Dimeric alcohol ether carboxylate surfactant and preparation method therefor, integrated fracturing-displacement system, and use

Abstract

The present invention relates to the technical field of shale oil development. Disclosed are a dimeric alcohol ether carboxylate surfactant and a preparation method therefor, an integrated fracturing-displacement system, and a use. The dimeric alcohol ether carboxylate surfactant comprises a structural unit A shown in formula (a), a structural unit B shown in formula (b), a structural unit C shown in formula (c), and a structural unit D shown in formula (d), wherein R is selected from one or more of H and C1-C10, m is 5-50, n is 5-50, and M is selected from Na and / or K. The dimeric alcohol ether carboxylate surfactant is applied to an integrated fracturing-displacement system, and can increase the recovery rate especially in a shale oil reservoir.

Description

Dipolyol ether carboxylate surfactant, preparation method thereof, pressure-driven integrated system and application thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application No. 202311221664.6 filed on September 20, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the technical field of shale oil development, and in particular to a dimer alcohol ether carboxylate surfactant, a preparation method thereof, and a pressure-drive integrated system and application thereof. Background Art

[0004] The development of shale oil can be divided into three stages: the shale oil exploration and discovery stage, which focused on finding reservoirs in mudstone fractures and saw annual shale oil production of less than 100,000 tons. The stage of understanding and technological breakthroughs in shale oil development shifted the focus to the dolomite and siltstone intervals of the middle Bakken Formation. With the successful application of horizontal wells and hydraulic fracturing, production rapidly increased. The rapid development stage of shale oil, characterized by persistently low gas prices, saw companies previously engaged in shale gas exploration and development turn to shale oil. Operations and production in the Bakken shale area increased rapidly, reaching a peak annual production of over 500 million tons. Continuous scientific and technological progress is key to the success of shale oil research and development. The integrated utilization of horizontal wells, hydraulic fracturing, and supporting technologies has enabled commercial shale oil and gas production. Production technologies, such as "well factories," have reduced the operating and management costs of shale oil and gas development, and continuous technological innovation has improved the efficiency of shale oil and gas exploration and development.

[0005] Shale oil development is also a key strategic direction for China's future oil and gas development. China's continental shale oil differs from North American marine shale oil in terms of definition, development environment, geological characteristics, some extraction methods, and evaluation standards. Simply copying North American technologies is not an option, and achieving large-scale, cost-effective development faces significant challenges. North American marine shale oil reservoirs are thicker and more continuous, located within the light oil-condensate window, with relatively high gasoline content and high formation energy. Utilizing horizontal wells and fracturing techniques, single wells can achieve high initial and cumulative production, enabling platform-based, factory-like production, allowing for rapid and cost-effective scale-up. China's continental shale oil reservoirs exhibit significant lateral variation and a relatively low degree of thermal evolution. Combined with the relatively high wax content and thin reservoir thickness of continental crude oil, these reservoirs present inherent limitations in terms of formation energy, daily production per well, and cumulative production per well. In particular, Daqing Gulong shale oil, with its well-developed lamellar structure, high clay content, nanoscale porosity, and poor fluidity and compressibility, differs significantly from shale oil sources both domestically and internationally. This makes it impossible to simply replicate successful development experiences both domestically and internationally, as mature theories and technologies are lacking. Horizontal well fracturing technology is key to the efficient development of shale oil. Fracturing fluids are a crucial component of fracturing technology, and their performance plays a crucial role in the operation. To date, the use of synthetic polymer water-based fracturing fluid systems in China has primarily focused on proppants with coarse particles and high sand-to-sand ratios. These systems can, to a certain extent, create high-conductivity primary fractures, reducing resistance to shale oil flow to the bottomhole, thereby increasing shale oil well production. To enhance shale oil reservoir recovery, previous studies have attempted to inject conventional surfactants, including anionic, cationic, and nonionic surfactants, into the reservoirs. While these methods have reduced the shale oil-water interfacial tension to some extent, the improvement in recovery has been limited.

[0006] To this end, in order to address the problems of low primary recovery rate and rapid production decline in pure shale oil reservoirs, it is necessary to design and develop an integrated pressure-drive composite system that can form a middle-phase microemulsion and has the functions of sand carrying, fracture creation and flushing. By highly matching the nano-scale particle size of the middle-phase microemulsion with the pores of pure shale, the effect of imbibition displacement and oil washing can be improved, thereby achieving the goal of significantly increasing the recovery rate of pure shale oil reservoirs.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to overcome the defect of low recovery rate in pure shale reservoirs in the prior art, and provide a dimer alcohol ether carboxylate surfactant and its preparation method and a pressure-driven integrated system and application. The dimer alcohol ether carboxylate surfactant is applied to the pressure-driven integrated system, especially to improve the recovery rate in pure shale reservoirs.

[0009] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a dimer alcohol ether carboxylate surfactant, wherein the preparation method comprises the following steps:

[0010] (1) reacting a 2,5-dialkyl-1,4-hydroquinone monomer represented by formula (A) with propylene oxide to produce a dialkyl-p-phenylene polyoxypropyl ether represented by formula (I);

[0011] Wherein, R is selected from H and C1-C 10 One or more of;

[0012] In formula (I), m is 5-50;

[0013] (2) reacting the dialkyl-p-phenylene polyoxypropyl ether represented by formula (I) with ethylene oxide to generate the dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II);

[0014] Wherein, m is 5-50, n is 5-50;

[0015] (3) reacting the dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II) with thionyl chloride to generate a chlorohydrin ether represented by formula (III);

[0016] (4) treating the chlorohydrin ether represented by formula (III) with NaH to obtain a dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV);

[0017] (5) hydrolyzing the dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV) with MOH to obtain 2,5-dialkyl-1,4-p-phenylene polyoxyalkylene ether malonate tetrasalt represented by formula (V);

[0018] wherein M is selected from Na and / or K.

[0019] The second aspect of the present invention provides a dimer alcohol ether carboxylate surfactant prepared by the aforementioned preparation method.

