Surfactant composition for steam thermal recovery eor and method of making and using same

Abstract

The application belongs to the field of oil field chemistry, and discloses a surfactant composition for steam thermal recovery of tertiary oil recovery, and a preparation method and application thereof. The surfactant composition comprises alpha-olefin sulfonate (AOS), betaine surfactant with a polyether fragment shown in formula (2), polyether anionic surfactant shown in formula (3) and water; R7O-(CH2CH2O)m1-(CH(CH3)CH2O)n1-(CH2CH2O) m2 -R8COOM formula (3); the surfactant composition is suitable for steam thermal recovery of tertiary oil recovery, has strong foaming capacity, good thermal stability of foam, and high salt resistance, especially stable to divalent ions, can meet the needs of high-temperature, high-mineral-density heavy oil exploitation, can reduce the viscosity of heavy oil and super-heavy oil, reduce the interfacial tension, and improve the enhanced oil recovery of thermal recovery of heavy oil.

Description

Technical Field

[0001] This invention belongs to the field of oilfield chemistry and relates to a surfactant composition for oil recovery in high-temperature, high-salinity heavy oil reservoirs. Specifically, it is a surfactant composition for enhancing oil recovery through steam thermal recovery in tertiary oil recovery, its preparation method, and its application. Background Technology

[0002] In recent years, my country's major oilfields have entered a high water-cut period after primary and secondary extraction. How to improve crude oil recovery rate and maximize the development of remaining reserves is a challenge facing researchers. Years of research have yielded various enhanced oil recovery technologies, including physical methods such as gas injection (gas drive, miscible drive) and thermal energy utilization (steam drive, hot water drive); chemical methods such as polymer flooding, alkaline water flooding, surfactant flooding, and alkaline / surfactant / polymer composite flooding; and biological methods such as endogenous and exogenous microbial flooding, which are also under exploration and development.

[0003] Steam foam was the earliest foam-enhanced oil recovery technology applied in oil fields. Shell conducted steam foam displacement in the Kern River oil field in California, USA, in 1976, using alpha olefin sulfonate (AOS) as the foaming agent. Two years after foam injection, crude oil production increased significantly. Five years after foam injection, the crude oil production increase rate was 8.5-14% OOIP (original oil in place) (Patzek & Koinis, 1990). Chevron's Unocal also conducted steam foam displacement in the Guadalupe Field and Midway-Sunset oil fields in California, USA, in 1984 and 1985, respectively. Alpha olefin sulfonate (AOS) or alkyl toluene sulfonate (ATS), brine, and nitrogen were injected along with steam. Its production-enhancing response is rapid. In the Midway-Sunset oilfield, two years of foam displacement resulted in a total increase in crude oil production of 32,900 m³ (Mohammadi, et al., 1989) (Mohammadi & McCollum, 1989). Document CN101717627A discloses a low-tension foaming agent and its preparation method for improving crude oil recovery in high-salinity reservoirs. The main components of this foaming agent are alkyl dimethylamine hydantoin, sodium dodecyl alcohol polyoxyethylene ether sulfate, and coconut oil monoethanolamine. However, its compatibility with formation water is generally poor, and its application temperature is only below 120°C. The examples were all conducted at 50°C, making it unsuitable for ultra-high temperature reservoirs.

[0004] Surfactants are common foaming agents. Surfactants adsorbed at the water-air interface prevent foam breakage through physicochemical interactions such as electrostatic repulsion, steric hindrance, and interfacial tension gradients. Therefore, many researchers are dedicated to finding surfactant formulations with high gas-liquid interfacial activity as efficient foaming agents. Sodium alkyl polyoxyethylene ether sulfonate, a popular surfactant from abroad, was tested in the Shengli oilfield. However, this surfactant proved ineffective in the Shengli reservoir conditions and is unsuitable for use alone; it must be used in combination with other surfactants.

[0005] If the advantages of chemical flooding and foam flooding can be combined, microemulsion foam technology combines the strengths of both technologies, aiming to reduce oil-water interfacial tension and improve oil washing efficiency while generating stable foam to increase sweep efficiency. For a long time, microemulsion technology has been dedicated to finding surfactant compositions that achieve a balanced oil-water phase, thereby developing corresponding oil displacement technologies and providing new methods for enhancing oil recovery in old oilfields.

[0006] However, although surfactants possess the ability to both enhance foaming performance and reduce oil-water interfacial tension, environmental factors, including gas phase composition, oil phase composition, temperature, salinity, and additives, often cause conventional surfactants to exhibit contradictory properties in enhancing foaming performance and reducing interfacial tension. Specifically, foaming agents with good foaming properties can only reduce oil / water interfacial tension to a limited extent, reaching only a few mN / m. According to the capillary force calculation formula, this interfacial tension is insufficient to effectively clean residual oil from the reservoir. Conversely, low-tension surfactants produce foam with poor performance, making it difficult to form stable plugs. Furthermore, existing foaming agents precipitate upon contact with divalent ions, failing to meet the requirements of high-temperature, high-salinity heavy oil extraction.

