Energy-increasing oil-displacing agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of shale oil in-situ conversion, and discloses an energizing oil-displacing agent as well as a preparation method and application thereof. The oil-displacing agent comprises acid etching minerals, alcohol, metal ions and an acidified water solvent, and based on the total weight of the oil-displacing agent, the content of the acid etching minerals 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 disclosed by the invention is good in oil-displacing effect and capable of continuously promoting discharge of generated oil gas and improving the oil discharge quantity and the oil gas yield of oil extraction of oil shale. The main raw materials of the preparation method of the oil-displacing agent are natural minerals, acid liquor and alcohol, the preparation process is a contact reaction, and the preparation method is low in cost, convenient to prepare, clean, environmentally friendly and suitable for large-scale industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of in-situ conversion of shale oil, in particular to an energy-boosting oil displacement agent and a preparation method and application thereof. BACKGROUND

[0002] Among numerous oil resources, shale oil has the advantage of large recoverable reserves (nearly 3 times the total amount of conventional oil resources), making shale oil the most potential replacement resource. Through in-situ conversion technology, it is expected to realize the large-scale development of shale oil. In order to reduce the cracking temperature of kerogen in oil shale layer, reduce the injection of external heat and improve the quality of oil production, catalytic pyrolysis is considered to be an effective means to realize cost reduction and efficiency increase of in-situ conversion of oil shale and promote the commercialization of technology. Although a large number of studies have confirmed that molecular sieves, clay minerals, inorganic salts, metal catalysts, etc. can promote the pyrolysis of oil shale and have strong acidity and high specific surface area, but due to the very dense and poor permeability of oil shale reservoir, its engineering implementability is not strong, and it is urgent to develop an oil displacement agent for promoting in-situ conversion of kerogen in oil shale and a preparation method thereof.

[0003] CN 114477317 B discloses a needle-shaped nanometer iron-based double metal hydroxide and an application method thereof for low-temperature regulation and control of oil shale pyrolysis product selectivity. The metal cations in the layer plate are composed of Fe 3+ and a divalent metal cation selected from Ni 2+ , Mn 2+ and Co 2+ . The interlayer region anions are composed of OH - , CO3 2- and OCN - . The 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.

[0004] CN 114522722 B discloses a rare earth mesoporous molecular sieve applied to catalytic cracking of oil shale and a preparation method of a catalyst thereof. The pore size of the rare earth mesoporous molecular sieve is 3-7 nm; the catalyst includes rare earth mesoporous molecular sieve, quaternary ammonium base, supported metal nano-alumina, cyclohexane ethyl acetate and surfactant. The patent can accelerate the conversion process of kerogen to oil and gas and reduce the cracking conversion temperature of oil shale, but has the problems of complicated preparation process and poor compatibility of components.

[0005] CN 109985627 A discloses a catalyst for improving oil yield of oil shale and a preparation method and application thereof. Specifically, bentonite is weighed according to a 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. Active ingredient Co salt and auxiliary NiO are impregnated on the carrier to obtain the catalyst. The technical defects or disadvantages of the prior art are that the catalyst cannot play the role of energy-increasing oil displacement.

[0006] Therefore, it is a technical problem in the field to develop an energy-increasing oil displacement agent which has good energy-increasing oil displacement effect and can continuously play the energy-increasing oil displacement effect. SUMMARY

[0007] The present application aims to overcome the problem of poor energy-increasing oil displacement effect in the prior art, and provides an energy-increasing oil displacement agent which can continuously play the energy-increasing oil displacement effect, has low cost, is easy to prepare, and has little pollution, as well as a preparation and application method thereof.

[0008] According to a first aspect of the present application, the present application provides an energy-increasing oil displacement agent, which comprises: acid-etched minerals, alcohol, metal ions, and acidified aqueous solvents. The content of the acid-etched minerals is 1.0-22wt%, the content of the alcohol is 0.4-10wt%, and the content of the metal ions is 0.5-25wt%, based on the total weight of the oil displacement agent.

[0009] According to a second aspect of the present application, the present application provides a preparation method of the oil displacement agent described in the present application, which comprises:

[0010] (1) contacting a natural mineral with an acid solution for acid treatment, and separating the solid and liquid to obtain acid-etched minerals and an acid treatment liquid phase;

[0011] (2) contacting alcohol with the acid treatment liquid phase to obtain an alcoholized acid treatment liquid phase;

[0012] (3) mixing the acid-etched minerals and optional aqueous solvents with the alcoholized acid treatment liquid phase to obtain the oil displacement agent.

[0013] According to a third aspect of the present application, the present application provides the oil displacement agent prepared by the preparation method of the present application.

[0014] According to a fourth aspect of the present application, the present application provides the application of the oil displacement agent described in the present application in oil exploitation.