[0020] The third aspect of the present invention provides a pressure-driven integrated system, wherein the pressure-driven integrated system includes a main surfactant, and the main surfactant is the aforementioned dimer alcohol ether carboxylate surfactant.

[0021] A fourth aspect of the present invention provides an application of the aforementioned integrated pressure-drive system in shale oil reservoirs.

[0022] Through the above technical solution, the present invention provides an integrated pressure-drive system. By using a 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasalt dimerol ether carboxylate surfactant as a main surfactant, and mainly adjusting the non-ionic segment length and alkyl chain length of polyoxyethylene ether (EO) and polyoxypropylene ether (PO) in the main surfactant, and the type and ratio of the co-surfactant and the polymer, the integrated pressure-drive system forms a high-viscosity sand-carrying fracturing fluid system when prepared on the ground, which can greatly improve the efficiency of oil absorption and washing. The washing and flushing system has both sand-carrying fracture creation and washing functions, forming an integrated pressure-drive development method, which is suitable for application in the efficient development of pure shale oil reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 shows the oil-water interfacial tension performance of the pressure-drive integrated system prepared in Example 1 of the present invention under the conditions of the Daqing Gulong shale reservoir;

[0024] FIG2 shows the emulsification performance of the integrated pressure-drive system prepared in Example 1 of the present invention under the conditions of the Daqing Gulong shale reservoir;

[0025] FIG3 shows the sand-carrying performance of the integrated pressure-drive system prepared in Example 1 of the present invention under the conditions of the Daqing Gulong shale reservoir;

[0026] FIG4 shows the imbibition performance of the integrated pressure-drive system, clean water, emulsion thickener, and associative fracturing fluid prepared in Example 1 of the present invention under the conditions of the Daqing Gulong shale reservoir;

[0027] FIG5 is a fluid discharge curve of the integrated pressure-drive system prepared in Example 1 of the present invention after fracturing in the Guye YH-Q4 well;

[0028] FIG6 is a fluid discharge curve of the high-viscosity guar gum system of Comparative Example 1 after fracturing in the Guye EH-Q4 well. DETAILED DESCRIPTION

[0029] The endpoints of the ranges and any values ​​disclosed herein 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 endpoints of each range, the endpoints of each range and 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 to be specifically disclosed herein.

[0030] As mentioned above, the first aspect of the present invention provides a method for preparing a dimer alcohol ether carboxylate surfactant, wherein the preparation method comprises:

[0031] (1) reacting a 2,5-dialkyl-1,4-hydroquinone monomer represented by formula (A) with propylene oxide to produce a dialkyl-p-phenylene polyoxypropyl ether represented by formula (I);

[0032] Wherein, R is selected from H and C1-C 10 One or more of;

[0033] In formula (I), m is 5-50;

[0034] (2) reacting the dialkyl-p-phenylene polyoxypropyl ether represented by formula (I) with ethylene oxide to generate the dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II);

[0035] Wherein, m is 5-50, n is 5-50;

[0036] (3) reacting the dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II) with thionyl chloride to generate a chlorohydrin ether represented by formula (III);

[0037] (4) treating the chlorohydrin ether represented by formula (III) with NaH to obtain a dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV);

[0038] (5) hydrolyzing the dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV) with MOH to obtain 2,5-dialkyl-1,4-p-phenylene polyoxyalkylene ether malonate tetrasalt represented by formula (V);

[0039] wherein M is selected from Na and / or K.

[0040] According to the present invention, in step (1), the molar ratio of the 2,5-dialkyl-1,4-hydroquinone monomer represented by formula (A) to propylene oxide is 1:2m.

[0041] According to the present invention, in step (2), the molar ratio of the dialkyl-p-phenylene polyoxypropyl ether represented by formula (I) to ethylene oxide is 1:2n.

[0042] According to the present invention, in step (3), the molar ratio of the dialkyl-p-phenylenedioxypropyl-polyoxyethylene ether represented by formula (II) to thionyl chloride is 1:(6-8).

[0043] According to the present invention, in step (4), the molar ratio of the chlorohydrin ether represented by formula (III) to NaH is 1:(2-5).

[0044] According to the present invention, in step (5), the molar ratio of the dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV) to MOH is 1:(2-5).

[0045] According to the present invention, in step (1) and step (2), the reaction conditions include: the reaction is carried out in a high-pressure reactor at a temperature of 120-160° C., and the reactor pressure is maintained at 0.2-0.4 MPa.

[0046] According to the present invention, in step (3), the reaction conditions include: the dropwise addition rate of thionyl chloride is 0.1-0.3 mol / hour, the temperature is 20-40°C, the reaction time is 0.8-2 hours, and after the dropwise addition is completed, the temperature is gradually raised to 70-90°C, and the reaction time is 3-5 hours.

[0047] According to the present invention, in step (4), the reaction conditions include: temperature of 60-80° C., and reaction time of 5-6 hours.

[0048] According to the present invention, in step (5), the temperature is 60-80° C. and the reaction time is 9-10 hours.

[0049] According to a preferred embodiment of the present invention, a method for preparing a dimer alcohol ether carboxylate surfactant comprises:

[0050] 2,5-dialkyl-1,4-hydroquinone and propylene oxide react to generate dialkyl-p-phenylene polyoxypropyl ether represented by formula (I), the dialkyl-p-phenylene polyoxypropyl ether represented by formula (I) reacts with ethylene oxide to generate dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II), the dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II) reacts with thionyl chloride to generate chlorohydrin ether represented by formula (III), the chlorohydrin ether represented by formula (III) reacts with NaH to obtain dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV), and then hydrolyzes with NaOH to obtain the final product 2,5-dialkyl-1,4-p-phenylene polyoxyalkylene ether malonate tetrasalt represented by formula (V).

[0051] The second aspect of the present invention provides a dimer alcohol ether carboxylate surfactant prepared by the aforementioned preparation method.

