Oil extraction agent, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention are an oil extraction agent, and a preparation method therefor and the use thereof. On the basis of the total weight of the oil extraction agent, the oil extraction agent of the present invention comprises: 2-30 wt% of an acid-etched mineral, 3-60 wt% of a metal salt, and 0.1-20 wt% of an amine compound. The oil extraction agent of the present invention has a great number of characteristics, such as a high oil-gas conversion rate, low preparation costs, cleanliness, environmental friendliness, high stability and a long-lasting oil displacement effect. The oil extraction agent of the present invention is used in shale oil extraction, can effectively improve the oil-gas conversion rate (the oil-gas yield being increased by as much as 21.56%) of the in-situ conversion of oil shale, and has extremely high practical and economic values.

Description

Oil extraction agent and preparation method and application thereof

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411229542.6, filed September 3, 2024, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of in-situ conversion of shale oil, in particular to an oil extraction agent and a preparation method and application thereof. BACKGROUND

[0004] Large-scale development of oil shale will effectively alleviate the tense situation of oil and gas supply. Some oil shale resources are buried deep, with an average thickness of 20-30 m, and are often interbedded with sandstone and mudstone, etc. Among them, a considerable part is poor ore with an oil content of less than 5%, and rich ore with an oil content of more than 10% is less, mainly resources with an oil content of 5-10%. In-situ conversion technology is the trend of oil shale resource development, but this technology has not been widely used due to high difficulty and development cost and other limiting factors.

[0005] In-situ mining converts solid hydrocarbons and their derivatives in oil shale into liquid hydrocarbons by high-temperature heating (350-500℃) of the oil shale reservoir, and then the liquid hydrocarbons are mined from the ground through traditional oil and gas drilling and oil extraction processes.

[0006] CN109424345B discloses a method for in-situ mining of oil shale, specifically: 1) drilling at least two wells to the oil shale reservoir on the surface of the oil shale distribution area; 2) modifying the oil shale reservoir to generate cracks; 3) injecting proppants containing magnetic nano-catalysts into the oil shale reservoir to distribute them in the cracks of the oil shale reservoir; 4) placing a heater in the heating well to heat the oil shale reservoir; under the heating condition, under the action of the magnetic nano-catalyst, the kerogen in the oil shale reservoir is cracked into output containing shale oil; 5) outputting the output to the surface through the production well, and separating and collecting it. The magnetic medium and catalyst component (i.e. active component) are Fe3O4 or at least one of Pt, Pd and Ni. However, this method has problems such as high cost of catalyst preparation, heavy metal pollution of the formation and difficult operation.

[0007] CN109985627A discloses a catalyst for improving oil yield of oil shale and a preparation method and application thereof, the catalyst is prepared by using acid-treated bentonite as a carrier, 0.1-1wt% of Co salt as an active component, 1-10wt% of Ni salt as a precursor, and NiO as an assistant prepared by calcination, impregnation and calcination, and the shale oil yield is high. The catalyst has problems of heavy metal pollution, high energy consumption in the preparation process, etc.

[0008] Therefore, it can be seen that the in-situ conversion technology has many advantages in the field of oil shale oil and gas conversion, but in the existing technology for improving the oil and gas conversion rate in the in-situ conversion process, there are problems of serious pollution to the formation, high preparation cost, low stability, etc. Therefore, it is of great significance to develop an oil extraction agent with high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, and long-lasting oil displacement effect. SUMMARY

[0009] In view of the above problems existing in the prior art, the present application provides an oil extraction agent and a preparation method and application thereof. The oil extraction agent has many characteristics such as high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, and long-lasting oil displacement effect.

[0010] The present application discloses an oil extraction agent, based on the total weight of the oil extraction agent, the oil extraction agent comprises: 1-30wt% of acid-etched minerals, 1-40wt% of metal salts, and 0.1-20wt% of amine root compounds.

[0011] In the present application, the content of acid-etched minerals is, for example, 5wt%, 10wt%, 15wt%, 18wt%, 20wt%, 25wt%, 28wt%, etc.

[0012] In the present application, the content of metal salts is, for example, 5wt%, 10wt%, 15wt%, 18wt%, 20wt%, 25wt%, 28wt%, 35wt%, etc.

[0013] In the present application, the content of amine root compounds is, for example, 1wt%, 3wt%, 5wt%, 7wt%, 10wt%, 12wt%, 15wt%, 17wt%, etc.

[0014] The oil extraction agent described in the present application has many characteristics such as high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, and long-lasting oil displacement effect, which can effectively improve the oil and gas conversion rate in the in-situ conversion of oil shale (the oil and gas yield increase is up to 21.56%), and has very high practical value and economic value.

[0015] In the present application, the pH of the oil recovery agent can be selected in a wide range, and the following exemplary description is provided, but the scope of the present application is not limited thereto. According to a preferred embodiment of the present application, the pH of the oil recovery agent is 2.5-6.5, for example, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, etc., preferably 5.5-6.5.

[0016] In the present application, the specific surface area and pore volume of the acid-etched mineral of the oil recovery agent can be selected in a wide range, and the following exemplary description is provided, but the scope of the present application is not limited thereto.

[0017] According to a preferred embodiment of the present application, the specific surface area of the acid-etched mineral is 50-200 m 2 / g, for example, 60 m 2 / g, 70 m 2 / g, 80 m 2 / g, 90 m 2 / g, 100 m 2 / g, 110 m 2 / g, 120 m 2 / g, 130 m 2 / g, 140 m 2 / g, 150 m 2 / g, 160 m 2 / g, 170 m 2 / g, 180 m 2 / g, 190 m 2 / g, etc., preferably 100-160 m 2 / g.

[0018] According to a preferred embodiment of the present application, the pore volume is 0.15-0.5 mL / g, for example, 0.2 mL / g, 0.25 mL / g, 0.3 mL / g, 0.35 mL / g, 0.4 mL / g, 0.45 mL / g, preferably 0.2-0.4 mL / g, etc.

[0019] According to a preferred embodiment of the present application, the oil recovery agent comprises 2-10 wt% of the acid-etched mineral, for example, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 9.0 wt%, etc., preferably 3.5-4.5 wt% of the acid-etched mineral.

[0020] According to a preferred embodiment of the present application, the oil recovery agent comprises 5-15 wt% of the metal salt, preferably 7-13 wt% of the metal salt, for example, 6 wt%, 8 wt%, 10 wt%, 12 wt%, etc.

