Surfactant composition for improving recovery efficiency through steam thermal recovery as well as preparation method and application of surfactant composition

Abstract

The invention belongs to the field of oilfield chemistry, and discloses a surfactant composition for improving recovery efficiency through tertiary oil recovery steam thermal recovery, and a preparation method and application thereof. The surfactant composition comprises alpha-olefin sulfonate (AOS) as shown in a formula (2), a betaine surfactant with a polyether fragment as shown in a formula (2), a polyether anionic surfactant as shown in a formula (3) and water, formula (3): # imgabs0 # R7O-(CH2CH2O) m1-(CH (CH3) CH2O) n1-(CH2CH2O) m2-R8COOM, and formula (4): (4): (4): (4): (4): (4): (4): (4): (5 The surfactant composition provided by the invention is suitable for tertiary oil recovery steam thermal recovery, has strong foaming ability, good foam thermal stability and relatively high salt resistance, is particularly stable when meeting divalent ions, can meet the recovery requirements of high-temperature and high-mineral-degree thickened oil, can reduce the viscosity of the thickened oil and extra-thickened oil, can reduce the interfacial tension, and can improve the recovery efficiency of the thickened oil and extra-thickened oil. And the recovery efficiency of thermal recovery of thickened oil is improved.

Description

Technical Field

[0001] The present invention belongs to the field of oilfield chemistry, and relates to a surfactant composition for oil production in high-temperature and high-salt heavy oil reservoirs. Specifically, it is a surfactant composition for enhanced oil recovery by steam thermal recovery in tertiary oil recovery, and its preparation method and application. Background Art

[0002] In recent years, after primary and secondary oil recoveries in major oilfields in China, they have entered the high water cut stage. How to improve the oil recovery rate and maximize the development of remaining reserves is a difficult problem faced by scientific researchers. Over the years, many enhanced oil recovery technologies have been proposed, including physical methods such as injecting gas (gas flooding, miscible flooding), using heat energy (steam flooding, hot water flooding); chemical methods such as polymer flooding, alkaline water flooding, surfactant flooding, alkaline / surfactant / polymer composite flooding; biological methods such as endogenous and exogenous microbial flooding are also being explored and developed.

[0003] Among them, steam foam is the earliest foam enhanced oil recovery technology applied in oilfields. Shell carried out steam foam flooding in the Kern River Oilfield in California, USA in 1976. Alpha olefin sulfonate (AOS) was used as the foaming agent. After 2 years of foam injection, the crude oil production increased significantly. After 5 years of foam injection, the crude oil production increase rate was 8.5 - 14% OOIP (original oil in place) (Patzek & Koinis, 1990). Unocal, a company under Chevron, also carried out steam foam flooding in the Guadalupe Field and Midway-Sunset Oilfield in California, USA in 1984 and 1985 respectively. Alpha olefin sulfonate (AOS) or alkyl toluene sulfonate (ATS), brine and nitrogen were injected together with steam. The production increase reaction was rapid. In the Midway-Sunset Oilfield, foam flooding was carried out for two years, and a total of 32,900 m3 of crude oil was produced (Mohammadi, et al., 1989) (Mohammadi & McCollum, 1989). Document CN101717627A discloses a low-tension foaming agent for improving the oil recovery rate in high-salt reservoirs and its preparation method. The main agent of the foaming agent described therein is alkyl dimethylamine ethylene lactone, sodium lauryl polyoxyethylene ether sulfate, and coconut oil acid monoethanolamine. However, its compatibility with formation water is general, and the temperature is only applicable below 120 °C. The examples are all at 50 °C and are not suitable for ultra-high temperature reservoirs.

[0004] Surfactants are common foaming agents. Surfactants adsorbed at the water-vapor interface prevent the rupture of foam through physicochemical actions such as electrostatic repulsion, steric resistance, and interfacial tension gradient. Therefore, many researchers are committed to finding surfactant formulations with high gas-liquid interfacial activity as efficient foaming agents. The Shengli Oilfield has tested the popular foreign alkyl polyoxyethylene ether sulfonate surfactant. However, for the conditions of the Shengli oil reservoir, this surfactant has poor effects and is not suitable for single use. It must be used in combination with other surfactants.

[0005] If the advantages of chemical flooding and foam flooding can be combined, the microemulsion foam technology combines the advantages of the above two technologies. It is hoped that while reducing the oil-water interfacial tension and improving the oil displacement efficiency, stable foam can be generated to increase the sweep efficiency. For a long time, the microemulsion technology has been committed to finding surfactant compositions that achieve the middle phase of oil and water, and then developing corresponding oil displacement technologies, which will provide new methods for enhancing oil recovery in old oilfields.

