Oil displacement agent for oil exploitation and preparation method thereof

Abstract

The invention relates to the technical field of oil-displacing agents, in particular to an oil-displacing agent for oil exploitation and a preparation method thereof. The oil-displacing agent for oil exploitation is prepared from the following raw materials: an active agent, a solvent and nano-particles, and the mass ratio of the active agent to the solvent to the nano-particles is 1: (0.6-0.8): (0.4-0.6); the active agent is prepared from mahogany petroleum sulfonate and sodium lignin sulfonate, and the mass ratio of the mahogany petroleum sulfonate to the sodium lignin sulfonate is 1: (0.6-0.8); the solvent is composed of absolute ethyl alcohol, nano silicon dioxide and polyacrylamide, and the mass ratio of the absolute ethyl alcohol to the nano silicon dioxide to the polyacrylamide is 1: (0.4-0.6): (0.1-0.3). According to the invention, the nano-particles with strong oleophylic and hydrophilic properties are obtained through filtration, and the nano-particles have a better immersion effect in pores, can be effectively applied to low-permeability oil reservoirs, are wide in applicable oil reservoir types, and effectively improve the oil exploitation efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of oil displacement agents, in particular to an oil displacement agent for petroleum exploitation and a preparation method thereof. Background Art

[0002] Oil displacing agents are chemicals used to displace crude oil from the pores of reservoir rocks during oil extraction, thereby increasing crude oil recovery. Oil displacing agents can improve the interaction between oil, water and rocks, making crude oil easier to extract.

[0003] In the prior art, the oil displacement agent currently on the market usually adds nano black card in order to improve the mining efficiency. Its main active ingredient is an inorganic compound molybdenum disulfide, which has hydrophilic and lipophilic amphiphilic properties. However, due to its physical and chemical properties, it has poor dispersion stability in practical applications, is very easy to precipitate, and even clumps will occur after long-term precipitation. Although it has a certain oil displacement effect, most of the active ingredients cannot play their due role, affecting the oil displacement efficiency. Based on this, the present invention provides an oil displacement agent for petroleum mining and a preparation method thereof. Summary of the invention

[0004] The purpose of the present invention is to provide an oil displacing agent for petroleum exploitation and a preparation method thereof. The oil displacing agent for petroleum exploitation prepared by the present invention not only has good oil recovery rate performance, but also has excellent viscosity reduction rate performance, thereby effectively improving the use performance of the oil displacing agent.

[0005] To achieve the above object, the present invention provides the following technical solutions: In the first aspect, the present invention provides an oil displacement agent for petroleum mining, which is composed of the following raw materials: Active agent, solvent and nanoparticles, wherein the mass ratio of the active agent, solvent and nanoparticles is 1: (0.6-0.8): (0.4-0.6); The active agent is composed of petroleum sulfonate and sodium lignin sulfonate, and the mass ratio of the petroleum sulfonate to sodium lignin sulfonate is 1: (0.6-0.8); The solvent consists of anhydrous ethanol, nano-silicon dioxide and polyacrylamide, and the mass ratio of the anhydrous ethanol, nano-silicon dioxide and polyacrylamide is 1: (0.4-0.6): (0.1-0.3).

[0006] Furthermore, the nanoparticles are prepared by the following method: sucrose powder and maleic anhydride are added into a beaker, wherein the mass of the maleic anhydride is 40-50% of the mass of the sucrose powder; xylene is added into the beaker, wherein the mass of the xylene is 30-40% of the mass of the sucrose powder; and the sucrose powder, maleic anhydride and xylene are stirred in the beaker at room temperature for 6-10 minutes to obtain a mixture.

[0007] Furthermore, the mixture is fed into a water bath, heated to 60-70° C., and after reaching the temperature, a reactant is added, stirred and mixed, and kept warm for reaction for 20-30 minutes to obtain powdered sugar particles.

[0008] Furthermore, the powdered sugar particles are immersed in an alkaline solution and stirred for hydrolysis, and allowed to stand for reaction for 20 to 30 minutes. The liquid is filtered to remove the solid, and the solid is sent to an oven and dried at 50 to 60° C. for 20 to 30 minutes to obtain nanoparticles.