[0015] 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 yield of oil shale oil production, and the increase of oil and gas yield 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 at the same time. 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 cheese root network structure of the oil shale layer, 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 can continuously exert the effect of energy-increasing oil displacement.

[0016] 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 preparation method is low in cost, convenient to prepare, clean and environmentally friendly, and suitable for large-scale industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Figure 1 is a scanning electron microscope photograph of the natural mineral before acid treatment in Example 4, with a magnification of 30000 times, a focal length of 13.2 mm, and an acceleration voltage of 5.0 kV.

[0018] Figure 2 Figure 2 is a scanning electron microscope photograph of the natural mineral after acid treatment in Example 4, with a magnification of 30000 times, a focal length of 9.9 mm, and an acceleration voltage of 2.0 kV. 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 the ranges herein are not limited to the precise range or value, and should be understood to include values close to the range or value. For numerical ranges, the endpoint values between each range, the endpoint values between 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 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 commonly used 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 an exemplary description, 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 an exemplary description, 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 the 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 an exemplary description, 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 ions are fully dissociated.

[0036] In this invention, the contact time in step (1) can be selected and adjusted according to the temperature. For example, the contact time is generally 10-60 minutes.

[0037] In this invention, the range of acidic conditions that can be selected in step (1) is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the pH of the contact is 2.8-6.0. Using the aforementioned pH value has the advantage of good acid etching effect.

[0038] In this invention, there are no special requirements for the type of acid; commonly used types can achieve the purpose of this invention. The acidic substance in the acid solution can be an inorganic acid and / or an organic acid.

[0039] In this invention, there are no special requirements for the type of inorganic acid; commonly used types can achieve the purpose of this invention. According to a preferred embodiment of this invention, the inorganic acid includes one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.

[0040] In this invention, there are no special requirements for the type of organic acid; commonly used types can achieve the purpose of this invention. According to a preferred embodiment of the invention, the organic acid includes C1-C6 acids; preferably selected from one or more of formic acid, citric acid, oxalic acid, and acetic acid.

[0041] In this invention, the concentration of the acid solution can be selected from a wide range. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the concentration of the acid solution is 0.1-20 mol / L.

[0042] In this invention, the amount of acid solution can be selected from a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the mass ratio of the acid solution to the natural mineral is 2:1-20:1.

[0043] In this invention, there are no special requirements for the metal ion content of the natural minerals; common contents are sufficient to achieve the purpose of this invention. According to a preferred embodiment of this invention, the total metal content (in atomic terms) in the natural minerals is 40-80 wt%.

[0044] In this invention, there are no special requirements for the type of natural mineral; commonly used types can achieve the purpose of this invention. According to a preferred embodiment of this invention, in step (1) of the preparation method, the natural mineral is selected from natural minerals rich in magnesium and calcium.

[0045] In this invention, the natural minerals rich in magnesium and calcium can be selected from various natural minerals, as illustrated below, but this does not limit the scope of the invention. For example, they can be selected from one or more of magnesite, calcite, dolomite and montmorillonite.

[0046] In this invention, in step (2), in order to ensure that the alcohol and the acid treatment liquid phase are in sufficient and uniform contact, the alcohol can be added to the acid treatment liquid phase by slow addition or dropwise addition.

[0047] In this invention, the contact temperature conditions in step (2) can be selected from a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the contact temperature in step (2) of this preparation method is 20-60°C.

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

[0049] In this invention, in order to ensure sufficient contact, the contact in step (1) and / or step (2) is carried out under dynamic conditions, such as by stirring, ultrasound, etc., as needed.

[0050] In this invention, there are no special requirements for the type of alcohol; commonly used types can achieve the purpose of this invention. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, in step (2) of the preparation method, the alcohol is a lower C1-C6 alcohol, preferably one or more of methanol, ethanol, and propanol.

[0051] In this invention, the use of alcohol is not limited to any form; it can be used alone or in solution. According to a preferred embodiment of the invention, in step (2) of the preparation method, the alcohol is provided in the form of an alcohol solution with a concentration of 10-100 wt%.

[0052] In this invention, the range of alcohol dosage is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, in step (2) of the preparation method, the mass ratio of alcohol to metal (in atomic terms) in the acid-treated liquid phase is 1:5-4:1.

[0053] This invention provides an oil displacement agent prepared by the preparation method described herein.

[0054] The oil displacement agent of the present invention is particularly suitable for use in oil extraction.

[0055] 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 combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, 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.

[0056] The present invention will be described in detail below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0057] For any experimental steps or conditions not specified in the examples and comparative examples, the procedures and conditions described in the literature in this field can be followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0058] A. Source of raw materials in the example

[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 chemically pure and purchased from Sinopharm Chemical Reagent Co., Ltd. Methanol, ethanol, and propanol were all analytically pure and purchased from Sinopharm Chemical Reagent Co., Ltd.

