637 results about "Oil displacement" patented technology

The invention relates to the technical field of oil-displacing agents, and particularly discloses a targeted nano oil-displacing agent and a preparation method thereof. A preparation method of a targeted nano oil displacement agent comprises the following steps: S1, dispersing 10-30 parts by mass of silanized inorganic nanoparticles in an alcoholic solution, adding 5-12 parts by mass of a functional monomer, 8-20 parts by mass of a hydrophilic monomer and 5-15 parts by mass of a hydrophobic monomer in an inert atmosphere, uniformly mixing, heating to 75-85 DEG C, adding an initiator, carrying out a constant temperature reaction for 4-6 h, and cooling to obtain a pre-grafted nanoparticle dispersion liquid; s2, mixing the pre-grafted nanoparticle dispersion liquid with a composite surfactant, adjusting the pH value to 6.5-7.5, and mixing at 30-40 DEG C for 22-26 hours to obtain the targeted nano oil displacement agent, the targeting type nano oil displacement agent prepared by the invention can still keep excellent dispersion stability and ultralow interfacial tension under the condition of a high-salt oil reservoir, so that the oil displacement efficiency is remarkably improved.

The invention relates to the technical field of materials, in particular to preparation of an amphiphilic tungsten disulfide nano material and application of the amphiphilic tungsten disulfide nano material in preparation of an oil displacement agent. The oil-displacing agent prepared from the amphiphilic tungsten disulfide nano material can reduce the interfacial tension of an oil-water interface, and can be quickly adsorbed to the oil-water interface to layer oil and water; the surface wettability of the rock is changed, the lipophilicity of the rock is changed into weak hydrophilicity, and the pore throat cannot be blocked due to excessive hydrophilicity while the oil phase is stripped. The nano oil-displacing agent disclosed by the invention can still have an enough stable use effect after being frozen at a low temperature and then unfrozen.

The present invention belongs to the technical field of oil and gas exploration and development. Disclosed are a nuclear-magnetic-resonance-based method and system for characterizing the degree of miscibility of CO2 flooding. The method comprises: on the basis of a slim tube method, testing the minimum miscible pressure of crude oil of a target oil reservoir and CO2 (S101); on the basis of the minimum miscible pressure, conducting CO2 oil displacement experiments using cylindrical cores, collecting, in real time, two-dimensional weighted nuclear magnetic resonance images and multi-component T2 spectra of a fluid in the cores varying over time and space, synchronously collecting an outlet-end fluid, and conducting a chromatographic test to obtain chromatographic test data (S102); and on the basis of the two-dimensional weighted nuclear magnetic resonance images, the multi-component T2 spectra and the chromatographic test data, performing dynamically-changing qualitative and quantitative characterization on the degree of miscibility, so as to obtain qualitative and quantitative characterization results of the degree of miscibility of CO2 and the crude oil (S103).

The invention discloses a multi-site intelligent response type CO2 gas channeling prevention gel and a preparation method, and belongs to the field of chemical oil displacement, and the preparation method comprises the following steps: taking a carbon dioxide response type monomer, acrylamide and sodium acrylate as monomers, and adopting water-soluble free radical polymerization to prepare a CO2 response type copolymer; the CO2 response type copolymer, a cross-linking agent, a stabilizer, a retarder and formation water are prepared into a polymer cross-linking agent mixed solution, a cross-linking reaction is carried out under the conditions of formation temperature and mineralization degree, and the multi-site intelligent response type CO2 gas channeling prevention gel is obtained. The gel effectively solves the problems that a traditional anti-channeling agent is poor in injectivity in a low-permeability and ultra-low-permeability oil reservoir and cannot achieve deep channeling sealing, CO2 gas channeling fractured channels can be effectively blocked, the carbon dioxide oil displacement effect is remarkably improved, and key technical support is provided for large-scale application of carbon dioxide displacement.

