Energy-enhancing oil-displacing agent, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of the in-situ conversion of shale oil. Disclosed are an energy-enhancing oil-displacing agent, and a preparation method therefor and the use thereof. The oil-displacing agent comprises: an acid-etched mineral, an alcohol, metal ions and an acidified aqueous solution. On the basis of the total weight of the oil-displacing agent, the content of the acid-etched mineral is 1.0-22 wt%; the content of the alcohol is 0.4-10 wt%; and the content of the metal ions is 0.5-25 wt%. The oil-displacing agent of the present invention has a good oil-displacing effect, and can continuously promote the expulsion of generated oil and gas, thereby improving the oil expulsion volume and oil and gas production of shale oil extraction. Main raw materials used in the preparation method for an oil-displacing agent of the present invention comprise a natural mineral, an acid solution and an alcohol, and the preparation process involves a contact reaction; therefore, the costs are low, the preparation process is convenient, clean and environmentally friendly, and the preparation method is suitable for large-scale industrial production.

Description

Energy-boosting oil displacement agent and its preparation method and application

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411229540.7, 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 oil shale, in particular to an energy-boosting oil displacement agent and its preparation method and application. BACKGROUND

[0004] With the increasing difficulty of exploring large reserves of oil fields, finding replacement areas for oil resources, ensuring stable and even increasing production of crude oil, has become an urgent need to ensure energy security. Among numerous oil resources, oil shale has the advantage of large recoverable reserves (nearly 3 times the total amount of conventional oil resources), making it the most potential replacement resource. Through in-situ conversion technology, it is expected to realize the large-scale development of oil shale. In order to reduce the cracking temperature of kerogen in oil shale layers, reduce external heat injection and improve oil quality, catalytic pyrolysis is considered an effective means to realize cost reduction and efficiency improvement of oil shale in-situ conversion and promote technology commercialization. Although a large number of studies have shown that molecular sieves, clay minerals, inorganic salts, metal catalysts, etc. can promote oil shale pyrolysis and have strong acidity and high specific surface area, but due to the very dense and poor permeability of oil shale reservoirs, its engineering implementability is not strong, and it is urgent to develop an energy-boosting oil displacement agent and its preparation method for promoting in-situ conversion of kerogen in oil shale.

[0005] CN114477317B discloses a needle-shaped nanometer iron-based double metal hydroxide and its application method for low-temperature regulation and control of oil shale pyrolysis product selectivity. The metal cations in its layer plate are composed of one divalent metal cation selected from Fe 3+ , Ni 2+ , Mn 2+ and Co 2+ , and the interlayer region anions are composed of OH - , CO3 2- and OCN - . This patent can realize catalytic pyrolysis of oil shale by catalyzing the conversion of kerogen to medium and low carbon hydrocarbon organic matter, but has the problems of single functional component of catalyst and insignificant effect of adding metal compounds on improving the component distribution of pyrolysis products.

[0006] CN114522722B discloses a rare earth mesoporous molecular sieve applied to oil shale catalytic cracking and a catalyst preparation method thereof. The pore size of the rare earth mesoporous molecular sieve is 3-7 nm; the catalyst comprises a rare earth mesoporous molecular sieve, a quaternary ammonium base, a supported metal nano alumina, cyclohexane ethyl acetate and a surfactant. The patent can accelerate the process of kerogen to oil and gas conversion and reduce the oil shale cracking conversion temperature, but there are problems such as complicated preparation process and poor compatibility of each component.

[0007] CN109985627A discloses a catalyst for improving oil yield of oil shale, a preparation method and application thereof. Specifically, bentonite is weighed according to the proportion, placed in an H2SO4 solution with a certain concentration and liquid-solid ratio, acidified at a certain temperature, filtered, washed with water and dried to obtain acidified bentonite. The active ingredient Co salt and the auxiliary NiO are impregnated on the carrier to obtain the catalyst. The defects of this technology or the deficiencies of the present application are that it cannot play the role of energy-increasing oil displacement.

[0008] Therefore, it is a technical problem in the field to develop an energy-increasing oil displacement agent that has good energy-increasing oil displacement effect and can continuously exert the energy-increasing oil displacement effect. SUMMARY

[0009] The purpose of the present application is to overcome the problem of poor energy-increasing oil displacement effect in the prior art, and to provide an oil displacement agent that can continuously exert the energy-increasing oil displacement effect, and has low cost, easy preparation and small pollution, as well as a preparation and application method thereof.

[0010] According to a first aspect of the present application, the present application provides an energy-increasing oil displacement agent, which comprises: an acid-etched mineral, an alcohol, a metal ion and an acidified aqueous solvent, wherein the content of the acid-etched mineral is 1.0-22 wt%, the content of the alcohol is 0.4-10 wt%, and the content of the metal ion is 0.5-25 wt%, based on the total weight of the oil displacement agent.

[0011] According to a second aspect of the present application, the present application provides a preparation method of the oil displacement agent, which comprises:

[0012] (1) contacting a natural mineral with an acid solution for acid treatment, and separating the solid and liquid to obtain an acid-etched mineral and an acid treatment liquid phase;

[0013] (2) contacting an alcohol with the acid treatment liquid phase to obtain an alcoholized acid treatment liquid phase;

[0014] (3) mixing the acid-etched mineral and an optional aqueous solvent with the alcoholized acid treatment liquid phase to obtain the oil displacement agent.

[0015] According to a third aspect of the present application, the present application provides an oil displacement agent prepared by the preparation method.

[0016] According to a fourth aspect of the present application, the present application provides use of the oil displacement agent in oil exploitation.

[0017] The oil displacement agent provided by the present application has good oil displacement effect, can continuously promote the discharge of generated oil and gas, and increase the discharge oil volume and oil and gas production of oil shale oil production, and the increase of oil and gas production can reach 24.14%. The reason is that the metal crystalline alcoholate and acid-etched mineral in the oil displacement agent can form a composite mineral system. When the oil displacement agent is in the oil shale temperature and pressure stratum, the alcoholate in the composite mineral system will react to form a complex of metal ions and alcohol, and release water. The released water is in a supercritical state under the stratum conditions, can efficiently dissolve hydrocarbons and salts in the stratum, and enter the voids of the net-like structure of the oil shale kerogen, thereby promoting the discharge of generated oil and gas, so as to achieve the effect of energy-increasing oil displacement. The reaction of the alcoholate to release water is continuously and slowly carried out, so that the oil displacement agent can continuously exert the effect of energy-increasing oil displacement.