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

[0062] B. Testing equipment

[0063] The BET specific surface area and pore volume of the samples were determined using an ASAP 2460 fully automated specific surface area analyzer from Micromeritics, USA.

[0064] The surface morphology of the scanning electron microscope samples was tested using an Ultra Plus scanning electron microscope from Carl Zeiss GmbH, Germany.

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

[0066] C. Testing Methods

[0067] Specific surface area and pore volume testing methods:

[0068] The samples were first pretreated at high temperature (300℃) (under vacuum) for 8 hours; then, they were analyzed at liquid nitrogen temperature of -196℃. The total specific surface area was calculated using the BET method, while the remaining surface area and micropore volume were calculated using the t-plot method, and the mesopore volume was calculated using the BJH method.

[0069] Scanning electron microscopy testing methods:

[0070] Operating parameters: accelerating voltage 5-20KV, working distance: WD = 8-12mm, magnification: 86-200Kx. Specific operating procedure: After the sample to be tested undergoes two gold sputtering treatments over 10 minutes, it is placed on the observation platform for observation.

[0071] Methods for evaluating oil displacement performance:

[0072] Testing was conducted according to the oil and gas industry standard SYT7035-2016. A 0.8g sample was taken from a mixture of oil displacement agent and oil shale at a mass ratio of 1:10-9:10 and placed in a gold tube hydrocarbon generation simulator for catalytic pyrolysis. The fluid pressure was 10-30 MPa, and the temperature was rapidly increased to 100-600℃ at a heating rate of 20℃ / min. After holding at this temperature for 72 hours, the sample was cooled and the gas and oil were collected for subsequent analysis.

[0073] 1) Quantitative analysis of gaseous products

[0074] The collection of gaseous products in the gold tube was carried out using a special quantitative collection device. First, the reacted gold tube was fixed in a suitable position on the sampling device, sealed tightly, and then evacuated to a near-vacuum state. The vacuum pressure (P1) was recorded. The gold tube was then punctured, and the pressure value was recorded after the pressure gauge showed equilibrium (P2). The gas volume was calculated using the following formula:

[0075] V = V0 × (P2 - P1) / P0

[0076] In the formula: V0 is the volume of the gas collection device; P0 is the atmospheric pressure when the gas is collected in a fixed quantity.

[0077] The simulated generated gas composition analysis was performed using an Agilent 6890 gas chromatograph with helium as the carrier gas. The injection port temperature for gas analysis was 250℃, and the split ratio was 25:1. Column oven temperature conditions were as follows: initial temperature 68℃, held for 7 min, then increased to 90℃ at a rate of 10℃ / min and held for 1.5 min, then increased to 175℃ at a rate of 15℃ / min, and finally held for 5 min.

[0078] The mass of each gas component is calculated using the ideal gas law:

[0079] M = V × m0 / 22.4

[0080] 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.

[0081] 2) Quantitative analysis of light hydrocarbons

[0082] Because light hydrocarbon solutions are volatile, direct measurement is difficult. In this experiment, the quantitative measurement of light hydrocarbons was performed using the difference method. First, the simulated gold tube containing the sample was weighed, and its weight (G) was recorded. t Then, after the gold tubes underwent gas analysis, they were left to stand for one day until all the gas and light hydrocarbons in the tubes had dissipated before being weighed and their weight (G) recorded. cz1 The weight of the light hydrocarbon (G1) is equal to the weight lost minus the total weight of the gas, that is:

[0083] G1 = G t -G cz1 -G0

[0084] 3) Liquid hydrocarbons / discharged oil metering

[0085] The amount of liquid hydrocarbons generated in the reaction / the amount of oil discharged was obtained by combining CH2Cl2 ultrasonic extraction and the weighing difference method. After gas analysis, the gold tube was placed in CH2Cl2 and cut open. The organic solvent soaking the gold tube was then ultrasonicated three times. The solid residue was then filtered through a chromatographic membrane. The resulting liquid solution was weighed after the organic solvent had completely evaporated to obtain the weight of the liquid hydrocarbons (G). cy1 ).

[0086] After the gold tubes and residues that have passed through extraction and filtration have been dried, they are 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 ),Right now:

[0087] G cy2 =G cz1 -G cz2

[0088] To reduce errors, the weight of liquid hydrocarbons (G) during the experiment... y Calculate using the following formula:

[0089] G y =(G cy1 +G cy2 ) / 2.

[0090] 4) Calculation of oil and gas increments

[0091] The total amount of oil and gas in Comparative Example 1 (G 对比例1 (Based on)

[0092] Increment in oil and gas volume = (Total oil and gas volume - G) 对比例1 / G 对比例1 )×100%.