[0006] However, although surfactants have the ability to improve the performance of foam and reduce the oil-water interfacial tension at the same time, they are affected by environmental factors, including gas phase composition, oil phase composition, temperature, salinity, additives, etc. As a result, existing conventional surfactants often show contradictory properties in improving foam performance and reducing interfacial tension. That is, foam agents with good foaming performance have limited ability to reduce the oil / water interfacial tension, only reaching a few mN / m. According to the calculation formula of capillary force, the residual oil in the reservoir cannot be effectively cleaned at this interfacial tension; while the foam performance formed by low-tension surfactants is relatively poor, and it is difficult to form stable plugs. Moreover, existing foam agents precipitate when encountering divalent ions and cannot meet the requirements for the exploitation of high-temperature and high-salinity heavy oil.

[0007] Therefore, developing a surfactant suitable for steam thermal recovery in tertiary oil recovery, which has strong foaming ability, good foam thermal stability, and high salt resistance, especially being stable even when encountering divalent ions, can meet the requirements for the exploitation of high-temperature and high-salinity heavy oil, can reduce the viscosity of heavy oil and extra-heavy oil, further lower the interfacial tension, and further improve the oil recovery of steam thermal recovery of heavy oil, is a problem that needs to be solved. Summary of the Invention

[0008] The present invention relates to a surfactant composition for enhancing oil recovery in steam thermal recovery of tertiary oil recovery, belonging to the field of steam stimulation for enhancing oil recovery in heavy oil and extra-heavy oil. It mainly solves the problems existing in the existing foaming agents, such as poor thermal stability, precipitation in the presence of divalent ions, and inability to meet the requirements of high-temperature and high salinity heavy oil exploitation. The present invention provides a surfactant composition for enhancing oil recovery in steam thermal recovery, its preparation method and application. The present invention adopts a microemulsion foaming agent composition containing a betaine-type zwitterionic surfactant with a polyether segment, and the viscosity reduction rate for heavy oil can reach more than 99.5%. The foam performance is stable, belonging to a very efficient viscosity reduction system, and the oil recovery in heavy oil is improved. The surfactant composition of the present invention not only has temperature and salt tolerance properties, can withstand a maximum salinity of 30,000 mg / L, but also has strong interfacial activity, can reduce the interfacial tension between crude oil / water to 10 -2 mN / m, and the effect of enhancing oil recovery is remarkable.

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

[0010] R 1 -CH=CH-CH 2 -SO 3 K formula (1);

[0011] In formula (1): R 1 is an alkyl group of C 5 ~C 30 , and K is any metal ion selected from alkali metals;

[0012]

[0013] In formula (2): R 6 is selected from any one of alkyl groups and alkenyl groups of C 6 ~C 30 , and the said R 2 and R 5 are both independently selected from any one of alkylene groups and hydroxy-substituted alkylene groups of C 1 ~C 22 , R 3 and R 4 are independently selected from any one of alkylene groups and hydroxy-substituted alkylene groups of C 1 ~C 12 , m + n = 1 to 100, x + y = 0 to 100, X is COOM or SO 3 N, and M and N are independently selected from hydrogen, alkali metals or by formula NR 4’ (R5’ )(R 6’ )(R 7’ ) at least one of the groups shown, R 4’ 、R 5’ 、R 6’ 、R 7’ are each independently selected from H, -(CH 2 ) j OH or -(CH 2 ) g CH 3 any one of them, j = 1 to 5, g is any integer from 0 to 7;

[0014] R 7 O-(CH 2 CH 2 O)m 1 -(CH(CH 3 )CH 2 O)n 1 -(CH 2 CH 2 O) m2 -R 8 COOM Formula (3);

[0015] In formula (3): R 7 is an aryl group substituted by a straight-chain or branched-chain saturated or unsaturated hydrocarbon group of C 1 to C 30 , m1 = 0 to 30, n 1 = 0 to 50, m 2 = 0 to 30, m 1 + m 2 < 60; R 8 is an alkylene group or a hydroxy-substituted alkylene group or a single bond of C 1 to C 9 , M is selected from hydrogen, an alkali metal, and at least one of the groups shown by NR 9 (R 10 )(R 11 )(R 12 ); R 9 、R 10 、R 11 and R 12 are each independently selected from H, -(CH 2 ) p OH or -(CH 2 ) q CH 3 any one of them, p = 1 to 5, q is any integer from 0 to 7.

[0016] According to the present invention, the amounts of the respective components can be selected within a relatively wide range. In a preferred embodiment of the present invention, based on parts by mass, 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; more preferably,

[0017] based on parts by mass, 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 the formula (1), R 1 is an alkyl group of C 8 to C 22 , and the alkali metal K is sodium or potassium.

[0019] According to a preferred embodiment of the present invention, in the formula (2): R 6 is any one of an alkyl group or an alkenyl group of C 8 to C 25 , R 2 is an alkylene group of C 2 to C 22 , R 5 is any one of an alkylene group or a hydroxy-substituted alkylene group of C 1 to C 5 , R 3 4 1 3 and R 4 are each an alkylene group of C 1 to C 3 , m + n = 1 to 30, and x + y = 0 to 10.

