Temperature-resistant and salt-resistant imbibition agent as well as preparation method and application thereof

Abstract

The invention belongs to the field of imbibition agents, and discloses a temperature-resistant and salt-resistant imbibition agent and a preparation method and application thereof, the imbibition agent is prepared from a temperature-resistant agent, a salt-resistant agent, a capillary force reinforcing agent, a cross-linking agent, a surfactant, a nanoparticle additive and deionized water according to a specific proportion; the nanoparticle additive is metal fluoride nanoparticles prepared by a specific process, so that the temperature resistance and salt resistance of the product are enhanced; the preparation method comprises the following steps: premixing, adding the cross-linking agent, heating, finally adding the surfactant and the nanoparticle additive, and uniformly dispersing. The imbibition agent has important application in oil exploitation, can effectively cope with a high-temperature and high-salt environment, and improves the exploitation efficiency.

Description

Technical Field

[0001] The invention belongs to the field of imbibition agents and discloses a temperature-resistant and salt-resistant imbibition agent and a preparation method and application thereof. Background Art

[0002] In the field of oil extraction, especially in complex geological environments such as high-temperature and high-salt formations, the performance of traditional imbibition agents is often severely challenged. Most of the imbibition agents in the existing technology rely on a single or limited combination of several materials, and in a high-salt environment, their molecular chains are easily interfered by ions, resulting in a significant decrease in the imbibition efficiency.

[0003] In terms of preparation technology, the preparation process of existing imbibition agents often lacks in-depth research on the interaction between the components, resulting in large fluctuations in the performance of the prepared products and difficulty in ensuring consistency. In particular, in the addition and dispersion of nanoparticles, the existing technology often finds it difficult to achieve uniform and stable dispersion of nanoparticles in imbibition agents, affecting the enhancement effect of nanoparticles on the performance of imbibition agents.

[0004] In summary, the performance of the imbibition agent in the prior art is poor in high temperature and high salt environment, and there are many deficiencies in the preparation process, which limits its application in oil production. Therefore, it is of great practical significance and application prospect to develop a new type of temperature-resistant and salt-resistant imbibition agent, optimize the raw material ratio and preparation process, realize the synergistic effect between the components, and improve the stability and performance of the imbibition agent in high temperature and high salt environment. Summary of the invention

[0005] In view of the above problems, the present invention discloses a temperature-resistant and salt-resistant imbibition agent and a preparation method and application thereof.

[0006] The purpose of the present invention is achieved through the following technical solutions.

[0007] A temperature-resistant and salt-resistant imbibition agent is prepared from the following raw materials in parts by weight:

[0008]

[0009] The nanoparticle additive is metal fluoride nanoparticles.

[0010] Furthermore, in the above-mentioned temperature-resistant and salt-resistant imbibition agent, the nanoparticle additive is prepared by the following steps:

[0011] 1) Mixing reactants: Under the protection of an inert atmosphere, add 2 parts of powdered ammonium fluoride, 1 to 2 parts of ferric chloride, and 2 to 4 parts of cupric chloride into 20 to 40 parts of propylene glycol solvent to obtain a mixed solution, where the parts are by weight;

[0012] 2) Heating reaction: Under the protection of an inert atmosphere, the mixed solution is heated to 80-120° C. with stirring, and the ammonium fluoride and the metal salt are reacted in an alcohol solvent for 2-4 hours. The solid is filtered and dried to obtain a solid;

[0013] 3) Annealing: annealing the solid product obtained after the reaction at a temperature of 250 to 500° C.;

[0014] 4) Washing and drying: The annealed product is washed several times with an appropriate solvent to remove residual solvent and impurities, and then the product is dried in a vacuum or inert atmosphere to a constant weight.

[0015] Further, in the above-mentioned heat-resistant and salt-resistant imbibition agent, the step 3) annealing comprises the following steps:

[0016] Start the heating system of the annealing furnace, gradually raise the furnace temperature to the predetermined annealing temperature of 250-500°C, and the heating rate is 5-10°C / min;

[0017] When the furnace temperature reaches the preset temperature, maintain it for 60 to 100 minutes;

[0018] After the insulation is completed, the workpiece is cooled to room temperature at a slower speed, with a cooling rate of 5 to 10°C / min.