[0007] Therefore, developing a surfactant suitable for tertiary oil recovery steam thermal recovery, possessing strong foaming ability, good foam thermal stability, and high salt resistance, especially stable even in the presence of divalent ions, to meet the needs of high-temperature, high-salt-content heavy oil extraction, reduce the viscosity of heavy and extra-heavy oils, further lower interfacial tension, and further improve the enhanced oil recovery rate of steam-recovered heavy oil, is a problem that needs to be solved. Summary of the Invention

[0008] This invention relates to a surfactant composition and its preparation method for enhanced oil recovery (EOR) using steam thermal recovery in tertiary oil recovery, belonging to the field of steam huff and puff technology for heavy and extra-heavy oils. It primarily addresses the problems of poor thermal stability and precipitation upon contact with divalent ions in existing foaming agents, failing to meet the requirements of high-temperature, high-saltage heavy oil extraction. This invention provides a surfactant composition, its preparation method, and its application for enhanced oil recovery using steam thermal recovery. The invention employs a microemulsion foaming agent composition containing a betaine-type zwitterionic surfactant with polyether fragments. It achieves a viscosity reduction rate of over 99.5% for heavy oil, exhibits stable foam performance, and is a highly efficient viscosity-reducing system, thus improving EOR in heavy oil. The surfactant composition of this invention not only possesses temperature and salt resistance, tolerating a maximum salinity of 30,000 mg / L, but also exhibits strong interfacial activity, reducing the crude oil / water interfacial tension to 10. -2 mN / m, significantly improving the recovery rate.

[0009] The first aspect of the present invention is to provide a surfactant composition comprising an α-olefin sulfonate AOS as shown in formula (1), a betaine surfactant having a polyether segment as shown in formula (2), a polyether anionic surfactant as shown in formula (3), and water;

[0010] R1-CH=CH-CH2-SO3K (Equation (1));

[0011] In equation (1): R1 is C5~C 30 The alkyl group, where K is any metal ion selected from alkali metals;

[0012]

[0013] In formula (2): R6 is selected from C6~C 30 The alkyl and alkenyl groups are selected from C1 to C5, wherein R2 and R5 are each independently selected from C1 to C5. 22 R3 and R4 are selected independently from C1 to C4, and either alkylene or hydroxylated alkylene. 12 The alkylene group is selected from any one of the alkylene group or the hydroxyl-substituted alkylene group, m+n = 1 to 100, x+y = 0 to 100, X is COOM or SO3N, and M and N are independently selected from hydrogen, alkali metals or the formula NR 4’ (R 5’ (R) 6’ (R) 7’ At least one of the groups shown in ) R 4’ R 5’ R 6’ R 7’ Each is independently selected from H and -(CH2). j OH or -(CH2) gAny one of CH3, j = 1 to 5, g = any integer from 0 to 7;

[0014] R7O-(CH2CH2O)m1-(CH(CH3)CH2O)n1-(CH2CH2O) m2 -R8COOM Equation (3);

[0015] In equation (3): R7 is C1~C 30 A straight-chain or branched saturated or unsaturated alkyl-substituted aryl group, m1 = 0–30, n1 = 0–50, m2 = 0–30, m1 + m2 < 60; R8 is a C1–C9 alkylene or hydroxyl-substituted alkylene or a single bond, M is selected from hydrogen, alkali metals and formula NR9(R 10 (R) 11 (R) 12 At least one of the groups shown in the diagram; R9, R 10 R 11 and R 12 Each is independently selected from H and -(CH2). p OH or -(CH2) q Any one of CH3, p = 1 to 5, q = any integer from 0 to 7.

[0016] According to the present invention, the amounts of each component can be selected within a wide range. In a preferred embodiment of the present invention, the surfactant composition contains, by weight, 1 to 20 parts of betaine surfactant, 0.1 to 10 parts of polyether anionic surfactant, and 90 to 100 parts of water, relative to 1 part of α-olefin sulfonate AOS; more preferably,

[0017] Based on parts by weight, relative to 1 part of α-olefin sulfonate AOS, the surfactant composition contains 1 to 10 parts of betaine surfactant, 0.1 to 1 part of polyether anionic surfactant and 90 to 98 parts of water.

[0018] According to a preferred embodiment of the present invention, in formula (1), R1 is C8~C 22 The alkyl group, wherein the alkali metal K is sodium or potassium.

[0019] According to a preferred embodiment of the present invention, in formula (2): R6 is C8~C 25 R2 is any one of alkyl or alkenyl groups, and R2 is C2 to C3. 22 R5 is any one of C1 to C5 alkylene or hydroxy-substituted alkylene, R3 and R4 are each C1 to C3 alkylene, m+n = 1 to 30, x+y = 0 to 10.

[0020] According to a preferred embodiment of the present invention, in formula (3): R7 is C12 ~C 24 Any one of alkyl or alkenyl groups or composed of C8 to C96 groups 12 Alkyl-substituted phenyl, where R8 is a C1-C7 alkylene or hydroxyl-substituted propylene group or a single bond.

[0021] According to a preferred embodiment of the present invention, in formula (3): M is selected from hydrogen, alkali metals and formula NR9(R 10 (R) 11 (R) 12 At least one of the groups shown in the diagram; R9, R 10 R 11 and R 12 Each is independently selected from H and -(CH2). p OH or -(CH2) q Any one of CH3, p=2, q=0 or 1; preferably, M is sodium or potassium among alkali metals, more preferably sodium.