[0021] According to a preferred embodiment of the present application, the oil recovery agent comprises 0.5-5 wt% of the amine radical compound, preferably 0.5-3 wt% of the amine radical compound.

[0022] In the present application, in addition to the above-mentioned main components, it is well known that the oil recovery agent further comprises a solvent, and the solvent in the oil recovery agent is not particularly limited, and is generally selected from one or more of water, ethanol, and diethyl ether.

[0023] In the present application, the metal salt is not particularly limited, and any suitable metal salt can be selected as long as the purpose of the present application is achieved, and according to a preferred embodiment of the present application, the metal salt is at least one of an organic acid salt of magnesium ion and / or calcium ion and / or an inorganic acid salt of magnesium ion and / or calcium ion.

[0024] In the present application, the type of the amine radical compound is not particularly limited, and is mainly a compound capable of forming a complex with the metal salt, for example, one or more selected from C1-C8 aliphatic amine, aromatic amine, alcohol amine, and quaternary ammonium salt.

[0025] According to a preferred embodiment of the present application, the metal salt is one or more of a sulfate salt of magnesium ion and / or calcium ion, a hydrochloride salt of magnesium ion and / or calcium ion, a nitrate salt of magnesium ion and / or calcium ion, a formate salt of magnesium ion and / or calcium ion, a phosphate salt of magnesium ion and / or calcium ion, a citrate salt of magnesium ion and / or calcium ion, an oxalate salt of magnesium ion and / or calcium ion, and an acetate salt of magnesium ion and / or calcium ion.

[0026] In the present application, the type of the amine radical compound is not particularly limited, and is mainly a compound capable of forming a complex with the metal salt, for example, one or more selected from methylamine, ethylamine, aniline, ethylenediamine, diisopropylamine, triethanolamine, and tetrabutylammonium bromide, and preferably methylamine and / or ethylenediamine.

[0027] In the present application, the acid-etched mineral has a wide selection range, and the following exemplary description is provided, but the scope of the present application is not limited thereto, and according to a preferred embodiment of the present application, the acid-etched mineral is selected from acid-etched natural minerals rich in magnesium and calcium.

[0028] In the present application, the natural mineral rich in magnesium and calcium is not particularly limited, and any suitable natural mineral rich in magnesium and calcium can be selected as long as the purpose of the present application is achieved, and according to a preferred embodiment of the present application, the natural mineral rich in magnesium and calcium is selected from one or more of magnesite, calcite, dolomite, and montmorillonite.

[0029] In the present application, the preparation method of the oil recovery agent has a wide selection range, and the following exemplary description is provided, but the scope of the present application is not limited thereto, and according to a preferred embodiment of the present application, the preparation method of the oil recovery agent comprises:

[0030] I) contacting a natural mineral with an acid solution to perform acid treatment, and separating a solid phase from a liquid phase to obtain a mixed product;

[0031] II) contacting an amine source with the liquid phase product, and then optionally adding a solvent to mix with the solid phase product to obtain an oil recovery agent.

[0032] The oil recovery agent prepared by the method has the characteristics of high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, and long-lasting oil displacement effect, and can effectively improve the oil and gas conversion rate in situ conversion of oil shale (the oil and gas yield increase is up to 21.56%), which has high practical value and economic value.

[0033] According to the present application, it can be understood that, in order to fully mix, the amine source can be slowly added to the liquid phase product in step II).

[0034] In the present application, the conditions for contacting in step II) are not particularly limited, and suitable contacting conditions can be selected as long as the purpose of the present application is achieved. According to one preferred embodiment of the present application, the conditions for the first contacting and the second contacting in step II) each include a temperature of 20-60°C.

[0035] In the present application, the time for contacting in step II) is not particularly limited, and suitable contacting times can be selected as long as the purpose of the present application is achieved. According to one preferred embodiment of the present application, the time for the first contacting and the second contacting in step II) each includes a time of 10-60 min.

[0036] In the present application, the conditions for contacting in step II) are not particularly limited, and suitable contacting conditions can be selected as long as the purpose of the present application is achieved. According to one preferred embodiment of the present application, the first contacting and the second contacting are performed under dynamic conditions, and can generally be selected as stirring or ultrasonic treatment.

[0037] In the present application, the total content of magnesium and calcium in the liquid phase product can be selected in a wide range, and the following exemplary descriptions are provided, but the scope of the present application is not limited thereto. According to one preferred embodiment of the present application, the total content of magnesium and calcium in the liquid phase product is 20-95wt% of the total content of magnesium and calcium in the natural mineral, for example, 15wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 60wt%, 65wt%, 70wt%, 75wt%, 85wt%, 95wt%, etc., and is preferably 50-60wt%.

[0038] In the present application, the kind of amine source in step II) is not particularly limited, and any suitable amine source can be selected as long as the purpose of the present application can be achieved. According to one preferred embodiment of the present application, the amine source can be selected from one or more of C1-C8 aliphatic amine, aromatic amine, alcohol amine, and quaternary ammonium salt, preferably one or more of methylamine, ethylamine, aniline, ethylenediamine, diisopropylamine, triethanolamine, and tetrabutylammonium bromide.

[0039] According to the present application, it can be understood that the amine source is provided in the form of an amine source solution.

[0040] In the present application, the concentration of the amine solution in step II) is not particularly limited, and any suitable concentration can be selected as long as the purpose of the present application can be achieved. According to one preferred embodiment of the present application, the concentration of the amine solution is 10-100 wt%, for example, 15 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 85 wt%, 95 wt%, etc.

[0041] In the present application, the solvent for forming the amine solution is not particularly limited, and for example, can be selected from one or more of water, ethanol, and diethyl ether.

[0042] In the present application, the mass ratio of the amine source to the total content of magnesium and calcium in the liquid phase product in step II) can be selected in a wide range, and the following exemplary descriptions are provided, but the scope of the present application is not limited thereto. According to one preferred embodiment of the present application, the mass ratio of the amine source to the total content of magnesium and calcium in the liquid phase product is 1:4-4:1, for example, 1:3, 1:2, 1:1, 2:1, 3:1, etc.

[0043] In the present application, the conditions for contacting in step I) are not particularly limited, and any suitable contacting conditions can be selected as long as the purpose of the present application can be achieved. According to one preferred embodiment of the present application, the conditions for contacting in step I) include that the contacting temperature is 20-100°C, preferably 30-60°C.