[0019] Furthermore, in the above-mentioned temperature-resistant and salt-resistant imbibition agent, the washing solvent in step 4) is ethanol.

[0020] Furthermore, in the above-mentioned temperature-resistant and salt-resistant imbibition agent, the capillary force enhancer is polyvinyl alcohol PVA1788, which enhances the capillary force by increasing the viscoelasticity of the liquid.

[0021] Furthermore, the above-mentioned temperature-resistant and salt-resistant imbibition agent is selected from one of graphene, nano-alumina or carbon fiber.

[0022] Furthermore, in the above-mentioned temperature-resistant and salt-resistant imbibition agent, the salt-resistant agent is selected from ethylenediaminetetraacetic acid or diethylenetriaminepentaacetic acid.

[0023] Furthermore, in the above-mentioned temperature-resistant and salt-resistant imbibition agent, the cross-linking agent is dicumyl peroxide; and the surfactant is polyoxyethylene polyoxypropylene propylene glycol ether.

[0024] The present invention also discloses a method for preparing the temperature-resistant and salt-resistant imbibition agent, which comprises the following steps:

[0025] S1 premixing: firstly, premix the temperature resistance agent, anti-salt agent, capillary force enhancer and deionized water in a high-speed mixer;

[0026] S2: adding the cross-linking agent: slowly adding the cross-linking agent to the pre-mixed material while keeping stirring;

[0027] S3 Heating and melting: transfer the mixed material into the reactor, heat it to 60-90°C, and keep it for 2-4h;

[0028] S4 Add surfactant and nanoparticles: Add surfactant and nanoparticle additives in sequence, continue stirring until evenly dispersed, and cool to room temperature.

[0029] The invention also discloses the application of the temperature-resistant and salt-resistant imbibition agent in petroleum production.

[0030] Compared with the existing technology, the present invention has the following advantages and beneficial effects:

[0031] The present invention discloses a heat-resistant and salt-resistant imbibition agent and its preparation method and application. Through the carefully designed raw material ratio and preparation process, the organic combination of a heat-resistant agent, a salt-resistant agent, a capillary force enhancer, a cross-linking agent, a surfactant and a nanoparticle additive is achieved. Among them, the heat-resistant agent enhances the stability of the imbibition agent at high temperature; the salt-resistant agent effectively resists the influence of the high-salt environment on the performance of the imbibition agent; the capillary force enhancer improves its permeability in porous media; the cross-linking agent promotes the imbibition agent to form a stable network structure to further enhance the capillary force; the surfactant improves the wettability and permeability of the imbibition agent; and the nanoparticle additive, especially the metal fluoride nanoparticles, not only improves the heat resistance and salt resistance of the imbibition agent, but also enhances its mechanical strength and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The capillary self-imbibition height (0.3% solution, 21342 mg / L, Ca 2+ Mg 2+ Total amount 544mg / L). DETAILED DESCRIPTION

[0033] A temperature-resistant and salt-resistant imbibition agent is prepared from the following raw materials in parts by weight:

[0034]

[0035] The nanoparticle additive is metal fluoride nanoparticles.

[0036] The nanoparticle additive is prepared by the following steps:

[0037] 1) Mixing reactants: Under the protection of an inert atmosphere, add 2 parts of powdered ammonium fluoride, 1 to 2 parts of ferric chloride, and 2 to 4 parts of cupric chloride into 20 to 40 parts of propylene glycol solvent to obtain a mixed solution, where the parts are by weight;

[0038] 2) Heating reaction: Under the protection of an inert atmosphere, the mixed solution is heated to 80-120° C. with stirring, and the ammonium fluoride and the metal salt are reacted in an alcohol solvent for 2-4 hours, and the solid is filtered and dried to obtain a solid;

[0039] 3) Annealing: annealing the solid product obtained after the reaction at a temperature of 250 to 500° C.;

[0040] 4) Washing and drying: The annealed product is washed several times with an appropriate solvent to remove residual solvent and impurities, and then the product is dried in a vacuum or inert atmosphere to a constant weight.