[0052] According to the present invention, the dimer alcohol ether carboxylate surfactant comprises structural unit A, structural unit B, structural unit C and structural unit D;

[0053] The structural unit A has a structure represented by formula (a), the structural unit B has a structure represented by formula (b), the structural unit C has a structure represented by formula (c), and the structural unit D has a structure represented by formula (d);

[0054] Wherein, in formula (a), R is selected from H and C1-C 10One or more of;

[0055] In formula (b), m is 5-50;

[0056] In formula (c), n is 5-50;

[0057] In formula (d), M is selected from Na and / or K.

[0058] According to the present invention, preferably, in formula (a), R is selected from H, CH3, C2H5, C3H7, C4H9, C5H 11 and C6H 13 One or more of .

[0059] According to the present invention, in formula (b), preferably, m is 20-40.

[0060] According to the present invention, in formula (c), preferably, n is 5-10.

[0061] According to the present invention, in formula (d), preferably, M is Na.

[0062] According to the present invention, the dimer alcohol ether carboxylate surfactant has the structural formula shown in formula (V):

[0063] The third aspect of the present invention provides a pressure-driven integrated system, wherein the pressure-driven integrated system includes a main surfactant, and the main surfactant is the aforementioned dimer alcohol ether carboxylate surfactant.

[0064] According to the present invention, preferably, the dimer alcohol ether carboxylate surfactant is 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate.

[0065] According to the present invention, the integrated pressure-drive system further contains a polymer with a concentration of 1500 mg / L-5000 mg / L.

[0066] According to the present invention, the polymer is selected from one or more of AMPS (2-acrylamido-2-methylpropanesulfonic acid), guar gum and its modified derivatives. In the integrated pressure-drive system of the present invention, the polymer can be AMPS heat-resistant and salt-resistant polymer or guar gum and its modified derivatives in the relevant field. The specific type, molecular weight and dosage of the polymer need to be determined according to the reservoir temperature conditions. When the reservoir temperature is less than 100°C, AMPS heat-resistant and salt-resistant polymer is selected; when the reservoir temperature is greater than 100°C, guar gum and its modified derivatives are selected, thereby ensuring that the integrated pressure-drive system can effectively carry sand and create fractures during the construction and transformation of pure shale reservoirs.

[0067] According to the present invention, the pressure-driven integrated system further includes a co-surfactant; preferably, based on the total weight of the pressure-driven integrated system, the content of the main surfactant is 0.05-0.5 weight%, and the content of the co-surfactant is 0.01-0.5 weight%; more preferably, based on the total weight of the pressure-driven integrated system, the content of the main surfactant is 0.3-0.5 weight%, and the content of the co-surfactant is 0.1-0.3 weight%.

[0068] According to the present invention, the co-surfactant is selected from one or more of internal olefin sulfonate (IOS), alkylbenzene sulfonate (ABS), α-olefin sulfonate (AOS), and triethylenetetramine (TETA). In the integrated pressure-driven system of the present invention, one or more of internal olefin sulfonate (IOS), alkylbenzene sulfonate (ABS), α-olefin sulfonate (AOS), and triethylenetetramine (TETA) are selected as co-surfactants. These co-surfactants can change the surface activity and hydrophilic-lipophilic balance of the surfactant, adjust the polarity of water and oil, and assist in the formation of micelles, thereby affecting the phase type of the integrated pressure-driven system.

[0069] According to the present invention, the integrated pressure-drive system further comprises an inorganic salt and a solvent.

[0070] According to the present invention, the solvent is selected from one or more of 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 3-methyl-1-butanol and 2,2-dimethyl-1-propanol.

[0071] According to the present invention, the inorganic salt is NaCl and / or KCl; in the integrated pressure-drive system of the present invention, one or two inorganic salts of NaCl and KCl are also selected to adjust the salinity of the system, increase the adsorption amount of the surfactant at the oil-water interface, reduce the interfacial tension, and promote the formation of a middle-phase microemulsion with nanometer-scale particle size.

[0072] According to the present invention, based on the total weight of the pressure-drive integrated system, the content of the inorganic salt is 0-2 weight%, and the content of the solvent is 0-0.3 weight%; preferably, based on the total weight of the pressure-drive integrated system, the content of the inorganic salt is 0.8-1.5 weight%, and the content of the solvent is 0.02-0.2 weight%.

[0073] According to the present invention, 100% as a reference refers to the pressure-driven integrated system, and the remainder is water.

[0074] In the pressure-driven integrated system of the present invention, a specific 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate tetrasodium salt derivative is selected as the main surfactant. The lipophilic group of the surfactant is an alkylbenzene with different carbon chain structures, specifically, R=H, CH3, C2H5, C3H7, C4H9, C5H 11 or C6H 13 , R can be a saturated straight-chain alkyl group or a branched-chain alkyl group; the hydrophilic group is a tetracarboxylic acid group.

[0075] According to the present invention, a main surfactant of tetrasodium salt of 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate is dissolved in oilfield formation water, wherein the mass fraction of the main surfactant in the aqueous solution is 0.05-0.5% by weight, the mass fraction of the cosurfactant is 0.01-0.5% by weight, the mass fraction of the solvent is 0-0.3% by weight, the mass fraction of the inorganic salt is 0-2% by weight, and the solution contains a polymer with a concentration of 1500 mg / L-5000 mg / L; preferably, the mass fraction of the main surfactant in the aqueous solution is 0.3-0.5% by weight, the mass fraction of the cosurfactant is 0.1-0.3% by weight, the mass fraction of the solvent is 0.02-0.2% by weight, the mass fraction of the inorganic salt is 0.8-1.5% by weight, and the solution contains a polymer with a concentration of 2000 mg / L-3000 mg / L; a middle phase microemulsion can be formed under a reservoir temperature of 110°C, the emulsion particle size is less than 100 nm, and the interfacial tension value of the Gulong shale oil / formation water is reduced to 10 -3 mN / m order of magnitude, and has high oil absorption and washing efficiency and excellent sand carrying performance.

[0076] A fourth aspect of the present invention provides an application of the aforementioned integrated pressure-drive system in shale oil reservoirs.