[0018] Further, the main raw materials of the preparation method of the oil displacement agent provided by the present application are natural minerals, acid liquor and alcohol, the preparation process is a contact reaction, and the oil displacement agent is low in cost, convenient to prepare, clean and environmentally friendly, and suitable for large-scale industrial production. DETAILED DESCRIPTION

[0019] The specific embodiments of the present application are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. The endpoints and any values disclosed in this text are not limited to the exact range or value, and these ranges or values should be understood to include values close to these ranges or values. For numerical value ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical value ranges, which should be regarded as specifically disclosed herein.

[0020] The present application provides a kind of oil displacement agent, the composition of the oil displacement agent includes: acid etching mineral, alcohol, metal ion, acidified water solvent, by input amount calculation, the content of acid etching mineral is 1.0-22wt%, preferably 2.0-17wt% in total weight of oil displacement agent;The content of alcohol is 0.4-10wt%, preferably 0.4-7wt%;The content of metal ion is 0.5-25wt%, preferably 1.0-15wt%.The oil displacement agent provided by the present application has good oil displacement effect, can continuously promote the discharge of generated oil and gas, improve the discharge oil volume and oil and gas production of oil shale oil production, and the increase of oil and gas production can reach 24.14%.The reason is speculated as follows: in the oil displacement agent of the present application, the crystalline alcoholate of metal and the acid etching mineral can form a composite mineral system.When the oil displacement agent is in the oil shale temperature zone under pressure formation condition, the alcoholate in the composite mineral system will react to form a complex of metal ion and alcohol, while releasing water.The released water is in supercritical state under the formation condition, can efficiently dissolve hydrocarbons and salts in the rock formation, enter the voids of oil shale kerogen network structure, thereby promoting the discharge of generated oil and gas, so as to achieve the effect of energy-increasing oil displacement.The reaction of the alcoholate releasing water is continuous and slow, so the oil displacement agent of the present application can continuously exert the effect of energy-increasing oil displacement.

[0021] In the present application, the optional range of metal elements in the oil displacement agent is wide, and various metal elements suitable for oil displacement agent can be used in the present application, which are exemplarily described below, but do not limit the scope of the present application.According to a preferred embodiment of the present application, the metal element is selected from magnesium and / or calcium.

[0022] According to a preferred embodiment of the present application, the specific surface area of the acid etching mineral is 80m 2 / g-180m 2 / g, and the pore volume is 0.18mL / g-0.40mL / g.The acid etching mineral in the oil displacement agent with the foregoing characteristics can fully adsorb and accommodate alcohol and continuously provide metal ions, and play the roles of slow release and stable structure.

[0023] In the present application, the type of acid etching mineral has no special requirement, and it can be prepared by selecting common natural minerals according to the needs of those skilled in the art and through a conventional acid etching step.According to a preferred embodiment of the present application, the acid etching mineral is selected from acid etched natural minerals rich in magnesium and calcium.

[0024] In the present application, the type of natural mineral rich in magnesium and calcium has no special requirement, and common types can achieve the purpose of the present application.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.

[0025] In the present application, the type of alcohol is not particularly limited, and any commonly used type can achieve the purpose of the present application. The following is exemplary, but does not limit the scope of the present application, according to a preferred embodiment of the present application, the alcohol is a C1-C6 lower alcohol, preferably one or more of methanol, ethanol, propanol.

[0026] According to a preferred embodiment of the present application, the pH of the oil displacement agent is in the range of 3.0-6.8, preferably 5.5-6.8. The oil displacement agent with the aforementioned pH value has the advantage of good oil displacement effect.

[0027] In the present application, the type of acid in the acidified aqueous solvent is not particularly limited, and any commonly used type can achieve the purpose of the present application. The acid in the acidified aqueous solvent can be an inorganic acid and / or an organic acid.

[0028] In the present application, the type of inorganic acid is not particularly limited, and any commonly used type can achieve the purpose of the present application. According to a preferred embodiment of the present application, the inorganic acid includes one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.

[0029] In the present application, the type of organic acid is not particularly limited, and any commonly used type can achieve the purpose of the present application. According to a preferred embodiment of the present application, the organic acid includes a C1-C6 acid, preferably one or more selected from formic acid, citric acid, oxalic acid, and acetic acid.

[0030] The oil displacement agent with the aforementioned characteristics can achieve the purpose of the present application, and the preparation method thereof is not particularly limited. The following is exemplary, but does not limit the scope of the present application, according to an embodiment of the present application, the preparation method of the oil displacement agent comprises:

[0031] (1) contacting the natural mineral with the acid solution for acid treatment, solid-liquid separation, to obtain acid-etched mineral and acid treatment liquid phase;

[0032] (2) contacting the alcohol with the acid treatment liquid phase to obtain alcoholized acid treatment liquid phase;

[0033] (3) mixing the acid-etched mineral and optional aqueous solvent with the alcoholized acid treatment liquid phase to obtain the oil displacement agent.

[0034] The preparation method of the oil displacement agent with the aforementioned characteristics is low in cost, convenient to prepare, clean and environmentally friendly, and suitable for large-scale industrial production.

[0035] In the present application, the temperature condition for contacting in step (1) can be selected in a wide range. The following is exemplary, but does not limit the scope of the present application, according to a preferred embodiment of the present application, in step (1) of the preparation method, the temperature for contacting is 20-100℃. Using the aforementioned temperature condition, the acid-etching effect is outstanding, and the metal ion is fully dissociated.

[0036] In the present application, the time of contacting in step (1) can be selected and adjusted according to the temperature, for example, the contacting time is generally 10-60 min.

[0037] In the present application, the acidic condition of contacting in step (1) 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 pH of contacting is 2.8-6.0. By using the aforementioned pH value, the advantage of good acid etching effect is achieved.

[0038] In the present application, the type of acid is not particularly required, and the commonly used types can achieve the purpose of the present application. The acid substance of the acid solution can be inorganic acid and / or organic acid.

[0039] In the present application, the type of inorganic acid is not particularly required, and the commonly used types can achieve the purpose of the present application. According to one preferred embodiment of the present application, the inorganic acid comprises one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.

[0040] In the present application, the type of organic acid is not particularly required, and the commonly used types can achieve the purpose of the present application. According to one preferred embodiment of the present application, the organic acid comprises C1-C6 acid; preferably selected from one or more of formic acid, citric acid, oxalic acid, and acetic acid.

[0041] In the present application, the concentration of the acid solution 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 0.1-20 mol / L.

[0042] In the present application, the amount of the acid solution 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 mass ratio of the acid solution to the natural mineral is 2:1-20:1.