[0020] According to a preferred embodiment of the present invention, in the formula (3): R 7 is any one of an alkyl group or an alkenyl group of C 12 to C 24 or a phenyl group substituted with an alkyl group of C 8 to C 12 , R 8 is an alkylene group of C 1 to C 7 or a hydroxy-substituted propylene group or a single bond.

[0021] According to a preferred embodiment of the present invention, in the formula (3): M is selected from at least one of hydrogen, an alkali metal, and a group represented by the formula NR 9 (R 10 )(R 11 )(R 12 ); R 9 , R 10 , R11 and R 12 are each independently selected from H, -(CH 2 ) p OH or -(CH 2 ) q CH 3 ; p = 2, q = 0 or 1; preferably, M is sodium or potassium in alkali metals, more preferably sodium.

[0022] In a more preferred embodiment of the present invention, in the formula (3): R 7 is an alkyl or alkenyl group of C 12 ~C 24 or a phenyl group substituted by an alkyl group of C 8 ~C 12 ; m 1 = 0 to 10, n 1 = 0 to 15, m 2 = 1 to 15; R 8 is an alkylene group or a hydroxy-substituted propylene group of C 1 ~C 3 or a single bond; further more preferably,

[0023] R 7 is an alkyl or alkenyl group of C 12 ~C 16 ; m 1 = 0 to 7, n 1 = 2 to 12, m 2 = 1 to 10; further more preferably, R 7 is an alkyl or alkenyl group of C 12 ~C 14 ; m1 = 0 to 5, n 1 = 4 to 10, m 2 = 1 to 8.

[0024] The surfactant composition of the present invention has good compatibility and may further contain other treatment agents commonly used in the art, such as foaming agents, small molecule organic substances (such as small molecule alcohols, small molecule amines, small molecule ethers, etc.), inorganic salts, inorganic bases and other oil recovery aids. The small molecule alcohol is selected from fatty alcohols of C 1 ~C 8 ; the small molecule amine is selected from C 1 ~C 8at least one of primary amines, secondary amines or tertiary amines; the inorganic salt AB is 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., where A is a metal ion such as Ca, Mg, Na, etc., and B is a halide salt, carbonate, bicarbonate, sulfate, sulfite, 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] The long-chain fatty acid or its ester reacts with the required amidating reagent to obtain an intermediate; under a protective atmosphere, the obtained intermediate is mixed and reacted with ethylene oxide, and then, in the presence of a protective gas and a catalyst, ethylene oxide or propylene oxide is optionally added and the reaction continues to obtain a hydrocarbyl polyoxyethylene ether; the obtained hydrocarbyl polyoxyethylene ether is then reacted with an ionizing reagent to obtain the betaine surfactant shown in formula (2).

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

[0028] In the present invention, ethylene oxide can be added in batches. For example, a part is added when reacting with the intermediate, and another part is added in the presence of a catalyst, or it can be added all at once when reacting with the intermediate and then continue to react in the presence of a catalyst.

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

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

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

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

[0033] According to the present invention, the molar ratio of the long-chain fatty acid or its ester: amidation reagent: ionization reagent can be selected within a relatively wide range. In a preferred embodiment of the present invention, the molar ratio of methyl long-chain fatty acid: amidation reagent: ionization reagent 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] The second aspect of the present invention is to provide a method for preparing the surfactant composition described in the first aspect, including the step of mixing the α-olefin sulfonate AOS, the betaine surfactant, the polyether anionic surfactant and water.

[0037] Preferably, the mixing step completely dissolves the raw materials in the composition.

[0038] The third aspect of the present invention is to provide an oil displacement agent, including a surfactant composition and water, where the surfactant composition is the surfactant composition described in the first aspect or the 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 the present invention, the salinity of the water is 0 - 30000 mg / L, and / or the sum of the concentrations of Ca 2+ and Mg 2+ is 0 - 8000 mg / L.

[0041] The surfactant composition of the present invention has good compatibility and can also contain other commonly used treatment agents in the art, such as foaming agents, small molecule organic substances (such as small molecule alcohols, small molecule amines, small molecule ethers, etc.), inorganic salts, inorganic bases and other oil recovery aids. The small molecule alcohol is selected from C 1 -C 8 fatty alcohols; the small molecule amine is selected from C 1 -C 8at least one of primary amines, secondary amines or tertiary amines; the inorganic salt AB is 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., where A is a metal ion such as Ca, Mg, Na, etc., and B is a halide salt, carbonate, bicarbonate, sulfate, sulfite, nitrate, etc.; the inorganic base is selected from at least one of alkali metal hydroxides, alkali metal carbonates or alkali metal bicarbonates.