[0022] According to a more preferred embodiment of the present invention, in formula (3): R7 is C 12 ~C 24 Alkyl or alkenyl groups or those composed of C8 to C96 groups 12 Alkyl-substituted phenyl; m1 = 0–10, n1 = 0–15, m2 = 1–15; R8 is a C1–C3 alkylene or hydroxyl-substituted propylene or a single bond; more preferably,

[0023] R7 is C 12 ~C 16 Alkyl or alkenyl groups, m1 = 0–7, n1 = 2–12, m2 = 1–10; more preferably, R7 is C 12 ~C 14 Alkyl or alkenyl groups, m1 = 0–5, n1 = 4–10, m2 = 1–8.

[0024] The surfactant composition of this invention has excellent compatibility and may also contain other commonly used processing agents in the art, such as foaming agents, small molecule organic compounds (e.g., small molecule alcohols, small molecule amines, small molecule ethers, etc.), inorganic salts, inorganic bases, and other oil recovery additives. The small molecule alcohol is selected from C1-C8 fatty alcohols; the small molecule amine is selected from at least one of C1-C8 primary, secondary, or tertiary amines; the inorganic salts AB are selected from at least one of alkali metal and / or alkaline earth metal halides, alkali metal and / or alkaline earth metal carbonates, alkali metal and / or alkaline earth metal bicarbonates, etc., wherein A is a metal ion such as Ca, Mg, or Na, and B is a halide, carbonate, bicarbonate, sulfate, sulfite, or nitrate, etc.; the inorganic base is selected from at least one of alkali metal hydroxides, alkali metal carbonates, or alkali metal bicarbonates.

[0025] According to a preferred embodiment of the present invention, the betaine surfactant is prepared by the following method:

[0026] Long-chain fatty acids or their esters are reacted with the desired amidation reagent to obtain an intermediate; under a protective atmosphere, the obtained intermediate is mixed with ethylene oxide and reacted, and then, in the presence of a protective gas and a catalyst, ethylene oxide or propylene oxide is optionally added to continue the reaction to obtain a hydrocarbon-based polyoxyethylene ether; the obtained hydrocarbon-based polyoxyethylene ether is then reacted with an ionizing reagent to obtain the betaine surfactant shown in formula (2).

[0027] According to a preferred embodiment of the present invention, the reaction conditions for preparing the intermediate include: reacting a long-chain fatty acid or its ester with the desired amidating agent at 100–160°C for 3–20 hours to obtain the intermediate.

[0028] In this invention, ethylene oxide can be added in batches. For example, a portion can be added during the reaction with the intermediate, and another portion can be added in the presence of a catalyst. Alternatively, it can be added all at once during the reaction with the intermediate, and then the reaction can continue in the presence of a catalyst.

[0029] In this invention, ethylene oxide and propylene oxide cannot be mixed before being added to the reaction system.

[0030] According to a preferred embodiment of the present invention, the reaction conditions for the intermediate and ethylene oxide include: heating and mixing under a protective atmosphere, preferably at 130-160°C for 0.5-4 hours.

[0031] According to a preferred embodiment of the present invention, the reaction conditions after adding the catalyst include: 80–180°C, gauge pressure 0–0.80 MPa, and reaction time 1–10 hours.

[0032] According to a preferred embodiment of the present invention, the reaction conditions with the ionizing reagent include: reacting at 50 to 100°C for 2 to 20 hours to obtain the betaine surfactant shown in formula (2).

[0033] According to the present invention, the molar ratio of long-chain fatty acid or its ester: amidating agent: ionizing agent can be selected within a wide range. In a preferred embodiment of the present invention, the molar ratio of long-chain fatty acid methyl ester: amidating agent: ionizing agent is 1:(0.01-30):(0.01-40).

[0034] According to the present invention, preferably, the protective gas is an inert gas and / or nitrogen.

[0035] According to the present invention, preferably, the catalyst is at least one of alkali metal hydroxides; preferably, barium hydroxide.

[0036] A second aspect of the present invention is to provide a method for preparing the surfactant composition described in the first aspect, comprising the step of mixing the α-olefin sulfonate AOS, the betaine surfactant, the polyether anionic surfactant, and water;

[0037] Preferably, the mixing step results in the complete dissolution of the raw materials in the composition.

[0038] A third aspect of the present invention is to provide an oil displacement agent comprising a surfactant composition and water, wherein the surfactant composition is the surfactant composition described in the first aspect or a surfactant composition prepared by the preparation method described in the second aspect.

[0039] According to a preferred embodiment of the present invention, the content of the surfactant composition in the oil displacement agent is 0.1-1 wt%, preferably 0.3-0.5 wt%.

[0040] In this invention, the water has a mineralization of 0–30000 mg / L, and / or, Ca 2+ and Mg 2+ The sum of their concentrations is 0-8000 mg / L.