[0043] In the present application, the metal ion content of the natural mineral is not particularly required, and the commonly seen content can achieve the purpose of the present application. According to one preferred embodiment of the present application, the total content of metal (in atom) in the natural mineral is 40-80 wt%.

[0044] In the present application, the type of natural mineral is not particularly required, and the commonly used types can achieve the purpose of the present application. According to one preferred embodiment of the present application, in step (1) of the preparation method, the natural mineral is selected from natural minerals rich in magnesium and calcium.

[0045] In the present application, the natural mineral rich in magnesium and calcium can select various natural minerals, which is exemplarily illustrated below, but the scope of the present application is not limited thereto, for example, selected from one or more of magnesite, calcite, dolomite, and montmorillonite.

[0046] In the present application, in step (2), in order to make the alcohol and the acid treatment liquid contact sufficiently and uniformly, the alcohol can be added to the acid treatment liquid in a slow addition or dropwise addition manner.

[0047] In the present application, the temperature condition for the contact in step (2) can be selected in a wide range, and the following is exemplarily described, but the present application is not limited thereto, according to a preferred embodiment of the present application, in step (2) of the preparation method, the temperature for the contact is 20-60℃.

[0048] In the present application, the time for the contact in step (2) can be selected and adjusted according to the temperature, for example, generally 10-60min.

[0049] In the present application, in order to contact sufficiently, the contact in step (1) and / or step (2) is carried out under dynamic conditions, for example, by stirring, ultrasonic and the like.

[0050] In the present application, the type of the alcohol is not particularly limited, and the commonly used types can all achieve the purpose of the present application. The following is exemplarily described, but the present application is not limited thereto, according to a preferred embodiment of the present application, in step (2) of the preparation method, the alcohol is a C1-C6 lower alcohol, preferably one or more of methanol, ethanol and propanol.

[0051] In the present application, the use of the alcohol is not limited in form, and the alcohol can be used alone or in a solution, according to a preferred embodiment of the present application, in step (2) of the preparation method, the alcohol is provided in the form of an alcohol solution, and the concentration of the alcohol solution is 10-100wt%.

[0052] In the present application, the optional range of the amount of the alcohol is wide, and the following is exemplarily described, but the present application is not limited thereto, according to a preferred embodiment of the present application, in step (2) of the preparation method, the mass ratio of the alcohol to the metal (in atom) in the acid treatment liquid is 1:5-4:1.

[0053] The present application provides an oil displacement agent prepared by the preparation method of the present application.

[0054] The oil displacement agent of the present application is particularly suitable for application in oil exploitation.

[0055] The above describes the preferred embodiments of the present application in detail, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present application does not further describe various possible combination manners. However, these simple modifications and combinations should also be regarded as the disclosed content of the present application, and all belong to the protection scope of the present application.

[0056] The application will be described in detail below by way of examples. It is necessary to point out here that the following examples are only used to further illustrate the application and cannot be understood as limiting the protection scope of the application, and those skilled in the art can make some non-essential improvements and adjustments to the application according to the above description of the application.

[0057] 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 used are not specified by the manufacturer, they are all conventional reagent products that can be obtained by purchase in the market.

[0058] A. Raw materials for examples

[0059] Magnesite (Mg: 47.82%, Ca: 5.18%), calcite (Mg: 30%, Ca: 50%), dolomite (Mg: 21.86%, Ca: 21.72%), and montmorillonite (Mg: 22%, Ca: 34%) were all purchased from Shandong Xinhai Mining Technology Equipment Co., Ltd.

[0060] Sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, formic acid, citric acid, oxalic acid, and acetic acid were all purchased from Sinopharm Chemical Reagent Co., Ltd. with a purity of chemical pure. Methanol, ethanol, and propanol were all purchased from Sinopharm Chemical Reagent Co., Ltd. with a purity of analytical pure.

[0061] Oil shale was selected from the ores mined by PetroChina Changqing Oilfield Branch, with a mesh size of 80-120 mesh and a TOC (Total Organic Carbon) content of 12.51%.

[0062] B. Test equipment

[0063] The BET specific surface area and pore volume of the sample were determined by using the ASAP 2460 full-automatic specific surface analyzer of Micromeritics Company, USA.

[0064] The morphology of the sample surface was tested by using the Ultra Plus scanning electron microscope of Carl Zeiss Company, Germany.

[0065] The oil displacement effect of the oil displacement agent was tested by using the gold tube hydrocarbon generation thermal simulation instrument (model: JGMN-1).

[0066] C. Test method

[0067] Specific surface area and pore volume test method:

[0068] The sample was first pre-treated at high temperature (300°C) (vacuum state) for 8h, and then analyzed at liquid nitrogen temperature of -196°C. The total specific surface area data was measured by BET method, while the rest of the surface area and micropore volume data were calculated by t-plot method, and the mesopore volume was calculated by BJH method.

[0069] Scanning Electron Microscope Test Method:

[0070] The sample to be tested was placed on the observation platform after being sprayed with gold for 10 minutes twice.

[0071] Oil displacement performance evaluation method:

[0072] According to the oil and gas industry standard SYT7035-2016, 0.8g of sample was mixed with oil shale at a mass ratio of 1:10-9:10, and then placed in a gold tube hydrocarbon simulation instrument. The fluid pressure was 10-30Mpa, the temperature was rapidly raised to 100-600°C at a rate of 20°C / min, and after constant temperature for 72 hours, the gas and oil were taken and analyzed.

[0073] 1) Quantitative determination of gaseous products

[0074] The collection of gaseous products in the gold tube was carried out in a special quantitative collection device. First, the reacted gold tube was fixed in the appropriate position of the sampling device, and after sealing, it was pumped to a near vacuum state, and the vacuum state pressure (P1) was recorded. The gold tube was pierced, and after the pressure gauge showed balance, the pressure value (P2) was recorded. The gas volume was calculated according to the following formula: V=V0×(P2-P1) / P0

[0075] In the formula: V0 is the volume of the gas collection device; P0 is the atmospheric pressure value when the gas is quantified.

[0076] The simulated gas component analysis used Agilent6890 gas chromatograph, and helium was used as the carrier gas. The sample inlet temperature for gas analysis was 250°C, and the split ratio was 25:1. The column oven temperature conditions were as follows: the initial temperature was 68°C, maintained for 7min, then raised to 90°C at a rate of 10°C / min, maintained for 1.5min, then raised to 175°C at a rate of 15°C / min, and finally maintained for 5min.

[0077] The mass of each gas component was calculated by the ideal gas state equation: M=V×m0 / 22.4

[0078] In the formula, m0 is the molar mass of the calculated gas component. The total weight (G0) of the gas component is the sum of the mass of each gas component.