[0041] The step 3) annealing comprises the following steps:

[0042] Start the heating system of the annealing furnace, gradually raise the furnace temperature to the predetermined annealing temperature of 250-500°C, and the heating rate is 5-10°C / min;

[0043] When the furnace temperature reaches the preset temperature, maintain it for 60 to 100 minutes;

[0044] After the insulation is completed, the workpiece is cooled to room temperature at a slower speed, with a cooling rate of 5 to 10°C / min.

[0045] In the step 4), the washing solvent is ethanol;

[0046] The capillary force enhancer is polyvinyl alcohol PVA 1788, which enhances the capillary force by increasing the viscoelasticity of the liquid.

[0047] The temperature resistant agent is selected from one of graphene, nano-alumina or carbon fiber;

[0048] The anti-salt agent is selected from ethylenediaminetetraacetic acid or diethylenetriaminepentaacetic acid;

[0049] The cross-linking agent is dicumyl peroxide; the surfactant is polyoxyethylene polyoxypropylene propylene glycol ether;

[0050] The preparation method of the above-mentioned temperature-resistant and salt-resistant imbibition agent comprises the following steps:

[0051] S1 premixing: firstly, premix the temperature resistance agent, anti-salt agent, capillary force enhancer and deionized water in a high-speed mixer;

[0052] S2: adding the cross-linking agent: slowly adding the cross-linking agent to the pre-mixed material while keeping stirring;

[0053] S3 Heating and melting: transfer the mixed material into the reactor, heat it to 60-90°C, and keep it for 2-4h;

[0054] S4 Add surfactant and nanoparticles: Add surfactant and nanoparticle additives in sequence, continue stirring until evenly dispersed, and cool to room temperature.

[0055] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below through embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0056] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0057] Example 1

[0058] A temperature-resistant and salt-resistant imbibition agent is prepared from the following raw materials in parts by weight:

[0059]

[0060] The nanoparticle additive is metal fluoride nanoparticles.

[0061] The nanoparticle additive is prepared by the following steps:

[0062] 1) Mixing reactants: Under the protection of an inert atmosphere, add 2 parts of powdered ammonium fluoride, 1 part of ferric chloride, and 2 parts of cupric chloride into 20 parts of propylene glycol solvent to obtain a mixed solution, where the parts are by weight;

[0063] 2) Heating reaction: Under the protection of an inert atmosphere, the mixed solution is heated to 80° C. with stirring, and the ammonium fluoride and the metal salt are reacted in an alcohol solvent for 4 hours. The solid is filtered and dried to obtain a solid;

[0064] 3) Annealing: The solid product obtained after the reaction is annealed at a temperature of 250° C.

[0065] 4) Washing and drying: The annealed product is washed several times with an appropriate solvent to remove residual solvent and impurities, and then the product is dried in a vacuum or inert atmosphere to a constant weight.

[0066] The step 3) annealing comprises the following steps:

[0067] Start the heating system of the annealing furnace and gradually raise the furnace temperature to the predetermined annealing temperature of 250°C at a heating rate of 5 to 10°C / min;

[0068] When the furnace temperature reaches the preset temperature, maintain it for 60 minutes;

[0069] After the insulation is completed, the workpiece is cooled to room temperature at a slower speed, with a cooling rate of 5 to 10°C / min.

[0070] In the step 4), the washing solvent is ethanol;

[0071] The capillary force enhancer is polyvinyl alcohol PVA 1788, which enhances the capillary force by increasing the viscoelasticity of the liquid.

[0072] The temperature resistant agent is selected from graphene;

[0073] The anti-salt agent is selected from ethylenediaminetetraacetic acid;

[0074] The cross-linking agent is dicumyl peroxide; the surfactant is polyoxyethylene polyoxypropylene propylene glycol ether;

[0075] The preparation method of the above-mentioned temperature-resistant and salt-resistant imbibition agent comprises the following steps:

[0076] S1 premixing: firstly, premix the temperature resistance agent, anti-salt agent, capillary force enhancer and deionized water in a high-speed mixer;

[0077] S2: adding the cross-linking agent: slowly adding the cross-linking agent to the pre-mixed material while keeping stirring;

[0078] S3 Heating and melting: transfer the mixed material into the reactor, heat it to 60-90°C, and keep it for 2-4h;

[0079] S4 Add surfactant and nanoparticles: Add surfactant and nanoparticle additives in sequence, continue stirring until evenly dispersed, and cool to room temperature.

