF-MS, it can be seen that m is 2 and n+z is 5 in the product of the structure shown in formula (1).

[0102] Add 1 g of intermediate I and 10 mL of N,N-dimethylformamide into a three-necked flask. At the same time, weigh 2 g of sulfur trioxide pyridine complex (active SO3 content 50 wt%) and dissolve it in 5 mL of N,N-dimethylformamide. Add it into the three-necked flask and stir to react at 50 °C for 2 h. Cool to room temperature, add 10 wt% sodium hydroxide aqueous solution to adjust the pH value to 7, remove the solvent by rotary evaporation and dry to obtain the product anionic sulfate surfactant T1 with a yield of 81%.

[0103] The anionic sulfate surfactant T1 was 1 H NMR characterization (the deuterated solvent used was deuterated water), the results are as follows Figure 2 As shown, 1 H NMR (D2O): δ=0.78(-C11 H 22 CH3),1.20-1.65(-C 11 H 22 CH3),3.28-3.85(-CH2OH,-CH-CH2-O-CH2-CHOH-C 12 H 25 ,-O-CH-CH-CH2-O-,-CHOH,),4.06(-CH-CH2-OSO3Na),4.18-4.49(-CH-CH2-OSO3Na,-CH-CH2-O-CH2-CHOH-C 12 H 25 ).

[0104] Depend on Figure 2 It can be seen that there are two broad peaks at 4.06 and 4.18-4.49 ppm. Among them, 4.06 ppm corresponds to -CH-CH2OSO3Na, and 4.18-4.49 ppm corresponds to -CH-CH2-OSO3Na and -CH-CH2-O-CH2-CHOH-C 12 H 25 , proving the successful progress of the sulfonation reaction and the existence of the sulfonation product. 1 The specific values ​​of n and z in the structure shown in formula (2) can be quantitatively calculated by integrating the proton peak area of ​​the H NMR spectrum. For the T1 molecule: n = 3, z = 2.

[0105] The average degree of sulfonation of the anionic sulfate surfactant T1 was 1.15 mmol / g.

[0106] Preparation Example 2

[0107] Preparation of anionic sulfate surfactant T2 based on α-cyclodextrin:

[0108]

[0109] The structures shown in formula (3) and formula (4) are the structures of intermediate II and anionic sulfate surfactant T2, respectively. In formula (3) and formula (4), m is 2, n+z is 4, the sum of m, n, and z is 6, -C 12 H 25 represents n-dodecyl.

[0110] Weigh 10 mmol of α-cyclodextrin and 90 mmol of 1,2-epoxytetradecane into a reaction bottle, then add 10 mL of water, 0.30 mmol of 4-dimethylaminopyridine and a magnet. Stir the reaction at 60°C for 8 hours, stop the reaction, filter and dry to obtain Intermediate II.

[0111] The mass spectrometry characterization of intermediate II showed the following results: Figure 3 The product spectrum has peaks at mass-to-charge ratios of 1207.304, 1419.462, 1631.613, 1843.762, 2055.906, and 2268.046, which correspond to the molecular ion peaks of the amphiphilic α-cyclodextrin shown in formula (3) obtained after 1-6 primary hydroxyl groups and 1,2-epoxytetradecane have contacted and reacted, proving that the product was successfully prepared. Figure 3 From the intensity of MALDI-TOF-MS, it can be seen that m is 2 and n+z is 4 in the structural product shown in formula (3).

[0112] Add 1 g of intermediate II, 10 mL of N,N-dimethylformamide and 1.4 g of chlorosulfonic acid into a three-necked flask, stir and react at 0°C for 1 h, add 10 wt % sodium hydroxide to adjust the pH value to 7, remove the solvent by rotary evaporation and dry to obtain anionic sulfate surfactant T2 with a yield of 77%.