[0079] 2) Quantitative determination of light hydrocarbons

[0080] Because of the volatilization of light hydrocarbon solution, it is difficult to directly measure. In the experiment, the light hydrocarbon quantification is carried out by the difference method. First, the gold tube filled with the sample is weighed, and the weight (G t ) is recorded. Then, after the gold tube is placed for 1 day after gas analysis, the gold tube is weighed again after the gas and light hydrocarbon in the gold tube are completely lost, and the weight (G cz1 ) is recorded. The weight (G1) of the light hydrocarbon is equal to the weight loss minus the total weight of the gas, that is: G1=G t -G cz1 -G0

[0081] 3) Liquid hydrocarbon / oil discharge quantification

[0082] The amount of liquid hydrocarbon / oil generated by the reaction is obtained by combining the CH2Cl2 ultrasonic extraction method and the weighing difference method. The gold tube after gas analysis is placed in CH2Cl2, and the organic solvent soaked in the gold tube is ultrasonically extracted for 3 times. Then, the solid residue is filtered through a chromatographic membrane, and the liquid solution obtained is weighed after the organic solvent is completely volatilized, that is, the weight (G cy1 ) of the liquid hydrocarbon is obtained.

[0083] After the gold tube and the residue obtained by extraction and filtration are dried, they are weighed again, and the weight (G cz2 ) is recorded. The difference between the weight (G cz1 ) of the gold tube and the sample after gas and light hydrocarbon analysis and the weight (G cy2 ) of the generated liquid hydrocarbon is also the weight (G cy2 ) of the generated liquid hydrocarbon, that is: G cz1 =G cz2

[0084] In order to reduce the error, the weight (G y ) of the liquid hydrocarbon in the experiment is calculated according to the following formula: G y =(G cy1 +G cy2 ) / 2.

[0085] 4) Oil and gas increment calculation

[0086] Taking the total amount of oil and gas (G 对比例1 ) of Comparative Example 1 as the reference:

[0087] Oil and gas increment=(total amount of oil and gas-G 对比例1 / G 对比例1 ) x 100%.

[0088] pH test method: at room temperature, immerse the pH electrode into the standard buffer solution, calibrate according to the instrument instructions, rinse the electrode with distilled water or deionized water to remove surface impurities. Immerse the pH electrode into the solution to be tested, and read the pH value after a few minutes when the value is stable.

[0089] Example 1

[0090] (1) 50 grams of magnesite and a sulfuric acid solution with a concentration of 0.1 mol / L were mixed at 20℃, the liquid-solid mass ratio was 2, the pH was 2.8, and the treatment time was 60 min. After filtration, acid-etched minerals 1 and an acid treatment liquid phase 1 were obtained. The total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase was 60% of the total mass of magnesium and calcium (in atoms) in the natural minerals;

[0091] (2) Then, 3.98 grams of a methanol solution with a concentration of 10 wt% was slowly added to the acid treatment liquid phase 1, and the mixture was fully stirred at 20℃ for 60 min. Crystalline alcoholates were formed in the acid treatment liquid phase 1, and an alcoholized acid treatment liquid phase 1 was obtained.

[0092] (3) 3 grams of water and 34.10 grams of acid-etched minerals were added to the alcoholized acid treatment liquid phase 1 to prepare a flooding agent 1.

[0093] The composition of the flooding agent 1 included 21.72 wt% of acid-etched minerals, 2.54 wt% of alcohol, 10.13 wt% of metal ions, and the rest was an acidified aqueous solvent, and the pH was 6.3. The specific surface area of the acid-etched minerals was 86 m 2 / g, and the pore volume was 0.18 mL / g.

[0094] After 2.7 grams of the flooding agent 1 and 3 grams of oil shale powder were fully mixed and uniformly weighed at 0.8 grams, a hydrocarbon generation simulation experiment was performed in a gold tube hydrocarbon generation simulator at a temperature increasing rate of 20℃ / min to 100℃, and the mixture was pyrolyzed at a constant temperature of 30 MPa for 72 h. After the reaction, the generated oil and gas were analyzed to obtain the final oil and gas production.

[0095] Example 2

[0096] (1) 20 grams of calcite and a hydrochloric acid solution with a concentration of 2.5 mol / L were mixed at 50℃, the liquid-solid mass ratio was 18, the pH was 6, and the treatment time was 40 min. After filtration, acid-etched minerals 2 and an acid treatment liquid phase 2 were obtained. The total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase was 30% of the total mass of magnesium and calcium (in atoms) in the natural minerals;

[0097] (2) Then, 2.06 grams of ethanol with a concentration of 100 wt% was slowly added to the acid treatment liquid phase 2, and the mixture was fully stirred at 60℃ for 10 min. Crystalline alcoholates were formed in the acid treatment liquid phase 2, and an alcoholized acid treatment liquid phase 2 was obtained.

[0098] (3) 30 grams of water and 15.20 grams of acid-etched minerals were added to the alcoholized acid treatment liquid phase 2 to prepare a flooding agent 2.

[0099] The composition of the oil displacement agent 2 includes: 3.69wt% of the acid-etched mineral, 0.50wt% of the alcohol, 1.16wt% of the metal ions, and the rest is the acidified aqueous solvent, the pH is 4.7, wherein the specific surface area of the acid-etched mineral is 102m 2 / g, and the pore volume is 0.21mL / g.

[0100] After 0.6 grams of the oil displacement agent 2 is uniformly mixed with 3 grams of the oil shale powder, 0.8 grams are weighed, the hydrocarbon generation simulation experiment evaluation is performed in the gold tube hydrocarbon generation simulator at a temperature increasing rate of 20℃ / min to 180℃, and the pyrolysis is performed at a constant temperature of 10Mpa for 72h, and the generated oil and gas are analyzed after the reaction to obtain the final oil and gas production.

[0101] Example 3

[0102] (1) 70 grams of the dolomite and a formic acid solution with a concentration of 20mol / L are fully mixed at 30℃, the liquid-solid mass ratio is 20, the pH is 3.2, and the treatment is performed for 20min, filtration is performed to obtain the acid-etched mineral 3 and the acid treatment liquid phase 3, and the total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase is 80% of the total mass of magnesium and calcium (in atoms) in the natural mineral;

[0103] (2) Then, 16.27 grams of an ethanol solution with a concentration of 20wt% is slowly added to the acid treatment liquid phase 3, fully stirred at 30℃ for 20min, and the crystalline alcoholate is formed in the acid treatment liquid phase 3 to obtain the alcoholized acid treatment liquid phase 3;

[0104] (3) 160 grams of water and 45.60 grams of the acid-etched mineral are added to the alcoholized acid treatment liquid phase 3 to prepare the oil displacement agent 3.