[0009] Furthermore, the mass of the alkali solution is 3 times the mass of the powdered sugar particles, and the concentration of the alkali solution is 4-6%.

[0010] Furthermore, the mass of the reactant is 40-50% of the mass of the mixture, and the reactant is composed of azobisisobutyronitrile powder, styrene and divinylbenzene, and the mass ratio of the azobisisobutyronitrile powder, styrene and divinylbenzene is 1:1:(0.4-0.6).

[0011] Furthermore, the reactant is prepared by the following method: the azobisisobutyronitrile powder, styrene and divinylbenzene are fed into a mixer, the mixer is set to 200-240 r / min and stirred for 8-12 minutes, then fed into an oven, set to 60-70° C. and dried for 12-16 minutes to obtain the reactant.

[0012] Furthermore, the active agent is prepared by the following method: the petroleum sulfonate is added to a mixer, the mixer is set to 100-120r / min to maintain a stirring state, sodium lignin sulfonate is divided into 10 portions, each portion of sodium lignin sulfonate is added to the mixer at intervals of 3-5 minutes, and after all the sodium lignin sulfonate is added, stirring is continued for 10 minutes to obtain the active agent.

[0013] Furthermore, the solvent is prepared by the following method: the anhydrous ethanol and nano-silicon dioxide are added to a mixer, the mixer is set at 300-400 r / min for mixing for 8-12 minutes, polyacrylamide is added after mixing, and the mixer is set at 400-500 r / min for mixing for 10-20 minutes to prepare the solvent.

[0014] In a second aspect, the present invention also provides a method for preparing an oil-displacing agent for petroleum exploitation, comprising the following steps: adding the active agent, solvent and nanoparticles into a reactor, setting the reactor to stir at 120 to 160 r / min for 1 to 3 hours, adding nanoparticles and water, wherein the mass of the water is 30 to 40% of the mass of the active agent, setting the reactor to stir at 140 to 180 r / min for 40 to 50 minutes, and obtaining the oil-displacing agent for petroleum exploitation.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, the carbonyl group of maleic anhydride can be effectively protected by the mixed reaction of maleic anhydride, xylene and sucrose powder, so that it is not destroyed by the subsequent reaction, and maleic anhydride is uniformly adsorbed and distributed on the sucrose powder. Azobisisobutyronitrile is fully dissolved in xylene to form a large number of free radicals. The addition of styrene allows maleic anhydride and styrene to undergo cross-chain polymerization at this temperature and with free radicals distributed everywhere. The addition of divinylbenzene allows them to undergo vertical chain polymerization at the same time. The two reactions are carried out simultaneously on the surface of sucrose powder and are compiled into strongly lipophilic and non-hydrophilic nanoparticles. The protected carbonyl group combines with hydroxide ions to form a hydrophilic carboxyl group. Sugar powder is dissolved in alkali solution, and the nanoparticles fall off. Nanoparticles with strong lipophilic and hydrophilic properties are obtained by filtration. The nanoparticles have a better immersion effect in pores, can be effectively used in low-permeability oil reservoirs, are applicable to a wide range of oil reservoir types, and effectively improve oil recovery efficiency.

[0016] 2. In the present invention, by adding nano-silicon dioxide to the solvent, nano-silicon dioxide can improve the rheological and adsorption properties of the oil displacement agent, the stability of the oil displacement agent, and thus improve the oil recovery efficiency. The addition of polyacrylamide can make the oil displacement agent evenly advance in the pores of the reservoir, expand the swept volume, and improve the oil recovery rate. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] This embodiment provides an oil displacement agent for oil mining, which is composed of the following raw materials: an active agent, a solvent and nanoparticles, and the mass ratio of the active agent, the solvent and the nanoparticles is 1: (0.6-0.8): (0.4-0.6). The active agent is composed of petroleum sulfonate and sodium lignin sulfonate, and the mass ratio of the petroleum sulfonate and sodium lignin sulfonate is 1: (0.6-0.8). The solvent is composed of anhydrous ethanol, nano-silicon dioxide and polyacrylamide, and the mass ratio of anhydrous ethanol, nano-silicon dioxide and polyacrylamide is 1: (0.4-0.6): (0.1-0.3).