[0080] Example 2

[0081] A temperature-resistant and salt-resistant imbibition agent is prepared from the following raw materials in parts by weight:

[0082]

[0083] The nanoparticle additive is metal fluoride nanoparticles.

[0084] The nanoparticle additive is prepared by the following steps:

[0085] 1) Mixing reactants: Under the protection of an inert atmosphere, 2 parts of powdered ammonium fluoride, 1.5 parts of ferric chloride, and 3 parts of cupric chloride are added to 30 parts of propylene glycol solvent to obtain a mixed solution, where the parts are by weight;

[0086] 2) Heating reaction: Under the protection of an inert atmosphere, the mixed solution is heated to 100° C. with stirring to allow ammonium fluoride and the metal salt to react in an alcohol solvent for 3 hours, and the solid is filtered and dried to obtain a solid;

[0087] 3) Annealing: The solid product obtained after the reaction is annealed at a temperature of 400° C.

[0088] 4) Washing and drying: The annealed product is washed several times with an appropriate solvent to remove residual solvent and impurities, and then the product is dried in a vacuum or inert atmosphere to a constant weight.

[0089] The step 3) annealing comprises the following steps:

[0090] Start the heating system of the annealing furnace and gradually raise the furnace temperature to the predetermined annealing temperature of 400°C at a heating rate of 5 to 10°C / min;

[0091] When the furnace temperature reaches the preset temperature, maintain it for 80 minutes;

[0092] After the insulation is completed, the workpiece is cooled to room temperature at a slower speed, with a cooling rate of 5-10℃ / min.

[0093] In the step 4), the washing solvent is ethanol;

[0094] The capillary force enhancer is polyvinyl alcohol PVA 1788, which enhances the capillary force by increasing the viscoelasticity of the liquid.

[0095] The temperature resistant agent is selected from nano-alumina;

[0096] The anti-salt agent is selected from ethylenediaminetetraacetic acid;

[0097] The thickener is polyacrylamide; the crosslinking agent is dicumyl peroxide; the surfactant is polyoxyethylene polyoxypropylene propylene glycol ether;

[0098] The preparation method of the above-mentioned temperature-resistant and salt-resistant imbibition agent comprises the following steps:

[0099] S1 premixing: firstly, premix the temperature resistance agent, anti-salt agent, capillary force enhancer and deionized water in a high-speed mixer;

[0100] S2: adding the cross-linking agent: slowly adding the cross-linking agent to the pre-mixed material while keeping stirring;

[0101] S3 Heating and melting: transfer the mixed material into the reactor, heat it to 60-90°C, and keep it for 2-4h;

[0102] S4 Add surfactant and nanoparticles: Add surfactant and nanoparticle additives in sequence, continue stirring until evenly dispersed, and cool to room temperature.

[0103] Example 3

[0104] A temperature-resistant and salt-resistant imbibition agent is prepared from the following raw materials in parts by weight:

[0105]

[0106] The nanoparticle additive is metal fluoride nanoparticles.

[0107] The nanoparticle additive is prepared by the following steps:

[0108] 1) Mixing reactants: Under the protection of an inert atmosphere, add 2 parts of powdered ammonium fluoride, 2 parts of ferric chloride, and 4 parts of cupric chloride into 40 parts of propylene glycol solvent to obtain a mixed solution, where the parts are by weight;

[0109] 2) Heating reaction: Under the protection of an inert atmosphere, the mixed solution is heated to 120° C. with stirring to allow ammonium fluoride and the metal salt to react in an alcohol solvent for 2 hours, and the solid is filtered and dried to obtain a solid;

[0110] 3) Annealing: The solid product obtained after the reaction is annealed at a temperature of 500° C.

[0111] 4) Washing and drying: The annealed product is washed several times with an appropriate solvent to remove residual solvent and impurities, and then the product is dried in a vacuum or inert atmosphere to a constant weight.

[0112] The step 3) annealing comprises the following steps:

[0113] Start the heating system of the annealing furnace and gradually raise the furnace temperature to the predetermined annealing temperature of 500°C at a heating rate of 5-10°C / min;

[0114] When the furnace temperature reaches the preset temperature, maintain it for 100 minutes;

[0115] After the insulation is completed, the workpiece is cooled to room temperature at a slower speed, with a cooling rate of 5 to 10°C / min.