[0044] In the present application, the conditions for contacting in step I) are not particularly limited, and any suitable contacting conditions can be selected as long as the purpose of the present application can be achieved. According to one preferred embodiment of the present application, the conditions for contacting in step I) include that the contacting time is 10-60 min, preferably 15-55 min.

[0045] In the present application, the conditions for contacting in step I) are not particularly limited, and any suitable contacting conditions can be selected as long as the purpose of the present application can be achieved. According to one preferred embodiment of the present application, the conditions for contacting in step I) include that the pH for contacting is 2.0-6.0, preferably 3.5-6.0.

[0046] In the present application, the contacting in step I) is not particularly limited, and any suitable contacting condition can be selected as long as the object of the present application can be achieved. According to one preferred embodiment of the present application, the contacting in step I) is carried out under the condition that the mass ratio of the acid solution to the natural mineral is 2-20, for example, 3, 5, 7, 9, 10, 12, 14, 16, 18, or the like, preferably 13-15.

[0047] In the present application, the acid substance of the acid solution in step I) is not particularly limited, and any suitable acid substance can be selected as long as the object of the present application can be achieved. According to one preferred embodiment of the present application, the acid substance of the acid solution is selected from inorganic acid and / or organic acid.

[0048] In the present application, the concentration of the acid solution in step I) can be selected in a wide range, which is exemplarily illustrated below, but the scope of the present application is not limited thereto. According to one preferred embodiment of the present application, the concentration of the acid solution is 0.01-20 mol / L, preferably 4-17 mol / L.

[0049] In the present application, the inorganic acid in step I) is not particularly limited, and any suitable inorganic acid can be selected as long as the object of the present application can be achieved. According to one preferred embodiment of the present application, the inorganic acid is selected from one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.

[0050] In the present application, the organic acid in step I) is not particularly limited, and any suitable organic acid can be selected as long as the object of the present application can be achieved. According to one preferred embodiment of the present application, the organic acid comprises C1-C8 organic acid, which is preferably selected from one or more of formic acid, citric acid, oxalic acid, and acetic acid.

[0051] In the present application, the natural mineral in step I) can be selected in a wide range, which is exemplarily illustrated below, but the scope of the present application is not limited thereto. According to one preferred embodiment of the present application, the natural mineral is selected from natural minerals rich in magnesium and calcium.

[0052] In the present application, the total content of magnesium and calcium in the natural mineral rich in magnesium and calcium in step I) can be selected in a wide range, which is exemplarily illustrated below, but the scope of the present application is not limited thereto. According to one preferred embodiment of the present application, the total content of magnesium and calcium in the natural mineral rich in magnesium and calcium is 30-90 wt%, preferably 40-80 wt%.

[0053] In the present application, in the step I), the natural mineral rich in magnesium and calcium can be selected from a wide range, and the following exemplary description is provided, but the scope of the present application is not limited thereto, according to a preferred embodiment of the present application, the natural mineral rich in magnesium and calcium can be selected from one or more of magnesite, calcite, dolomite and montmorillonite.

[0054] The oil extraction agent prepared by the preparation method.

[0055] The oil extraction agent has high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, long-lasting oil displacement effect and other characteristics.

[0056] The oil extraction agent has high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, long-lasting oil displacement effect and other characteristics.

[0057] The oil extraction agent has high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, long-lasting oil displacement effect and other characteristics. DETAILED DESCRIPTION

[0058] The endpoints of the ranges and any values claimed herein are presented as approximations only. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Also, as used herein, the indefinite article "a" or "an" means "one or more" unless otherwise specifically indicated.

[0059] The specific embodiments of the present application are described in detail below, but it should be noted that the scope of protection of the present application is not limited by these specific embodiments, but is determined by the claims of the appendix.

[0060] All publications, patent applications, patents and other references mentioned in this specification are hereby incorporated by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present specification will control.

[0061] When the specification derives materials, substances, methods, steps, devices or components, etc. with the word head "known to those skilled in the art", "prior art" or similar language, the object derived by the word head covers those commonly used in the art at the time the present application is proposed, but also includes those not commonly used at present, but will be recognized as suitable for similar purposes in the art.

[0062] It should be particularly noted that two or more aspects (or embodiments) disclosed in the context of the present specification can be combined with each other arbitrarily, and the technical solutions (such as methods or systems) formed thereby belong to the part of the original disclosure of the present specification and also fall within the protection scope of the present application.

[0063] In the prior art, the oil and gas conversion rate in the in-situ conversion process is improved, and the problems of serious pollution to the formation, high preparation cost and low stability are widespread. To solve the above technical problems, the present application provides an oil extraction agent and its preparation method and application. The oil extraction agent has the characteristics of high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, long-lasting oil displacement effect and the like. The oil extraction agent is used in oil shale oil extraction, which can effectively improve the oil and gas conversion rate in the in-situ conversion of oil shale (the oil and gas yield increase is up to 21.56%), and has high practical value and economic value.

[0064] The oil extraction agent has the characteristics of high oil and gas conversion rate, low preparation cost, clean and environmentally friendly, high stability, long-lasting oil displacement effect and the like.

[0065] The oil extraction agent is used in oil shale oil extraction, which can effectively improve the oil and gas conversion rate in the in-situ conversion of oil shale (the oil and gas yield increase is up to 21.56%), and has high practical value and economic value.

[0066] The present application will be described in detail below through examples. It is necessary to point out here that the following examples are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above content of the present application.

[0067] If the specific experimental steps or conditions are not specified in the examples and comparative examples, the operations or conditions can be carried out according to the conventional experimental steps described in the literature in the art. If the reagents or instruments are not specified by the manufacturer, they are all conventional reagent products that can be obtained by market purchase.

[0068] In the present application, the composition of the oil extraction agent is calculated by feeding.

[0069] 1. Source of raw materials or equipment:

[0070] Dolomite, calcite, dolomite and montmorillonite are commercially available products, all from Shandong Xinhai Mining Equipment Co., Ltd. The content of Mg and Ca in each ore is as follows:

[0071] Dolomite (Mg: 43.82%, Ca: 9.18%);

[0072] Calcite (Mg: 30%, Ca: 50%);

[0073] Dolomite (Mg: 22.23%, Ca: 21.71%);

[0074] Montmorillonite: (Mg: 22%, Ca: 34%).