[0019] In some embodiments, nanoparticles are prepared by the following method: sucrose powder and maleic anhydride are added to a beaker, the mass of maleic anhydride is 40-50% of the mass of sucrose powder, xylene is added to the beaker, the mass of xylene is 30-40% of the mass of sucrose powder, and sucrose powder, maleic anhydride and xylene are stirred in a beaker at room temperature for 6-10 minutes to obtain a mixture.

[0020] In this embodiment, the carbonyl group of maleic anhydride can be effectively protected from being destroyed by the subsequent reaction through the mixed reaction of maleic anhydride, xylene and sucrose powder, and the maleic anhydride can be evenly adsorbed and distributed on the sucrose powder.

[0021] In some embodiments, the mixture is fed into a water bath, heated to 60-70°C, and after reaching the temperature, a reactant is added, stirred and mixed, and kept warm for 20-30 minutes to obtain powdered sugar particles. The mass of the reactant is 40-50% of the mass of the mixture, and the reactant is composed of azobisisobutyronitrile powder, styrene and divinylbenzene, and the mass ratio of azobisisobutyronitrile powder, styrene and divinylbenzene is 1:1:(0.4-0.6).

[0022] In this embodiment, azobisisobutyronitrile is fully dissolved in xylene to form a large number of free radicals. The addition of styrene allows maleic anhydride and styrene to undergo cross-chain polymerization at this temperature and with free radicals distributed throughout. The addition of divinylbenzene allows vertical chain polymerization to occur simultaneously. Both reactions occur simultaneously on the surface of sucrose powder and are compiled into highly lipophilic and non-hydrophilic nanoparticles.

[0023] The reactant is prepared by the following method: azobisisobutyronitrile powder, styrene and divinylbenzene are fed into a mixer, the mixer is set to stir at 200-240 r / min for 8-12 minutes, and then fed into an oven, set to dry at 60-70° C. for 12-16 minutes to prepare the reactant.

[0024] In some embodiments, the powdered sugar particles are immersed in an alkali solution and stirred for hydrolysis, and then allowed to react for 20 to 30 minutes. The liquid is filtered to remove the liquid, and the solid is retained. The solid is sent to an oven and dried at 50 to 60° C. for 20 to 30 minutes to obtain nanoparticles. The mass of the alkali solution is 3 times the mass of the powdered sugar particles, and the concentration of the alkali solution is 4 to 6%.

[0025] In this embodiment, the protected carbonyl group combines with the hydroxide ion to form a hydrophilic carboxyl group, the powdered sugar dissolves in the alkali solution, the nanoparticles fall off, and after filtration, nanoparticles with strong lipophilic and hydrophilic properties are obtained. The nanoparticles have a better immersion effect in the pores and can also be effectively used in low-permeability oil reservoirs. It is applicable to a wide range of oil reservoir types and effectively improves the efficiency of oil extraction.

[0026] In some embodiments, the active agent is prepared by the following method: petroleum sulfonate is added to a mixer, the mixer is set to 100-120 r / min to maintain stirring, sodium lignin sulfonate is divided into 10 portions, each portion of sodium lignin sulfonate is added to the mixer at intervals of 3-5 minutes, and after all the sodium lignin sulfonate is added, stirring is continued for 10 minutes to obtain the active agent.

[0027] In some embodiments, the solvent is prepared by the following method: anhydrous ethanol and nano-silicon dioxide are added to a mixer, the mixer is set at 300-400 r / min for mixing for 8-12 minutes, polyacrylamide is added after mixing, and the mixer is set at 400-500 r / min for mixing for 10-20 minutes to prepare the solvent.

[0028] In this embodiment, by adding nano-silica to the solvent, nano-silica can improve the rheological and adsorption properties of the oil displacement agent, the stability of the oil displacement agent, and thus improve the oil extraction efficiency. The addition of polyacrylamide can make the oil displacement agent evenly advance in the pores of the reservoir, expand the swept volume, and improve the oil recovery rate.