[0042] The fourth aspect of the present invention is to provide an application of the surfactant composition described in the first aspect, or 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 recovery method is steam thermal recovery; more preferably,

[0044] for tertiary oil recovery under the conditions of a temperature of 50 - 150 °C and a salinity of 0 - 30000 mg / L.

[0045] The fifth aspect of the present invention is an application of the surfactant composition described in the first aspect, or the surfactant composition prepared by the preparation method described in the second aspect, or the oil displacement agent described in the third aspect in enhancing the crude oil recovery rate in an oilfield.

[0046] In the tertiary oil recovery working conditions, steam thermal recovery has a relatively high temperature. Steam thermal recovery in tertiary oil recovery has high requirements for surfactants to be heat-resistant and resistant to divalent salts. Generally, the anionic surfactants in the prior art cannot withstand temperatures above 90 °C. The betaine surfactant in the present invention has a polyether segment and the characteristics of an amphoteric surfactant, which is different from 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 applicable to oil reservoirs with a temperature of 80 - 250 °C, a salinity lower than 30000 mg / L, and a Ca 2+ +Mg 2+ concentration lower than 8000 mg / L. This surfactant composition forms a stable foam when mixed with nitrogen, air, carbon dioxide, and natural gas. Applied to the indoor test of the formation water foam system in the Shengli Oilfield, its interfacial tension reaches 10 -2 mN / m at 90 °C, and the viscosity reduction rate of the composition for Shengli heavy oil can reach more than 99.5% at 90 °C.

[0049] The surfactant composition of the present invention is suitable for steam thermal recovery in tertiary oil recovery, has strong foaming ability, good foam thermal stability, and also has high salt resistance. In particular, it can be stable even in the presence of divalent ions, can meet the requirements of high-temperature and high-salinity heavy oil exploitation, can reduce the viscosity of heavy oil and extra-heavy oil, reduce the interfacial tension, and improve the oil recovery rate of thermal recovery heavy oil. Detailed implementation mode

[0050] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that the following embodiments are only for further illustration of the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art to the present invention based on the content of the present invention still fall within the protection scope of the present invention.

[0051] In order to better understand the present invention, the content of the present invention will be further elaborated below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments.

[0052] The polyether carboxylate in the following embodiments of the present invention is prepared by an existing preparation method. Specific reference: Research on temperature-responsive viscoelastic surfactant. Petrochemical Technology, 2021(02): 144-149.

[0053] Sodium α-olefin sulfonate (AOS 14-16 ) is a conventional commercially available product.

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

[0055]

Example 1

[0056] 1. Preparation of surfactant composition

[0057] (1) Preparation of erucic acid amide carboxybetaine amphoteric surfactant (R 6 =C 21 , R 2 =C 2 , R 3 \R 4 =C 2 , R 5 =C 1 , m + n = 4)

[0058] Methyl erucate and the required amount of amidation reagent N,N-bis(2-hydroxyethyl)ethylenediamine were added to a reaction kettle, and the reaction was carried out at 145 °C for 7 hours. Then, a vacuum pump was turned on to remove the excess N,N-bis(2-hydroxyethyl)ethylenediamine, and the erucic acid acyl tertiary amine product was obtained. Then, while nitrogen was being passed through, the reactor equipped with a condensing device and a stirring device was heated to 150 °C. After heating for 40 minutes, ethylene oxide (2 moles) was added, and the temperature was maintained at 150 °C and stirred for 1 hour. The temperature was lowered to 80 °C, barium hydroxide was added as a catalyst, and the mixture was heated to 140 °C. The vacuum system was turned on, and dehydration was carried out under high vacuum for 1 hour. Then, the system was purged with nitrogen 4 times to remove the air in the system. Then, the reaction temperature of the system was adjusted to 165 °C, and ethylene oxide (2 moles) was slowly passed through. The alkoxylation reaction was carried out while controlling the pressure <0.80 MPa until the reaction was completed. The system was purged with nitrogen, and after cooling, it was neutralized and dehydrated to obtain erucic acid polyoxyethylene (m + n = 4) ether tertiary amine. Then, the required amount of sodium chloroacetate was added, and the reaction was carried out at 75 °C for 10 hours. After purification by recrystallization with absolute ethanol, a long-chain betaine surfactant was obtained; among them, the molar ratio of methyl erucate:N,N-bis(2-hydroxyethyl)ethylenediamine:sodium chloroacetate was 1:1.5:1.5.

[0059] (2) Under normal temperature and pressure, 10 g of sodium α-olefin sulfonate (AOS 14-16 ), 10 g of erucic acid amide carboxybetaine amphoteric surfactant, and 6.8 g of polyether carboxylate RO-EO 3 -PO 8 -EO 10 -COONa (where R is C 12 ~C 14 ) were added to a reaction kettle, and then 973.2 g of local tap water was added. The mixture was stirred thoroughly for 30 min until completely dissolved, and thus a surfactant composition was obtained.