[0075] Sulfuric acid, hydrochloric acid, phosphoric acid, formic acid, citric acid, oxalic acid, acetic acid, methylamine, ethylamine, aniline, ethylenediamine, diisopropylamine, triethanolamine, tetrabutylammonium bromide are all from National Pharmaceutical Group Chemical Reagent Co., Ltd., and the purity is chemical pure.

[0076] Oil shale is selected from the mined ore of PetroChina Changqing Oilfield Branch, the mesh number is 80-120, and the TOC (Total Organic Carbon) content is 12.13%.

[0077] 2. Test equipment and method

[0078] 2.1, Oil and gas product analysis: Agilent 6890 gas chromatograph is used, and helium is used as the carrier gas. The sample inlet temperature for gas analysis is 250°C, and the split ratio is 25:1. The column oven temperature conditions are as follows: the initial temperature is 68°C, which is maintained for 7 min, then the temperature is increased to 90°C at a rate of 10°C / min, maintained for 1.5 min, then increased to 175°C at a rate of 15°C / min, and finally maintained for 5 min.

[0079] 2.2, Oil and gas production test: JGMN-1 type gold tube hydrocarbon simulation instrument is used, and the test is carried out according to the oil and gas industry standard SYT7035-2016. The test method is as follows: the oil recovery agent and the oil shale mixed sample are put into the instrument, the pressure is set to the target test pressure, and the temperature is increased to the target test temperature at a rate of 20°C / min. The oil shale pyrolysis conversion is carried out for 72 hours under the conditions of target pressure and target temperature, the oil and gas products are analyzed by gas chromatograph, and the test results are analyzed subsequently to obtain the oil and gas production test results.

[0080] 2.3, Hydrocarbon gas metering analysis:

[0081] The collection of gas products in the gold tube is carried out in a special quantitative collection device. First, the reacted gold tube is fixed in the appropriate position of the sampling device, and after sealing, it is extracted to a near-vacuum state, and the vacuum state pressure (P1) is recorded. The gold tube is pierced, and after the pressure gauge shows balance, the pressure value (P2) is recorded. The gas volume is calculated according to the following formula: V = V0 x (P2-P1) / P0

[0082] In the formula: V0 is the volume of the gas collection device; P0 is the atmospheric pressure value when the gas is quantified.

[0083] The mass of each gas component is calculated by the ideal gas state equation: M = V x m0 / 22.4

[0084] In the formula, m0 is the molar mass of the gas component being calculated; the total weight of the gas components (G0) is the sum of the masses of each gas component.

[0085] M is the value in the "hydrocarbons" column of Table 1.

[0086] 2.4 Oil and Gas Quantitative Analysis:

[0087] a) Light hydrocarbons in oil and gas

[0088] Because light hydrocarbon solutions are volatile, direct measurement is difficult. Therefore, the difference method was used for quantitative analysis of light hydrocarbons in the experiment. First, the simulated gold tube containing the sample was weighed, and its weight (G) was recorded. t Then, after the gas analysis was performed, the gold tube was left to stand for one day until all the gas and light hydrocarbons in the gold tube had dissipated before being weighed and its weight (G) was recorded. cz1 The weight of the light hydrocarbon (G1) is equal to the weight lost minus the total weight of the gas, that is: G1 = G t -G cz1 -G0

[0089] b) Liquid hydrocarbons in oil and gas

[0090] To minimize errors, the weight of liquid hydrocarbons during the experiment was measured using two methods, and the average value of the data obtained from the two methods was used as the standard.

[0091] The first testing method: The amount of liquid hydrocarbons generated in the reaction / the amount of oil discharged is obtained by combining CH2Cl2 ultrasonic extraction and the weighing difference method. The gold tube, after gas analysis, is placed in CH2Cl2 solvent and cut open. The CH2Cl2 solvent used to soak the gold tube is then ultrasonically treated three times. Solid residues are filtered out using a chromatographic membrane. The resulting liquid solution is then weighed after the organic solvent has completely evaporated to obtain the weight of the liquid hydrocarbons (G). cy1 ).

[0092] The second testing method: After the gold tube and residue have been extracted and filtered, they are dried and then weighed, and their weight (G) is recorded. cz2 This weight is the same as the weight of the gold tube and sample after gas and light hydrocarbon analysis (G). cz1 The difference is also the weight of the liquid hydrocarbons produced (G). cy2 ), that is: G cy2 =G cz1 -G cz2

[0093] The average of the two test methods is taken as the weight of liquid hydrocarbon (G). y ): G y =(G cy1 +G cy2 ) / 2

[0094] G1 and G y The value in the column of "oil discharge" in Table 1 is the sum of the values in the columns of "calcium" and "magnesium".

[0095] The value in the column of "total oil and gas" in Table 1 is the sum of the values in the columns of "hydrocarbon gas" and "oil discharge".

[0096] The column of "oil and gas increment" in Table 1 is the value obtained by comparing the total oil and gas values of the other examples with the total oil and gas value of Comparative Example 1.

[0097] 2.5, Surface morphology characterization of oil recovery agent: a scanning electron microscope is used to observe the surface morphology of the sample. Test method: first, the sample to be tested is treated with 2 times of gold spraying for 10 minutes, and then placed on the observation platform for sample observation.

[0098] 2.6, Specific surface area and pore volume test of acid-etched minerals: an ASAP 2460 full-automatic specific surface analyzer of Micromeritics Company of the United States is used to determine the BET specific surface area and pore volume of the sample. Test method: first, the sample is pretreated (vacuum state) at high temperature (300°C) for 8h; the sample is cooled using liquid nitrogen, and when the sample temperature is -196°C, the sample is analyzed. The total specific surface area data is calculated by BET method; the micropore volume data is calculated by t-plot method, the mesopore volume is calculated by BJH method, and the sum of the two is the pore volume.

[0099] 2.7, pH value test method: at room temperature, immerse the pH meter electrode into the standard buffer solution, calibrate according to the instrument instructions, rinse the electrode with distilled water or deionized water to remove the impurities attached to the surface. Immerse the pH meter electrode into the solution to be tested, and read the pH value after the value is stable.