[0077] According to the present invention, the oil reservoir is a shale oil reservoir, that is, the Daqing Gulong shale oil reservoir used is a terrestrial pure shale reservoir.

[0078] According to the present invention, the conditions of the Daqing Gulong shale reservoir include: temperature of 120-150°C, permeability of 10 -2 mD-10 -6 mD.

[0079] According to a particularly preferred embodiment of the present invention, a pressure-driven integrated development method for a flooding and washing system with mid-phase microemulsion characteristics is provided. Daqing Gulong shale oil is a terrestrial pure shale reservoir. During the development process, a field application formula was optimized based on the results of indoor evaluation experiments: the pressure-driven integrated system of the present invention (0.3% by mass of 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate tetrasodium salt + 0.1% by mass of internal olefin sulfonate + 0.02% by mass of n-butanol + 0.8% by mass of KCl + 3000mg / L guar gum) was thoroughly stirred and mixed with proppants of different particle sizes in a sand mixer and then pressed into the shale reservoir. The system can not only carry sand to transform the reservoir, but also form a medium-phase microemulsion with Gulong shale oil after entering the formation. Its particle size is at the nanometer level, which has good compatibility with the pore throat size of the shale, improving the diffusion and miscibility effect, significantly enhancing the permeation and oil washing capacity, and improving the shale oil recovery rate, thus realizing the integrated pressure-driven development method of pure shale reservoirs. The test well saw oil at a low return rate (0.4%), and the maximum daily oil production could reach 35m 3 The above, the current cumulative oil production has reached 9586m 3 , is still in the process of further mining, and it is expected that the recovery rate can be increased by more than 10%.

[0080] In summary, the present invention provides a pressure-driven integrated system and its application. The 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate tetrasalt integrated flooding and washing system provided by the present invention has both sand-carrying and fracture-forming functions and flooding and washing functions, and can form a middle-phase microemulsion with Gulong shale oil. The excellent interfacial tension and emulsification properties of the system are utilized to reduce capillary forces, achieve oil-water miscibility and wettability changes, and at the same time, the nano-scale particle size of the emulsion is highly matched with the pore throat size of the shale, thereby enhancing the imbibition replacement effect, and through the transformation of the emulsification type, a significant improvement in the efficiency of imbibition and washing oil is achieved. It is applied to the pure shale reservoir of Gulong, Daqing, forming a pressure-driven integrated development method, achieving good shale oil recovery effect, and providing technical support for the efficient development of Daqing Gulong shale oil.

[0081] The present invention will be described in detail below through examples.

[0082] In the following examples and comparative examples:

[0083] Hydroquinone, KOH, ethylene oxide, propylene oxide, 4-dimethylaminopyridine, thionyl chloride, tetrahydrofuran, and ethanol were all commercially available products from Tianjin Chemical Reagent Factory No. 3.

[0084] Preparation Example 1

[0085] This preparation example is to illustrate the tetrasodium salt of 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate ((R)2C6H6(C3H6O) 40Preparation of (C2H4O)5(CH)2(COONa)4).

[0086] (1) Dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether (II)

[0087] To a 0.5L autoclave, add 0.9 mol of 2,5-dialkyl-1,4-hydroquinone and 1.8 mol of KOH and heat to 120°C. High-purity nitrogen is introduced with stirring, followed by vacuuming. This replacement operation is repeated three times. The temperature is then raised to 160°C, and propylene oxide is introduced until the reactor pressure reaches 0.40 MPa. Cooling water is then added to maintain the system temperature at 160°C. Propylene oxide is continuously introduced, maintaining the reactor pressure at 0.2 MPa. When the theoretical addition amount reaches 72 mol, the propylene oxide introduction is stopped. Ethylene oxide is then continuously introduced, maintaining the reactor pressure at 0.2 MPa. The system temperature is then maintained at 120°C. When the theoretical addition amount reaches 9 mol, the ethylene oxide introduction is stopped. The reaction continues until the pressure drops to 0 MPa. Heating is terminated, and the temperature is cooled to 70°C. The product, dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether, is weighed. Finally, acetic acid is added in an amount equal to the molar amount of KOH to neutralize the base.

[0088] (2) Dialkyl-p-phenylenedioxypropyl-polyoxyethylene chlorohydrin ether (III)

[0089] 0.0225 mol of dialkyl-p-phenylenedioxypropyl-polyoxyethylene ether product was added to a 500 ml three-necked flask, and a small amount of 4-dimethylaminopyridine (DMAP) was added as a catalyst. 0.135 mol of thionyl chloride was slowly added dropwise to the three-necked flask using a constant pressure dropping funnel at 30°C. A large amount of acidic gas was generated during the reaction, and tail gas was absorbed with a NaOH solution. The thionyl chloride addition time was controlled to be approximately 1 hour. After the addition was completed, the temperature was gradually raised to 80°C and the reaction was allowed to proceed for 4 hours. After the reaction was completed, the mixture was naturally cooled, and then the excess thionyl chloride was removed using a rotary evaporator at 45°C and the temperature was brought to 55°C. After 45 minutes, the chlorohydrin ether intermediate was obtained.

[0090] (3) Dialkyl-p-phenylene polyoxypropyl-polyoxyethylene malonate (IV)

[0091] Add 0.06 mol NaH to a 500 ml three-necked flask, wash with 50 ml petroleum ether three times, add tetrahydrofuran solvent, stir magnetically, condense and reflux with a drying ball, add 0.03 mol diethyl malonate dropwise at room temperature, raise the temperature to 70 ° C after the addition is completed, add the treated chlorohydrin ether to the three-necked flask, start stirring and react for 5-6 hours, and after the reaction is completed, add water to desalinate, take the tetrahydrofuran layer, and remove tetrahydrofuran by rotary evaporation to obtain dialkyl-p-phenylene polyoxypropyl-polyoxyethylene malonate.