[0041] The surfactant composition of this invention has excellent compatibility and may also contain other commonly used processing agents in the art, such as foaming agents, small molecule organic compounds (e.g., small molecule alcohols, small molecule amines, small molecule ethers, etc.), inorganic salts, inorganic bases, and other oil recovery additives. The small molecule alcohol is selected from C1-C8 fatty alcohols; the small molecule amine is selected from at least one of C1-C8 primary, secondary, or tertiary amines; the inorganic salts AB are selected from at least one of alkali metal and / or alkaline earth metal halides, alkali metal and / or alkaline earth metal carbonates, alkali metal and / or alkaline earth metal bicarbonates, etc., wherein A is a metal ion such as Ca, Mg, or Na, and B is a halide, carbonate, bicarbonate, sulfate, sulfite, or nitrate, etc.; the inorganic base is selected from at least one of alkali metal hydroxides, alkali metal carbonates, or alkali metal bicarbonates.

[0042] A fourth aspect of the present invention is to provide the application of the surfactant composition described in the first aspect, the surfactant composition prepared by the preparation method described in the second aspect, or the oil displacement agent described in the third aspect in tertiary oil recovery.

[0043] Preferably, the oil extraction method is steam thermal recovery; more preferably,

[0044] It is used for tertiary oil recovery under conditions of 50–150℃ and salinity of 0–30000 mg / L.

[0045] The fifth aspect of the present invention is the application of a surfactant composition prepared according to the surfactant composition of the first aspect or the preparation method of the second aspect or the oil displacement agent of the third aspect in enhancing oil recovery in an oil field.

[0046] In tertiary oil recovery operations, steam thermal recovery involves high temperatures, requiring surfactants that are resistant to high temperatures and divalent salts. Existing anionic surfactants generally cannot withstand temperatures above 90°C. The betaine surfactant in this invention possesses polyether fragments and is an amphoteric surfactant characteristic, unlike conventional betaine surfactants.

[0047] Compared with the prior art, the present invention has the following advantages:

[0048] The surfactant composition of the present invention is suitable for reservoirs with temperatures of 80–250°C and mineralization below 30,000 mg / L, and Ca... 2+ +Mg 2+ Oil reservoirs with concentrations below 8000 mg / L. This surfactant composition, when mixed with nitrogen, air, carbon dioxide, and natural gas, forms a stable foam. In laboratory tests of the Shengli Oilfield formation water foam system, its interfacial tension reached 10 at 90℃. -2 The viscosity reduction rate of the composition on Shengli heavy oil can reach over 99.5% at 90℃ (mN / m).

[0049] The surfactant composition of the present invention is suitable for tertiary oil recovery steam thermal recovery. It has strong foaming ability, good foam thermal stability, and high salt resistance. In particular, it can be stabilized even when exposed to divalent ions. It can meet the requirements of high-temperature, high-salt heavy oil extraction, reduce the viscosity of heavy oil and extra-heavy oil, reduce interfacial tension, and improve the enhanced oil recovery rate of thermally recovered heavy oil. Detailed Implementation

[0050] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0051] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0052] The polyether carboxylates in the following embodiments of the present invention were prepared using existing preparation methods. For details, please refer to: Study on temperature-responsive viscoelastic surfactants. Petrochemical Technology, 2021(02):144-149.

[0053] Sodium α-olefin sulfonate (AOS) 14-16 Regular commercially available products.

[0054] Unless otherwise specified, all other raw materials are standard commercially available products.

[0055]

Example 1

[0056] 1. Preparation of surfactant compositions

[0057] (1) Erucamide carboxybetaine amphoteric surfactant (R6=C) 21 Preparation of (R2=C2, R3\R4=C2, R5=C1, m+n=4)

[0058] Methyl erucic acid and the required amount of amidating agent N,N-bis(2-hydroxyethyl)ethylenediamine were added to a reaction vessel and reacted at 145°C for 7 hours. The vacuum pump was turned on to remove excess N,N-bis(2-hydroxyethyl)ethylenediamine, yielding erucic acid acyl tertiary amine product. Nitrogen gas was then introduced into a reactor equipped with a condenser and a stirrer and heated to 150°C. After heating for 40 minutes, ethylene oxide (2 moles) was added, and the temperature was maintained at 150°C while stirring for 1 hour. The temperature was lowered to 80℃, barium hydroxide was added as a catalyst, and the mixture was heated to 140℃. The vacuum system was turned on, and the mixture was dehydrated under high vacuum for 1 hour. Then, the system was purged with nitrogen four times to remove air from the system. The reaction temperature was then adjusted to 165℃, and ethylene oxide (2 moles) was slowly introduced. The pressure was controlled at <0.80MPa to carry out the alkoxylation reaction until the reaction was completed. The system was purged with nitrogen, cooled, neutralized, and dehydrated to obtain erucic acid polyoxyethylene (m+n=4) ether tertiary amine. The required amount of sodium chloroacetate was then added, and the reaction was carried out at 75℃ for 10 hours. After recrystallization and purification with anhydrous ethanol, a long-chain betaine surfactant was obtained. The molar ratio of methyl erucic acid: N,N-bis(2-hydroxyethyl)ethylenediamine: sodium chloroacetate was 1:1.5:1.5.