[0100] Example 1

[0101] (1) Acid treatment of natural minerals:

[0102] Mix 50g of magnesite and a 0.1mol / L sulfuric acid aqueous solution at 20°C, the liquid-solid mass ratio is 2, under the condition of pH=2.8, filter after 60 minutes of treatment to obtain liquid product 1 and solid product 1, the content of magnesium and calcium (in atoms) in the liquid phase after acid treatment accounts for 60wt% of the total magnesium and calcium content (in atoms) of the original natural mineral;

[0103] (2) Combination with amine:

[0104] Slowly add 3.98g of 10wt% concentration of methylamine aqueous solution to liquid product 1, stir thoroughly at 20°C for 60min, then add 3g of water to prepare oil recovery agent 1 with solid product 1.

[0105] (3) Oil extraction agent composition and physical property characterization:

[0106] The pH of the oil extraction agent 1 is 6.5, and the composition includes: 21.72wt% of acid-etched minerals, 39.17wt% of metal salts, and 2.53wt% of amine root compounds;

[0107] The specific surface area of the acid-etched minerals is 85m 2 / g, and the pore volume is 0.19mL / g;

[0108] (4) Oil and gas production test:

[0109] After 2.7 grams of oil extraction agent 1 and 3 grams of oil shale powder are thoroughly mixed and evenly distributed, 0.8 grams are weighed for hydrocarbon generation simulation experiment, the target temperature is 100℃, and the experiment is carried out at 100℃, 30Mpa for 72h; the oil and gas produced in the hydrocarbon generation simulation experiment is analyzed, and the final oil and gas production test result is obtained.

[0110] Example 2

[0111] (1) Natural mineral acid treatment:

[0112] 20 grams of calcite and 2.5mol / L hydrochloric acid aqueous solution are thoroughly mixed at 50℃, the liquid-solid mass ratio is 18, and after 40 minutes of treatment at pH=6, filtration is carried out to obtain liquid product 2 and solid product 2, and the content of magnesium and calcium in the liquid phase after acid treatment accounts for 30wt% of the total magnesium and calcium content of the original natural mineral (in atoms);

[0113] (2) Combine amine:

[0114] 2.06 grams of 100wt% concentrated ethylamine is slowly added to the acid treatment product 2, and after 10 minutes of thorough stirring at 60℃, 30 grams of ethylamine is added to prepare oil extraction agent 2 with the solid product 2;

[0115] (3) Oil extraction agent composition and physical property characterization:

[0116] The pH of the oil extraction agent 2 is 4.5, and the composition includes: 3.69wt% of acid-etched minerals, 3.92wt% of metal salts, and 0.50wt% of amine root compounds;

[0117] The specific surface area of the acid-etched minerals is 99m 2 / g, and the pore volume is 0.21mL / g;

[0118] (4) Oil and gas production test:

[0119] 0.6 grams of oil agent 2 and 3 grams of oil shale powder were mixed evenly, 0.8 grams of which were weighed for the hydrocarbon generation simulation experiment, the target temperature was 180 DEG C, and the hydrocarbon generation simulation experiment was carried out at 180 DEG C and 10 MPa for 72 h. The oil and gas produced in the hydrocarbon generation simulation experiment were analyzed, and the final oil and gas production test results were obtained.

[0120] Example 3

[0121] (1) Natural mineral acid treatment:

[0122] 70 grams of dolomite and a 20 mol / L formic acid aqueous solution were mixed at 30 DEG C, the liquid-solid mass ratio was 20, and the treatment was carried out at pH = 3.2 for 20 minutes, and then filtered to obtain liquid product 3 and solid product 3. After acid treatment, the content of magnesium and calcium in the liquid phase (in atoms) accounted for 80wt% of the total magnesium and calcium content (in atoms) of the original natural mineral;

[0123] (2) Amine combination:

[0124] 17.15 grams of a 20wt% aniline-ethanol solution was added to the liquid product 3, and after being stirred at 30 DEG C for 20 min, 160 grams of ethanol and solid product 3 were added to prepare oil agent 3;

[0125] (3) Oil agent composition and physical property characterization:

[0126] The pH of the oil agent 3 was 3.0, and the composition included 2.69wt% of acid-etched minerals, 7.83wt% of metal salts, and 1.04wt% of amine root compounds;

[0127] The specific surface area of the acid-etched mineral was 167m 2 / g, and the pore volume was 0.35 mL / g;

[0128] (4) Oil and gas production test:

[0129] 0.3 grams of oil agent 3 and 3 grams of oil shale powder were mixed evenly, 0.8 grams of which were weighed for the hydrocarbon generation simulation experiment, the target temperature was 600 DEG C, and the hydrocarbon generation simulation experiment was carried out at 600 DEG C and 20 MPa for 72 h. The oil and gas produced in the hydrocarbon generation simulation experiment were analyzed, and the final oil and gas production test results were obtained.

[0130] Example 4

[0131] (1) Natural mineral acid treatment:

[0132] Mix 60 g of montmorillonite and formic acid aqueous solution with a concentration of 15 mol / L at 70 ℃, the liquid-solid mass ratio is 5, under the condition of pH = 3.9, after treatment for 30 min, filter to obtain liquid product 4 and solid product 4, the content of magnesium and calcium (in atom) in the liquid phase after acid treatment accounts for 90wt% of the total magnesium and calcium content (in atom) of the original natural mineral;

[0133] (2) Combine amine:

[0134] Slowly add 30.24 g of 30% concentration ethylenediamine aqueous solution to the liquid product 4, after fully stirring at 50 ℃ for 30 min, add 80 g of water and solid product 4 to prepare oil recovery agent 4;

[0135] (3) Oil recovery agent composition and physical property characterization:

[0136] The pH of the oil recovery agent 4 is 3.8, and the composition includes: 6.33wt% of acid-etched minerals, 21.65wt% of metal salts, and 6.43wt% of amine root compounds;

[0137] The specific surface area of the acid-etched minerals is 132 m 2 / g, and the pore volume is 0.31 mL / g;

[0138] (4) Oil and gas production test:

[0139] After 0.9 g of oil recovery agent 4 is fully mixed with 3 g of oil shale powder, 0.8 g is weighed for hydrocarbon generation simulation experiment, the target temperature is 500 ℃, and the experiment is kept at 500 ℃ and 15 MPa for 72 h; analyze the oil and gas produced in the hydrocarbon generation simulation experiment to obtain the final oil and gas production test results.