[0093] pH testing method: At room temperature, immerse the pH meter electrode in a standard buffer solution and calibrate according to the instrument instructions. Rinse the electrode with distilled or deionized water to remove surface impurities. Immerse the pH meter electrode in the solution to be tested, allow it to stand for a moment until the value stabilizes, and then read the pH value.

[0094] Example 1

[0095] (1) Mix 50 g of magnesite and a 0.1 mol / L sulfuric acid solution at 20 °C. The liquid-solid mass ratio is 2 and the pH is 2.8. The mixture is treated for 60 min and filtered to obtain acid-etched mineral 1 and acid-treated liquid phase 1. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase is 60% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0096] (2) Then, 3.98 g of 10 wt% methanol solution was slowly added to acid treatment liquid phase 1 and stirred thoroughly at 20 °C for 60 min to form crystalline alcohol in acid treatment liquid phase 1, thus obtaining alcoholized acid treatment liquid phase 1;

[0097] (3) Add 3 grams of water and 34.10 grams of acid-etched minerals to the alcoholic acid-treated liquid phase 1 to prepare oil displacement agent 1.

[0098] The composition of oil displacement agent 1 includes: 21.72 wt% acid-etched minerals, 2.54 wt% alcohol, 10.13 wt% metal ions, and the remainder is acidified water solvent with a pH of 6.3. The specific surface area of ​​the acid-etched minerals is 86 m². 2 / g, pore volume is 0.18mL / g.

[0099] After thoroughly mixing 2.7 g of oil displacement agent 1 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 100 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then pyrolyzed at a constant temperature of 30 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0100] Example 2

[0101] (1) 20 grams of calcite and a 2.5 mol / L hydrochloric acid solution were thoroughly mixed at 50°C with a liquid-to-solid mass ratio of 18 and a pH of 6 for 40 min. After filtration, acid-etched mineral 2 and acid-treated liquid phase 2 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 30% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0102] (2) Then 2.06 g of 100 wt% ethanol was slowly added to the acid treatment liquid phase 2 and stirred thoroughly at 60 °C for 10 min to form crystalline alcohol in the acid treatment liquid phase 2, thus obtaining the alcoholized acid treatment liquid phase 2.

[0103] (3) Add 30 g of water and 15.20 g of acid-etched minerals to the alcoholic acid-treated liquid phase 2 to prepare oil displacement agent 2.

[0104] The composition of oil displacement agent 2 includes: 3.69 wt% acid-etching minerals, 0.50 wt% alcohol, 1.16 wt% metal ions, and the remainder is acidified water solvent with a pH of 4.7. The specific surface area of ​​the acid-etching minerals is 102 m². 2 / g, pore volume is 0.21mL / g.

[0105] After thoroughly mixing 0.6 g of oil displacement agent 2 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 180 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then kept at a constant temperature of 10 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0106] Example 3

[0107] (1) 70 g of dolomite and a 20 mol / L formic acid solution were thoroughly mixed at 30 °C with a liquid-to-solid mass ratio of 20 and a pH of 3.2 for 20 min. After filtration, acid-etched mineral 3 and acid-treated liquid phase 3 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 80% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0108] (2) Then, 16.27 g of 20 wt% ethanol solution was slowly added to acid treatment liquid phase 3 and stirred thoroughly at 30 °C for 20 min to form crystalline alcohol in acid treatment liquid phase 3, thus obtaining alcoholized acid treatment liquid phase 3;

[0109] (3) Add 160 g of water and 45.60 g of acid-etched minerals to the alcoholic acid-treated liquid phase 3 to prepare oil displacement agent 3.

[0110] The composition of oil displacement agent 3 includes: 2.77 wt% acid-etching minerals, 0.99 wt% alcohol, 1.48 wt% metal ions, and the remainder is acidified water solvent with a pH of 3.3. The specific surface area of ​​the acid-etching minerals is 167 m². 2 / g, pore volume is 0.35mL / g.

[0111] After thoroughly mixing 0.3 g of oil displacement agent 3 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 600 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then subjected to constant temperature pyrolysis at 20 MPa for 72 h to evaluate hydrocarbon generation. The resulting oil and gas were analyzed to obtain the final oil and gas production.

[0112] Example 4

[0113] (1) 60 g of montmorillonite and a 15 mol / L formic acid solution were thoroughly mixed at 70 °C with a liquid-to-solid mass ratio of 5 and a pH of 3.9 for 30 min. After filtration, acid-etched mineral 4 and acid-treated liquid phase 4 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 90% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0114] (2) Then, 30.24 g of 30 wt% propanol solution was slowly added to acid treatment liquid phase 4 and stirred thoroughly at 50 °C for 30 min to form crystalline alcohol in acid treatment liquid phase 4, thus obtaining alcoholized acid treatment liquid phase 4.

