Method for testing adsorption capacity of surfactant in presence of eutectic solvent

Abstract

The invention relates to the technical field of oilfield development, in particular to a method for testing the adsorption capacity of a surfactant in the presence of a eutectic solvent. The method comprises the following steps: determining a surface tension-concentration standard relation curve of a eutectic solvent and surfactant mixed solution under different concentrations; selecting a mixed solution with a target concentration, and mixing and contacting the mixed solution with the target concentration with the selected rock particles to form a rock solution system; extracting the centrifugate of the rock solution system, measuring the surface tension of the centrifugate, and determining the corresponding concentration of the surfactant in the centrifugate according to the surface tension of the centrifugate and the surface tension-concentration standard relation curve; and determining the adsorption quantity of the surfactant on the rock according to the concentration of the surfactant in the mixed solution with the target concentration and the centrifugate. The invention aims to solve the problems that the adsorption capacity of the surfactant on the rock surface cannot be accurately tested in the presence of the eutectic solvent by the existing ultraviolet spectrophotometric method, so that the subsequent construction scheme cannot be reasonably adjusted, and the development of an oil-gas field is influenced.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield development, and in particular to a method for testing the adsorption amount of a surfactant in the presence of a low eutectic solvent. Background Art

[0002] Chemical flooding represented by surfactants is an extremely important technology for improving oil and gas recovery. The amount of surfactant adsorbed on rocks is a key factor affecting reservoir wettability. Low eutectic solvents are a direction for improving water flooding as water flooding additives. One of its mechanisms is to add a compound system of low eutectic solvents and surfactants to the injected water. Through the competitive adsorption of low-cost low eutectic solvents and surfactants, they are preferentially adsorbed on the rock surface, achieving the purpose of sacrificing themselves and reducing the amount of surfactant adsorption, so that the surfactant can be transported to the deep formation, thereby achieving the purpose of improving recovery. Accurate characterization of the amount of surfactant adsorbed on rocks in the presence of low eutectic solvents is crucial for the rational regulation of oilfield construction methods. At present, the adsorption of surfactants on the rock surface is mainly tested by ultraviolet spectrophotometry, but low eutectic solvents will affect the degree of light absorption of surfactants. The ultraviolet spectrophotometry method cannot accurately characterize the adsorption of surfactants on the rock surface in the presence of low eutectic solvents. Summary of the invention

[0003] The present invention proposes a method for testing the adsorption amount of a surfactant in the presence of a low eutectic solvent, so as to solve the problem that the existing ultraviolet spectrophotometry method cannot accurately test the adsorption amount of the surfactant on the rock surface in the presence of a low eutectic solvent, resulting in the inability to reasonably adjust the subsequent construction plan, thus affecting the development of oil and gas fields.

[0004] According to one aspect of the present invention, there is provided a method for testing the adsorption amount of a surfactant in the presence of a deep eutectic solvent, comprising:

[0005] Determine the surface tension-concentration standard relationship curve of the mixed solution of deep eutectic solvent and surfactant at different concentrations;

[0006] Selecting a mixed solution of target concentration, and mixing and contacting the mixed solution of target concentration with selected rock particles to form a rock-solution system;

[0007] Extracting the centrifuge liquid of the rock-solution system, measuring its surface tension, and determining the corresponding concentration of the surfactant in the centrifuge liquid according to the surface tension of the centrifuge liquid and the surface tension-concentration standard relationship curve;

[0008] The adsorption amount of the surfactant on the rock is determined according to the concentration of the surfactant in the mixed solution of the target concentration and in the centrifuged liquid.

[0009] Preferably, the method for determining the surface tension-concentration standard relationship curve of the mixed solution of the deep eutectic solvent and the surfactant at different concentrations comprises:

[0010] preparing a low eutectic solvent, and mixing the prepared low eutectic solvent with a selected surfactant to form a mixed solution;

[0011] The surface tension of the mixed solution at different concentrations was measured using a surface tension meter, and a standard relationship curve between the surface tension and concentration of the mixed solution was established.