[0105] The composition of the oil displacement agent 3 includes: 2.77wt% of the acid-etched mineral, 0.99wt% of the alcohol, 1.48wt% of the metal ions, and the rest is the acidified aqueous solvent, the pH is 3.3, wherein the specific surface area of the acid-etched mineral is 167m 2 / g, and the pore volume is 0.35mL / g.

[0106] After 0.3 grams of the oil displacement agent 3 is uniformly mixed with 3 grams of the oil shale powder, 0.8 grams are weighed, the hydrocarbon generation simulation experiment evaluation is performed in the gold tube hydrocarbon generation simulator at a temperature increasing rate of 20℃ / min to 600℃, and the pyrolysis is performed at a constant temperature of 20Mpa for 72h, and the generated oil and gas are analyzed after the reaction to obtain the final oil and gas production.

[0107] Example 4

[0108] (1) 60 g of montmorillonite and a formic acid solution with a concentration of 15 mol / L were mixed at 70°C, the liquid-to-solid mass ratio was 5, the pH was 3.9, and the treatment time was 30 min, followed by filtration to obtain acid-etched minerals 4 and an acid treatment liquid phase 4, and the total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase was 90% of the total mass of magnesium and calcium (in atoms) in the natural minerals;

[0109] (2) Then, 30.24 g of a propanol solution with a concentration of 30 wt% was slowly added to the acid treatment liquid phase 4, and the mixture was fully stirred at 50°C for 30 min to form crystalline alcoholates in the acid treatment liquid phase 4, thereby obtaining an alcoholated acid treatment liquid phase 4;

[0110] (3) 80 g of water and 29.76 g of the acid-etched minerals were added to the alcoholated acid treatment liquid phase 4 to prepare a flooding agent 4.

[0111] The composition of the flooding agent 4 includes 6.33 wt% of acid-etched minerals, 6.43 wt% of alcohol, 6.43 wt% of metal ions, and the rest is an acidified aqueous solvent, and the pH is 3.9, wherein the specific surface area of the acid-etched minerals is 137 m 2 / g, and the pore volume is 0.31 mL / g.

[0112] After 0.9 g of the flooding agent 4 was fully mixed with 3 g of oil shale powder, 0.8 g of the mixture was weighed, and a hydrocarbon generation simulation experiment was performed in a gold tube hydrocarbon generation simulator at a temperature increasing rate of 20°C / min to 500°C, and the mixture was pyrolyzed at a constant temperature of 15 MPa for 72 h. The produced oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0113] Example 5

[0114] (1) 80 g of montmorillonite and a citric acid solution with a concentration of 7 mol / L were mixed at 40°C, the liquid-to-solid mass ratio was 7, the pH was 5.2, and the treatment time was 45 min, followed by filtration to obtain acid-etched minerals 5 and an acid treatment liquid phase 5, and the total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase was 20% of the total mass of magnesium and calcium (in atoms) in the natural minerals;

[0115] (2) Then, 12.72 g of a methanol solution with a concentration of 45 wt% was slowly added to the acid treatment liquid phase 5, and the mixture was fully stirred at 55°C for 35 min to form crystalline alcoholates in the acid treatment liquid phase 5, thereby obtaining an alcoholated acid treatment liquid phase 5;

[0116] (3) 100 g of water and 71.52 g of the acid-etched minerals were added to the alcoholated acid treatment liquid phase 5 to prepare a flooding agent 5.

[0117] The composition of the oil displacement agent 5 includes: 9.50wt% of the acid-etched mineral, 1.69wt% of the alcohol, 1.19wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 3.5, wherein the specific surface area of the acid-etched mineral is 110m 2 / g, and the pore volume is 0.26mL / g.

[0118] After 2.1 grams of the oil displacement agent 5 is uniformly mixed with 3 grams of the oil shale powder, 0.8 grams is weighed, and the hydrocarbon generation simulation experiment evaluation is performed in the gold tube hydrocarbon generation simulator at a temperature increasing rate of 20℃ / min to 400℃, and the pyrolysis is performed at a constant temperature of 25Mpa for 72h. After the reaction, the generated oil and gas are analyzed to obtain the final oil and gas production.

[0119] Example 6

[0120] (1) 100 grams of dolomite and a citric acid solution with a concentration of 9mol / L are mixed at 80℃ for 50min, the liquid-solid mass ratio is 9, and the pH is 4.4. After filtration, the acid-etched mineral 6 and the acid treatment liquid phase 6 are obtained, and the total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase is 95% of the total mass of magnesium and calcium (in atoms) in the natural mineral;

[0121] (2) Then, 96.60 grams of an ethanol solution with a concentration of 55wt% is slowly added to the acid treatment liquid phase 6, and the crystalline alcoholate is formed in the acid treatment liquid phase 6 after being fully stirred at 35℃ for 25min, to obtain the alcoholized acid treatment liquid phase 6;

[0122] (3) 150 grams of water and 58.60 grams of the acid-etched mineral are added to the alcoholized acid treatment liquid phase 6 to prepare the oil displacement agent 6.

[0123] The composition of the oil displacement agent 6 includes: 4.70wt% of the acid-etched mineral, 7.75wt% of the alcohol, 3.32wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 4.5, wherein the specific surface area of the acid-etched mineral is 119m 2 / g, and the pore volume is 0.23mL / g.

[0124] After 1.2 grams of the oil displacement agent 6 is uniformly mixed with 3 grams of the oil shale powder, 0.8 grams is weighed, and the hydrocarbon generation simulation experiment evaluation is performed in the gold tube hydrocarbon generation simulator at a temperature increasing rate of 20℃ / min to 550℃, and the pyrolysis is performed at a constant temperature of 12Mpa for 72h. After the reaction, the generated oil and gas are analyzed to obtain the final oil and gas production.

[0125] Example 7

[0126] (1) 70 g of the magnesite and a phosphoric acid solution with a concentration of 13 mol / L were mixed at 100 ℃ for 10 min, the liquid-solid mass ratio was 11, and the pH was 4.9. Filtration was performed to obtain the acid-etched mineral 7 and the acid treatment liquid phase 7, and the total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase was 40% of the total mass of magnesium and calcium (in atoms) in the natural mineral;

[0127] (2) Then, 59.36 g of an ethanol solution with a concentration of 65 wt% was slowly added to the acid treatment liquid phase 7, and the mixture was stirred at 25 ℃ for 45 min. Crystalline alcoholates were formed in the acid treatment liquid phase 7 to obtain the alcoholated acid treatment liquid phase 7;

[0128] (3) 220 g of water and 55.16 g of the acid-etched mineral were added to the alcoholated acid treatment liquid phase 7 to prepare the oil displacement agent 7.