[0059] (2) At room temperature and pressure, 10g of sodium α-olefin sulfonate (AOS) 14-16 ), 10g of erucamide carboxybetaine amphoteric surfactant, 6.8g of polyether carboxylate RO-EO3-PO8-EO 10 -COONa(where R is C) 12 ~C 14 Add the surfactant to the reaction vessel, then add 973.2g of local tap water, and stir thoroughly for 30 minutes until completely dissolved to obtain the surfactant composition.

[0060] Performance testing: At a mineralization of 120,000 mg / L, Ca 2+ +Mg 2+ A solution of 0.3 wt% surfactant composition was prepared at a concentration of 3000 mg / L.

[0061] 2. Performance Evaluation

[0062] (1) Viscosity test

[0063] The surfactant composition was diluted to a concentration of 0.3%. Then, a solution was prepared using Shengli West crude oil (viscosity of 8000 mP·s at 50℃) at a 7:3 oil-to-water ratio. The solution was aged in an oven at 90℃ for 1 hour, stirred at a constant temperature of 250 r / min for 2 minutes, and then the viscosity was measured. Test conditions: A Thermo viscometer was used at 90℃ and a stirring speed of 7.34 s⁻¹. -1 Under the conditions, the viscosity of the above-mentioned 0.3% concentration surfactant composition and crude oil (heavy oil) was measured. The results of crude oil viscosity are shown in Table 2. As can be seen from Table 2, the viscosity reduction rate of the composition in Example 1 can reach 99.5%.

[0064] (2) Evaluation of interfacial tension

[0065] The interfacial tension between the above-mentioned 0.15wt% surfactant composition and dehydrated crude oil from Shengli Oilfield was determined using a TX-500C rotating drop interfacial tensiometer manufactured by the University of Texas, USA, according to method SY / T5370-1999, at 90℃ and a rotation speed of 4500 rpm. The results are shown in Table 2.

[0066] (3) Evaluation of oil displacement experiment

[0067] Using the QY-C12 automatic core flooding unit manufactured by Jiangsu Huaan Company, with a temperature of 90℃, a pressure of 5MPa, and a surfactant composition concentration of 0.3%, and employing a Φ38×300mm sand-packed pipe, the water permeability was measured to be 2.43 Darcy. Water flooding was first performed to a water cut of 98%. After the water flooding was completed, 0.5pv (core pore volume) of the aforementioned 0.3wt% concentration of oil displacement agent (surfactant composition) was injected, followed by water flooding to a water cut of 100%. The results of the improved oil recovery rate are shown in Table 2.

[0068] In this invention, the components and proportions of the surfactants in the following examples and comparative examples are shown in Table 1. Unless otherwise specified, the other conditions are the same as in Example 1.

[0069]

Example 2

[0070] Ingredients: C 14 ~C 16 Sodium α-olefin sulfonate (AOS) 14-16 10g, hexadecanoic acid sulfonyl betaine 15.5g (R6=C) 15 R2 = C2, R3 / R4 = C2, R5 = C2, m + n = 6), polyether carboxylate RO-PO8-EO6-COONa (where R is C 12 ~C14 4.5g of local tap water and 970g of local tap water were used to obtain a surfactant composition.

[0071] The raw materials and preparation process are the same as in [Example 1], with different degrees of mineralization.

[0072] Preparation steps: Under normal temperature and pressure, 10g of sodium α-olefin sulfonate (AOS) was added... 14-16 Add 15.5g of hexadecanoic acid sulfobetaine and 4.5g of polyether carboxylate ROPO8-EO6-COONa to the reactor, then add 970g of local tap water and stir thoroughly for 30 minutes until completely dissolved.

[0073] Performance testing: At a mineralization of 200,000 mg / L, Ca 2+ +Mg 2+ A solution of a surfactant composition of 0.3 wt% was prepared at a concentration of 3000 mg / L.

[0074]

Example 3

[0075] Example 3: Betaine surfactant with polyether fragments (R6=C) 21 The method for combining R2=C3, R3\R4=C2, R5=C1, m+n=4, x+y=2 is as follows:

[0076] Methyl erucic acid and the required amount of amidating agent N,N-bis(2-hydroxyethyl)propylenediamine were added to a reaction vessel and reacted at 145°C for 7 hours. The vacuum pump was turned on to remove excess N,N-bis(2-hydroxyethyl)ethylenediamine, yielding the erucic acid acyl tertiary amine product. Nitrogen gas was then introduced into a reactor equipped with a condenser and a stirrer and heated to 150°C. After heating for 40 minutes, ethylene oxide (4 moles) was added, and the temperature was maintained at 150°C while stirring for 1 hour. The temperature was lowered to 80℃, barium hydroxide was added as a catalyst, and the mixture was heated to 140℃. The vacuum system was turned on, and the mixture was dehydrated under high vacuum for 1 hour. Then, the system was purged with nitrogen 4 times to remove air from the system. The reaction temperature was then adjusted to 165℃, and propylene oxide (2 moles) was slowly introduced. The pressure was controlled at <0.80MPa to carry out the alkoxylation reaction until the reaction was completed. The system was purged with nitrogen, cooled, neutralized, and dehydrated to obtain erucic acid polyoxyethylene polyoxypropylene (m+n=4, x+y=2) ether tertiary amine. The required amount of sodium chloroacetate was then added, and the reaction was carried out at 75℃ for 10 hours. After recrystallization and purification with anhydrous ethanol, a long-chain betaine surfactant was obtained. The molar ratio of methyl erucic acid: N,N-bis(2-hydroxyethyl)propylenediamine: sodium chloroacetate was 1:1.5:1.6.