[0092] (4) 2,5-Dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt (V)

[0093] 0.019 mol of dialkyl-p-phenylene polyoxypropyl-polyoxyethylene malonate was added to a 500 ml three-necked flask, ethanol was added as a solvent, the mixture was condensed and refluxed, the temperature was raised to 70° C., 0.152 mol of NaOH was added, and hydrolysis was carried out for 10 hours. After the reaction was completed, the final product, 2,5-dialkyl-1,4-p-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt, was obtained. The structural formula of the 2,5-dialkyl-1,4-p-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt is as follows:

[0094] Among them, (R)2C6H6(C3H6O) m (C2H4O) n (CH)2(COONa)4, R=C2H5, m=40, n=5.

[0095] Preparation Example 2

[0096] This preparation example is to illustrate the tetrasodium salt of 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate ((R)2C6H6(C3H6O) 20 Preparation of (C2H4O)5(CH)2(COONa)4).

[0097] Tetrasodium salt of 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate was prepared in the same manner as in Example 1, except that: propylene oxide was introduced until the pressure in the reactor was raised to 0.35 MPa, cooling water was passed through the system to allow the reaction to proceed at 150°C, and propylene oxide was continuously introduced until the theoretical addition amount reached 36 mol, at which point the introduction of propylene oxide was stopped. Ethylene oxide was then continuously introduced until the pressure in the reactor was maintained at 0.2 MPa, the system temperature was maintained at 120°C, and the introduction of ethylene oxide was stopped until the theoretical addition amount reached 9 mol, at which point the introduction of ethylene oxide was stopped. The reaction continued until the pressure dropped to 0 MPa, heating was terminated, the temperature was lowered to 70°C, and the product was discharged. The dialkyl-phenylene polyoxypropyl-polyoxyethylene ether product was weighed, and finally, acetic acid in an amount equimolar to KOH was added as a neutralizing base.

[0098] As a result, the final product, 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt, is obtained. The structural formula of the 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt is as follows:

[0099] Among them, (R)2C6H6(C3H6O) m (C2H4O) n (CH)2(COONa)4, R=C2H5, m=20, n=5.

[0100] Preparation Example 3

[0101] This preparation example is to illustrate the tetrasodium salt of 2,5-dialkyl-1,4-phenylene polyoxyalkylene ether malonate ((R)2C6H6(C3H6O) 20 (C2H4O) 10 Preparation of (CH)2(COONa)4).

[0102] 2,5-dialkyl-1,4-p-phenylene polyoxyalkylene ether malonate tetrasodium salt was prepared according to the same method as in Example 1, except that: propylene oxide was introduced until the pressure of the reactor was raised to 0.35 MPa, cooling water was passed through the system to react at 150°C, and propylene oxide was continuously introduced until the theoretical addition value of 36 mol was reached, at which time the introduction of propylene oxide was stopped. Ethylene oxide was then continuously introduced until the pressure of the reactor was maintained at 0.3 MPa, the system temperature was kept at 130°C, and the introduction of ethylene oxide was stopped until the theoretical addition value of 18 mol was reached. The reaction continued until the pressure dropped to 0 MPa, heating was terminated, the temperature was lowered to 70°C, and the product was discharged. The dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether product was weighed, and finally, acetic acid was added in an amount equal to KOH as a neutralizing base.

[0103] As a result, the final product, 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt, is obtained. The structural formula of the 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt is as follows:

[0104] Among them, (R)2C6H6(C3H6O) m (C2H4O) n (CH)2(COONa)4, R=C2H5, m=20, n=10.

[0105] Example 1

[0106] This embodiment is intended to illustrate the preparation of a pressure-driven integrated system.

[0107] The pressure-driven integrated system comprises: preparing 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt ((R)2C6H6(C3H6O) prepared in Preparation Example 1 m (C2H4O) n(CH)2(COONa)4, R=C2H5, m=40, n=5) as the main surfactant was dissolved with internal olefin sulfonate (IOS), KCl, n-butanol and fast hydration guar gum in the injection water of the Daqing Gulong shale oil fracturing site to prepare an aqueous solution, wherein the mass fraction of the main surfactant was 0.3% by weight, the mass fraction of IOS was 0.1% by weight, the mass fraction of KCl was 0.8% by weight, the mass fraction of the solvent n-butanol was 0.02% by weight, and the concentration of guar gum was 3000 mg / L.

[0108] Example 2

[0109] This embodiment is intended to illustrate the preparation of a pressure-driven integrated system.

[0110] A pressure-driven integrated system was prepared in the same manner as in Example 1, except that the mass fraction of the main surfactant was 0.2 wt %, the mass fraction of IOS was 0.1 wt %, the mass fraction of KCl was 0.8 wt %, the mass fraction of the solvent n-butanol was 0.02 wt %, and the concentration of guar gum was 3000 mg / L.

[0111] Example 3

[0112] This embodiment is intended to illustrate the preparation of a pressure-driven integrated system.

[0113] A pressure-driven integrated system was prepared in the same manner as in Example 1, except that the "2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt prepared in Preparation Example 1" was replaced with the "2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt prepared in Preparation Example 2".

[0114] Example 4

[0115] This embodiment is intended to illustrate the preparation of a pressure-driven integrated system.

[0116] A pressure-driven integrated system was prepared in the same manner as in Example 1, except that the "2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt prepared in Preparation Example 1" was replaced with the "2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt prepared in Preparation Example 3".

[0117] Comparative Example 1

[0118] The integrated pressure-drive system was prepared in the same manner as in Example 1, except that tetrasodium 2,5-dialkyl-1,4-phenylenepolyoxypropyl-polyoxyethylenemalonic acid, cosurfactant, KCl, and solvent were not added to the fracturing fluid system, and the rapidly hydrated guar gum was replaced with an emulsion polymer.

[0119] Advantageously, the emulsion polymer is a polyacrylamide polymer with a molecular weight of 300,000 to 500,000.

[0120] Comparative Example 2

[0121] An integrated pressure-drive system was prepared in the same manner as in Example 1, except that tetrasodium 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate, cosurfactant, KCl, and solvent were not added to the fracturing fluid system, and the rapidly hydrated guar gum was replaced with an associative polymer.