[0115] (3) Add 80 g of water and 29.76 g of acid-etched minerals to the alcoholic acid-treated liquid phase 4 to prepare oil displacement agent 4.

[0116] The composition of oil displacement agent 4 includes: 6.33 wt% acid-etched minerals, 6.43 wt% alcohol, 6.43 wt% metal ions, and the remainder is acidified water solvent with a pH of 3.9. The specific surface area of ​​the acid-etched minerals is 137 m². 2 / g, pore volume is 0.31mL / g.

[0117] After thoroughly mixing 0.9 g of oil displacement agent 4 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 500 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then pyrolyzed at 15 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0118] Figure 1 The image shown is a scanning electron microscope image of the natural mineral before acid treatment in Example 4, with a magnification of 30,000x, a focal length of 13.2mm, and an accelerating voltage of 5.0kV.

[0119] Figure 2 The image is a scanning electron microscope image of the natural mineral acid treated in Example 4, with a magnification of 30,000x, a focal length of 9.9mm, and an accelerating voltage of 2.0kV.

[0120] contrast Figure 1 and Figure 2This indicates that the specific surface area of ​​the acid-etched minerals obtained after acid treatment of natural minerals is significantly larger than that of the natural minerals before acid treatment.

[0121] Example 5

[0122] (1) 80 g of montmorillonite and a 7 mol / L citric acid solution were thoroughly mixed at 40 °C with a liquid-to-solid mass ratio of 7 and a pH of 5.2 for 45 min. After filtration, acid-etched mineral 5 and acid-treated liquid phase 5 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 20% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0123] (2) Then, 12.72 g of 45 wt% methanol solution was slowly added to acid treatment liquid phase 5 and stirred thoroughly at 55 °C for 35 min to form crystalline alcohol in acid treatment liquid phase 5, thus obtaining alcoholized acid treatment liquid phase 5.

[0124] (3) Add 100g of water and 71.52g of acid-etched minerals to the alcoholic acid-treated liquid phase 5 to prepare oil displacement agent 5.

[0125] The composition of oil displacement agent 5 includes: 9.50 wt% acid-etching minerals, 1.69 wt% alcohol, 1.19 wt% metal ions, and the remainder being acidified aqueous solvent with a pH of 3.5. The specific surface area of ​​the acid-etching minerals is 110 m². 2 / g, pore volume is 0.26mL / g.

[0126] After thoroughly mixing 2.1 g of oil displacement agent 5 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 400 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then pyrolyzed at a constant temperature of 25 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0127] Example 6

[0128] (1) 100g of dolomite and 9mol / L citric acid solution were thoroughly mixed at 80℃ with a liquid-solid mass ratio of 9 and pH of 4.4 for 50min. After filtration, acid-etched mineral 6 and acid-treated liquid phase 6 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 95% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0129] (2) Then, 96.60 g of 55 wt% ethanol solution was slowly added to acid treatment liquid phase 6 and stirred thoroughly at 35 °C for 25 min to form crystalline alcohol in acid treatment liquid phase 6, thus obtaining alcoholized acid treatment liquid phase 6.

[0130] (3) Add 150 g of water and 58.60 g of acid-etched minerals to the alcoholic acid-treated liquid phase 6 to prepare oil displacement agent 6.

[0131] The composition of oil displacement agent 6 includes: 4.70 wt% acid-etching minerals, 7.75 wt% alcohol, 3.32 wt% metal ions, and the remainder is acidified water solvent with a pH of 4.5. The specific surface area of ​​the acid-etching minerals is 119 m². 2 / g, pore volume is 0.23mL / g.

[0132] After thoroughly mixing 1.2 g of oil displacement agent 6 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 550 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then pyrolyzed at 12 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0133] Example 7

[0134] (1) 70 g of magnesite and a 13 mol / L phosphoric acid solution were thoroughly mixed at 100 °C with a liquid-to-solid mass ratio of 11 and a pH of 4.9 for 10 min. After filtration, acid-etched mineral 7 and acid-treated liquid phase 7 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 40% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0135] (2) Then, 59.36 g of 65 wt% ethanol solution was slowly added to the acid treatment liquid phase 7 and stirred thoroughly at 25 °C for 45 min to form crystalline alcohol in the acid treatment liquid phase 7, thus obtaining the alcoholized acid treatment liquid phase 7.

[0136] (3) Add 220 g of water and 55.16 g of acid-etched minerals to the alcoholic acid-treated liquid phase 7 to prepare oil displacement agent 7.