[0140] Example 5

[0141] (1) Natural mineral acid treatment:

[0142] Mix 80 g of montmorillonite and citric acid aqueous solution with a concentration of 7 mol / L at 40 ℃, the liquid-solid mass ratio is 7, under the condition of pH = 5.2, after treatment for 45 min, filter to obtain liquid product 5 and solid product 5, the content of magnesium and calcium (in atom) in the liquid phase after acid treatment accounts for 20wt% of the total magnesium and calcium content (in atom) of the original natural mineral;

[0143] (2) Combine amine:

[0144] Slowly add 12.72 g of 45wt% concentration diisopropylamine ethyl ether solution to the liquid product 5, after fully stirring at 55 ℃ for 35 min, add 100 g of ethyl ether and solid product 5 to prepare oil recovery agent 5;

[0145] (3) Oil recovery agent composition and physical property characterization:

[0146] The pH of the oil extraction agent 5 is 3.5, and the composition includes: 9.55wt% of the acid-etched mineral, 23.03wt% of the metal salt, and 1.69wt% of the amine root compound;

[0147] The specific surface area of the acid-etched mineral is 109m 2 / g, and the pore volume is 0.26mL / g;

[0148] (4) Oil and gas production test:

[0149] After 2.1 grams of the above oil extraction agent 5 and 3 grams of oil shale powder are mixed uniformly, 0.8 grams are weighed for the hydrocarbon generation simulation experiment, the target temperature is 400°C, and the experiment is kept at 400°C and 25Mpa for 72h; the oil and gas produced in the hydrocarbon generation simulation experiment is analyzed to obtain the final oil and gas production test result.

[0150] Example 6

[0151] (1) Natural mineral acid treatment:

[0152] 100 grams of dolomite and a 9mol / L citric acid aqueous solution are mixed at 80°C, the liquid-solid mass ratio is 9, and the treatment is kept at pH=4.4 for 50 minutes, then filtered to obtain liquid product 6 and solid product 6, and the content of magnesium and calcium (in atoms) in the liquid phase after acid treatment accounts for 95wt% of the total magnesium and calcium content (in atoms) of the original natural mineral;

[0153] (2) Combine amine:

[0154] 101.83 grams of a 55wt% triethanolamine ethanol solution is slowly added to the liquid product 6, and after being stirred at 35°C for 25min, 150 grams of ethanol and the solid product 6 are added to prepare the oil extraction agent 6;

[0155] (3) Oil extraction agent composition and physical property characterization:

[0156] The pH of the oil extraction agent 6 is 4.3, and the composition includes: 4.50wt% of the acid-etched mineral, 29.8wt% of the metal salt, and 8.13wt% of the amine root compound;

[0157] The specific surface area of the acid-etched mineral is 116m 2 / g, and the pore volume is 0.23mL / g;

[0158] (4) Oil and gas production test:

[0159] The 1.2 grams of the oil extraction agent 6 and 3 grams of oil shale powder were mixed evenly, 0.8 grams of the mixture was weighed and subjected to hydrocarbon generation simulation experiment, the target temperature was 550 DEG C, and the hydrocarbon generation simulation experiment was carried out at 550 DEG C and 12 Mpa for 72 h; the oil and gas generated in the hydrocarbon generation simulation experiment was analyzed, and the final oil and gas production test result was obtained.

[0160] Example 7

[0161] (1) Acid treatment of natural mineral:

[0162] 70 grams of magnesite and a phosphoric acid aqueous solution with a concentration of 13 mol / L were mixed at 100 DEG C, the liquid-solid mass ratio was 11, and the treatment was carried out at pH = 4.9 for 10 minutes, and then filtration was carried out, to obtain the liquid phase product 7 and the solid phase product 7, the content of magnesium and calcium in the liquid phase after acid treatment accounted for 40wt% of the total magnesium and calcium content (in atoms) of the original natural mineral;

[0163] (2) Amine combination:

[0164] 59.36 grams of a tetrabutylammonium bromide aqueous solution with a concentration of 65wt% was slowly added to the liquid phase product 7, and after being fully stirred at 25 DEG C for 45 min, 220 grams of water was added to prepare the oil extraction agent 7 together with the solid phase product 7;

[0165] (3) Composition and physical property characterization of oil extraction agent:

[0166] The pH of the oil extraction agent 7 was 4.8, and the composition included 4.93wt% of acid-etched mineral, 11.62wt% of metal salt and 5.30wt% of amine root compound;

[0167] The specific surface area of the acid-etched mineral was 113 m 2 / g, and the pore volume was 0.31 mL / g;

[0168] (4) Oil and gas production test:

[0169] 1.5 grams of the oil extraction agent 7 and 3 grams of oil shale powder were mixed evenly, 0.8 grams of the mixture was weighed and subjected to hydrocarbon generation simulation experiment, the target temperature was 450 DEG C, and the hydrocarbon generation simulation experiment was carried out at 450 DEG C and 17 Mpa for 72 h; the oil and gas generated in the hydrocarbon generation simulation experiment was analyzed, and the final oil and gas production test result was obtained.

[0170] Example 8

[0171] (1) Acid treatment of natural mineral:

[0172] 65 grams of calcite and oxalic acid aqueous solution with a concentration of 17 mol / L were mixed at 30℃, the liquid-solid mass ratio was 13, under the condition of pH = 5.8, after 55 minutes of treatment, filtering was performed to obtain liquid product 8 and solid product 8, the content of magnesium and calcium (in atoms) in the liquid phase after acid treatment accounted for 50wt% of the total magnesium and calcium content (in atoms) of the original natural mineral;

[0173] (2) Combined amine:

[0174] 26 grams of 70wt% concentration of methylamine aqueous solution was added to the liquid product 8, after fully stirring at 30℃ for 40 min, 80 grams of water was added to prepare the oil recovery agent 8 with the solid product 8;

[0175] (3) Composition and physical property characterization of oil recovery agent:

[0176] The pH of the oil recovery agent 8 was 6.5, and the composition included: 3.84wt% of acid-etched minerals, 12.65wt% of metal salts, and 2.56wt% of amine root compounds;

[0177] The specific surface area of the acid-etched minerals was 154m 2 / g, and the pore volume was 0.33mL / g;

[0178] (4) Oil and gas production test:

[0179] 1.8 grams of the above oil recovery agent 8 was mixed with 3 grams of oil shale powder, and 0.8 grams was weighed for hydrocarbon generation simulation experiment, the target temperature was 300℃, and the experiment was kept at 300℃, 22Mpa for 72h; the oil and gas produced in the hydrocarbon generation simulation experiment was analyzed to obtain the final oil and gas production test results.