[0129] The composition of the oil displacement agent 7 included 4.93 wt% of the acid-etched mineral, 5.30 wt% of the alcohol, 1.33 wt% of the metal ions, and the rest was the acidified aqueous solvent, and the pH was 5.0. The specific surface area of the acid-etched mineral was 113 m 2 / g, and the pore volume was 0.31 mL / g.

[0130] After 1.5 g of the oil displacement agent 7 was uniformly mixed with 3 g of oil shale powder, 0.8 g was weighed, and the mixture was subjected to a hydrocarbon generation simulation experiment in a gold tube hydrocarbon generation simulator at a temperature increasing rate of 20 ℃ / min to 450 ℃, and then pyrolysis was performed at a constant temperature of 17 MPa for 72 h. The generated oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0131] Example 8

[0132] (1) 65 g of the calcite and an oxalic acid solution with a concentration of 17 mol / L were mixed at 30 ℃ for 55 min, the liquid-solid mass ratio was 13, and the pH was 5.8. Filtration was performed to obtain the acid-etched mineral 8 and the acid treatment liquid phase 8, and the total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase was 50% of the total mass of magnesium and calcium (in atoms) in the natural mineral;

[0133] (2) Then, 26 g of a methanol solution with a concentration of 70 wt% was slowly added to the acid treatment liquid phase 8, and the mixture was stirred at 30 ℃ for 40 min. Crystalline alcoholates were formed in the acid treatment liquid phase 8 to obtain the alcoholated acid treatment liquid phase 8;

[0134] (3) 80 g of water and 39 g of the acid-etched mineral were added to the alcoholated acid treatment liquid phase 8 to prepare the oil displacement agent 8.

[0135] The composition of the oil displacement agent 8 includes: 3.84wt% of the acid-etched mineral, 2.56wt% of the alcohol, 2.56wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 6.5, wherein the specific surface area of the acid-etched mineral is 145m 2 / g, and the pore volume is 0.33mL / g.

[0136] After 1.8 grams of the oil displacement agent 8 is uniformly mixed with 3 grams of the oil shale powder, 0.8 grams is weighed, and the hydrocarbon generation simulation experiment evaluation is performed in the gold tube hydrocarbon generation simulator at a temperature increasing rate of 20℃ / min to 300℃, and pyrolysis is performed at a constant temperature of 22Mpa for 72h. After the reaction, the generated oil and gas are analyzed to obtain the final oil and gas production.

[0137] Example 9

[0138] (1) 40 grams of dolomite and an acetic acid solution with a concentration of 4mol / L are mixed at 60℃, the liquid-solid mass ratio is 15, the pH is 3.6, and the treatment time is 15min. After filtration, the acid-etched mineral 9 and the acid treatment liquid phase 9 are obtained, and the total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase is 60% of the total mass of magnesium and calcium (in atoms) in the natural mineral;

[0139] (2) Then, 3.49 grams of a propanol solution with a concentration of 80wt% is slowly added to the acid treatment liquid phase 9, and the mixture is stirred at 20℃ for 50min to form a crystalline alcoholate in the acid treatment liquid phase 9, thereby obtaining the alcoholized acid treatment liquid phase 9;

[0140] (3) 60 grams of water and 29.54 grams of the acid-etched mineral are added to the alcoholized acid treatment liquid phase 9 to prepare the oil displacement agent 9.

[0141] The composition of the oil displacement agent 9 includes: 4.20wt% of the acid-etched mineral, 0.50wt% of the alcohol, 1.49wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 5.7, wherein the specific surface area of the acid-etched mineral is 105m 2 / g, and the pore volume is 0.22mL / g.

[0142] After 2.4 grams of the oil displacement agent 9 is uniformly mixed with 3 grams of the oil shale powder, 0.8 grams is weighed, and the hydrocarbon generation simulation experiment evaluation is performed in the gold tube hydrocarbon generation simulator at a temperature increasing rate of 20℃ / min to 350℃, and pyrolysis is performed at a constant temperature of 27Mpa for 72h. After the reaction, the generated oil and gas are analyzed to obtain the final oil and gas production.

[0143] Example 10

[0144] (1) 90 g of montmorillonite and a sulfuric acid solution with a concentration of 12 mol / L were mixed thoroughly at 75°C, the liquid-to-solid mass ratio was 19, and the pH was 3.8 for 25 min, then filtered to obtain an acid-etched mineral 10 and an acid-treated liquid phase 10, and the total mass of magnesium and calcium (in atoms) in the acid-treated liquid phase was 70% of the total mass of magnesium and calcium (in atoms) in the natural mineral;

[0145] (2) Then, 18.99 g of a methanol solution with a concentration of 90 wt% was slowly added to the acid-treated liquid phase 10, stirred thoroughly at 45°C for 15 min, and crystalline alcoholates were formed in the acid-treated liquid phase 10 to obtain an alcoholated acid-treated liquid phase 10;

[0146] (3) 130 g of water and 54.72 g of the acid-etched mineral were added to the alcoholated acid-treated liquid phase 10 to prepare a flooding agent 10.

[0147] The composition of the flooding agent 10 included 2.81 wt% of the acid-etched mineral, 0.97 wt% of the alcohol, 1.81 wt% of the metal ions, and the rest was an acidified aqueous solvent, and the pH was 5.3, wherein the specific surface area of the acid-etched mineral was 131 m 2 / g, and the pore volume was 0.30 mL / g.

[0148] After 0.75 g of the flooding agent 10 was mixed thoroughly and uniformly with 3 g of oil shale powder, 0.8 g was weighed, and a hydrocarbon generation simulation experiment was performed in a gold tube hydrocarbon generation simulator at a temperature increasing rate of 20°C / min to 200°C, and the pyrolysis was performed at a constant temperature of 19 MPa for 72 h. After the reaction, the generated oil and gas were analyzed to obtain the final oil and gas production.

[0149] Example 11

[0150] According to the method of Example 8, except that 74 g of methanol with a concentration of 100 wt% was added.

[0151] The composition of the flooding agent 11 included 3.67 wt% of the acid-etched mineral, 6.95 wt% of the alcohol, 2.44 wt% of the metal ions, and the rest was an acidified aqueous solvent, and the pH was 6.8, wherein the specific surface area of the acid-etched mineral was 145 m 2 / g, and the pore volume was 0.33 mL / g.

[0152] Example 12

[0153] According to the method of Example 8, except that 5.49 g of methanol with a concentration of 10 wt% was added.