[0077] Ingredients: C 14 ~C 16 Sodium α-olefin sulfonate (AOS)14-16 10g of erucamide carboxybetaine (R6=C) 21 R2=C3, R3\R4=C2, R5=C1, m+n=4, x+y=2), polyether carboxylate RO-PO8-EO6-COONa (where R is C 12 ~C 14 6.5g of local tap water and 973.5g of local tap water were used to obtain a surfactant composition.

[0078] Preparation steps: Under normal temperature and pressure, 10g of sodium α-olefin sulfonate (AOS) was added... 14-16 Add 10g of erucamide carboxybetaine and 6.5g of polyether carboxylate RO-PO8-EO6-COONa to the reactor, then add 973.5g of local tap water and stir thoroughly for 30 minutes until completely dissolved.

[0079] Performance testing: At a mineralization of 150,000 mg / L, Ca 2+ +Mg 2+ Prepare a 0.3 wt% solution at a concentration of 5000 mg / L.

[0080]

Example 4

[0081] Ingredients: C 14 ~C 16 Sodium α-olefin sulfonate (AOS) 14-16 10g, nonanoic acid amide carboxybetaine 10g (R6=C8,R2=C2,R3\R4=C2,R5=C1,m+n=4), polyether carboxylate RO-EO3-PO8-EO 10 COONa (where R is C) 12 ~C 14 6.8g of local tap water and 973.2g of local tap water were used to obtain a surfactant composition.

[0082] Preparation steps: Under normal temperature and pressure, 10g of sodium α-olefin sulfonate (AOS) was added... 14-16 ), 10g of nonanoic acid amide carboxybetaine, 6.5g of polyether carboxylate RO-EO3-PO8-EO 10 Add COONa to the reactor, then add 973.5g of local tap water, and stir thoroughly for 30 minutes until completely dissolved.

[0083] Performance testing: At a mineralization of 150,000 mg / L, Ca 2+ +Mg 2+ Prepare a 0.3 wt% solution at a concentration of 2000 mg / L.

[0084]

Example 5

[0085] The RO-EO3-PO8-EO in Example 1 was replaced with RO-PO8-EO8-COONa. 10 -COONa, and everything else is the same as in Example 1, to obtain the surfactant composition in this example.

[0086]

Example 6

[0087] The RO-EO3-PO8-EO in Example 1 was replaced with RO-EO6-COONa. 10 -COONa, and everything else is the same as in Example 1, to obtain the surfactant composition in this example.

[0088]

Example 7

[0089] Long-chain betaine surfactant R6=C was used. 17 Replace R6=C in Example 1 21 Everything else is the same as in Example 1, and the surfactant composition in this example is obtained.

[0090]

Example 8

[0091] The same raw materials as in Example 1 were used, except that the ratio of the surfactant composition was different, and RO-EO3-PO8-EO in Example 1 was replaced with RO-PO8-EO8-COONa. 10 -COONa, see Table 1.

[0092]

Comparative Example 1

[0093] Similar to Example 3, except that the reactions with propylene oxide and ethylene oxide are not carried out sequentially, but rather the two are mixed and then reacted in one step. Specifically, a mixture of 2 moles of propylene oxide and 4 moles of ethylene oxide is slowly introduced at 110–180°C, with the rest remaining the same, to obtain a betaine amphoteric and anionic mixed surfactant.

[0094] Performance testing: At a mineralization of 120,000 mg / L, Ca 2+ +Mg 2+ A 0.3% surfactant composition solution was prepared at a concentration of 3000 mg / L.

[0095] The performance test was carried out in the same manner as in Example 1, and compared with the surfactant composition prepared in the corresponding example. The concentration of the surfactant composition was 0.3 wt%. The results are shown in Table 2.

[0096] [Comparative Example 2]

[0097] Similar to Example 3, except that the reactions with propylene oxide and ethylene oxide are not carried out sequentially, but rather the two are mixed and then reacted in one step. Specifically, a mixture of 2 moles of propylene oxide and 4 moles of ethylene oxide is slowly introduced at 110–180°C, with the rest remaining the same, to obtain a betaine amphoteric and anionic mixed surfactant.

[0098] Performance testing: At a mineralization of 150,000 mg / L, Ca 2+ +Mg 2+ A 0.3% surfactant composition solution was prepared at a concentration of 2000 mg / L.

[0099] The performance test was carried out in the same manner as in Example 1, and compared with the surfactant prepared in the corresponding example. The concentration of the surfactant composition was 0.3 wt%. The results are shown in Table 2.

[0100] [Comparative Example 3]

[0101] According to the method described in patent CN101717627A, the preparation steps are as follows: at 80°C, 30g of alkyl dimethylamine hydantoin, 15g of sodium dodecyl alcohol polyoxyethylene ether sulfate and 15g of coconut oil monoethanolamine are added to a reaction vessel, and then 40g of local tap water is added. The mixture is stirred thoroughly for 30 minutes until it is completely dissolved to obtain a surfactant composition.