[0137] The composition of oil displacement agent 7 includes: 4.93 wt% acid-etched minerals, 5.30 wt% alcohol, 1.33 wt% metal ions, and the remainder being acidified aqueous solvent with a pH of 5.0. The specific surface area of ​​the acid-etched minerals is 113 m². 2 / g, pore volume is 0.31mL / g.

[0138] After thoroughly mixing 1.5 g of oil displacement agent 7 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 450 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then kept at a constant temperature of 17 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0139] Example 8

[0140] (1) 65 g of calcite and 17 mol / L oxalic acid solution were thoroughly mixed at 30 °C with a liquid-solid mass ratio of 13 and a pH of 5.8 for 55 min. After filtration, acid-etched mineral 8 and acid-treated liquid phase 8 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 50% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0141] (2) Then, 26 g of 70 wt% methanol solution was slowly added to acid treatment liquid phase 8 and stirred thoroughly at 30 °C for 40 min to form crystalline alcohol in acid treatment liquid phase 8, thus obtaining alcoholized acid treatment liquid phase 8.

[0142] (3) Add 80 grams of water and 39 grams of acid-etched minerals to the alcoholic acid-treated liquid phase 8 to prepare an oil displacement agent 8.

[0143] The composition of oil displacement agent 8 includes: 3.84 wt% acid-etching minerals, 2.56 wt% alcohol, 2.56 wt% metal ions, and the remainder is acidified water solvent with a pH of 6.5. The specific surface area of ​​the acid-etching minerals is 145 m². 2 / g, pore volume is 0.33mL / g.

[0144] After thoroughly mixing 1.8 g of oil displacement agent 8 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 300 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then kept at a constant temperature of 22 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0145] Example 9

[0146] (1) 40 g of dolomite and acetic acid solution with a concentration of 4 mol / L were thoroughly mixed at 60 °C. The liquid-solid mass ratio was 15 and the pH was 3.6. The mixture was treated for 15 min and filtered to obtain acid-etched mineral 9 and acid-treated liquid phase 9. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 60% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0147] (2) Then, 3.49 g of 80 wt% propanol solution was slowly added to acid treatment liquid phase 9 and stirred thoroughly at 20 °C for 50 min to form crystalline alcohol in acid treatment liquid phase 9, thus obtaining alcoholized acid treatment liquid phase 9.

[0148] (3) Add 60 g of water and 29.54 g of acid-etched minerals to the alcoholic acid-treated liquid phase 9 to prepare oil displacement agent 9.

[0149] The composition of oil displacement agent 9 includes: 4.20 wt% acid-etching minerals, 0.50 wt% alcohol, 1.49 wt% metal ions, and the remainder is acidified water solvent with a pH of 5.7. The specific surface area of ​​the acid-etching minerals is 105 m². 2 / g, pore volume is 0.22mL / g.

[0150] After thoroughly mixing 2.4 g of oil displacement agent 9 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 350 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then kept at a constant temperature of 27 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0151] Example 10

[0152] (1) 90 g of montmorillonite and a 12 mol / L sulfuric acid solution were thoroughly mixed at 75 °C with a liquid-to-solid mass ratio of 1:9 and a pH of 3.8 for 25 min. After filtration, acid-etched mineral 10 and acid-treated liquid phase 10 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 70% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0153] (2) Then, 18.99 g of 90 wt% methanol solution was slowly added to acid treatment liquid phase 10 and stirred thoroughly at 45 °C for 15 min to form crystalline alcohol in acid treatment liquid phase 10, thus obtaining alcoholized acid treatment liquid phase 10.

[0154] (3) Add 130 g of water and 54.72 g of acid-etched minerals to the alcoholic acid-treated liquid phase 10 to prepare oil displacement agent 10.

[0155] The composition of oil displacement agent 10 includes: 2.81 wt% acid-etching minerals, 0.97 wt% alcohol, 1.81 wt% metal ions, and the remainder is acidified water solvent with a pH of 5.3. The specific surface area of ​​the acid-etching minerals is 131 m². 2 / g, pore volume is 0.30mL / g.

[0156] After thoroughly mixing 0.75 g of oil displacement agent 10 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 200 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then subjected to constant temperature pyrolysis at 19 MPa for 72 h to evaluate hydrocarbon generation. The resulting oil and gas were analyzed to obtain the final oil and gas production.

[0157] Example 11

[0158] The method is the same as in Example 8, except that 74 grams of 100wt% methanol is added.

[0159] The composition of oil displacement agent 11 includes: 3.67 wt% acid-etching minerals, 6.95 wt% alcohol, 2.44 wt% metal ions, and the remainder is acidified water solvent with a pH of 6.8. The specific surface area of ​​the acid-etching minerals is 145 m². 2 / g, pore volume is 0.33mL / g.