[0060] Performance determination: Under the conditions of a salinity of 120,000 mg / L and a Ca 2+ +Mg 2+ concentration of 3000 mg / L, a solution of 0.3 wt% surfactant composition was prepared.

[0061] 2. Performance evaluation

[0062] (1) Viscosity test

[0063] The surfactant composition was diluted to a concentration of 0.3%, and then a solution was prepared with Shengli West crude oil (the viscosity of the crude oil at 50 °C was 8000 mP·s) at an oil-water ratio of 7:3. The solution was aged in an oven at 90 °C for 1 h, stirred at a constant temperature of 250 r / min for 2 min, and then the viscosity was measured. Test conditions: Using a Thermo-type viscometer, at 90 °C, the rotation speed was 7.34S -1Under the conditions, the viscosity of crude oil (heavy oil) was measured with the surfactant composition at a concentration of 0.3%. The results of the 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) Interfacial tension evaluation

[0065] Using a TX-500C rotary drop interfacial tension meter produced by the University of Texas in the United States, and according to Method SY / T5370-1999, the interfacial tension between the surfactant composition at a concentration of 0.15 wt% and dehydrated crude oil from Shengli Oilfield was measured at 90 °C and a rotation speed of 4500 revolutions per minute. The results are shown in Table 2.

[0066] (3) Oil displacement experiment evaluation

[0067] Using a QY-C12 type automatic core oil displacement device produced by Jiangsu Hua'an Company, at a temperature of 90 °C, a pressure of 5 MPa, and a concentration of the surfactant composition of 0.3%. A sand-packed tube with a diameter of Φ38×300 mm was used, and the water permeability was 2.43 darcies. First, water flooding was carried out until the water cut reached 98%. After the water flooding ended, 0.5 pv (core pore volume) of the oil displacement agent (surfactant composition) at a concentration of 0.3 wt% was injected, and then water flooding was carried out until the water cut reached 100%. The results of improving the crude oil recovery rate are shown in Table 2.

[0068] In the present invention, the components and ratios of the surfactants in the following examples and comparative examples are shown in Table 1. Unless otherwise specified, the remaining conditions are the same as those in Example 1.

[0069]

Example 2

[0070] Raw materials: 10 g of α-olefin sulfonate (AOS) of C 14 ~C 16 , 15.5 g of hexadecanamide sulfobetaine (R 14-16 = C 6 , R 15 = C 2 , R 2 , R 3 \R 4 = C 2 , R 5 = C 2 , m + n = 6), 4.5 g of polyether carboxylate RO-PO 8 -EO 6 -COONa (where R is C 12 ~C 14 ), and 970 g of local tap water were used to obtain a surfactant composition.

[0071] The raw materials and preparation process were referred to

Example 1

[0072] Preparation steps: At normal temperature and pressure, add 10 g of sodium α-olefin sulfonate (AOS 14-16 ), 15.5 g of hexadecanamide sulfobetaine, and 4.5 g of polyether carboxylate ROPO 8 -EO 6 -COONa into the reaction kettle, and then add 970 g of local tap water, and stir well for 30 min until completely dissolved.

[0073] Performance measurement: Under the conditions of a salinity of 200000 mg / L and a Ca 2+ +Mg 2+ concentration of 3000 mg / L, prepare a solution of a surfactant composition with a concentration of 0.3 wt%.

[0074]

Example 3

[0075] The synthesis method of the betaine surfactant with a polyether segment in Example 3 (R 6 =C 21 , R 2 =C 3 , R 3 \R 4 =C 2 , R 5 =C 1 , m + n = 4, x + y = 2) is as follows:

[0076] Add methyl erucate and the required amount of amidation reagent N,N-bis(2-hydroxyethyl)propylenediamine into the reaction kettle, react at 145 °C for 7 hours, turn on the vacuum pump to remove the excessive N,N-bis(2-hydroxyethyl)ethylenediamine, and obtain the erucic acid acyl tertiary amine product. Then, while heating to 150 °C while passing nitrogen into the reactor equipped with a condensing device and a stirring device, after heating for 40 minutes, add ethylene oxide (4 moles), maintain the temperature at 150 °C and stir for 1 hour. Cool down to 80 °C, add barium hydroxide as a catalyst, heat to 140 °C, turn on the vacuum system, dehydrate under high vacuum for 1 hour, then purge with nitrogen 4 times to remove the air in the system. Then, adjust the reaction temperature of the system to 165 °C and slowly pass in propylene oxide (2 moles), control the pressure <0.80 MPa for alkoxylation reaction until the reaction ends, purge the system with nitrogen, neutralize and dehydrate after cooling to obtain erucic acid polyoxyethylene polyoxypropylene (m + n = 4, x + y = 2) ether tertiary amine, and then add the required amount of sodium chloroacetate, react at 75 °C for 10 hours, and obtain the long-chain betaine surfactant after recrystallization and purification with absolute ethanol; among them, the molar ratio of methyl erucate:N,N-bis(2-hydroxyethyl)propylenediamine:sodium chloroacetate is 1:1.5:1.6.