[0122] Advantageously, the associative polymer is a hydrophobically associating water-soluble polymer with a molecular weight of 12 million.

[0123] Test Example 1

[0124] The integrated pressure-drive system reduces the shale oil / formation water interfacial tension.

[0125] The interfacial tension of the pressure-driven integrated systems prepared in Examples 1-4 and Comparative Examples 1-2 was tested, specifically:

[0126] The 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt in the pressure-drive integrated system prepared in Examples 1-4 was used as the main surfactant and dissolved with IOS, KCl, n-butanol and fast-hydrated guar gum in the injection water at the Daqing Gulong shale oil fracturing site to prepare an aqueous solution, i.e., a pressure-drive integrated system.

[0127] The interfacial tension was measured using a TX-500C rotating drop interfacial tension meter. The experimental oil was dehydrated and degassed shale oil from the Daqing Gulong shale oil wellhead, and the experimental water was water injected at the Daqing Gulong shale oil fracturing site.

[0128] The interfacial tension test results are shown in Table 1.

[0129] Table 1

[0130] In addition, FIG1 is a diagram showing the oil-water interfacial tension performance of the pressure-driven integrated system prepared in Example 1 of the present invention under the conditions of the Daqing Gulong shale reservoir. As shown in FIG1 , when the mass fraction of KCl in the system is 0.5-1.6 wt % and the concentration of the main surfactant is 0.1-0.4 wt %, the Daqing shale oil / formation water interfacial tension can be reduced to 10 at 80°C. -3 mN / m order of magnitude.

[0131] Furthermore, the oil-water interfacial tensions of the integrated pressure-drive systems prepared in Examples 2, 3, and 4 of the present invention under the conditions of the Daqing Gulong shale reservoir were 0.0053 mN / m, 0.0089 mN / m, and 0.0095 mN / m, respectively, all of which were able to be reduced to the ultra-low range. Comparative Examples 1 and 2, due to the lack of the addition of a primary surfactant, were unable to reduce the oil-water interfacial tension to the ultra-low range.

[0132] Test Example 2

[0133] Emulsification performance of integrated pressure-drive system under the conditions of Daqing Gulong shale reservoir.

[0134] The emulsification performance of the pressure-driven integrated systems prepared in Examples 1-4 and Comparative Examples 1-2 was tested, specifically:

[0135] The 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt prepared in Examples 1-4 was respectively used as the main surfactant and dissolved with IOS, KCl, n-butanol and fast hydration guar gum in the injection water of the Daqing Gulong shale oil fracturing site to prepare an aqueous solution, wherein the main surfactant in Example 1 ((R)2C6H6(C3H6O) m (C2H4O) n The mass fraction of (CH)2(COONa)4, R=C2H5, m=40, n=5) is 0.3 wt %, the mass fraction of IOS is 0.1 wt %, the mass fraction of solvent is 0.02 wt %, the concentration of guar gum is 3000 mg / L, the mass fraction of KCl is 0.8 wt %, that is, the pressure-driven integrated system prepared in Example 1; the main surfactant ((R)2C6H6(C3H6O) in Example 2 m (C2H4O) n The mass fractions of (CH)2(COONa)4, R=C2H5, m=40, n=5) are 0.2 wt % respectively, the mass fraction of IOS is 0.1 wt %, the mass fraction of solvent is 0.02 wt %, the concentration of guar gum is 3000 mg / L, and the mass fraction of KCl is 0.8 wt %, that is, the pressure-driven integrated system prepared in Example 2; the main surfactant ((R)2C6H6(C3H6O) in Example 3 m (C2H4O) n The mass fraction of (CH)2(COONa)4, R=C2H5, m=20, n=5) is 0.3 wt %, the mass fraction of IOS is 0.1 wt %, the mass fraction of solvent is 0.02 wt %, the concentration of guar gum is 3000 mg / L, and the mass fraction of KCl is 0.8 wt %, that is, the pressure-driven integrated system prepared in Example 3; the main surfactant ((R)2C6H6(C3H6O) in Example 4 m(C2H4O) n The mass fraction of (CH)2(COONa)4, R=C2H5, m=20, n=10) is 0.3 wt %, the mass fraction of IOS is 0.1 wt %, the mass fraction of the solvent is 0.02 wt %, the concentration of guar gum is 3000 mg / L, and the mass fraction of KCl is 0.8 wt %, that is, the pressure-driven integrated system prepared in Example 4.

[0136] In a 5ml pipette, add 2.5ml of the integrated pressure-driven flushing system and 2.5ml of Daqing Gulong shale oil wellhead dehydrated and degassed shale oil prepared according to the above ratio, melt and seal both ends of the pipette, shake it upside down 200 times, and place it upright in a constant temperature oven at 80°C.

[0137] The emulsification performance test results are shown in Table 2.

[0138] Table 2

[0139] In addition, Figure 2 shows the emulsification performance of the integrated pressure-drive system prepared in Example 1 of the present invention under the conditions of the Daqing Gulong shale oil reservoir. As shown in Figure 2, the emulsification state of the integrated pressure-drive flooding system and the shale oil was observed after 12 hours. When the mass fraction of the active agent was 0.3% by weight and the mass fractions of KCl in the system were 0.8% by weight, 0.9% by weight, 1.0% by weight, and 1.2% by weight, respectively, the solution in the pipette formed a Winsor III emulsion with a distinct intermediate phase, good phase characteristics, and achieved the optimal hydrophilic-lipophilic balance.

[0140] Test Example 3

[0141] Sand carrying performance of integrated pressure-drive system under the conditions of Daqing Gulong shale reservoir.

[0142] The sand carrying performance of the pressure-driven integrated systems prepared in Examples 1-4 and Comparative Examples 1-2 was tested, specifically:

[0143] 435 mL of the pressure-driven integrated system prepared in Examples 1-4 and Comparative Examples 1-2 were measured and placed in a 1000 mL beaker. The beaker was placed under an electric stirrer with the speed adjusted to 1000 r / min. 100 mL of quartz sand was measured and slowly added to the beaker. Stirring was stopped until the quartz sand was evenly dispersed in the sample. The beaker was removed from the stirrer and the sample was poured into a 500 mL graduated cylinder. The cylinder was placed in an 80°C oven and the height of the quartz sand in the cylinder was observed at different times, recorded as H1. The sand entrainment rate was calculated according to the formula (W = (H1 / 500) / 100).