[0160] Example 12

[0161] The method is the same as in Example 8, except that the alcohol added is 5.49 g of a 10 wt% methanol solution.

[0162] The composition of oil displacement agent 12 includes: 3.92 wt% acid-etching minerals, 0.55 wt% alcohol, 2.61 wt% metal ions, and the remainder is acidified water solvent with a pH of 6.1. The specific surface area of ​​the acid-etching minerals is 145 m². 2 / g, pore volume is 0.33mL / g.

[0163] Example 13

[0164] The method is the same as in Example 8, except that the alcohol added is 26 grams of a 70 wt% ethanol solution.

[0165] The composition of oil displacement agent 13 includes: 3.84 wt% acid-etching minerals, 2.56 wt% alcohol, 2.56 wt% metal ions, and the remainder is acidified water solvent with a pH of 6.6. The specific surface area of ​​the acid-etching minerals is 145 m². 2 / g, pore volume is 0.33mL / g.

[0166] Example 14

[0167] The method is the same as in Example 8, except that the alcohol added is 26 grams of a 70 wt% propanol solution.

[0168] The composition of oil displacement agent 14 includes: 3.84 wt% acid-etching minerals, 2.56 wt% alcohol, 2.56 wt% metal ions, and the remainder is acidified water solvent with a pH of 6.6. The specific surface area of ​​the acid-etching minerals is 145 m². 2 / g, pore volume is 0.33mL / g.

[0169] Example 15

[0170] The method is the same as in Example 8, except that 65 grams of magnesite are used as the natural mineral.

[0171] The composition of oil displacement agent 15 includes: 3.87 wt% acid-etching minerals, 2.58 wt% alcohol, 1.71 wt% metal ions, and the remainder is acidified aqueous solvent with a pH of 6.6. The specific surface area of ​​the acid-etching minerals is 155 m². 2 / g, pore volume is 0.33mL / g.

[0172] Example 16

[0173] (1) 65 g of calcite and 20 mol / L oxalic acid solution were thoroughly mixed at 100 °C with a liquid-solid mass ratio of 20 and a pH of 2.8 for 60 min. After filtration, acid-etched mineral 16 and acid-treated liquid phase 16 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 70% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0174] (2) Then, 36.4 g of 70 wt% methanol solution was slowly added to acid treatment liquid phase 16 and stirred thoroughly at 30 °C for 40 min to form crystalline alcohol in acid treatment liquid phase 16, thus obtaining alcoholic acid treatment liquid phase 16.

[0175] (3) Add 80 g of water and 36.4 g of acid-etched minerals to the alcoholic acid-treated liquid phase 16 to prepare oil displacement agent 16.

[0176] The composition of oil displacement agent 16 includes: 2.44 wt% acid-etching minerals, 2.44 wt% alcohol, 2.44 wt% metal ions, and the remainder is acidified water solvent with a pH of 5.6. The specific surface area of ​​the acid-etching minerals is 175 m². 2 / g, pore volume is 0.37mL / g.

[0177] After thoroughly mixing 1.8 g of oil displacement agent 16 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 300 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then kept at a constant temperature of 22 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0178] Example 17

[0179] (1) 65 g of calcite and 20 mol / L oxalic acid solution were thoroughly mixed at 30 °C with a liquid-solid mass ratio of 2 and a pH of 6.0 for 20 min. After filtration, acid-etched mineral 17 and acid-treated liquid phase 17 were obtained. The total mass of magnesium and calcium (in atomic terms) in the acid-treated liquid phase was 70% of the total mass of magnesium and calcium (in atomic terms) in the natural mineral.

[0180] (2) Then, 10.4 g of 70 wt% methanol solution was slowly added to acid treatment liquid phase 17 and stirred thoroughly at 30 °C for 40 min to form crystalline alcohol in acid treatment liquid phase 17, thus obtaining alcoholized acid treatment liquid phase 17.

[0181] (3) Add 80 g of water and 54.6 g of acid-etched minerals to the alcoholic acid-treated liquid phase 17 to prepare oil displacement agent 17.

[0182] The composition of oil displacement agent 17 includes: 17.53 wt% acid-etching minerals, 3.34 wt% alcohol, 11.69 wt% metal ions, and the remainder is an acidified aqueous solvent with a pH of 6.0. The specific surface area of ​​the acid-etching minerals is 115 m². 2 / g, pore volume is 0.31mL / g.

[0183] After thoroughly mixing 1.8 g of oil displacement agent 17 with 3 g of oil shale powder, 0.8 g of the mixture was weighed out and heated to 300 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then pyrolyzed at 22 MPa for 72 h to conduct a hydrocarbon generation simulation experiment. The resulting oil and gas were analyzed after the reaction to obtain the final oil and gas production.