[0113] The anionic sulfate surfactant T2 was 1 H NMR characterization (the deuterated solvent used was deuterated DMSO), the results are as follows Figure 4 As shown, 1 H NMR (DMSO-d6): δ=0.97(-C 11 H 22 CH3),1.36-1.67(-C 11 H 22 CH3),3.66-3.76(-CH2OH,-CH-CH2-O-CH2-CHOH-C 12 H 25 ,-O-CH-CH-CH2-O-,-CHOH,),3.99(-CH-CH2-OSO3Na),4.22(-CH-CH2-OSO3Na,-CH-CH2-O-CH2-CHOH-C 12 H 25 ),5.22(-O-CH-O-).

[0114] Depend on Figure 4 It can be seen that there are two broad peaks at 3.99-4.22ppm. Among them, 3.99ppm corresponds to -CH-CH2OSO3Na, 4.22ppm corresponds to -CH-CH2-OSO3Na, -CH-CH2-O-CH2-CHOH-C 12 H 25 , proving the success of the sulfonation reaction and the existence of the sulfonation product. 1The specific values ​​of n and z in the structure shown in formula (4) can be quantitatively calculated by integrating the proton peak area of ​​the H NMR spectrum. For the T2 molecule: n = 3, z = 1.

[0115] The average degree of sulfonation of the anionic sulfate surfactant T2 was 1.16 mmol / g.

[0116] Preparation Example 3

[0117] Preparation of anionic sulfate surfactant T3 based on γ-cyclodextrin:

[0118]

[0119] The structures shown in formula (5) and formula (6) are the structures of intermediate III and anionic sulfate surfactant T3, respectively. In formula (5) and formula (6), m is 2, n+z is 6, the sum of m, n, and z is 8, and -C 12 H 25 represents n-dodecyl.

[0120] Weigh 10 mmol of γ-cyclodextrin and 320 mmol of 1,2-epoxytetradecane into a reaction bottle, then add 100 mL of water, 0.80 mmol of 4-dimethylaminopyridine and a magnet. Stir the reaction at 90°C for 3 hours, stop the reaction, filter and dry to obtain a white intermediate III.

[0121] The mass spectrometry characterization of intermediate III showed the following results: Figure 5 The product spectrum has peaks at mass-to-charge ratios of 1531.287, 1743.433, 1955.569, 2167.702, 2379.833, 2591.964, 2804.094, and 3016.224, which correspond to the molecular ion peaks of the amphiphilic γ-cyclodextrin shown in formula (5) obtained after 1-8 primary hydroxyl groups and 1,2-epoxytetradecane have contacted and reacted, proving that the product was successfully prepared. Figure 5 From the intensity of MALDI-TOF-MS, it can be seen that m is 2 and n+z is 6 in the structural product shown in formula (5).

[0122] At 0°C, 1 g of intermediate III, 10 mL of N,N-dimethylformamide and 2.35 g of concentrated sulfuric acid were added to a three-necked flask, and the mixture was stirred for reaction for 1 h. 10 wt % of potassium hydroxide was added to adjust the pH value to 7. The solvent was removed by rotary evaporation and dried to obtain anionic sulfate surfactant T3 with a yield of 76%.

[0123] The anionic sulfate surfactant T3 was 1 H NMR characterization (the deuterated solvent used was deuterated DMSO), the results are as follows Figure 6 As shown, 1H NMR (DMSO-d6): δ=0.97(-C 11 H 22 CH3),1.35-1.67(-C 11 H 22 CH3),3.73-3.98(-CH2OH,-CH-CH2-O-CH2-CHOH-C 12 H 25 ,-O-CH-CH-CH2-O-,-CHOH,-CH-CH2-OSO3Na),4.16(-CH-CH2-OSO3Na,-CH-CH2-O-CH2-CHOH-C 12 H 25 ),5.26(-O-CH-O-).