[0144] The sand carrying rate results of the test are shown in Table 3.

[0145] Table 3

[0146] In addition, FIG3 shows the sand carrying performance of the integrated pressure drive system prepared in Example 1 of the present invention under the conditions of the Daqing Gulong shale reservoir. As shown in FIG3 , after being placed at 80° C. for 8 hours, the sand carrying rate of the integrated pressure drive and flushing system can still be as high as 85.2%.

[0147] Test Example 4

[0148] Imbibition performance of the integrated pressure-drive system under the conditions of the Daqing Gulong shale reservoir.

[0149] The imbibition performance of the pressure-driven integrated systems prepared in Examples 1-4 and Comparative Examples 1-2 was tested, specifically:

[0150] In a 250 mL imbibition bottle, an oil-saturated Gulong shale core and the integrated pressure-drive systems prepared in Examples 1-4 and Comparative Examples 1-2 were placed successively. Aqueous solution was injected at the fracturing site and the bottles were placed in an 85°C high-temperature oven to examine the imbibition and oil-washing effect. The oil yield was recorded every 2 hours, and the imbibition recovery rate was calculated based on the saturated oil yield.

[0151] The results of the imbibition recovery test are shown in Table 4.

[0152] Table 4

[0153] The experimental results show that Figure 4 shows the imbibition performance of the integrated pressure-drive system, clean water, emulsion thickener, and associative fracturing fluid prepared in Example 1 of the present invention under the conditions of the Daqing Gulong shale oil reservoir. As shown in Figure 4, the integrated pressure-drive flushing system of the present invention can achieve an imbibition recovery rate of shale cores of 54.68%, which is 32.78% and 23.94% higher than the imbibition recovery rates of the comparative experiments using emulsion polymer and associative fracturing fluid as soaking fluids, respectively.

[0154] Test Example 5

[0155] Field test of horizontal well fracturing in Daqing Gulong continental shale reservoir

[0156] 0.3 wt% of 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate tetrasodium salt ((R)2C6H6(C3H6O) m (C2H4O) n(CH)2(COONa)4, R=C2H5, m=40, n=5) as the main surfactant was dissolved with 0.1 wt% IOS, 0.8 wt% KCl and 0.02 wt% n-butanol in the injection water at the Daqing Gulong shale oil fracturing site to prepare an integrated pressure-drive system. The system was then mixed evenly with 3000 mg / L of fast-hydrated guar gum in a sand mixer, and then fully mixed with proppants of different particle sizes. The system was then injected into the Daqing Guye YH-Q4 shale oil test well (the specific parameters of the well include: horizontal well, 2500 meters vertical section, 2500 meters horizontal section, and formation temperature of 120°C). The system not only uses high-viscosity sand to transform the reservoir, but also forms a medium-phase microemulsion with the Gulong shale oil in the reservoir. Its particle size is at the nanometer level, which has a good match with the pore throat size of the shale, improving the diffusion and miscibility effect, significantly enhancing the infiltration and oil washing capacity, and improving the shale oil recovery rate.

[0157] Figure 5 is a fluid discharge curve of the integrated pressure-drive system prepared in Example 1 of the present invention after fracturing in the Guye YH-Q4 well. The test well produced oil at a low flowback rate of 0.4%, and the maximum daily oil production could reach 35m3. 3 The above, cumulative oil production is 6129.47m 3 , cumulative gas production 695377m 3 , cumulative water production 16567.95m 3 The flowback rate is 23.40%, and it is still in the process of continuous and efficient production. Based on historical matching, the development effect of the test well was predicted using numerical simulation technology based on fine description of artificial fractures. The results showed that after 10 years of production, the flowback rate of the test well reached 71.81%, and the cumulative oil production was 25343m 3 , showing good application prospects.

[0158] Comparative Example 1: Rapidly hydrated guar gum at a concentration of 3000 mg / L was evenly stirred in a sand mixer, then thoroughly mixed with proppants of different particle sizes, and then injected into the Daqing Guye EH-Q4 shale oil test well (specific parameters of the well include: horizontal well, vertical section 2500 meters, horizontal section 2450 meters, formation temperature 120°C).

[0159] In Comparative Example 1, it should be noted that since the field test was a horizontal well fracturing, the injection could not be carried out into the same well. In the present invention, the geological conditions of the Guye YH-Q4 well and the Guye EH-Q4 shale oil test well are very similar and can be used as a comparison to illustrate the problem.

[0160] Figure 6 is a blowout curve of the high-viscosity guar gum system in Example 1 after fracturing in the Guye EH-Q4 well. This comparative test well only uses the high-viscosity guar gum system to carry sand to transform the reservoir, and does not add the integrated pressure-drive system of the present invention. After the well is shut down and flowed back, the effect is significantly lower than that of the YH-Q4 well test well. The EH-Q4 test well sees oil at a flowback rate of 11.49%, and the maximum daily oil production is only 2.1m 3 , cumulative oil production of 145.04m 3 , cumulative gas production of 319,546m 3 , cumulative water production 17501.64m 3 , the return rate is 25.17%.

[0161] The above examples and experimental evaluation results demonstrate that the present invention provides an integrated pressure-displacement system for tetrasodium salt of 2,5-dialkyl-1,4-phenylene polyoxypropyl-polyoxyethylene malonate. By adjusting the nonionic segment length and alkyl chain length of the polyoxyethylene ether (EO) and polyoxypropylene ether (PO) in the primary surfactant, as well as the types and ratios of the co-surfactant, solvent, and inorganic salt, the integrated pressure-displacement system forms a highly viscous sand-carrying fracturing system during surface preparation. After injection into the formation, it forms a mid-phase microemulsion with the Gulong shale oil. The system's excellent interfacial tension and emulsifying properties reduce capillary forces, achieving oil-water miscibility and wettability changes. Furthermore, the nanoparticle size of the emulsion is highly compatible with the pore throat size of the shale, enhancing the imbibition displacement effect and significantly improving the efficiency of imbibition and oil washing. This displacement and washing system combines sand-carrying fracture creation with washing, forming an integrated pressure-displacement development method suitable for the efficient development of pure shale reservoirs.