[0029] In some embodiments, a method for preparing an oil-displacing agent for petroleum extraction comprises the following steps: adding an active agent, a solvent and nanoparticles into a reactor, setting the reactor to stir at 120 to 160 r / min for 1 to 3 hours, adding nanoparticles and water, wherein the mass of the water is 30 to 40% of the mass of the active agent, setting the reactor to stir at 140 to 180 r / min for 40 to 50 minutes, and obtaining the oil-displacing agent for petroleum extraction.

[0030] Based on the above embodiments, the following multiple experiments were also conducted: It should be noted that the raw materials used in the following experiments are all commercially available raw materials.

[0031] Experiment 1: Raw materials selection: active agent, solvent and nanoparticles, the mass ratio of active agent, solvent and nanoparticles is 1:0.6:0.4, the active agent is composed of petroleum sulfonate and sodium lignin sulfonate, the mass ratio of petroleum sulfonate and sodium lignin sulfonate is 1:0.6, the solvent is composed of anhydrous ethanol, nano-silicon dioxide and polyacrylamide, the mass ratio of anhydrous ethanol, nano-silicon dioxide and polyacrylamide is 1:0.4:0.1; Preparation of reactant: The reactant is prepared by the following method: the reactant is composed of azobisisobutyronitrile powder, styrene and divinylbenzene, the mass ratio of azobisisobutyronitrile powder, styrene and divinylbenzene is 1:1:0.4, the azobisisobutyronitrile powder, styrene and divinylbenzene are fed into a mixer, the mixer is set to stir at 200r / min for 8min, and then fed into an oven, set to 60°C for drying for 12min, to prepare the reactant; Preparation of nanoparticles: sucrose powder and maleic anhydride are added to a beaker, the mass of maleic anhydride is 40% of the mass of sucrose powder, xylene is added to the beaker, the mass of xylene is 30% of the mass of sucrose powder, sucrose powder, maleic anhydride and xylene are stirred in the beaker at room temperature for 6 minutes to obtain a mixture, the mixture is sent to a water bath, heated to 60°C in a water bath, and a reactant is added after reaching the temperature, the mass of the reactant is 40% of the mass of the mixture, stirred and mixed, and kept warm for reaction for 20 minutes to obtain sugar powder particles, the sugar powder particles are immersed in alkali solution and stirred for hydrolysis, the mass of the alkali solution is 3 times the mass of the sugar powder particles, and the concentration of the alkali solution is 4%, and the reaction is allowed to stand for 20 minutes, the liquid is filtered to remove the liquid, and the solid is retained. The solid is sent to an oven and set at 50°C for drying for 20 minutes to obtain nanoparticles; Preparation of active agent: petroleum sulfonate is added to a mixer, and the mixer is set to 100r / min to keep stirring. Sodium lignin sulfonate is divided into 10 portions, and each portion of sodium lignin sulfonate is added to the mixer at intervals of 3 minutes. After all the sodium lignin sulfonate is added, stirring is continued for 10 minutes to obtain the active agent; Preparation of solvent: anhydrous ethanol and nano-silicon dioxide are added to a mixer, the mixer is set at 300 r / min for mixing for 8 minutes, polyacrylamide is added after mixing, and the mixer is set at 400 r / min for mixing for 10 minutes to prepare a solvent; Preparation of oil displacement agent: add active agent, solvent and nanoparticles into the reactor, set the reactor to stir at 120r / min for 1h, add nanoparticles and water, the mass of water is 30% of the mass of the active agent, set the reactor to stir at 140r / min for 40min, and obtain the oil displacement agent for petroleum mining.