[0116] In the step 4), the washing solvent is ethanol;

[0117] The capillary force enhancer is polyvinyl alcohol PVA 1788, which enhances the capillary force by increasing the viscoelasticity of the liquid.

[0118] The temperature resistant agent is selected from carbon fiber;

[0119] The anti-salt agent is selected from diethylenetriaminepentaacetic acid;

[0120] The cross-linking agent is dicumyl peroxide; the surfactant is polyoxyethylene polyoxypropylene propylene glycol ether;

[0121] The preparation method of the above-mentioned temperature-resistant and salt-resistant imbibition agent comprises the following steps:

[0122] S1 premixing: firstly, premix the temperature resistance agent, anti-salt agent, capillary force enhancer and deionized water in a high-speed mixer;

[0123] S2: adding the cross-linking agent: slowly adding the cross-linking agent to the pre-mixed material while keeping stirring;

[0124] S3 Heating and melting: transfer the mixed material into the reactor, heat it to 60-90°C, and keep it for 2-4h;

[0125] S4 Add surfactant and nanoparticles: Add surfactant and nanoparticle additives in sequence, continue stirring until evenly dispersed, and cool to room temperature.

[0126] Comparative Example 1

[0127] A temperature-resistant and salt-resistant imbibition agent is prepared from the following raw materials in parts by weight:

[0128]

[0129] The nanoparticle additive is metal fluoride nanoparticles.

[0130] The nanoparticle additive is prepared by the following steps:

[0131] 1) Mixing reactants: Under the protection of an inert atmosphere, add 2 parts of powdered ammonium fluoride and 2 parts of ferric chloride into 40 parts of propylene glycol solvent to obtain a mixed solution, where the parts are by weight;

[0132] 2) Heating reaction: Under the protection of an inert atmosphere, the mixed solution is heated to 120° C. with stirring to allow ammonium fluoride and the metal salt to react in an alcohol solvent for 2 hours, and the solid is filtered and dried to obtain a solid;

[0133] 3) Annealing: The solid product obtained after the reaction is annealed at a temperature of 500° C.

[0134] 4) Washing and drying: The annealed product is washed several times with an appropriate solvent to remove residual solvent and impurities, and then the product is dried in a vacuum or inert atmosphere to a constant weight.

[0135] The step 3) annealing comprises the following steps:

[0136] Start the heating system of the annealing furnace and gradually raise the furnace temperature to the predetermined annealing temperature of 500°C at a heating rate of 5-10°C / min;

[0137] When the furnace temperature reaches the preset temperature, maintain it for 100 minutes;

[0138] After the insulation is completed, the workpiece is cooled to room temperature at a slower speed, with a cooling rate of 5 to 10°C / min.

[0139] In the step 4), the washing solvent is ethanol;

[0140] The capillary force enhancer is polyvinyl alcohol PVA 1788, which enhances the capillary force by increasing the viscoelasticity of the liquid.

[0141] The temperature resistant agent is selected from carbon fiber;

[0142] The anti-salt agent is selected from diethylenetriaminepentaacetic acid;

[0143] The cross-linking agent is dicumyl peroxide; the surfactant is polyoxyethylene polyoxypropylene propylene glycol ether;

[0144] The preparation method of the above-mentioned temperature-resistant and salt-resistant imbibition agent comprises the following steps:

[0145] S1 premixing: firstly, premix the temperature resistance agent, anti-salt agent, capillary force enhancer and deionized water in a high-speed mixer;

[0146] S2: adding the cross-linking agent: slowly adding the cross-linking agent to the pre-mixed material while keeping stirring;

[0147] S3 Heating and melting: transfer the mixed material into the reactor, heat it to 60-90°C, and keep it for 2-4h;

[0148] S4 Add surfactant and nanoparticles: Add surfactant and nanoparticle additives in sequence, continue stirring until evenly dispersed, and cool to room temperature.

[0149] Compared with Example 3, the nanoparticles of this comparative example do not contain 4 parts of copper chloride, and the rest is the same as Example 3.

[0150] Comparative Example 2

[0151] Compared with Example 3, the nanoparticles of this comparative example do not contain 2 parts of ferric chloride, and the rest is the same as Example 3.