[0154] The composition of the flooding agent 12 included 3.92 wt% of the acid-etched mineral, 0.55 wt% of the alcohol, 2.61 wt% of the metal ions, and the rest was an acidified aqueous solvent, and the pH was 6.1, wherein the specific surface area of the acid-etched mineral was 145 m2 / g, and the pore volume is 0.33 mL / g.

[0155] Example 13

[0156] According to the method of Example 8, except that 26 grams of 70 wt% concentration of ethanol solution was added.

[0157] The composition of the oil displacement agent 13 includes 3.84 wt% of the acid-etched mineral, 2.56 wt% of the alcohol, 2.56 wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 6.6, wherein the specific surface area of the acid-etched mineral is 145 m 2 / g, and the pore volume is 0.33 mL / g.

[0158] Example 14

[0159] According to the method of Example 8, except that 26 grams of 70 wt% concentration of ethanol solution was added.

[0160] The composition of the oil displacement agent 14 includes 3.84 wt% of the acid-etched mineral, 2.56 wt% of the alcohol, 2.56 wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 6.6, wherein the specific surface area of the acid-etched mineral is 145 m 2 / g, and the pore volume is 0.33 mL / g.

[0161] Example 15

[0162] According to the method of Example 8, except that 65 grams of natural mineral of magnesite was used.

[0163] The composition of the oil displacement agent 15 includes 3.87 wt% of the acid-etched mineral, 2.58 wt% of the alcohol, 1.71 wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 6.6, wherein the specific surface area of the acid-etched mineral is 155 m 2 / g, and the pore volume is 0.33 mL / g.

[0164] Example 16

[0165] (1) 65 grams of calcite and oxalic acid solution with a concentration of 20 mol / L were mixed at 100°C, the liquid-solid mass ratio was 20, the pH was 2.8, and the treatment time was 60 min, then filtered to obtain the acid-etched mineral 16 and the acid treatment liquid phase 16, and the total mass of magnesium and calcium (in atom) in the acid treatment liquid phase was 70% of the total mass of magnesium and calcium (in atom) in the natural mineral;

[0166] (2) Then 36.4 grams of 70 wt% concentration of methanol solution was slowly added to the acid treatment liquid phase 16, and stirred at 30°C for 40 min, and the crystalline alcoholate was formed in the acid treatment liquid phase 16 to obtain the alcoholate acid treatment liquid phase 16;

[0167] (3) 80 grams of water and 36.4 grams of the acid-etched mineral were added to the alcoholated acid treatment liquid phase 16 to prepare the oil displacement agent 16.

[0168] The composition of the oil displacement agent 16 includes 2.44wt% of the acid-etched mineral, 2.44wt% of the alcohol, 2.44wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 5.6, wherein the specific surface area of the acid-etched mineral is 175 m 2 / g, and the pore volume is 0.37 mL / g.

[0169] After 1.8 grams of the oil displacement agent 16 were uniformly mixed with 3 grams of oil shale powder, 0.8 grams were weighed, and the hydrocarbon generation simulation experiment was evaluated in the gold tube hydrocarbon generation simulation instrument at a temperature increasing rate of 20℃ / min to 300℃, and pyrolysis was performed at 22Mpa for 72h. After the reaction, the produced oil and gas were analyzed to obtain the final oil and gas production.

[0170] Example 17

[0171] (1) 65 grams of calcite and an oxalic acid solution with a concentration of 20 mol / L were fully mixed at 30℃, the liquid-solid mass ratio was 2, the pH was 6.0, and the treatment time was 20 min. After filtration, the acid-etched mineral 17 and the acid treatment liquid phase 17 were obtained, and the total mass of magnesium and calcium (in atoms) in the acid treatment liquid phase was 70% of the total mass of magnesium and calcium (in atoms) in the natural mineral;

[0172] (2) Then, 10.4 grams of a methanol solution with a concentration of 70wt% was slowly added to the acid treatment liquid phase 17, fully stirred at 30℃ for 40 min, and the crystalline alcoholate was formed in the acid treatment liquid phase 17 to obtain the alcoholated acid treatment liquid phase 17;

[0173] (3) 80 grams of water and 54.6 grams of the acid-etched mineral were added to the alcoholated acid treatment liquid phase 17 to prepare the oil displacement agent 17.

[0174] The composition of the oil displacement agent 17 includes 17.53wt% of the acid-etched mineral, 3.34wt% of the alcohol, 11.69wt% of the metal ions, and the rest is the acidified aqueous solvent, and the pH is 6.0, wherein the specific surface area of the acid-etched mineral is 115 m 2 / g, and the pore volume is 0.31 mL / g.

[0175] After 1.8 grams of the oil displacement agent 17 were uniformly mixed with 3 grams of oil shale powder, 0.8 grams were weighed, and the hydrocarbon generation simulation experiment was evaluated in the gold tube hydrocarbon generation simulation instrument at a temperature increasing rate of 20℃ / min to 300℃, and pyrolysis was performed at 22Mpa for 72h. After the reaction, the produced oil and gas were analyzed to obtain the final oil and gas production.

[0176] Example 18

[0177] The method of Example 8 was followed, except that the stirring temperature when the alcohol solution was added was 100°C and the stirring time was 60 min.

[0178] The composition of the oil displacement agent 18 includes: 3.84wt% of acid-etched minerals, 2.56wt% of alcohol, 2.56wt% of metal ions, and the rest is acidified aqueous solvent, with a pH of 6.5, wherein the specific surface area of the acid-etched minerals is 145m 2 / g, and the pore volume is 0.33mL / g.

[0179] Comparative Example 1

[0180] In contrast to Example 10, Comparative Example 1 did not add any catalyst, and 0.8 grams of oil shale was weighed for oil displacement performance evaluation.

[0181] Comparative Example 2

[0182] In contrast to Example 7, Comparative Example 2 mixed 59.36 grams of 65wt% concentration of ethanol aqueous solution with 3 grams of oil shale uniformly, and then weighed 0.8 grams for oil displacement performance evaluation.

[0183] Comparative Example 3

[0184] In contrast to Example 3, 70 grams of dolomite and formic acid solution with a concentration of 20mol / L were mixed at 30°C, with a liquid-solid mass ratio of 20 and a pH of 3.2 for 20 min to obtain an acid-treated product; 0.3 grams of the acid-treated product was mixed with 3 grams of oil shale uniformly, and then weighed 0.8 grams for oil displacement performance evaluation.