[0012] Preferably, the method of selecting a mixed solution of target concentration at the critical micelle concentration and mixing it with rock particles to form a rock-solution system comprises:

[0013] Take a predetermined milliliter of the target concentration mixed solution and mix it with a predetermined number of grams of rock particles;

[0014] The mixed rock particles and the target concentration mixed solution are placed in a constant temperature oscillator, oscillated at a predetermined speed for a first predetermined time, and then left to stand for a second predetermined time to reach an equilibrium state.

[0015] Preferably, the method of extracting the centrifuge of the rock-solution system, measuring its surface tension, and determining the corresponding concentration of the surfactant in the centrifuge according to the surface tension of the centrifuge and the surface tension-concentration standard relationship curve comprises:

[0016] The supernatant of the rock-solution system is subjected to high-speed centrifugation, and the upper layer of the centrifuge formed after the high-speed centrifugation is taken, and its surface tension is measured;

[0017] According to the measured surface tension of the centrifuge, the corresponding concentration value is found on the surface tension-concentration standard relationship curve, which is the corresponding concentration of the surfactant in the centrifuge.

[0018] Preferably, the method for determining the amount of surfactant adsorbed on the rock according to the surfactant concentration in the target concentration mixed solution and the concentration in the centrifuge comprises:

[0019] According to the concentration of the surfactant in the mixed solution of the target concentration and in the centrifuge solution, the adsorption amount of the surfactant on the rock is calculated using formula (1);

[0020]

[0021] Where: C0 is the initial concentration, mg / L, C e is the final concentration, mg / L, V S is the volume of the test solution, ml, and m is the weight of the core particles used, g.

[0022] Preferably, the method for selecting a mixed solution of target concentration comprises:

[0023] Determining the critical micelle concentration of the surfactant in the mixed solution according to the surface tension-concentration standard relationship curve;

[0024] The concentration of the surfactant in the target concentration mixed solution is less than the critical micelle concentration.

[0025] Preferably, the organic matter configuring the low eutectic solvent includes choline chloride, and also includes but is not limited to: one or more of oxalic acid, glycolic acid, glycerol and urea.

[0026] Preferably, the types of the surfactant selected include, but are not limited to, sodium lauryl sulfate, petroleum sulfonate, hexadecyltrimethylammonium bromide and heavy alkylbenzene sulfonate.

[0027] Preferably, the selected rock particles are mixed with the target concentration mixed liquid in a ratio of 1:10.

[0028] The present invention has at least the following beneficial effects:

[0029] The present invention proposes a method for testing the adsorption amount of a surfactant in the presence of a low eutectic solvent. The method determines the surface tension-concentration standard relationship curve of a mixed solution of a low eutectic solvent and a surfactant, and reversely infers the adsorption amount of the surfactant on the rock based on the surface tension value of the mixed solution before and after adsorption on the rock, thereby achieving accurate measurement of the adsorption amount of the surfactant on the rock surface in the presence of a low eutectic solvent, which is beneficial to the reasonable adjustment of the construction plan on the oil field site and the efficient development of oil and gas fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.

[0031] Figure 1 A flow chart showing a method for testing the adsorption amount of a surfactant in the presence of a deep eutectic solvent according to an embodiment of the present invention;

[0032] Figure 2 A graph showing a standard relationship between surface tension and concentration of a mixed solution according to an embodiment of the present invention is shown;

[0033] Figure 3 A comparison chart of the adsorption amounts of composite solutions of different deep eutectic solvents and hexadecyltrimethylammonium bromide according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0034] Various exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0035] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0036] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0037] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0038] Figure 1 A flow chart showing a method for testing the adsorption amount of a surfactant in the presence of a deep eutectic solvent according to an embodiment of the present invention; Figure 2 A graph showing a standard relationship between surface tension and concentration of a mixed solution according to an embodiment of the present invention is shown; Figure 3 FIG. 4 shows a comparison of the adsorption amounts of different deep eutectic solvents and hexadecyltrimethylammonium bromide composite solutions according to an embodiment of the present invention. Figure 1-3 As shown, a method for testing the adsorption amount of a surfactant in the presence of a low eutectic solvent comprises: step S01: determining a surface tension-concentration standard relationship curve of a mixed solution of a low eutectic solvent and a surfactant at different concentrations; step S02: selecting a mixed solution of a target concentration, mixing and contacting the mixed solution of the target concentration with selected rock particles to form a rock-solution system; step S03: extracting a centrifuge of the rock-solution system, measuring its surface tension, and determining the corresponding concentration of the surfactant in the centrifuge according to the surface tension of the centrifuge and the surface tension-concentration standard relationship curve; step S04: determining the adsorption amount of the surfactant on the rock according to the concentration of the surfactant in the mixed solution of the target concentration and in the centrifuge.