[0152] Comparative Example 3

[0153] Compared with Example 3, this comparative example does not contain the nanoparticle additive, and the rest is the same as Example 3.

[0154] Comparative Example 4

[0155] Commercially available imbibition agent (TC-1 Shengli Oilfield Shengli Chemical Co., Ltd.)

[0156] Test Case

[0157] The surface tension, interfacial tension and capillary self-imbibition height of the imbibition agents prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were tested under different conditions. The results are shown in Tables 1, 2 and 3.

[0158] The interfacial tension test method is as follows:

[0159] (1) Sample: 0.3% osmolyte solution;

[0160] (2) Testing instrument: TX-500C rotating drop interfacial tension meter;

[0161] (3) Test oil: aviation kerosene.

[0162] The surface tension test method is as follows:

[0163] (1) Sample: 0.3% osmolyte solution;

[0164] (2) Testing instrument: K100 fully automatic surface tension meter.

[0165] The capillary self-priming height test method is as follows:

[0166] (1) Oil-wet capillary preparation

[0167] ① Capillary surface activation

[0168] Capillary specifications: standard capillary inner diameter 0.35mm

[0169] a) using carbon tetrachloride, benzene:acetone:ethanol=7:1.5:1.5 (volume ratio) to perform ultrasonic treatment for 30 min in sequence to remove organic matter on the surface;

[0170] b) using dilute hydrochloric acid solution (1:10) and hydrofluoric acid solution (10%) for ultrasonic treatment to roughen and activate the capillary surface for 30 minutes;

[0171] c) ultrasonic cleaning with distilled water to remove residual acid until pH>6.5, and drying at 105°C;

[0172] d) preparing aged oil according to the ratio, wherein the aged oil composition is crude oil: aviation kerosene: 90# asphalt = 2:5:3;

[0173] e) completely immersing the capillary tube treated in step c) in aging oil and aging it at 60° C. for 2 to 4 weeks;

[0174] f) Take out the capillary and soak it with kerosene for 2 minutes to clean the asphalt deposited on the inner and outer walls of the capillary, so as not to affect the observation;

[0175] g) Use nitrogen to blow dry the kerosene outside the tube, place it in a closed environment at 60°C for drying to obtain an oil-wet capillary tube, which is stored for future use.

[0176] (2) Sample preparation

[0177] Prepare a 0.3% osmolyte solution and stain with 0.05% methylene blue.

[0178] (3) Experimental procedures

[0179] ① Pour the osmotic agent solution into the cuvette to the top edge, and place the ruler close to the back wall;

[0180] ② Place the treated capillary vertically in the cuvette. After the liquid level in the capillary is stable, read and record the difference between the liquid level in the capillary and the height of the cuvette (e.g. Figure 1 shown).

[0181] Table 1: Factory performance test results of the imbibition agent

[0182]

[0183]

[0184] Table 2: Temperature resistance test of wicking agent (0.3% solution, 150°C, 3d)

[0185]

[0186] Table 3: Salt tolerance test of osmotic agent (0.3% solution, 21342 mg / L, Ca 2+ Mg 2+ Total 544mg / L)

[0187]

[0188] Summary: From the data in Tables 1 to 3, it can be seen that the heat-resistant and salt-resistant imbibition agents prepared in Examples 1 to 3 can still maintain low interfacial tension, low surface tension and high capillary self-imbibition height under high temperature treatment and high salt conditions, indicating that the heat-resistant and salt-resistant imbibition agent prepared by the present invention has good resistance to formation adsorption and can exert a lasting oil displacement effect in-depth into the formation. Compared with the commercially available imbibition agent of Comparative Example 4, the heat resistance and salt resistance are greatly increased. From the comparison between Example 3 and Comparative Examples 1 to 3, it can be seen that after adding the nanoparticle additive, the heat resistance and salt resistance are greatly increased, and the iron and copper elements in the nanoparticle additive work synergistically.