[0185] Comparative Example 4

[0186] 0.3 grams of organic matter naphthenic ketone was mixed with 3 grams of oil shale uniformly, and then weighed 0.8 grams for hydrocarbon generation simulation experiment evaluation in a gold tube hydrocarbon generation simulator, with a temperature rise rate of 20°C / min to 600°C, and pyrolysis at 20Mpa for 72h. After the reaction, the produced oil and gas were analyzed to obtain the final oil and gas production.

[0187] Table 1: Reaction evaluation results of examples and comparative examples

[0188] From the data in the above table, compared with Comparative Example 1 without adding a catalyst, Examples 1-18 slowly undergo chemical reactions under simulated formation conditions through crystalline alcoholates, forming magnesium, calcium and alcohol complexes, while continuously releasing water molecules in a supercritical state, which can efficiently dissolve hydrocarbons and salts in the rock formation, thereby achieving the effect of energy enhancement and oil displacement, and the total amount of oil and gas is significantly increased, with an increase of 9.35-24.14%.

[0189] Comparative Example 2 is only adding alcohol and mixing with oil shale and evaluating, Comparative Example 3 is only adding acid treatment product and mixing with oil shale and evaluating, the evaluation result shows that the catalyst which does not form alcoholate cannot produce the effect of energy-increasing oil displacement, and the oil and gas yield is not increased. Comparative Example 4 is a traditional oil displacement agent, and the effect is not ideal.

[0190] In summary, the oil displacement agent for promoting the conversion of kerogen and the preparation method thereof have the characteristics of low cost, clean and environmental protection, and the advantage of continuously exerting the effect of energy-increasing oil displacement.

[0191] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application. However, these corresponding changes and modifications should belong to the protection scope of the claims of the present application.

Claims

1. An energized oil-displacing agent, characterized by, The oil displacement agent comprises an acid-etched mineral, an alcohol, a metal ion, and an acidified aqueous solvent, wherein the acid-etched mineral accounts for 1.0-22 wt%, the alcohol accounts for 0.4-10 wt%, and the metal ion accounts for 0.5-25 wt% based on the total weight of the oil displacement agent.

2. The oil displacement agent according to claim 1, wherein the acid-etched mineral accounts for 2.0-17 wt%, the alcohol accounts for 0.4-7 wt%, and the metal ion accounts for 1.0-15 wt% based on the total weight of the oil displacement agent. The acid-etched mineral accounts for 2.0-17 wt%, the alcohol accounts for 0.4-7 wt%, and the metal ion accounts for 1.0-15 wt% based on the total weight of the oil displacement agent. The metal element in the oil displacement agent is selected from magnesium and / or calcium.

3. The oil displacement agent according to claim 1 or 2, characterized by, The acid-etched mineral has a specific surface area of 80 m 2 / g-180 m 2 / g, a pore volume of 0.18 mL / g-0.40 mL / g.

4. The oil displacement agent according to claim 1 or 2, characterized by, The acid-etched mineral is selected from acid-etched natural minerals rich in magnesium and calcium.

5. The oil displacement agent according to claim 4, characterized in that, The natural mineral rich in magnesium and calcium is selected from one or more of magnesite, calcite, dolomite, and montmorillonite.

6. The oil displacement agent according to claim 1 or 2, characterized by, The alcohol is a C1-C6 lower alcohol.

7. The oil displacement agent according to claim 6, characterized in that, The C1-C6 lower alcohol is one or more of methanol, ethanol, and propanol.

8. The oil displacement agent according to claim 1 or 2, characterized by, The acid of the acidified aqueous solvent is an inorganic acid and / or an organic acid.

9. The oil displacement agent according to claim 8, wherein the inorganic acid comprises one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid; and / or the organic acid comprises a C1-C6 acid.

10. The oil displacement agent according to claim 9, wherein the organic acid comprises one or more of formic acid, citric acid, oxalic acid, and acetic acid. The pH of the oil displacement agent ranges from 3.0 to 6.

8. The pH of the oil displacement agent ranges from 5.5 to 6.

8. The method comprises:

11. The oil displacement agent according to claim 1 or 2, characterized by, (1) contacting a natural mineral with an acid solution for acid treatment, and separating the solid and liquid phases to obtain an acid-etched mineral and an acid treatment liquid phase; 12. The oil displacement agent of claim 11, wherein, (2) contacting an alcohol with the acid treatment liquid phase to obtain an alcoholized acid treatment liquid phase; 13. A method for preparing an oil displacement agent, characterized by, (3) mixing the acid-etched mineral and an optional aqueous solvent with the alcoholized acid treatment liquid phase to obtain an oil displacement agent. In step (1), the contacting conditions comprise: a temperature of 20-100°C; and / or a time of 10-60 min; and / or 14. The method of claim 13, wherein, a pH of 2.8-6.

0. In step (1), the acid substance of the acid solution comprises an inorganic acid and / or an organic acid; and / or the concentration of the acid solution is 0.1-20 mol / L; and / or 15. The production method according to claim 13 or 14, characterized by, the mass ratio of the acid solution to the natural mineral is 2:1-20:

1. In step (1), the inorganic acid comprises one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid; and / or the organic acid comprises a C1-C6 acid.

16. The method of claim 15, wherein, In step (1), the organic acid comprises one or more of formic acid, citric acid, oxalic acid, and acetic acid. In step (1), the total content of metal (in atoms) in the natural mineral is 40-80 wt%.

17. The preparation method according to claim 16, characterized in that, In step (1), the natural mineral is selected from natural minerals rich in magnesium and calcium. In step (1), the natural mineral rich in magnesium and calcium is selected from one or more of magnesite, calcite, dolomite, and montmorillonite.

18. The production method according to claim 13 or 14, characterized by, In step (2), the contacting conditions comprise:

19. The production method according to claim 13 or 14, characterized by, a temperature of 20-60°C; and / or 20. The method of claim 19, wherein, a time of 10-60 min.

21. The method of manufacturing according to claim 13 or 14, wherein, In step (2), the alcohol is a C1-C6 lower alcohol. In step (2), the C1-C6 lower alcohol is one or more of methanol, ethanol, and propanol. In step (2), the concentration of the alcohol is 10-100 wt%.

22. The method of manufacturing according to claim 13 or 14, wherein, ​ 23. The preparation method according to claim 22, characterized in that, ​ 24. The method of manufacturing according to claim 13 or 14, wherein, ​ 25. The method of manufacturing according to claim 13 or 14, wherein, In step (2), the mass ratio of alcohol to metal (in atom) in the acid treatment solution is 1:5-4:

1.

26. The oil displacement agent prepared by the preparation method of any one of claims 13-25.

27. The use of the oil displacement agent of any one of claims 1-12, 26 in oil exploitation.

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