[0184] Example 18

[0185] The method is the same as in Example 8, except that the stirring temperature when adding the alcohol solution is 100°C and the stirring time is 60 min.

[0186] The composition of oil displacement agent 18 includes: 3.84 wt% acid-etching minerals, 2.56 wt% alcohol, 2.56 wt% metal ions, and the remainder is acidified water solvent with a pH of 6.5. The specific surface area of ​​the acid-etching minerals is 145 m². 2 / g, pore volume is 0.33mL / g.

[0187] Comparative Example 1

[0188] Compared with Example 10, Comparative Example 1 did not add any catalyst, and 0.8 grams of oil shale was weighed for oil displacement performance evaluation.

[0189] Comparative Example 2

[0190] Compared with Example 7, in Comparative Example 2, 59.36 g of 65 wt% ethanol aqueous solution was mixed evenly with 3 g of oil shale, and 0.8 g of the mixture was weighed out for oil displacement performance evaluation.

[0191] Comparative Example 3

[0192] Compared with Example 3, 70 grams of dolomite and a 20 mol / L formic acid solution were thoroughly mixed at 30°C with a liquid-to-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 evenly with 3 grams of oil shale and 0.8 grams were weighed out for oil displacement performance evaluation.

[0193] Comparative Example 4

[0194] 0.3 g of organic cycloalkyl ketone was thoroughly mixed with 3 g of oil shale, and 0.8 g of the mixture was weighed out and heated to 600 °C at a heating rate of 20 °C / min in a gold tube hydrocarbon generation simulator. The mixture was then pyrolyzed at a constant temperature of 20 MPa for 72 h to evaluate hydrocarbon generation. The resulting oil and gas were analyzed to obtain the final oil and gas production.

[0195] Table 1 Evaluation results of the examples and comparative examples

[0196]

[0197]

[0198] As can be seen from the data in the table above, compared with Comparative Example 1 without catalyst, Examples 1-18 involve the slow chemical reaction of crystalline alcohols under simulated formation conditions to form complexes of magnesium, calcium, and alcohols, while continuously releasing water molecules. The released water molecules are in a supercritical state, which can efficiently dissolve hydrocarbons and salts in the rock formation, thereby achieving the effect of enhancing oil recovery and significantly increasing both the amount of oil discharged and the total amount of oil and gas, with an increase in oil and gas production of 9.35% to 24.14%.

[0199] Comparative Example 2 involved adding only alcohols to oil shale and then evaluating the mixture. Comparative Example 3 involved adding only acid-treated products to oil shale and then evaluating the mixture. The evaluation results showed that the catalyst without the formation of alcohols could not produce an enhanced oil displacement effect, and no increase in oil and gas yield was observed. Comparative Example 4 used a traditional oil displacement agent, and the effect was not ideal.

[0200] In summary, the oil displacement agent and its preparation method provided by this invention, which enhances the oil displacement and promotes kerogen conversion, are characterized by low cost, cleanliness and environmental friendliness, and have the advantage of continuously exerting the effect of enhancing the oil displacement.

[0201] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

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; preferably 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, preferably from 5.5 to 6.

8. The method comprises:

10. 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; 11. A method for preparing an oil displacement agent, characterized by, (2) contacting an alcohol with the acid treatment liquid phase to obtain an alcoholized acid treatment liquid phase; (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 include: a temperature of 20-100°C; and / or 12. The method of claim 11, wherein, a time of 10-60 min; and / or 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 13. The production method according to claim 11 or 12, characterized by, the concentration of the acid solution is 0.1-20 mol / L; and / or 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 14. The method of claim 13, wherein, the organic acid comprises a C1-C6 acid; preferably 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%. In step (1), the natural mineral is selected from natural minerals rich in magnesium and calcium.

15. The production method according to claim 11 or 12, characterized by, In step (1), the natural mineral rich in magnesium and calcium is selected from one or more of magnesite, calcite, dolomite, and montmorillonite.

16. The production method according to claim 11 or 12, characterized by, In step (2), the contacting conditions include:

17. The method of claim 16, wherein, a temperature of 20-60°C; and / or 18. The method of manufacturing according to claim 11 or 12, wherein, a time of 10-60 min. 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.

19. The production method according to claim 11 or 12, characterized by, In step (2), the concentration of the alcohol is 10-100 wt%.

20. The method of claim 19, wherein, In step (2), the mass ratio of the alcohol to the metal (in atoms) in the acid treatment liquid phase is 1:5-4:

1.

21. The method of manufacturing according to claim 11 or 12, wherein, ​ 22. The method of claim 11 or 12, wherein, ​ 23. The oil displacement agent produced by the process of any one of claims 11 to 22.

24. Use of the oil displacement agent of any one of claims 1 to 10, 23 in oil recovery.

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