[0077] Raw materials: C 14 ~C 16Sodium α-olefin sulfonate (AOS 14-16 ) 10 g, erucamide carboxybetaine 10 g (R 6 =C 21 , R 2 =C 3 , R 3 \R 4 =C 2 , R 5 =C 1 , m + n = 4, x + y = 2), polyether carboxylate RO-PO 8 -EO 6 -COONa (where R is C 12 ~C 14 ), 6.5 g, local tap water 973.5 g, to obtain a surfactant composition.

[0078] Preparation steps: At normal temperature and pressure, add 10 g of sodium α-olefin sulfonate (AOS 14-16 ), 10 g of erucamide carboxybetaine, and 6.5 g of polyether carboxylate RO-PO 8 -EO 6 -COONa into the reaction kettle, and then add 973.5 g of local tap water, and stir well for 30 min until completely dissolved.

[0079] Performance measurement: Under the conditions of salinity 150,000 mg / L and Ca 2+ +Mg 2+ concentration 5000 mg / L, prepare a 0.3 wt% solution.

[0080]

Example 4

[0081] Raw materials: C 14 ~C 16 sodium α-olefin sulfonate (AOS 14-16 ), 10 g, nonanamide carboxybetaine 10 g (R 6 =C 8 , R 2 =C 2 , R 3 \R 4 =C 2 , R 5 =C 1 , m + n = 4), polyether carboxylate RO-EO 3 -PO 8 -EO 10 COONa (where R is C 12 ~C 14 ), 6.8 g, local tap water 973.2 g, to obtain a surfactant composition.

[0082] Preparation steps: At normal temperature and pressure, add 10 g of sodium α-olefin sulfonate (AOS 14-16 ), 10 g of nonanamide carboxybetaine, and 6.5 g of polyether carboxylate RO-EO 3 -PO 8 -EO 10 -COONa into the reaction kettle, and then add 973.5 g of local tap water, and stir well for 30 min until completely dissolved.

[0083] Performance measurement: Under the conditions of a salinity of 150,000 mg / L and a Ca 2+ +Mg 2+ concentration of 2,000 mg / L, prepare a 0.3 wt% solution.

[0084]

Example 5

[0085] Use RO-PO 8 -EO 8 -COONa to replace RO-EO in Example 1 3 -PO 8 -EO 10 -COONa, and the others are the same as in Example 1 to obtain the surfactant composition in this example.

[0086]

Example 6

[0087] Use RO-EO 6 -COONa to replace RO-EO in Example 1 3 -PO 8 -EO 10 -COONa, and the others are the same as in Example 1 to obtain the surfactant composition in this example.

[0088]

Example 7

[0089] Use the long-chain betaine surfactant R 6 =C 17 to replace R in Example 1 6 =C 21 , and the others are the same as in Example 1 to obtain the surfactant composition in this example.

[0090]

Example 8

[0091] Use the same raw materials as in Example 1, the difference is that the ratio of the surfactant composition is different, and RO-PO 8 -EO 8 -COONa is used to replace RO-EO in Example 1 3 -PO 8 -EO 10-COONa, as shown in Table 1.

[0092]

Comparative Example 1

[0093] Same as

Example 3

[0094] Performance measurement: Under the conditions of salinity 120,000 mg / L and Ca 2+ +Mg 2+ concentration 3,000 mg / L, a 0.3% surfactant composition solution was prepared.

[0095] Performance measurement tests were carried out in the same way as in

Example 1

[0096]

Comparative Example 2

[0097] Same as

Example 3

[0098] Performance measurement: Under the conditions of salinity 150,000 mg / L and Ca 2+ +Mg 2+ concentration 2,000 mg / L, a 0.3% surfactant composition solution was prepared.

[0099] Performance measurement tests were carried out in the same way as in

Example 1

[0100]

Comparative Example 3

[0101] According to the method described in Patent CN101717627A, the preparation steps were as follows: At 80°C, 30 g of alkyldimethylamine ethoxylate, 15 g of sodium lauryl polyoxyethylene sulfate, and 15 g of coconut oil monoethanolamine were added to a reaction kettle, and then 40 g of local tap water was added. After stirring thoroughly for 30 min until completely dissolved, a surfactant composition was obtained.

[0102] Performance measurement: Under the conditions of salinity 200,000 mg / L and Ca 2+ +Mg 2+Under the condition of a concentration of 3000 mg / L, it is formulated into a 0.3 wt% solution.