[0039] The method for testing the adsorption amount of a surfactant in the presence of a deep eutectic solvent provided in an embodiment of the present invention specifically comprises the following steps:

[0040] Step S01: determining a surface tension-concentration standard relationship curve of a mixed solution of a deep eutectic solvent and a surfactant at different concentrations.

[0041] In the present invention, the method for determining the surface tension-concentration standard relationship curve of a mixed solution of a deep eutectic solvent and a surfactant at different concentrations comprises: preparing a deep eutectic solvent, mixing the prepared deep eutectic solvent with a selected surfactant to form a mixed solution; using a surface tension meter to measure the surface tension of the mixed solution at different concentrations, and establishing a surface tension-concentration standard relationship curve of the mixed solution.

[0042] In the present invention, the organic matter configuring the deep eutectic solvent includes choline chloride, and also includes but is not limited to: one or more of oxalic acid, glycolic acid, glycerol and urea.

[0043] In the present invention, the types of the surfactant selected include but are not limited to: sodium dodecyl sulfate, petroleum sulfonate, hexadecyltrimethylammonium bromide and heavy alkylbenzene sulfonate.

[0044] In the embodiment of the present invention, the low eutectic solvent is configured based on choline chloride, supplemented by different organic substances fully mixed at high temperature to form a solution; the surfactant can be selected from the commonly used types of oilfield chemical flooding.

[0045] The surfactant is exemplified by cetyltrimethylammonium bromide (CTAB); the low eutectic solvent configuration is exemplified by choline chloride: urea 1:2, choline chloride: glycerol 1:3, choline chloride: oxalic acid 2:1, choline chloride: glycolic acid 1:1, choline chloride: maleic acid 2:1, and choline chloride: citric acid 1:1. The low eutectic solvent solution and the surfactant solution are fully mixed in a predetermined ratio to form a mixed solution.

[0046] The surface tension of the mixed solution of the low eutectic solvent and the surfactant at different concentrations, that is, after mixing with the salt water, is measured using a surface tension meter. The surface tension is the surface tension before mixing; a standard curve of the relationship between the surface tension and the surfactant concentration in the mixed solution is established. Taking the low eutectic solvent as choline chloride: citric acid = 1:1 as an example, the surface tension-concentration standard curve of the mixed solution at different concentrations is established as follows Figure 2 shown.

[0047] The formula and concentration of the deep eutectic solvent can be selected according to the specific practical application, the surfactant includes but is not limited to the type and concentration of the surfactant used in chemical flooding, and the concentration interval of the mixed solution can be prepared according to a certain decreasing rule. The surface tension meter can be a QBZY series fully automatic interfacial tension meter.

[0048] In the present invention, the method for selecting a mixed solution of target concentration comprises: determining the critical micelle concentration of the surfactant in the mixed solution according to the surface tension-concentration standard relationship curve; the concentration of the surfactant in the mixed solution of target concentration is less than the critical micelle concentration.

[0049] In the embodiments of the present invention, it is found in experimental measurements that the effect of the deep eutectic solvent on the surface tension of the mixed solution is negligible. Based on this, the critical micelle concentration of the surfactant in the mixed solution can be determined according to the standard relationship curve between surface tension and concentration.

[0050] According to the standard relationship curve, the critical micelle concentration of the surfactant in the mixed solution is analyzed. It is generally believed that when the surfactant exceeds a certain concentration in the solution, it will associate from a single ion or molecule into a colloidal aggregate, that is, form micelles. The concentration at which the properties of the solution suddenly change, that is, the concentration of the solution when micelles begin to form, is called the critical micelle concentration, denoted as C0. The concentration of the surfactant used in the target concentration mixed solution cannot exceed the critical micelle concentration because after exceeding the critical micelle concentration, the surfactant will aggregate into a mass, resulting in no change in the surface tension of the mixed solution, and the standard relationship curve cannot be formed, and the method of the present invention will not be applicable.