[0102] Performance testing: At a mineralization of 200,000 mg / L, Ca 2+ +Mg 2+ Prepare a 0.3 wt% solution at a concentration of 3000 mg / L.

[0103] [Comparative Example 4]

[0104] According to the method described in patent CN106590607B, the preparation steps are as follows: 15.85 g of dodecyl polyoxypropylene (8) ether acetate (LAPO8CH2COOH) is added to a reaction vessel, an appropriate amount of local tap water is added to dissolve it, and then an appropriate amount of sodium hydroxide is added to obtain sodium dodecyl polyoxypropylene (8) ether acetate (LAPO8CH2COONa); then 10 g of C is added to it. 14 ~C 16 Sodium α-olefin sulfonate (AOS) 14-16 Add 5 grams of 3-sulfopropyldodecyl dimethyl betaine to a sufficient amount of local tap water to a final volume of 100 grams to prepare a 30 wt% solution. Stir thoroughly for 30 minutes until completely dissolved to obtain composition ZY-1, which is a pale yellow paste.

[0105] Performance testing: At a mineralization of 200,000 mg / L, Ca 2+ +Mg2+ Prepare a 0.3 wt% solution at a concentration of 3000 mg / L.

[0106] [Comparative Example 5]

[0107] The difference from [Example 1] is that the RO-EO3-PO8-EO in Example 1 is changed. 10 -The COONa component was removed, and everything else was the same as in Example 1, to obtain the surfactant composition in this example.

[0108] The surfactant compositions in the examples and comparative examples consist of:

[0109] R1-CH=CH-CH2-SO3K Equation (1);

[0110]

[0111] R7O-(CH2CH2O)m1-(CH(CH3)CH2O)n1-(CH2CH2O) m2 -R8COOM Equation (3).

[0112] Table 1

[0113]

[0114]

[0115] Table 2 Evaluation of oil displacement agent performance in examples and comparative examples

[0116]

[0117]

[0118] As can be seen from the comparison between Comparative Examples 1 and 2 and Example 1, the method of adding ethylene oxide and propylene oxide separately rather than together unexpectedly reduced the viscosity (mPa.s) and interfacial tension, and further improved the oil recovery rate.

[0119] As can be seen from the comparison between Example 1 and Comparative Example 3, the present invention uses three specific surfactants in the general formula to work synergistically, which significantly reduces viscosity (mPa.s) and interfacial tension, and significantly improves the recovery rate.

[0120] In particular, in Examples 5, 6, and 7, it can be seen that under the preferred conditions of component 1: α-olefin sulfonate AOS and component 2: C21 betaine amphoteric surfactant, the change in the number of EO| and PO of the polyether anionic surfactant in this invention can further reduce viscosity (mPa.s) and interfacial tension, and further improve the recovery rate.

[0121] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

[0122] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0123] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0124] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values; such ranges or values ​​should be understood to include values ​​close to them. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In principle, various technical solutions can be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0125] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

[0126] Furthermore, any implementation described herein can be freely combined with one or more other implementations described herein, and the resulting technical solutions or technical ideas shall be regarded as part of the original disclosure or original record of the present invention, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider the combination to be obviously unreasonable.

Claims

1. A surfactant composition comprising α-olefin sulfonate AOS as shown in formula (1), betaine surfactant having a polyether segment as shown in formula (2), polyether anionic surfactant as shown in formula (3), and water; Equation (1); In equation (1): R1 is C5~C 30 alkyl groups, K It is any metal ion selected from alkali metals; Equation (2); In equation (2): R6 is selected from C6~C 30 R2 and R5 are both independently selected from C1 to C5. 22 R3 and R4 are selected independently from C1 to C4, and either alkylene or hydroxylated alkylene. 12 The alkylene group is selected from any one of the alkylene group or the hydroxyl-substituted alkylene group, m+n=1~100, x+y=0~100, X is COOM' or SO3N', and M' and N' are independently selected from hydrogen, alkali metals or the formula NR 4’ (R 5’ (R) 6’ (R) 7’ At least one of the groups shown in ) and R 4’ R 5’ R 6’ R 7’ Each is independently selected from H and -(CH2). j OH or -(CH2) g Any one of CH3, j=1~5, g=0~7; Equation (3); In equation (3): R7 is C1 to C 30 A straight-chain or branched saturated or unsaturated alkyl-substituted aryl group, m1=0~30, n1=0~50, m2=0~30, m1+m2<60; R8 is a C1~C9 alkylene or hydroxyl-substituted alkylene or a single bond, M is selected from hydrogen, alkali metals and formula NR9(R 10 (R) 11 (R) 12 At least one of the groups shown in the diagram; R9, R 10 R 11 and R 12 Each is independently selected from H and -(CH2). p OH or -(CH2) q Any one of CH3, p = any integer from 1 to 5, q = any integer from 0 to 7.

2. The surfactant composition according to claim 1, characterized in that: Based on parts by weight, relative to 1 part of α-olefin sulfonate AOS, the surfactant composition contains 1 to 20 parts of betaine surfactant, 0.1 to 10 parts of polyether anionic surfactant and 90 to 100 parts of water.