[0180] Example 9

[0181] (1) Acid treatment of natural mineral:

[0182] 40 grams of dolomite and acetic acid solution with a concentration of 4mol / L were mixed at 60℃, the liquid-solid mass ratio was 15, under the condition of pH = 3.6, after 15 minutes of treatment, filtering was performed to obtain liquid product 9 and solid product 9, the content of magnesium and calcium (in atoms) in the liquid phase after acid treatment accounted for 60wt% of the total magnesium and calcium content (in atoms) of the original natural mineral;

[0183] (2) Combined amine:

[0184] 3.68 grams of 80wt% concentration of ethylenediamine aqueous solution was slowly added to the liquid product 9, after fully stirring at 20℃ for 50 min, 60 grams of water was added to prepare the oil recovery agent 9 with the solid product 9;

[0185] (3) Composition and physical property characterization of oil recovery agent:

[0186] The pH of the oil recovery agent 9 is 5.7, and the composition includes: 4.12wt% of the acid-etched mineral, 7.44wt% of the metal salt, and 0.52wt% of the amine root compound;

[0187] The specific surface area of the acid-etched mineral is 102m 2 / g, and the pore volume is 0.22mL / g;

[0188] (4) Oil and gas production test:

[0189] After 2.4 grams of the above oil recovery agent 9 and 3 grams of oil shale powder are mixed uniformly, 0.8 grams are weighed for the hydrocarbon generation simulation experiment, the target temperature is 350°C, and the experiment is kept at 350°C and 27Mpa for 72h; the oil and gas produced in the hydrocarbon generation simulation experiment is analyzed to obtain the final oil and gas production test result.

[0190] Example 10

[0191] (1) Natural mineral acid treatment:

[0192] 90 grams of montmorillonite and a sulfuric acid aqueous solution with a concentration of 12mol / L are mixed at 75°C, the liquid-solid mass ratio is 19, and the treatment is kept at pH=3.8 for 25 minutes before filtration to obtain liquid product 10 and solid product 10. After acid treatment, the content of magnesium and calcium (in atoms) in the liquid phase accounts for 70wt% of the total magnesium and calcium content (in atoms) of the original natural mineral;

[0193] (2) Amine combination:

[0194] 18.99 grams of aniline ethyl ether solution with a concentration of 90wt% is slowly added to the liquid product 10, and after being stirred at 45°C for 15min, 130 grams of ethyl ether is added to the solid product 10 to prepare the oil recovery agent 10;

[0195] (3) Oil recovery agent composition and physical property characterization:

[0196] The pH of the oil recovery agent 10 is 5.2, and the composition includes: 2.81wt% of the acid-etched mineral, 7.26wt% of the metal salt, and 0.97wt% of the amine root compound;

[0197] The specific surface area of the acid-etched mineral is 132m 2 / g, and the pore volume is 0.30mL / g;

[0198] (4) Oil and gas production test:

[0199] 0.75 grams of the above oil recovery agent 10 was mixed with 3 grams of oil shale powder, and 0.8 grams of the mixture was weighed for the hydrocarbon generation simulation experiment, the target temperature was 200℃, and the experiment was carried out at 200℃ and 19Mpa for 72h; the oil and gas produced in the hydrocarbon generation simulation experiment was analyzed, and the final oil and gas production test results were obtained.

[0200] Comparative Example 1

[0201] 0.8 grams of oil shale was directly weighed for the hydrocarbon generation simulation experiment, the target temperature was 200℃, and the experiment was carried out at 200℃ and 19Mpa for 72h; the oil and gas produced in the hydrocarbon generation simulation experiment was analyzed, and the final oil and gas production test results were obtained.

[0202] Comparative Example 2

[0203] 59.36 grams of 65% concentration of tetrabutylammonium bromide aqueous solution was directly mixed with 118.72 grams of oil shale powder, and 0.8 grams of the mixture was weighed for the hydrocarbon generation simulation experiment, the target temperature was 450℃, and the experiment was carried out at 450℃ and 17Mpa for 72h; the oil and gas produced in the hydrocarbon generation simulation experiment was analyzed, and the final oil and gas production test results were obtained.

[0204] Comparative Example 3

[0205] 70 grams of dolomite and 20 mol / L concentration of formic acid aqueous solution were mixed at 30℃, the liquid-solid mass ratio was 20, and the liquid phase product D3 and the solid phase product D3 were obtained after filtration under the condition of pH=3.2 for 20 minutes;

[0206] 25.73 grams of the solid phase product D3 was directly mixed with 257.3 grams of oil shale powder, and 0.8 grams of the mixture was weighed for the hydrocarbon generation simulation experiment, the target temperature was 600℃, and the experiment was carried out at 600℃ and 20Mpa for 72h; the oil and gas produced in the hydrocarbon generation simulation experiment was analyzed, and the final oil and gas production test results were obtained.

[0207] Table 1 Reaction evaluation results of examples and comparative examples

[0208] As shown in Table 1 above, the oil and gas production of Examples 1-10 (with added oil recovery agent) was significantly increased compared to Comparative Example 1 (without added oil recovery agent). The likely reason is that the magnesium- and calcium-rich natural minerals, after acid treatment and amination, form an oil recovery agent with an amination mineral system. When the oil recovery agent is in a temperate or pressurized shale formation, the amine compounds in the agent continuously and slowly release NH3. NH3 reacts with water molecules in the formation to form an alkaline solution, reducing surface tension, emulsifying and carrying oil molecules, altering the wettability of the formation, and enhancing the oil displacement effect, thereby improving the oil and gas recovery rate of shale oil. The oil recovery agent prepared in this way is low-cost, clean, and environmentally friendly, while also exhibiting good stability and continuous oil displacement effect. The maximum oil and gas increase can reach 21.56%. Comparative Examples 2 and 3 were not implemented according to this technology, so the in-situ conversion effect was poor, and the oil and gas increase was low.

[0209] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An oil recovery agent, characterized by, The oil extraction agent comprises 1-30 wt% of the acid-etched mineral, 1-40 wt% of the metal salt, and 0.1-20 wt% of the amine base compound, based on the total weight of the oil extraction agent.