[0051] Step S02: Select a mixed solution of target concentration, and mix and contact the mixed solution of target concentration with selected rock particles to form a rock-solution system.

[0052] In the present invention, the method of selecting a mixed solution of target concentration at the critical micelle concentration, mixing it with rock particles to form a rock-solution system comprises: taking a predetermined milliliter of the mixed solution of target concentration, mixing it with a predetermined number of grams of rock particles; placing the mixed rock particles and the mixed solution of target concentration in a constant temperature oscillator, oscillating at a predetermined speed for a first predetermined time, and then standing for a second predetermined time to reach an equilibrium state.

[0053] In the present invention, the ratio of the selected rock particles to the target concentration mixed liquid is 1:10.

[0054] In an embodiment of the present invention, 20 ml of a mixed solution containing a low eutectic solvent and a surfactant at a critical micelle concentration is mixed with 2 g of rock particles, and the rock particle specification is selected to be 100-140 mesh; the ratio of rock particles to the mixed solution includes but is not limited to 1:10; the type of rock particles is selected according to the geological conditions of the specific work area, including but not limited to Berea sandstone, ordinary sandstone, carbonate rock, etc.

[0055] Add a blank sample, mix 20 ml of hexadecyltrimethylammonium bromide solution with 2 g of sandstone particles, and the blank sample is used to calculate the amount of single surfactant adsorbed on the rock surface.

[0056] The predetermined rotation speed is 110 r / min, the predetermined first time and the predetermined second time are 24 hours. The mixed rock particles and the mixed solution are placed in a constant temperature oscillator and oscillated at 110 r / min for 24 hours. After the oscillation, the mixture is allowed to stand for 24 hours to reach an equilibrium state.

[0057] Step S03: extracting the centrifuge liquid of the rock-solution system, measuring its surface tension, and determining the corresponding concentration of the surfactant in the centrifuge liquid according to the surface tension of the centrifuge liquid and the surface tension-concentration standard relationship curve.

[0058] In the present invention, the method of extracting the centrifuge of the rock-solution system, measuring its surface tension, and determining the corresponding concentration of the surfactant in the centrifuge according to the surface tension of the centrifuge and the surface tension-concentration standard relationship curve comprises: performing high-speed centrifugation on the supernatant of the rock-solution system, taking the upper layer of the centrifuge formed after the high-speed centrifugation, and measuring its surface tension; according to the measured surface tension of the centrifuge, finding the corresponding concentration value on the surface tension-concentration standard relationship curve, which is the corresponding concentration of the surfactant in the centrifuge.

[0059] In the embodiment of the present invention, after being fully mixed and allowed to stand, the rock-solution system will separate a supernatant, which is centrifuged at high speed, and the upper layer of the centrifuged liquid is taken to measure its surface tension using a surface tension meter. This surface tension is the surface tension after mixing. On the surface tension-concentration standard relationship curve, find the surfactant concentration corresponding to the surface tension value before mixing that is the same as the surface tension value after mixing, and record it as C e .

[0060] There is no specific restriction on the oscillation parameters and centrifugation parameters. The experimental equipment can be selected from THZ-D constant temperature oscillator and Lu Xiangyi TGL-16MS high-speed centrifuge.

[0061] The mixed solutions of different types of low eutectic solvents and surfactants are adsorbed on rock particles, and then the surface tension is tested. The corresponding concentration C is found according to the surface tension-concentration standard relationship curve. e , the results are shown in Table 1 below.

[0062] Table 1: Surface tension and concentration after adsorption with different deep eutectic solvents

[0063] Solution type Surface tension (mN / m) Concentration (mg / L) CTAB 25.3 98.53 Choline chloride:glycerol 1:3-CTAB 17.5 282.84 Choline chloride:glycolic acid 1:1-CTAB 21.43 181.46 Choline chloride:urea 1:2-CTAB 19.57 226.94 Choline chloride:maleic acid 2:1-CTAB 22.7 152.75 Choline chloride:oxalate 2:1-CTAB 21.8 172.98 Choline chloride:citric acid 1:1-CTAB 21.67 176.05

[0064] Step S04: Determine the adsorption amount of the surfactant on the rock according to the concentration of the surfactant in the target concentration mixed solution and the concentration of the surfactant in the centrifuge solution.