Claims

1. A method for preparing a dimer alcohol ether carboxylate surfactant, characterized in that: The preparation method comprises the following steps: (1) reacting a 2,5-dialkyl-1,4-hydroquinone monomer represented by formula (A) with propylene oxide to produce a dialkyl-p-phenylene polyoxypropyl ether represented by formula (I); Wherein, R is selected from H and C1-C 10 One or more of; In formula (I), m is 5-50; (2) reacting the dialkyl-p-phenylene polyoxypropyl ether represented by formula (I) with ethylene oxide to generate the dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II); Wherein, n is 5-50; (3) reacting the dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II) with thionyl chloride to generate the chlorohydrin ether represented by formula (III); (4) treating the chlorohydrin ether represented by formula (III) with NaH to obtain a dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV); (5) hydrolyzing the dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV) with MOH to obtain 2,5-dialkyl-1,4-p-phenylene polyoxyalkylene ether malonate tetrasodium salt represented by formula (V); Wherein, M is selected from Na and / or K.

2. The preparation method according to claim 1, wherein In step (1), the molar ratio of the 2,5-dialkyl-1,4-hydroquinone monomer represented by formula (A) to propylene oxide is 1:2m, wherein m is 5-50; preferably, m is 20-40.

3. The preparation method according to claim 1, wherein In step (2), the molar ratio of the dialkyl-p-phenylene polyoxypropyl ether represented by formula (I) to ethylene oxide is 1:2n, wherein n is 5-50; preferably, n is 5-10.

4. The preparation method according to claim 1, wherein In step (3), the molar ratio of the dialkyl-p-phenylene polyoxypropyl-polyoxyethylene ether represented by formula (II) to thionyl chloride is 1:(6-8).

5. The preparation method according to claim 1, wherein In step (4), the molar ratio of the chlorohydrin ether represented by formula (III) to NaH is 1:(2-5).

6. The preparation method according to claim 1, wherein In step (5), the molar ratio of the dialkyl-p-phenylene polyoxyalkylene malonate represented by formula (IV) to MOH is 1:(2-5).

7. The preparation method according to claim 1, wherein In step (1) and step (2), the reaction conditions include: the reaction is carried out in a high-pressure reactor at a temperature of 120-160° C., and the reactor pressure is maintained at 0.2-0.4 MPa.

8. The preparation method according to claim 1, wherein In step (3), the reaction conditions include: the dropwise addition rate of thionyl chloride is 0.1-0.3 mol / hour, the temperature is 20-40°C, the reaction time is 0.8-2 hours, and after the dropwise addition is completed, the temperature is gradually raised to 70-90°C, and the reaction time is 3-5 hours.

9. The preparation method according to claim 1, wherein In step (4), the reaction conditions include: temperature of 60-80° C., and reaction time of 5-6 hours.

10. The preparation method according to claim 1, wherein: In step (5), the temperature is 60-80°C and the reaction time is 9-10 hours.

11. A dimer alcohol ether carboxylate surfactant prepared by the preparation method according to any one of claims 1 to 10.

12. The dimer alcohol ether carboxylate surfactant according to claim 11, wherein The dimer alcohol ether carboxylate surfactant comprises structural unit A, structural unit B, structural unit C and structural unit D; The structural unit A has a structure shown in formula (a), the structural unit B has a structure shown in formula (b), the structural unit C has a structure shown in formula (c), and the structural unit D has a structure shown in formula (d); Wherein, in formula (a), R is selected from H and C1-C 10 One or more of; In formula (b), m is 5-50; In formula (c), n is 5-50; In formula (d), M is selected from Na and / or K.

13. The dimer alcohol ether carboxylate surfactant according to claim 12, wherein In formula (a), R is selected from H, CH3, C2H5, C3H7, C4H9, C5H 11 and C6H 13 One or more of; In formula (b), m is 20-40; In formula (c), n is 5-10; In formula (d), M is Na.

14. The dimer alcohol ether carboxylate surfactant according to claim 12 or 13, wherein The dimer alcohol ether carboxylate surfactant has a structural formula shown in formula (V):

15. A pressure-driven integrated system, characterized in that: The pressure-driven integrated system comprises a main surfactant, and the main surfactant is the dimer alcohol ether carboxylate surfactant described in any one of claims 11-14.

16. The pressure-driven integrated system according to claim 15, wherein: The pressure-driven integrated system also contains a polymer at a concentration of 1500 mg / L-5000 mg / L; Preferably, the polymer is selected from one or more of AMPS, guar gum and modified derivatives thereof.

17. The pressure-driven integrated system according to claim 15 or 16, wherein: The pressure-driven integrated system further includes a co-surfactant; Preferably, the co-surfactant is selected from one or more of internal olefin sulfonates, alkylbenzene sulfonates, α-olefin sulfonates and triethylenetetramine; Preferably, based on the total weight of the pressure-driven integrated system, the content of the main surfactant is 0.05-0.5% by weight, and the content of the co-surfactant is 0.01-0.5% by weight.

18. The pressure-driven integrated system according to claim 15 or 16, wherein: The pressure-drive integrated system further includes an inorganic salt and a solvent; Preferably, the inorganic salt is NaCl and / or KCl; Preferably, the solvent is selected from one or more of 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 3-methyl-1-butanol and 2,2-dimethyl-1-propanol; Preferably, based on the total weight of the pressure-drive integrated system, the content of the inorganic salt is 0-2% by weight, and the content of the solvent is 0-0.3% by weight.

19. Use of the integrated pressure-drive system according to any one of claims 15 to 18 in shale oil reservoirs.

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