[0124] Depend on Figure 6 It can be seen that there are two peaks in the proton chemical shift at 3.98-4.16ppm. Among them, 3.98ppm corresponds to -CH-CH2OSO3Na, 4.16ppm corresponds to -CH-CH2-OSO3Na, -CH-CH2-O-CH2-CHOH-C 12 H 25 , proving the successful progress of the sulfonation reaction and the existence of the sulfonation product. 1 The specific values ​​of n and z in the structure shown in formula (6) can be quantitatively calculated by integrating the proton peak area of ​​the H NMR spectrum. For the T3 molecule: n = 4, z = 2.

[0125] The average degree of sulfonation of the anionic sulfate surfactant T3 in this example is 1.12 mmol / g.

[0126] The following examples are used to illustrate the preparation of the emulsified viscosity reducer composition of the present invention.

[0127] Example 1

[0128] Under magnetic stirring conditions of 20° C. and 300 rpm, 1.0 g of the product T1 in Preparation Example 1 and 1.0 g of dodecylpropyl hydroxysulfobetaine were added to 98.0 g of water and stirred for 30 min until completely dissolved to obtain an ultra-heavy oil emulsified viscosity reducer composition, No. A1.

[0129] Example 2

[0130] Under magnetic stirring conditions at 25° C. and 200 rpm, 1.2 g of the product T2 in Preparation Example 2 and 1.3 g of cocamidopropyl hydroxysulfobetaine were added to 97.5 g of water and stirred for 40 min until completely dissolved to obtain an ultra-heavy oil emulsified viscosity reducer composition, numbered A2.

[0131] Example 3

[0132] Under magnetic stirring conditions at 30° C. and 400 rpm, 0.8 g of the product T3 in Preparation Example 3 and 0.8 g of lauramide propyl hydroxysulfobetaine were added to 98.4 g of water and stirred for 20 min until completely dissolved to obtain an ultra-heavy oil emulsified viscosity reducer composition, numbered A3.

[0133] Example 4

[0134] Under magnetic stirring conditions at 30° C. and 300 rpm, 1.0 g of the product T1 in Preparation Example 1 and 1.0 g of erucic acid amide propyl hydroxysulfobetaine were added to 98.0 g of water and stirred for 30 min until completely dissolved to obtain an ultra-heavy oil emulsified viscosity reducer composition, No. A4.

[0135] Example 5

[0136] Under magnetic stirring conditions at 20° C. and 300 rpm, 0.5 g of the product T1 in Preparation Example 1 and 1.5 g of dodecylpropyl hydroxysulfobetaine were added to 98.0 g of water and stirred for 30 min until completely dissolved to obtain an ultra-heavy oil emulsified viscosity reducer composition, No. A5.

[0137] Example 6

[0138] Under magnetic stirring conditions at 20° C. and 300 rpm, 1.5 g of the product T1 in Preparation Example 1 and 0.5 g of dodecylpropyl hydroxysulfobetaine were added to 98.0 g of water and stirred for 30 min until completely dissolved to obtain an ultra-heavy oil emulsified viscosity reducer composition, No. A6.

[0139] Example 7

[0140] The method of Example 1 was followed, except that an equal amount of dodecyl dimethyl betaine was used to replace dodecyl propyl hydroxysulfobetaine to obtain an emulsified viscosity reducer composition, numbered A7.

[0141] Comparative Example 1

[0142] The method of Example 1 was followed, except that an equal mass of sodium dodecyl sulfate (SDS) was used to replace T1. The resulting composition was recorded as DA1.

[0143] Comparative Example 2

[0144] Under magnetic stirring conditions at 20° C. and 300 rpm, 2 g of the product T1 in Preparation Example 1 was added to 98 g of water and stirred for 30 min until it was completely dissolved. The obtained composition was numbered DA2.

[0145] Comparative Example 3

[0146] Under the condition of magnetic stirring at 20° C. and 300 rpm, 2 g of dodecylpropyl hydroxysulfobetaine was added to 98 g of water and stirred for 30 min until it was completely dissolved. The obtained composition was numbered DA3.