[0065] In the present invention, the method for determining the amount of surfactant adsorbed on the rock according to the surfactant concentration in the target concentration mixed solution and the centrifuge liquid comprises: calculating the amount of surfactant adsorbed on the rock according to the surfactant concentration in the target concentration mixed solution and the centrifuge liquid using formula (1);

[0066]

[0067] Where: C0 is the initial concentration, mg / L, C e is the final concentration, mg / L, V S is the volume of the test solution, ml, and m is the weight of the core particles used, g.

[0068] In the embodiment of the present invention, the adsorption amount of the surfactant on the rock surface is calculated according to the above formula (1), wherein the initial concentration is the concentration of the surfactant in the mixed solution, and the final concentration is the concentration of the surfactant in the supernatant after mixing with the rock particles, oscillating, standing, and centrifuging.

[0069] The adsorption amount of surfactant on rock in mixed solutions of different types of low eutectic solvents and surfactants was calculated according to formula (1). The results are shown in Table 2 below.

[0070] Table 2: Surfactant adsorption after adding different types of deep eutectic solvents

[0071] Mixed solution type Adsorption capacity (mg / g) CTAB 2.2947 Choline chloride:glycerol 1:3-CTAB 0.4516 Choline chloride:glycolic acid 1:1-CTAB 1.4654 Choline chloride:urea 1:2-CTAB 1.0106 Choline chloride:maleic acid 2:1-CTAB 1.7525 Choline chloride:oxalate 2:1-CTAB 1.5502 Choline chloride:citric acid 1:1-CTAB 1.5195

[0072] Figure 3 The comparison chart of the adsorption amount of different types of deep eutectic solvents and hexadecyltrimethylammonium bromide mixed solution is shown in Figure 2. Figure 3 As shown in the figure, the reduction degree of surfactant adsorption by different types of deep eutectic solvents is compared. The type with the most obvious reduction effect is: choline chloride-glycerol (1:3), which can reduce the adsorption of the surfactant on the rock surface by 80%. It can be seen that in practical applications, the type of deep eutectic solvent that can be preferably configured is: choline chloride-glycerol (1:3).

[0073] It can be understood that the above-mentioned various method embodiments mentioned in the present invention can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present invention will not go into details.

[0074] Those skilled in the art will appreciate that, in the above method of specific implementation, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of the steps should be determined by their functions and possible internal logic.

[0075] Under normal circumstances, the method for testing the amount of surfactant adsorbed on the rock surface is mainly ultraviolet spectrophotometry, but the presence of low eutectic solvents will affect the degree of light absorption by surfactants, and it is impossible to accurately detect the amount of surfactant adsorbed on the rock in the presence of low eutectic solvents. Through the experiment of detecting the adsorption amount by ultraviolet spectrometer method, it was found that the spectrophotometric value after adsorption was much larger than the spectrophotometric value before adsorption, which was mainly due to the influence of low eutectic solvents, and thus it was impossible to accurately characterize the amount of surfactant adsorbed on the rock in the presence of low eutectic solvents.

[0076] The present invention overcomes the problem that the ultraviolet spectrophotometer cannot accurately characterize the amount of surfactant adsorbed on the rock surface in the presence of a low eutectic solvent. The surface tension of the mixed solution of the low eutectic solvent and the surfactant at different concentrations is measured by surface tension, and a surface tension-concentration standard relationship curve is constructed. According to the surface tension difference characteristics of the mixed solution before and after adsorption on the rock surface, the adsorption amount is reversed by the surface tension value with the help of the standard relationship curve, and the amount of surfactant adsorbed on the rock surface under the condition of the low eutectic solvent is accurately calculated, thereby realizing the accurate characterization of the amount of surfactant adsorbed on the rock surface in the presence of the low eutectic solvent. The problem that the ultraviolet spectrophotometer in the prior art cannot accurately measure the adsorption amount of a mixed solution of multiple substances is solved. The method of the present invention optimizes the most suitable low eutectic solvent configuration scheme for the work area, thereby promoting the migration of surfactants to the deep reservoir, and adjusting the dosage scheme of surfactants on the oil field site, further reducing costs and increasing efficiency, and greatly improving the oil field recovery rate has great practical significance.