[0032] Experiment 2: Raw materials selection: active agent, solvent and nanoparticles, the mass ratio of active agent, solvent and nanoparticles is 1:0.7:0.5, the active agent is composed of petroleum sulfonate and sodium lignin sulfonate, the mass ratio of petroleum sulfonate and sodium lignin sulfonate is 1:0.7, the solvent is composed of anhydrous ethanol, nano-silicon dioxide and polyacrylamide, the mass ratio of anhydrous ethanol, nano-silicon dioxide and polyacrylamide is 1:0.5:0.2; Preparation of reactant: The reactant is prepared by the following method: the reactant is composed of azobisisobutyronitrile powder, styrene and divinylbenzene, the mass ratio of azobisisobutyronitrile powder, styrene and divinylbenzene is 1:1:0.5, the azobisisobutyronitrile powder, styrene and divinylbenzene are fed into a mixer, the mixer is set to stir at 220r / min for 10min, and then fed into an oven, set to 65°C for drying for 14min, to prepare the reactant; Preparation of nanoparticles: sucrose powder and maleic anhydride are added to a beaker, the mass of maleic anhydride is 40-50% of the mass of sucrose powder, xylene is added to the beaker, the mass of xylene is 35% of the mass of sucrose powder, sucrose powder, maleic anhydride and xylene are stirred in the beaker at room temperature for 8 minutes to obtain a mixture, the mixture is sent to a water bath, heated to 65°C in a water bath, and a reactant is added after reaching the temperature, the mass of the reactant is 45% of the mass of the mixture, stirred and mixed, and kept warm for reaction for 25 minutes to obtain sugar powder particles, the sugar powder particles are immersed in alkali solution and stirred for hydrolysis, the mass of the alkali solution is 3 times the mass of the sugar powder particles, the concentration of the alkali solution is 5%, and the reaction is allowed to stand for 25 minutes, the liquid is filtered to remove the liquid, the solid is retained, the solid is sent to an oven, set at 55°C for drying for 25 minutes, and the nanoparticles are obtained; Preparation of active agent: petroleum sulfonate is added to a mixer, and the mixer is set at 110r / min to keep stirring. Sodium lignin sulfonate is divided into 10 portions, and each portion of sodium lignin sulfonate is added to the mixer at an interval of 4 minutes. After all the sodium lignin sulfonate is added, stirring is continued for 10 minutes to obtain the active agent; Preparation of solvent: anhydrous ethanol and nano-silicon dioxide are added to a mixer, and the mixer is set at 350 r / min for 10 min. After mixing, polyacrylamide is added, and the mixer is set at 450 r / min for 15 min to prepare a solvent; Preparation of oil displacement agent: add active agent, solvent and nanoparticles into the reactor, set the reactor to stir at 140r / min for 2h, add nanoparticles and water, the mass of water is 35% of the mass of the active agent, set the reactor to stir at 160r / min for 45min, and obtain the oil displacement agent for petroleum mining.

[0033] Experiment 3: Raw materials selection: active agent, solvent and nanoparticles, the mass ratio of active agent, solvent and nanoparticles is 1:0.8:0.6, the active agent is composed of petroleum sulfonate and sodium lignin sulfonate, the mass ratio of petroleum sulfonate and sodium lignin sulfonate is 1:0.8, the solvent is composed of anhydrous ethanol, nano-silicon dioxide and polyacrylamide, the mass ratio of anhydrous ethanol, nano-silicon dioxide and polyacrylamide is 1:0.6:0.3; Preparation of reactant: The reactant is prepared by the following method: the reactant is composed of azobisisobutyronitrile powder, styrene and divinylbenzene, the mass ratio of azobisisobutyronitrile powder, styrene and divinylbenzene is 1:1:0.6, the azobisisobutyronitrile powder, styrene and divinylbenzene are fed into a mixer, the mixer is set to stir at 240r / min for 12min, and then fed into an oven, set to 70°C for drying for 16min, to prepare the reactant; Preparation of nanoparticles: sucrose powder and maleic anhydride are added to a beaker, the mass of maleic anhydride is 50% of the mass of sucrose powder, xylene is added to the beaker, the mass of xylene is 40% of the mass of sucrose powder, sucrose powder, maleic anhydride and xylene are stirred in the beaker at room temperature for 10 minutes to obtain a mixture, the mixture is sent to a water bath, heated to 70°C in a water bath, and a reactant is added after reaching the temperature, the mass of the reactant is 50% of the mass of the mixture, stirred and mixed, and kept warm for reaction for 30 minutes to obtain sugar powder particles, the sugar powder particles are immersed in alkali solution and stirred for hydrolysis, the mass of the alkali solution is 3 times the mass of the sugar powder particles, and the concentration of the alkali solution is 6%, and the reaction is allowed to stand for 30 minutes, the liquid is filtered to remove the liquid, and the solid is retained. The solid is sent to an oven and set at 60°C for drying for 30 minutes to obtain nanoparticles; Preparation of active agent: petroleum sulfonate is added to a mixer, the mixer is set at 120r / min to keep stirring, sodium lignin sulfonate is divided into 10 portions, each portion of sodium lignin sulfonate is added to the mixer at intervals of 5 minutes, after all the sodium lignin sulfonate is added, stirring is continued for 10 minutes to obtain the active agent; Preparation of solvent: anhydrous ethanol and nano-silicon dioxide are added to a mixer, the mixer is set at 400 r / min for 12 min, polyacrylamide is added after mixing, and the mixer is set at 500 r / min for 20 min to prepare a solvent; Preparation of oil displacement agent: add active agent, solvent and nanoparticles into the reactor, set the reactor to stir at 160r / min for 3h, add nanoparticles and water, the mass of water is 40% of the mass of the active agent, set the reactor to stir at 180r / min for 50min, and obtain the oil displacement agent for petroleum mining.