[0147] Test Case

[0148] The extra heavy oil (viscosity of 125300 mPa·s at 50℃) from Shengli Oilfield was selected as the test oil to measure the emulsified viscosity and viscosity reduction rate of the extra heavy oil.

[0149] 1. Determination of emulsified viscosity and viscosity reduction rate:

[0150] Take 25g of the super heavy oil emulsification viscosity reducer in the above examples or comparative examples, add it to 50g of the test oil, place the beaker in a 70℃ water bath, keep it at constant temperature for 1h, use a biological shaker to simulate the emulsification viscosity reduction process under weak shear conditions, the shaking level is level 1, the mixing rate is 6rpm, the shaking time is 30min, and observe the emulsified morphology of the heavy oil. Then use a Brookfield DV-II viscometer at 50℃ at a shear rate of 7.34s -1 The viscosity of the heavy oil after viscosity reduction was measured, and the results are shown in Table 2.

[0151] Wherein, viscosity reduction rate (%) = (viscosity of heavy oil before viscosity reduction - viscosity of heavy oil after viscosity reduction) / viscosity of heavy oil before viscosity reduction × 100%.

[0152] Table 2

[0153]

[0154]

[0155] The results in Table 2 show that the emulsified viscosity reducer composition provided by the present invention can achieve emulsified viscosity reduction of super heavy oil with a viscosity of 125300 mPa·s under simulated weak shearing, and the viscosity reduction rate reaches more than 99.37%. However, conventional anionic surfactants cannot achieve uniform emulsification and dispersion of super heavy oil under weak shearing force, and the viscosity reduction effect is poor. Comparing A1 with DA1 and DA2, the use of anionic sulfate surfactants alone or amphoteric surfactants alone cannot achieve uniform emulsification and dispersion of super heavy oil under weak shearing force, and the viscosity reduction effect is poor.

[0156] 2. Temperature resistance test of emulsified viscosity reducer composition:

[0157] Before the emulsification viscosity reduction test, the emulsified viscosity reducer compositions A1, A2, A7 and DA1 were placed in a pressure autoclave, nitrogen was passed to replace the viscosity reducer and the air in the autoclave, the temperature was raised to 190°C and heated for aging for 4 hours, and then the heavy oil emulsification viscosity reduction performance test was carried out according to the viscosity reduction process in Test Example 1. The results are shown in Table 3.

[0158] Table 3

[0159]

[0160] It can be seen from the results in Table 3 that, compared with conventional anionic surfactants, the super-heavy oil emulsified viscosity reducer composition provided by the present invention can still emulsify super-heavy oil after being heated to 190° C. and aged for 4 hours, and the viscosity reduction rate is above 90%, and preferably can reach above 99%. This indicates that the super-heavy oil emulsified viscosity reducer in the present invention has good temperature resistance.

[0161] 3. Salt resistance test:

[0162] In order to simulate the ultra-heavy oil environment of formation water containing high calcium and magnesium ions, the solvent water in Example 1, Example 2 and Comparative Example 1 was replaced with mineralized water (mineralization degree was 150000 mg / L, wherein Ca 2+ Concentration: 5000mg / L, Mg 2+ Concentration: 5000 mg / L), compositions A1', A2' and DA1' were prepared respectively, and then the heavy oil emulsification viscosity reduction performance test was carried out according to the method of Test Example 1. The results are shown in Table 4.

[0163] Table 4

[0164]

[0165] It can be seen from the results in Table 4 that the viscosity reducer composition provided by the present invention has good salt resistance and is also well adaptable to super-heavy oil in formation water containing high calcium and magnesium ions.