The application provides a low-grade oil reservoir water injection development effect evaluation method, comprising the following steps: S1, collecting core scale limit oil displacement efficiency data; S2, collecting well pattern controlled reserve degree data; S3, calculating sweep efficiency of the low-grade water drive oil reservoir; S4, correcting the sweep efficiency according to the changes of reservoir physical property parameters caused by near-well pollution and reservoir energy decline; and S5, calculating the reference recovery rate and evaluating the development effect. The application can effectively avoid collecting and arranging a large number of cumbersome production dynamic data, fully utilize the flow characteristics and dynamic physical property parameter evolution of the low-grade oil reservoir, accurately evaluate the development effect of the low-grade oil reservoir, and be beneficial to efficient development of the low-grade oil reservoir.

The invention relates to the technical field of microbial engineering, and particularly discloses a Gordonia sp. DH2, a biological oil displacement agent and application of the Gordonia sp. DH2, the Gordonia sp. DH2 is preserved in China Center for Type Culture Collection on June 3, 2024, the preservation number is CCTCC NO: M 20241126, and the Gordonia sp. DH2 is classified and named as Gordonia sp. DH2. The Gordonia provided by the invention can degrade saturated hydrocarbons and sulfur-containing compounds in crude oil, and the saturated hydrocarbons and the sulfur-containing compounds are used as a unique carbon source to generate a biological oil-displacing agent, degrade, disperse and emulsify the crude oil, so that the Gordonia can be used for improving the fluidity of the crude oil in a stratum and increasing the recovery rate of the crude oil.

According to the carbon dioxide oil displacement tank capable of automatically adjusting the pressure, during daily storage, the change speed and amplitude of the pressure in the tank are maximum, so that the stability of equipment can be influenced, an air bag is arranged in a third air cavity, and when the pressure in the third air cavity changes, the air bag is closed, so that the stability of the equipment is improved. The air bag can be matched with the third electric valve and the second electric valve to release or suck air so as to adjust pressure change, the speed and amplitude of the pressure change are slowed down to be within a controllable range, and therefore the stability of air stored in the device is improved, the interior of the tank body is divided into three storage units, and the storage effect is good. The third air cavity, the second air cavity and the first air cavity are sequentially arranged from inside to outside, when the first air cavity leaks, the third air cavity and the second air cavity are in a closed state and do not leak with the first air cavity at the same time, the capacity of the first air cavity is the minimum, the capacity of the third air cavity is the maximum, and if the first air cavity leaks, the loss can be reduced to the minimum. Therefore, the safety of the device can be improved.

The invention provides a composite surfactant for oil displacement of a hypersalinity oil reservoir and a preparation method of the composite surfactant, and relates to the technical field of petrochemical engineering. The composite surfactant is prepared from the following components in percentage by weight: 0.1 to 0.3 percent of anionic-nonionic surfactant, 0.01 to 0.03 percent of cationic surfactant and the balance of formation water, wherein the anionic-nonionic surfactant is prepared by the following steps: reacting a hydroxyl-containing compound with ethylene oxide to obtain polyoxyethylene ether, then carrying out esterification modification by using aconitic acid modified rosin, then sulfonating by using a sulfonating agent, and finally neutralizing. The composite surfactant shows relatively low interfacial tension under the condition of hypersalinity (50000-200000 mg / L), is high in stability, and can be used for improving the recovery efficiency of hypersalinity oil reservoirs.

The invention discloses a high-pressure CO2 oil displacement micro-fluidic chip device which comprises an upper polar plate, a middle partition plate, a lower polar plate, a speed measurement module, a porous medium radial flow module and a liquid outlet module, the speed measurement module is arranged on the upper surface of the middle partition plate; the porous medium radial flow module and the liquid outlet module are arranged on the upper surface of the lower polar plate; the upper polar plate, the middle partition plate and the lower polar plate are sequentially stacked from top to bottom; the speed measurement module is connected with the porous medium radial flow module; and the porous medium radial flow module is connected with the liquid outlet module. According to the device disclosed by the invention, a pore throat structure in rock is simulated by constructing a micron-sized or even smaller complex flow channel, and the CO2 flooding crude oil flow characteristic and the CO2 distribution rule are simulated; a transparent visualization device structure is designed, and visualization of the action mechanism of the CO2 oil displacement system and the reservoir fluid distribution characteristics is guaranteed.