[0034] Comparative Example 1: The difference between this comparative example and Experiment 1 is that: This comparative example does not contain a reactant.

[0035] Comparative Example 2: The difference between this comparative example and Experiment 1 is that: This comparative example does not contain maleic anhydride.

[0036] Comparative Example 3: The difference between this comparative example and Experiment 1 is that: In this comparative example, an equal amount of sucrose powder was used to replace the nanoparticles.

[0037] Comparative Example 4: The difference between this comparative example and Experiment 1 is that: In this comparative example, an equal amount of nano black card was used to replace the nano particles.

[0038] Performance test: The performance test of the oil displacement agent prepared in Experiment 1, Experiment 2, Experiment 3, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 was carried out.

[0039] In the performance test, artificial cores were established, and the oil recovery rate and viscosity reduction rate performance tests were performed on the oil displacement agents prepared in Experiment 1, Experiment 2, Experiment 3, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, respectively. The test data obtained are recorded in Table 1: Table 1 Oil recovery rate and viscosity reduction rate record

[0040] Among them, the oil recovery rates of the oil-displacing agents prepared in Experiment 1, Experiment 2, Experiment 3, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 were 42.65%, 41.58%, 42.19%, 24.91%, 23.43%, 17.6% and 19.04% respectively; the viscosity reduction rates of the oil-displacing agents prepared in Experiment 1, Experiment 2, Experiment 3, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 were 95.58%, 92.19%, 93.06%, 77.26%, 76.19%, 70.07% and 69.35% respectively.

[0041] It can be seen that the oil recovery rate and viscosity reduction rate of the oil displacement agent prepared in Comparative Examples 1, 2, 3, and 4 are lower than those in Experiments 1, 2, and 3; this shows that: through the mixed reaction of maleic anhydride, xylene and sucrose powder, the carbonyl group of maleic anhydride can be effectively protected from being destroyed by the subsequent reaction, and the maleic anhydride is evenly adsorbed and distributed on the sucrose powder, azobisisobutyronitrile is fully dissolved in xylene to form a large number of free radicals, and the addition of styrene allows maleic anhydride and styrene to react at this temperature and with free radicals distributed. The addition of divinylbenzene enables the vertical chain polymerization reaction to proceed at the same time. The two reactions proceed simultaneously on the surface of the sucrose powder and are compiled into strongly lipophilic and non-hydrophilic nanoparticles. The protected carbonyl group combines with the hydroxide ion to form a hydrophilic carboxyl group. The sugar powder dissolves in the alkali solution, and the nanoparticles fall off. After filtration, nanoparticles with strong lipophilic and hydrophilic properties are obtained. The nanoparticles have a better immersion effect in the pores and can also be effectively used in low-permeability oil reservoirs. They are suitable for a wide range of oil reservoir types and effectively improve the efficiency of oil extraction.

[0042] By comparing and analyzing the relevant data in the table, it can be seen that the oil displacing agent for petroleum production prepared by the present invention not only has good oil recovery performance, but also has excellent viscosity reduction performance. This shows that the oil displacing agent for petroleum production and the preparation method thereof provided by the present invention have a broader market prospect and are more suitable for promotion.