[0166] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An emulsified viscosity reducer composition, characterized in that: The composition includes an anionic sulfate surfactant, an amphoteric surfactant and a solvent; Wherein, the anionic sulfate surfactant has a structure shown in formula (1), Wherein, R1 is selected from C8-C 22 The alkyl group; R3 and R4 are each independently selected from H or -SO3M, and at least one of R3 and R4 is -SO3M; Each R2 is independently selected from H, 2-hydroxypropyl, methyl; M is selected from any one of Li, Na, K, and NH4; m is selected from any integer of 1-10, n is selected from any integer of 1-10, z is selected from any integer of 0-9, and the sum of m, n and z is any integer of 5-11.

2. The composition according to claim 1, wherein R1 is selected from C8-C 16 The alkyl group is preferably C 10 -C 14 The alkyl group; Preferably, M is Na or K; Preferably, m is selected from any integer of 1-7, n is selected from any integer of 1-7, z is selected from any integer of 0-6, and the sum of m, n and z is any integer of 6-8.

3. The composition according to claim 1 or 2, wherein The anionic sulfate surfactant has a structure shown in formula (M-1) and / or formula (M-2), In formula (M-1) and formula (M-2), R1 is selected from C8-C 16 The alkyl group is preferably C 10 -C 14 The alkyl group; M is selected from any one of Na and K; m is selected from any integer of 1-7, n is selected from any integer of 1-7, z is selected from any integer of 0-6, and the sum of m, n and z is any integer of 6-8.

4. The composition according to any one of claims 1 to 3, wherein The amphoteric surfactant is a betaine type amphoteric surfactant; Preferably, the betaine-type amphoteric surfactant is at least one selected from alkyl betaine, alkyl amide betaine, sulfonate betaine and hydroxysulfonate betaine.

5. The composition according to claim 4, wherein The amphoteric surfactant is selected from at least one of alkylpropyl hydroxysulfobetaine, lauramidopropyl hydroxysulfobetaine, cocamidopropyl hydroxysulfobetaine and erucamidopropyl hydroxysulfobetaine; Preferably, the number of carbon atoms in the alkyl carbon chain of the alkylpropylhydroxysulfonate is 8-20, preferably 12-18.

6. The composition according to any one of claims 1 to 5, wherein Based on the total mass of the composition, the content of the anionic sulfate surfactant is 0.1-2wt%, the content of the amphoteric surfactant is 0.1-2wt%, and the content of the solvent is 96-99.8wt%; Preferably, based on the total mass of the composition, the content of the anionic sulfate surfactant is 0.5-1.5wt%, the content of the amphoteric surfactant is 0.5-1.5wt%, and the content of the solvent is 97-99wt%; Preferably, the mass ratio of the anionic sulfate surfactant to the amphoteric surfactant is 1:0.3-3, preferably 1:0.7-1.

5.

7. The composition according to any one of claims 1 to 6, wherein The solvent is water.

8. A method for preparing the emulsified viscosity reducer composition according to any one of claims 1 to 7, comprising: Mixing anionic sulfate surfactant, amphoteric surfactant and solvent; Preferably, the mixing is performed under stirring conditions, and the mixing conditions include: a temperature of 15-40° C., a stirring speed of 50-600 rpm, and a stirring time of 10-80 min.

9. Use of the emulsified viscosity reducer composition according to any one of claims 1 to 7 in the exploitation of super heavy oil reservoirs.

10. A method for reducing the viscosity of super heavy oil by emulsification, characterized in that: The method comprises: mixing the emulsified viscosity reducer composition according to any one of claims 1 to 7 with super heavy oil; Preferably, the mixing conditions include: a temperature of 60-90° C. and a mixing speed of 1-10 rpm. Preferably, the amount of the emulsified viscosity reducer composition is 25-400 parts by weight relative to 100 parts by weight of the super heavy oil; further preferably, the amount of the emulsified viscosity reducer composition is 40-100 parts by weight relative to 100 parts by weight of the super heavy oil; Preferably, the viscosity of the super heavy oil at 50° C. is not less than 50,000 mPa·s, preferably 50,000-300,000 mPa·s.

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