The invention discloses a molecular dynamics simulation method for CO2-ion oil displacement, and belongs to the technical field of CO2 oil displacement. The method comprises the steps that an oil molecule model, a water molecule model, a CO2 molecule model, a CaCl2 molecule model and a graphene plate model corresponding to target oil reservoir characteristics are established; carrying out geometric structure optimization on each model; the optimized molecular model is assembled into a 'CO2-CaCl2-H2O' ternary displacement system, and molecular dynamics simulation is executed; during simulation, an NVT ensemble is selected, periodic boundary conditions are applied, a COMPASS II force field is adopted, atomic potential parameters are configured, and after operation energy is minimized and temperature is initialized, displacement process simulation is executed; and quantitatively evaluating the oil displacement effect of the displacement medium of the 'CO2-CaCl2-H2O' ternary system on the basis of the trajectory file output by simulation. According to the method, the behavior of molecules under the synergistic effect of multiple displacement media can be better explained, the oil displacement micromechanism under the synergistic effect of the multiple displacement media is embodied, and the method has important significance for optimizing the compact oil reservoir development effect and improving the recovery efficiency.

The invention discloses a high-temperature-resistant oil-displacing agent for an oil field and a preparation method thereof, and relates to the technical field of oilfield exploitation. The prepared oil displacement agent for the oil field comprises the following raw materials in parts by weight: 15-25 parts of polyacrylamide, 1-5 parts of nano silicon dioxide, 25-35 parts of an enhanced surfactant and 40-60 parts of water. The oil-displacing agent is prepared by mixing and stirring the raw materials, and has excellent oil-displacing performance, low surface tension and excellent high-temperature resistance when being used in the oilfield exploitation process; compared with a traditional surfactant, due to the introduction of the enhanced surfactant, the high temperature resistance and the oil displacement efficiency of the oil displacement agent are improved.

The invention relates to the technical field of oil-displacing agents, in particular to a polyacrylamide-containing oil-displacing agent and a preparation method thereof.The polyacrylamide-containing oil-displacing agent is prepared from, by weight, 35-40% of functionalized polyacrylamide, 5-8% of loading filler, 2-3% of n-amyl alcohol, 5-7% of cyclohexane and the balance water; the polyacrylamide is subjected to functional modification, and the loading filler loaded with the zwitterionic surfactant is added, so that the oil-displacing agent can still keep a good synergistic effect in a complex high-temperature and high-salt environment, and a good oil-displacing characteristic is exerted.

The invention relates to the technical field of chemical oil displacement, and particularly discloses a self-emulsifying nano-composite modifying and flooding agent for an oil field and a preparation process of the self-emulsifying nano-composite modifying and flooding agent. The invention relates to a self-emulsifying nano composite modifying and flooding agent for an oil field. The self-emulsifying nano composite modifying and flooding agent is prepared from the following 100 parts by mass of raw materials: 3-5 parts of amphiphilic nano silicon dioxide, 1-2 parts of a zwitterionic surfactant, 0.5-1 part of a nonionic surfactant and the balance of water, the zwitterionic surfactant comprises hydroxyl sulfobetaine and imidazoline, and the zwitterionic surfactant comprises hydroxyl sulfobetaine and imidazoline; and the non-ionic surface active agent is an ethyoxyl-propoxyl block copolymer. The self-emulsifying nano-composite modifying and flooding agent prepared by the invention effectively realizes the balance of low interfacial tension and self-emulsifying efficiency.