[0189] The present invention discloses a heat-resistant and salt-resistant imbibition agent and its preparation method and application. Through the carefully designed raw material ratio and preparation process, the organic combination of a heat-resistant agent, a salt-resistant agent, a capillary force enhancer, a cross-linking agent, a surfactant and a nanoparticle additive is achieved. Among them, the heat-resistant agent enhances the stability of the imbibition agent at high temperature; the salt-resistant agent effectively resists the influence of the high-salt environment on the performance of the imbibition agent; the capillary force enhancer improves its permeability in porous media; the cross-linking agent promotes the imbibition agent to form a stable network structure to further enhance the capillary force; the surfactant improves the wettability and permeability of the imbibition agent; and the nanoparticle additive, especially the metal fluoride nanoparticles coordinated by iron and copper elements, not only improves the heat resistance and salt resistance of the imbibition agent, but also enhances its mechanical strength and stability.

[0190] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Therefore, based on the innovative concept of the present invention, changes and modifications to the embodiments described herein, or equivalent structural or equivalent process transformations made using the contents of the specification and drawings of the present invention, directly or indirectly applying the above technical solutions to other related technical fields are all included in the protection scope of the patent of the present invention.

Claims

1. A temperature-resistant and salt-resistant imbibition agent, characterized in that: Made from the following raw materials by weight: The nanoparticle additive is metal fluoride nanoparticles.

2. A temperature-resistant and salt-resistant imbibition agent according to claim 1, characterized in that: The nanoparticle additive is prepared by the following steps: 1) Mixing reactants: Under the protection of an inert atmosphere, 2 parts of powdered ammonium fluoride, 1 to 2 parts of ferric chloride, and 2 to 4 parts of cupric chloride are added to 20 to 40 parts of propylene glycol solvent to obtain a mixed solution, where the parts are by weight; 2) Heating reaction: Under the protection of an inert atmosphere, the mixed solution is heated to 80-120° C. with stirring, and the ammonium fluoride and the metal salt are reacted in an alcohol solvent for 2-4 hours, and the solid is filtered and dried to obtain a solid; 3) Annealing: annealing the solid product obtained after the reaction at a temperature of 250 to 500° C.; 4) Washing and drying: The annealed product is washed several times with an appropriate solvent to remove residual solvent and impurities, and then the product is dried in a vacuum or inert atmosphere to a constant weight.

3. A temperature-resistant and salt-resistant imbibition agent according to claim 2, characterized in that: The step 3) annealing comprises the following steps: Start the heating system of the annealing furnace, gradually raise the furnace temperature to the predetermined annealing temperature of 250-500°C, and the heating rate is 5-10°C / min; When the furnace temperature reaches the preset temperature, maintain it for 60 to 100 minutes; After the insulation is completed, the workpiece is cooled to room temperature at a slower speed, with a cooling rate of 5 to 10°C / min.

4. A temperature-resistant and salt-resistant imbibition agent according to claim 2, characterized in that: The washing solvent in step 4) is ethanol.

5. A temperature-resistant and salt-resistant imbibition agent according to claim 1, characterized in that: The capillary force enhancer is polyvinyl alcohol PVA 1788, which enhances the capillary force by increasing the viscoelasticity of the liquid.

6. The heat-resistant and salt-resistant imbibition agent according to claim 1, characterized in that: The temperature resistant agent is selected from one of graphene, nano-aluminum oxide or carbon fiber.

7. The heat-resistant and salt-resistant imbibition agent according to claim 1, characterized in that: The anti-salt agent is selected from ethylenediaminetetraacetic acid or diethylenetriaminepentaacetic acid.

8. The heat-resistant and salt-resistant imbibition agent according to claim 1, characterized in that: The cross-linking agent is dicumyl peroxide; the surfactant is polyoxyethylene polyoxypropylene propylene glycol ether.

9. The method for preparing the heat-resistant and salt-resistant imbibition agent according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1 premixing: firstly, premix the temperature resistance agent, anti-salt agent, capillary force enhancer and deionized water in a high-speed mixer; S2: adding the cross-linking agent: slowly adding the cross-linking agent to the pre-mixed material while keeping stirring; S3 Heating and melting: transfer the mixed material into the reactor, heat it to 60-90°C, and keep it for 2-4h; S4 Add surfactant and nanoparticles: Add surfactant and nanoparticle additives in sequence, continue stirring until evenly dispersed, and cool to room temperature.

10. Use of the temperature-resistant and salt-resistant imbibition agent according to any one of claims 1 to 8 in oil production.

Images