2. The oil recovery agent according to claim 1, characterized in that, The pH of the oil extraction agent is 2.5-6.

5.

3. The oil recovery agent of claim 2, wherein The pH of the oil extraction agent is 5.5-6.

5.

4. The oil production agent according to any one of claims 1 to 3, characterized in that, The acid-etched mineral has a specific surface area of 50-200 m 2 / g; a pore volume of 0.15-0.5 mL / g.

5. The oil recovery agent of claim 4, wherein The specific surface area of the acid-etched mineral is 100-160 m 2 / g; the pore volume is 0.2-0.4 mL / g.

6. The oil extraction agent according to any one of claims 1-3, wherein the oil extraction agent comprises 2-10 wt% of the acid-etched mineral, 5-15 wt% of the metal salt, and 0.5-5 wt% of the amine base compound. The oil extraction agent comprises 2-10 wt% of the acid-etched mineral, 5-15 wt% of the metal salt, and 0.5-5 wt% of the amine base compound. The solvent in the oil extraction agent is selected from one or more of water, ethanol, and diethyl ether.

7. The oil extraction agent according to claim 6, wherein the oil extraction agent comprises 3.5-4.5 wt% of the acid-etched mineral, 7-13 wt% of the metal salt, and 0.5-3 wt% of the amine base compound.

8. The oil extraction agent according to any one of claims 1-3, wherein the metal salt is one or more of an organic acid salt of magnesium ion and / or calcium ion and / or an inorganic acid salt of magnesium ion and / or calcium ion; and / or the amine base compound is selected from one or more of a C1-C8 aliphatic amine, an aromatic amine, an alcohol amine, and a quaternary ammonium salt.

9. The oil extraction agent according to any one of claims 1-3, wherein the metal salt is one or more of a sulfate salt of magnesium ion and / or calcium ion, a chloride salt of magnesium ion and / or calcium ion, a nitrate salt of magnesium ion and / or calcium ion, a formate salt of magnesium ion and / or calcium ion, a phosphate salt of magnesium ion and / or calcium ion, a citrate salt of magnesium ion and / or calcium ion, an oxalate salt of magnesium ion and / or calcium ion, and an acetate salt of magnesium ion and / or calcium ion; and / or the amine base compound is selected from one or more of methylamine, ethylamine, aniline, ethylenediamine, diisopropylamine, triethanolamine, and tetrabutylammonium bromide.

10. The oil extraction agent according to claim 9, wherein the amine base compound is methylamine and / or ethylenediamine. The acid-etched mineral is selected from an acid-etched natural mineral rich in magnesium and calcium. The natural mineral rich in magnesium and calcium is selected from one or more of magnesite, calcite, dolomite, and montmorillonite. The method comprises: I) contacting a natural mineral with an acid solution for acid treatment, and separating the solid and liquid phases to obtain a liquid phase product and a solid phase product; II) contacting an amine source with the liquid phase product, and then optionally adding a solvent to mix with the solid phase product to obtain the oil extraction agent. In step II), the contacting conditions each comprise:

11. The oil recovery agent of any one of claims 1 to 3, wherein a temperature of 20-60°C; and / or 12. The oil recovery agent of claim 11, wherein, a time of 10-60 min; and / or 13. A method for producing an oil recovery agent, characterized by, under dynamic conditions. In the liquid phase product, the total content of magnesium and calcium is 20-95 wt% of the total content of magnesium and calcium in the natural mineral. In the liquid phase product, the total content of magnesium and calcium is 50-60 wt% of the total content of magnesium and calcium in the natural mineral.

14. The method of claim 13, wherein, In step II), the amine source is one or more of a C1-C8 aliphatic amine, an aromatic amine, an alcohol amine, and a quaternary ammonium salt; and / or the amine source is provided in the form of an amine solution, and the concentration of the amine solution is 10-100 wt%, and the solvent is one or more of water, ethanol, and diethyl ether. In step II), 15. The preparation method according to claim 13, characterized in that, ​ 16. The method of claim 15, wherein, ​ 17. The production method according to claim 13 or 14, characterized by, ​ ​ ​ 18. The method of claim 17, wherein, ​ The amine source is one or more of methylamine, ethylamine, aniline, ethylenediamine, diisopropylamine, triethanolamine, and tetrabutylammonium bromide.

19. The production method according to claim 13 or 14, characterized by, In step II), the mass ratio of the amine source to the total content of magnesium and calcium in the liquid product is 1:4-4:1 in atom.

20. The method of manufacturing according to claim 13 or 14, wherein, In step I), the conditions for the contacting include: the temperature is 20-100℃; and / or the time is 10-60min; and / or the pH is 2.0-6.0; and / or the mass ratio of the acid solution to the natural mineral is 2-20.

21. The method of claim 20, wherein, In step I), the conditions for the contacting include: the temperature is 30-60℃; and / or the time is 15-55min; and / or the pH is 3.5-6.0; and / or the mass ratio of the acid solution to the natural mineral is 13-15.

22. The method of manufacturing according to claim 13 or 14, wherein, In step I), the acid substance of the acid solution includes inorganic acid and / or organic acid; and / or the concentration of the acid solution is 0.01-20mol / L.

23. The preparation method according to claim 22, characterized in that, In step I), the inorganic acid includes one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid; and / or the organic acid includes C1-C8 organic acid; and / or the concentration of the acid solution is 4-17mol / L.

24. The method of claim 23, wherein, In step I), the organic acid includes one or more of formic acid, citric acid, oxalic acid, and acetic acid.

25. The method of manufacturing according to claim 13 or 14, wherein, In step I), the natural mineral is selected from natural minerals rich in magnesium and calcium.

26. The method of claim 25, wherein, In step I), the total content of magnesium and calcium in the natural mineral rich in magnesium and calcium is 30-90wt% in atom.

27. The method of claim 26, wherein, In step I), the total content of magnesium and calcium in the natural mineral rich in magnesium and calcium is 40-80wt% in atom.

28. The method of claim 25, wherein, In step I), the natural mineral rich in magnesium and calcium is selected from one or more of magnesite, calcite, dolomite, and montmorillonite.

29. The oil recovery agent prepared by the preparation method of any one of claims 13-28.

30. The use of the oil recovery agent of any one of claims 1-12 and 29 in the field of oil recovery.

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