3. The surfactant composition according to claim 1, characterized in that: Based on parts by weight, relative to 1 part of α-olefin sulfonate AOS, the surfactant composition contains 1 to 10 parts of betaine surfactant, 0.1 to 1 part of polyether anionic surfactant and 90 to 98 parts of water.

4. The surfactant composition according to claim 1, characterized in that: In equation (1), R1 is C8~C 22 alkyl groups, the alkali metal K It is sodium or potassium.

5. The surfactant composition according to claim 1, characterized in that: In equation (2): R6 is C8~C 25 R2 is any one of alkyl or alkenyl groups, where R2 is C2~C3. 22 The alkylene group, R5 is any one of C1 to C5 alkylene or hydroxy-substituted alkylene, R3 and R4 are each C1 to C3 alkylene, m+n=1~30, x+y=0~10.

6. The surfactant composition according to claim 1, characterized in that: In equation (3): R7 is C 12 ~C 24 Any one of alkyl or alkenyl groups or composed of C8 to C96 groups 12 Alkyl-substituted phenyl, where R8 is a C1-C7 alkylene or hydroxyl-substituted propylene group or a single bond.

7. The surfactant composition according to claim 1, characterized in that: In formula (3): M is selected from hydrogen, alkali metals, and formula NR9(R 10 (R) 11 (R) 12 At least one of the groups shown in the diagram; R9, R 10 R 11 and R 12 Each is independently selected from H and -(CH2). p OH or -(CH2) q Any of the CH3 groups, p=2, q=0 or 1.

8. The surfactant composition according to claim 7, characterized in that: M represents sodium or potassium, both alkali metals.

9. The surfactant composition according to claim 1, characterized in that: In equation (3): R7 is C 12 ~C 24 Alkyl or alkenyl groups or those composed of C8 to C96 groups 12 Alkyl-substituted phenyl; m1=0~10, n1=0~15, m2=1~15; R8 is a C1~C3 alkylene or hydroxyl-substituted propylene or a single bond.

10. The surfactant composition according to claim 1, characterized in that: In equation (3): R7 is C 12 ~C 16 Alkyl or alkenyl groups, m1=0~7, n1=2~12, m2=1~10.

11. The surfactant composition according to claim 1, characterized in that: In equation (3): R7 is C 12 ~C 14 Alkyl or alkenyl groups, m1=0~5, n1=4~10, m2=1~8.

12. The surfactant composition according to any one of claims 1 to 11, characterized in that: The betaine surfactant is prepared by the following method: Long-chain fatty acids or their esters are reacted with the desired amidating agent to obtain an intermediate; under a protective atmosphere, the obtained intermediate is mixed with ethylene oxide and reacted, and then, in the presence of a protective gas and a catalyst, ethylene oxide or propylene oxide is optionally added to continue the reaction to obtain a hydrocarbon-based polyoxyethylene ether; the obtained hydrocarbon-based polyoxyethylene ether is then reacted with an ionizing agent to obtain the betaine surfactant shown in formula (2).

13. The surfactant composition according to claim 12, characterized in that: The molar ratio of long-chain fatty acids or their esters:amining reagent:ionizing reagent is 1:(0.01~30):(0.01~40); and / or, The protective gas is an inert gas and / or nitrogen; and / or, The catalyst is at least one of alkali metal hydroxides.

14. The surfactant composition according to claim 12, characterized in that: The catalyst is barium hydroxide.

15. A method for preparing a surfactant composition according to any one of claims 1 to 14, comprising the step of mixing the α-olefin sulfonate AOS, the betaine surfactant, the polyether anionic surfactant, and water.

16. The preparation method according to claim 15, characterized in that: The mixing step ensures that the raw materials in the composition are completely dissolved.

17. An oil displacement agent comprising a surfactant composition and water, wherein the surfactant composition is any one of claims 1 to 14 or a surfactant composition prepared by the preparation method described in claim 15 or 16.

18. The oil displacement agent according to claim 17, characterized in that: The content of the surfactant composition in the oil displacement agent is 0.1–1 wt%; and / or, The water has a mineralization of 0–30000 mg / L, and / or, Ca 2+ and Mg 2+ The sum of their concentrations is 0–8000 mg / L.

19. The oil displacement agent according to claim 17, characterized in that: The content of the surfactant composition in the oil displacement agent is 0.3 to 0.5 wt%.

20. The use of a surfactant composition according to any one of claims 1 to 14, or a surfactant composition prepared by the preparation method according to claims 15 or 16, or an oil displacement agent according to any one of claims 17 to 19, in tertiary oil recovery.

21. The application according to claim 20, characterized in that: The oil extraction method is steam thermal recovery.

22. The application according to claim 20, characterized in that: It is used for tertiary oil recovery under conditions of 50–150℃ and salinity of 0–30000 mg / L.

23. The application of a surfactant composition according to any one of claims 1 to 14, or a surfactant composition prepared by the preparation method according to claims 15 or 16, or an oil displacement agent according to any one of claims 17 to 19, in enhancing oil recovery in oil fields.

Images