The invention provides a high-temperature-resistant lipopeptide reinforced foam flooding system and a screening method and application, and relates to the technical field of microbial oil recovery, the high-temperature-resistant lipopeptide reinforced foam flooding system comprises the following steps: S1, screening applied oil reservoirs; s2, based on the oil reservoir temperature and the crude oil viscosity selected in S1, screening a high-temperature-resistant lipopeptide reinforced foam flooding system; the high-temperature-resistant lipopeptide reinforced foam oil displacement system comprises a foaming agent, a foam stabilizer, gas and water, the foaming agent comprises one or more of surfactin (C12-18), scabrin (C14-18), iturin (C14-17), deocytin, serratia marcescens and mucin fermentation liquor, and the foaming agent comprises one or more of lipopeptide, a foaming agent and a foaming agent. The foam stabilizer comprises one or more of biosynthetic nano-silver, nano-iron, nano-copper, nano-zinc, nano-zirconium and nano-nickel. The method has the beneficial effects that the oil reservoir application range is wide, the pertinence is high, the field test effect is good, and a high-temperature-resistant lipopeptide enhanced foam oil displacement system is specifically constructed according to the temperature-resistant stability characteristics of lipopeptide surfactants and biosynthetic nano materials of different structures and types.

The invention provides a medium-low permeability oil reservoir rhamnolipid foam oil displacement system and a screening method and application, and relates to the technical field of microbial oil recovery, the medium-low permeability oil reservoir rhamnolipid foam oil displacement system comprises the following steps: S1, screening an applied oil reservoir; s2, determining a rhamnolipid foam flooding system based on the oil reservoir mineralization degree; s3, based on the porosity of the oil reservoir, the injection mode of a rhamnolipid foam oil displacement system is determined, the rhamnolipid foam oil displacement system comprises a foaming agent, a foam stabilizer, nitrogen and water, the foaming agent comprises one or more of dirhamnose difat, dirhamnose monofat, single rhamnose monofat and single rhamnose difat fermentation liquor, and the foam stabilizer comprises one or more of dirhamnose difat, dirhamnose monofat, single rhamnose monofat and single rhamnose difat fermentation liquor. The foam stabilizer is prepared from one or more of xanthan gum, welan gum, Wollan gum, Dide gum, gellan gum, rhamnose gum, diidine gum, plant cellulose and bacterial cellulose. The method has the beneficial effects that the oil reservoir application range is wide, the pertinence is high, the field test effect is good, efficient generation and long-acting migration of foam in the oil reservoir are guaranteed, green and high-quality development of old oil fields is promoted, and achievement of the national dual-carbon strategy is assisted.

The invention discloses an automatic gas generation foam channeling sealing agent as well as a preparation method and application thereof, and relates to the technical field of oil and gas recovery. The self-gas-generating foam channeling sealing agent comprises an agent A and an agent B. The agent A comprises 0-5% of an accelerant, the agent B comprises 5-20% of a gas generating agent, 0.1-1.0% of a foaming agent, 0.05-1.0% of a foam stabilizer and the balance of saline water according to the total mass percentage of the self-gas-generating foam channeling sealing agent, the gas generating agent is an azo organic compound, and the agent A and the agent B independently exist. According to the self-gas-generating foam channeling sealing agent, the azo organic matter serves as the gas generating agent and is nitrogen which is good in stability, high in gas generation rate and difficult to compress at the normal temperature, the thermal decomposition reaction serves as the exothermic reaction, energy increasing and heat increasing of a system are facilitated, the oil displacement efficiency is improved, the decomposition temperature and the gas generation rate of the gas generating agent are adjusted through the variety and the dosage of the accelerant, and the self-gas-generating foam channeling sealing agent is obtained. The method can be widely applied to thermal oil recovery such as steam drive, steam huff and puff and in-situ combustion in thickened oil recovery.

The invention relates to a low-permeability heavy oil composite nano oil displacement agent, which comprises a surfactant, fatty alcohol-polyoxyethylene ether, polyacrylamide, nano particles and water, and comprises the following components: 40%-60% of betaine, 10%-30% of fatty alcohol-polyoxyethylene ether, 20%-40% of polyacrylamide, 2% of nano particles (the particle size ranges from 5 nm to 50 nm), 0.1% of a pH regulator 0.01 and the balance of water. According to the composite nano oil-displacing agent disclosed by the invention, a stable nano particle solution is formed by optimizing the variety and proportion of the surfactant, the variety and proportion of the fatty alcohol-polyoxyethylene ether, the variety and proportion of the polyacrylamide and the variety, size and proportion of the nano particles through complex interaction among the components. The composite nano oil displacement agent is high in stability, and can change the wettability of rock, remarkably reduce the surface tension of an oil-water interface, improve the fluid viscosity, peel residual oil and weaken hydrogen bonds, so that the composite oil displacement agent can pass through a micro-capillary pore throat and enlarge the swept area. In the exploitation of low-permeability common thickened oil, the method can obviously improve the recovery efficiency, has excellent technical and economic advantages, and achieves an excellent effect in the practical application of a certain oil field.