[0043] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0044] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. Oil displacement agent is used in oil mining, characterized by: It is composed of the following raw materials: Active agent, solvent and nanoparticles, wherein the mass ratio of the active agent, solvent and nanoparticles is 1: (0.6-0.8): (0.4-0.6); The active agent is composed of petroleum sulfonate and sodium lignin sulfonate, and the mass ratio of the petroleum sulfonate to sodium lignin sulfonate is 1: (0.6-0.8); The solvent consists of anhydrous ethanol, nano-silicon dioxide and polyacrylamide, and the mass ratio of the anhydrous ethanol, nano-silicon dioxide and polyacrylamide is 1: (0.4-0.6): (0.1-0.3).

2. The oil displacing agent for petroleum mining according to claim 1, characterized in that: The nanoparticles are prepared by the following method: sucrose powder and maleic anhydride are added into a beaker, wherein the mass of the maleic anhydride is 40-50% of the mass of the sucrose powder; xylene is added into the beaker, wherein the mass of the xylene is 30-40% of the mass of the sucrose powder; and the sucrose powder, maleic anhydride and xylene are stirred in the beaker at room temperature for 6-10 minutes to obtain a mixture.

3. The oil displacing agent for petroleum mining according to claim 2, characterized in that: The mixture is put into a water bath and heated to 60-70° C. After reaching the temperature, the reactant is added, stirred and mixed, and kept warm for reaction for 20-30 minutes to obtain sugar powder particles.

4. The oil displacing agent for petroleum mining according to claim 3, characterized in that: The powdered sugar particles are immersed in an alkaline solution and stirred for hydrolysis, and allowed to stand for reaction for 20 to 30 minutes. The liquid is filtered to remove the solid, and the solid is sent to an oven and dried at 50 to 60° C. for 20 to 30 minutes to obtain nanoparticles.

5. The oil displacing agent for petroleum mining according to claim 4, characterized in that: The mass of the alkali solution is 3 times the mass of the sugar powder particles, and the concentration of the alkali solution is 4-6%.

6. The oil displacement agent for petroleum mining according to claim 3, characterized in that: The mass of the reactant is 40-50% of the mass of the mixture. The reactant is composed of azobisisobutyronitrile powder, styrene and divinylbenzene. The mass ratio of the azobisisobutyronitrile powder, styrene and divinylbenzene is 1:1:(0.4-0.6).

7. The oil displacing agent for petroleum mining according to claim 6, characterized in that: The reactant is prepared by the following method: the azobisisobutyronitrile powder, styrene and divinylbenzene are fed into a mixer, the mixer is set at 200-240 r / min and stirred for 8-12 minutes, then fed into an oven, set at 60-70° C. for drying for 12-16 minutes to prepare the reactant.

8. The oil displacing agent for petroleum mining according to claim 1, characterized in that: The active agent is prepared by the following method: the petroleum sulfonate is added into a mixer, the mixer is set at 100-120 r / min to keep stirring, sodium lignin sulfonate is divided into 10 portions, each portion of sodium lignin sulfonate is added into the mixer at intervals of 3-5 minutes, and after all the sodium lignin sulfonate is added, stirring is continued for 10 minutes to prepare the active agent.

9. The oil displacing agent for petroleum mining according to claim 1, characterized in that: The solvent is prepared by the following method: the anhydrous ethanol and nano silicon dioxide are added into a mixer, the mixer is set at 300-400 r / min for mixing for 8-12 minutes, polyacrylamide is added after mixing, and the mixer is set at 400-500 r / min for mixing for 10-20 minutes to prepare the solvent.

10. The method for preparing an oil displacement agent for petroleum mining according to any one of claims 1 to 9, characterized in that: The following steps are involved: The active agent, solvent and nanoparticles are added to a reactor, which is stirred at 120-160 r / min for 1-3 hours, and nanoparticles and water are added, wherein the mass of the water is 30-40% of the mass of the active agent, and the reactor is stirred at 140-180 r / min for 40-50 minutes to obtain an oil displacement agent for petroleum mining.

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