[0077] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for testing the adsorption of surfactants in the presence of a deep eutectic solvent, characterized in that: include: Determine the surface tension-concentration standard relationship curve of the mixed solution of deep eutectic solvent and surfactant at different concentrations; Selecting a mixed solution of target concentration, and mixing and contacting the mixed solution of target concentration with selected rock particles to form a rock-solution system; Extracting the centrifuge liquid of the rock-solution system, measuring its surface tension, and determining the corresponding concentration of the surfactant in the centrifuge liquid according to the surface tension of the centrifuge liquid and the surface tension-concentration standard relationship curve; The adsorption amount of the surfactant on the rock is determined according to the concentration of the surfactant in the mixed solution of the target concentration and in the centrifuged liquid.

2. The method for testing the adsorption amount of surfactant in the presence of a deep eutectic solvent according to claim 1, characterized in that: The method for determining the surface tension-concentration standard relationship curve of a mixed solution of a deep eutectic solvent and a surfactant at different concentrations comprises: preparing a low eutectic solvent, and mixing the prepared low eutectic solvent with a selected surfactant to form a mixed solution; The surface tension of the mixed solution at different concentrations was measured using a surface tension meter, and a standard relationship curve between the surface tension and concentration of the mixed solution was established.

3. The method for testing the adsorption amount of surfactant in the presence of a deep eutectic solvent according to claim 1, characterized in that: The method of selecting a mixed solution of target concentration at the critical micelle concentration and mixing it with rock particles to form a rock-solution system comprises: Take a predetermined milliliter of the target concentration mixed solution and mix it with a predetermined number of grams of rock particles; The mixed rock particles and the target concentration mixed solution are placed in a constant temperature oscillator, oscillated at a predetermined speed for a first predetermined time, and then left to stand for a second predetermined time to reach an equilibrium state.

4. The method for testing the adsorption amount of surfactant in the presence of a deep eutectic solvent according to claim 1, characterized in that: The method of extracting the centrifuge of the rock-solution system, measuring its surface tension, and determining the corresponding concentration of the surfactant in the centrifuge according to the surface tension of the centrifuge and the surface tension-concentration standard relationship curve comprises: The supernatant of the rock-solution system is subjected to high-speed centrifugation, and the upper layer of the centrifuge formed after the high-speed centrifugation is taken, and its surface tension is measured; According to the measured surface tension of the centrifuge, the corresponding concentration value is found on the surface tension-concentration standard relationship curve, which is the corresponding concentration of the surfactant in the centrifuge.

5. The method for testing the adsorption amount of surfactant in the presence of a deep eutectic solvent according to claim 1, characterized in that: The method for determining the amount of surfactant adsorbed on the rock according to the surfactant concentration in the target concentration mixed solution and the concentration in the centrifuge liquid comprises: According to the concentration of the surfactant in the mixed solution of the target concentration and in the centrifuge solution, the adsorption amount of the surfactant on the rock is calculated using formula (1); Where: C0 is the initial concentration, mg / L, C e is the final concentration, mg / L, V S is the volume of the test solution, ml, and m is the weight of the core particles used, g.

6. The method for testing the adsorption amount of surfactant in the presence of a deep eutectic solvent according to claim 1, characterized in that: The method for selecting a mixed solution of target concentration comprises: Determining the critical micelle concentration of the surfactant in the mixed solution according to the surface tension-concentration standard relationship curve; The concentration of the surfactant in the target concentration mixed solution is less than the critical micelle concentration.

7. The method for testing the adsorption of surfactant in the presence of a deep eutectic solvent according to claim 2, characterized in that: The organic matter for configuring the low eutectic solvent includes choline chloride, and also includes but is not limited to: one or more of oxalic acid, glycolic acid, glycerol and urea.

8. The method for testing the adsorption of surfactant in the presence of a deep eutectic solvent according to claim 2, characterized in that: The types of surfactants selected include, but are not limited to, sodium lauryl sulfate, petroleum sulfonate, hexadecyltrimethylammonium bromide and heavy alkylbenzene sulfonate.

9. The method for testing the adsorption of surfactant in the presence of a deep eutectic solvent according to any one of claims 1 to 8, characterized in that: The selected rock particles are mixed with the target concentration mixed liquid in a ratio of 1:10.

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