This invention belongs to the technical field of large-channel or dominant channel treatment and plugging in water-driven oil reservoirs, specifically involving an in-situ modification and plugging method within fly ash reservoirs. The method includes: mixing a modified working fluid and fly ash; pumping the resulting mixture into a sand-filled pipe at a constant rate; and then allowing it to stand at reservoir temperature, resulting in modified fly ash and simultaneous plugging. This invention transfers the fly ash modification treatment from the surface to the reservoir pores, achieving the same modification effect as surface modification while simplifying the process, avoiding investment in surface treatment equipment, and saving on waste liquid treatment costs. Furthermore, the waste liquid contains alkali and polymer solutions, forming an "alkali / polymer" binary system, which helps improve oil displacement efficiency. Therefore, the in-situ modification treatment and combined plugging effect within fly ash reservoirs can effectively expand the swept volume and improve oil displacement efficiency, significantly increasing oil recovery.

This invention belongs to the technical field of oil and gas field development and enhanced oil recovery, specifically relating to a bio-based ternary composite enhanced oil recovery system and its preparation method. The bio-based ternary composite enhanced oil recovery system of this invention, by weight, comprises: 800-2000 parts of biopolymer; 600-3000 parts of biosurfactant; 40-400 parts of bionanomaterials; and 200-800 parts of water. In the bio-based ternary composite enhanced oil recovery system provided by this invention, the composite enhanced oil recovery system of biopolymer, biosurfactant, and bionanomaterials fully leverages the synergistic effect of each component, demonstrating significant advantages in improving crude oil recovery and reducing environmental risks, and possessing good industrial application prospects and promotional value.

The invention discloses an interfacial tension prediction method and device based on machine learning and molecular dynamics, and relates to the technical field of molecular dynamics simulation. The method comprises the following steps: constructing a mixed system model comprising CO2, surfactant molecules and crude oil, defining related parameters of a surfactant as a variable set, simulating by adopting molecular dynamics software, acquiring simulation data and interfacial tension data, and preprocessing; and taking the temperature, the pressure and the variable set as input characteristics, taking the interfacial tension as a target variable, and training a LightGBM model to obtain a prediction model. Each particle represents the configuration of one surfactant, the prediction model is used for obtaining the predicted interfacial tension corresponding to each particle, the speed and position of the particles are iteratively updated, and the optimal configuration of the surfactant for minimizing the interfacial tension is obtained. The problem of low oil exploitation efficiency caused by multiple exploitation operations due to poor oil displacement effect caused by incapability of accurately predicting the interfacial tension is solved.

The invention discloses thermoanaerobacter sp SA-1, and the preservation number of the thermoanaerobacter sp SA-1 is CGMCC (China General Microbiological Culture Collection Center) No.28132. The invention further discloses a preparation method of the thermoanaerobacter sp SA-1. The thermophilic anaerobacter SA-1 has the beneficial effects that (1) the thermophilic anaerobacter SA-1 provided by the invention has the growth temperature of 60-85 DEG C, can quickly grow and breed under the anaerobic condition of medium-high-temperature oil reservoirs, metabolizes heavy components of heavy oil in a hydrocarbon-philic manner, generates a biological surfactant, reduces the oil-water interfacial tension to 28-35mN / m, improves the fluidity of the heavy oil, improves the recovery efficiency, and reduces the production cost; the recovery ratio is increased by more than 25% through a physical simulation experiment; (2) the fermentation liquor of the thermoanaerobacter SA-1 is applied to microorganism single well huff and puff, the average single well oil increasing amount is more than 1000t, and the validity period is more than 300d; and (3) the fermentation liquor of the thermoanaerobacter SA-1 is applied to microbial well group oil displacement, and the average daily oil increase of a well group is more than 10t.