[0103]

Comparative Example 4

[0104] According to the method described in Patent CN106590607B, the preparation steps are as follows: Add 15.85 grams of lauryl polyoxypropylene (8) ether acetic acid (LAPO 8 CH 2 COOH) to the reaction kettle, add an appropriate amount of local tap water to dissolve it, and then add an appropriate amount of sodium hydroxide to obtain sodium lauryl polyoxypropylene (8) ether acetate (LAPO 8 CH 2 COONa); then add 10 grams of C 14 ~C 16 α-olefin sulfonate (AOS 14-16 ), 5 grams of 3-sulfopropyl dodecyldimethyl betaine, and then add sufficient local tap water to 100 grams to formulate a 30 wt% solution. Stir well for 30 minutes until completely dissolved to obtain the composition ZY-1. The product is a light yellow paste.

[0105] Performance measurement: Under the conditions of a salinity of 200000 mg / L and a Ca 2+ +Mg 2+ concentration of 3000 mg / L, it is formulated into a 0.3 wt% solution.

[0106]

Comparative Example 5

[0107] The difference from

Example 1

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

[0109] R 1 -CH=CH-CH 2 -SO 3 K Formula (1);

[0110]

[0111] R 7 O-(CH 2 CH 2 O)m 1 -(CH(CH 3 )CH 2 O)n 1 -(CH2 CH 2 O) m2 -R 8 COOM Formula (3).

[0112] Table 1

[0113]

[0114]

[0115] Table 2 Performance Evaluation of Oil Displacement Agents in Examples and Comparative Examples

[0116]

[0117]

[0118] It can be seen from the comparison between Comparative Example 1 and Comparative Example 2 and Example 1 that the method of separately adding ethylene oxide and propylene oxide instead of adding them together in the present invention unexpectedly reduces the viscosity (mPa·s) and interfacial tension, and further improves the oil recovery rate;

[0119] It can be seen from the comparison between Example 1 and Comparative Example 3 that the present invention uses three specific surfactants in the general formula to cooperate synergistically, significantly reducing the viscosity (mPa·s) and interfacial tension, and significantly improving the oil recovery rate.

[0120] Especially in Examples 5, 6, and 7, it can be seen that under the conditions of the preferred Component 1: α-olefin sulfonate AOS and Component 2: C21 betaine amphoteric surfactant, changing the numbers of EO and PO of the polyether anionic surfactant in the present invention can further reduce the viscosity (mPa·s) and interfacial tension, and further improve the oil recovery rate.

[0121] It should be noted that the above-described embodiments are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described by referring to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words rather than limiting words. Modifications can be made to the present invention within the scope of the claims of the present invention as stipulated, and the present invention can be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same functions.

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

[0123] When this specification uses prefixes such as "well-known to those skilled in the art", "prior art", or similar terms to introduce materials, substances, methods, steps, devices, or components, etc., the objects introduced by such prefixes cover those commonly used in the art at the time of filing of this application, but also include those that are not commonly used at present but will become recognized in the art as suitable for similar purposes.

[0124] In the ranges disclosed in this application document, the endpoints and any values are not limited to the exact ranges or values. 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, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein. In the following, in principle, the various technical solutions can be combined with each other to obtain new technical solutions, and this should also be regarded as specifically disclosed herein.

[0125] In the context of this specification, any matters or things not mentioned, except as explicitly stated, shall directly apply those known in the art without any change.

[0126] Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or technical ideas thus formed shall be regarded as part of the original disclosure or original record of the present invention, and shall not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider such combination to be clearly unreasonable.

Claims

1. A surfactant composition comprising an α-olefin sulfonate AOS represented by formula (1), a betaine surfactant having a polyether segment represented by formula (2), a polyether anionic surfactant represented by formula (3), and water; R 1 -CH=CH-CH 2 -SO 3 Formula (1) of K; In formula (1): R 1 C 5 ~C 30 An alkyl group, K is any metal ion selected from alkali metals; In formula (2): R 6 Selected from C 6 ~C 30 Any of the alkyl and alkenyl groups, R 2 and R 5 All independently selected from C 1 ~C 22 alkylene, alkylene substituted with hydroxyl, R 3 and R 4 Independently selected from C 1 ~C 12 Any one of alkylene, hydroxyl substituted alkylene, m+n=1~100, x+y=0~100, X is COOM' or SO 3 N', M' and N' are independently selected from hydrogen, an alkali metal or a 4’ (R 5’ )(R 6’ )(R 7’ ) shown in at least one of the groups, R 4’ , R 5’ , R 6’ , R 7’ Each independently selected from H, -(CH 2 ) j OH or -(CH 2 ) g CH 3 Any one of, j = 1 to 5, g = any integer from 0 to 7; R 7 O-(CH 2 CH 2 O)m 1 -(CH(CH 3 )CH 2 O)n 1 -(CH 2 CH 2 O) m2 -R 8 COOM of formula (3); In formula (3): R 7 C 1 ~C 30 A linear or branched saturated hydrocarbon or unsaturated hydrocarbon substituted aromatic group, m 1 =0~30,n 1 =0~50,m 2 =0~30,m 1 +m 2 <60; R 8 C 1 ~C 9 Alkylene or hydroxy substituted alkylene or single bond, M is selected from hydrogen, alkali metal and formula NR 9 (R 10 )(R 11 )(R 12 ) shown in at least one of the groups; R 9 , R 10 , R 11 and R 12 Each independently selected from H, -(CH 2 ) p OH or -(CH 2 ) q CH 3 Any one of the following, p=any integer from 1 to 5, q=any integer from 0 to 7.

2. The surfactant composition according to claim 1, Features: In parts by mass, 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; preferably, 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 relative to 1 part of α-olefin sulfonate AOS in parts by mass.

3. The surfactant composition according to claim 1, Features: In formula (1), R 1 C 8 ~C 22 The alkali metal K is sodium or potassium.

4. The surfactant composition according to claim 1, Features: In formula (2): R 6 C 8 ~C 25 Any of the alkyl or alkenyl groups, R 2 C 2 ~C 22 The alkylene group, R 5 C 1 ~C 5 Any one of alkylene or hydroxy substituted alkylene, R 3 and R 4 Each is C 1 ~C 3 Alkylene, m+n=1~30, x+y=0~10.

5. The surfactant composition according to claim 1, Features: In formula (3): R 7 C 12 ~C 24 Any one of the alkyl or alkenyl groups or C 8 ~C 12 Alkyl substituted phenyl, R 8 C 1 ~C 7 The alkylene or hydroxyl substituted propylene or is a single bond; and / or, M is selected from hydrogen, alkali metal, formula NR 9 (R 10 )(R 11 )(R 12 ) shown in at least one of the groups; R 9 , R 10 , R 11 and R 12 Each independently selected from H, -(CH 2 ) p OH or -(CH 2 ) q CH 3 Any one of the following, p=2, q=0 or 1; preferably, M is sodium or potassium among alkali metals, more preferably sodium.

6. The surfactant composition according to claim 1, Features: In formula (3): R 7 C 12 ~C 24 Alkyl or alkenyl or C 8 ~C 12 Alkyl substituted phenyl; m 1 =0~10,n 1 =0~15,m 2 =1~15; R 8 C 1 ~C 3 The alkylene or hydroxyl substituted propylene or is a single bond; preferably, R 7 C 12 ~C 16 The alkyl or alkenyl group, m 1 =0~7,n 1 =2~12,m 2 =1 to 10; more preferably, R 7 C 12 ~C 14 The alkyl or alkenyl group, m 1 =0~5,n 1 =4~10,m 2 =1~8.

7. The surfactant composition according to any one of claims 1 to 6, Features: The betaine surfactant is prepared by the following method: A long-chain fatty acid or its ester is reacted with a desired amidation agent to obtain an intermediate; the obtained intermediate is mixed with ethylene oxide under a protective atmosphere for reaction, and then ethylene oxide or propylene oxide is optionally added in the presence of a protective gas and a catalyst to continue the reaction to obtain a hydrocarbon polyoxyethylene ether; and the obtained hydrocarbon polyoxyethylene ether is reacted with an ionizing agent to obtain a betaine surfactant shown in formula (2).

8. The surfactant composition according to claim 7, Features: The molar ratio of long-chain fatty acid or its ester: amidating agent: ionizing agent 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, preferably barium hydroxide.

9. A method for preparing the surfactant composition according to any one of claims 1 to 8, comprising the step of mixing the α-olefin sulfonate AOS, the betaine surfactant, the polyether anionic surfactant and water; Preferably, the mixing step allows complete dissolution of the raw materials in the composition.

10. An oil-displacing agent comprising a surfactant composition and water, wherein the surfactant composition is the surfactant composition according to any one of claims 1 to 8 or the surfactant composition prepared by the preparation method according to claim 9.

11. The oil-displacing agent according to claim 10, Features: The content of the surfactant composition in the oil displacing agent is 0.1 to 1 wt%, preferably 0.3 to 0.5 wt%; and / or, The mineralization of the water is 0 to 30,000 mg / L, and / or Ca 2+ and Mg 2+ The sum of the concentrations is 0~8000mg / L.

12. Use of the surfactant composition according to any one of claims 1 to 8, the surfactant composition obtained by the preparation method according to claim 9, or the oil displacement agent according to any one of claims 10 to 11 in tertiary oil recovery, Preferably, the oil recovery method is steam thermal recovery; more preferably, Used for tertiary oil recovery at temperatures of 50-150°C and salinity of 0-30000 mg / L.

13. Use of the surfactant composition according to any one of claims 1 to 8, the surfactant composition obtained by the preparation method according to claim 9, or the oil displacement agent according to any one of claims 10 to 11 in improving crude oil recovery in an oil field.

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