The invention discloses a preparation method of high-temperature-resistant and salt-resistant polyacrylamide for oil displacement of an oil field in the technical field of oilfield chemical agents, which comprises the following steps: firstly, preparing a layered double hydroxide precursor by a hydrothermal method, modifying by polydopamine to enhance the surface adhesion, and then synthesizing a polyfunctional group sulfonated polyether ether ketone cross-linking agent containing double bonds and sulfo groups, so as to obtain the high-temperature-resistant and salt-resistant polyacrylamide for oil displacement of the oil field. Performing in-situ free radical polymerization on the three components to obtain a gradient composite modified material; then dispersing and activating the modified material, copolymerizing with acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinyl pyrrolidone and other monomers, controlling the temperature gradient to initiate and polymerize, adding a cross-linking agent at the later stage to reinforce a network structure, and washing, granulating, drying and crushing to obtain the product. According to the method, the temperature resistance, salt resistance and shear resistance of polyacrylamide are remarkably improved through synergistic enhancement of gradient structure design and a multi-step complex process, and the method is suitable for oil displacement application of an oil field.

The invention relates to a double CO2 response type nanoparticle reinforced foam system as well as a preparation method and application thereof. The foam system is composed of a CO2 response type surfactant, CO2 response type nanoparticles and water. According to the invention, a dual CO2 response mechanism of CO2 response type nanoparticles and a CO2 response type surfactant is utilized, and a dual CO2 response type nanoparticle reinforced foam system is creatively prepared. The system is sensitive to CO2 response, has the characteristics of stable and clean foam, reusability and the like, not only solves the technical defects of reservoir pollution and the like caused by poor foam stability, low cyclic utilization rate and difficulty in defoaming in oil and gas field exploitation work, but also is beneficial to efficient utilization and storage of CO2. The double CO2 response type nanoparticle reinforced foam system can be used in the fields of fracturing, chemical oil displacement and the like in the oil and gas field development engineering technology.

This invention discloses an amphiphilic uniform penetration inhibitor oil displacement agent, its preparation method, its application, and a method for improving oil recovery. The preparation method of the amphiphilic uniform penetration inhibitor oil displacement agent comprises the following steps: In the presence of an initiator and a solvent, sodium styrene sulfonate, acrylamide, N-ethoxymethyl-N-isobutoxymethylacrylamide, and 3-acetamino-N-ethyl-N,N-dimethylpropyl-1-amine undergo a solution polymerization reaction. The molar ratio of sodium styrene sulfonate, acrylamide, N-ethoxymethyl-N-isobutoxymethylacrylamide, and 3-acetamino-N-ethyl-N,N-dimethylpropyl-1-amine is 1:0.01–25:0.01–50:0.01–50. The solution polymerization reaction results in an amphiphilic uniform penetration inhibitor oil displacement agent with a viscosity-average molecular weight of 35 million to 40 million.

The invention discloses a low-permeability reservoir CO2 oil displacement storage synergistic interaction regulation and control device, which belongs to the technical field of low-permeability reservoir development and carbon storage, and comprises a CO2 source supply unit, an intelligent injection allocation regulation and control unit, a reservoir injection unit, an oil displacement monitoring unit and a storage synergistic unit which are communicated in sequence, all the units are networked through pipelines and are internally provided with data interaction modules to realize information closed-loop transmission, and the intelligent injection allocation regulation and control unit is a core control end; according to the low-permeability reservoir CO2 oil displacement and storage synergistic interaction regulation and control device, a supply, regulation and control, injection, monitoring and storage integrated closed-loop system is constructed, an intelligent injection allocation regulation and control unit serves as a core, the multi-element coupling relation of oil displacement efficiency, storage capacity and injection parameters is established through a synergistic interaction algorithm model, and according to the real-time dynamic state of an oil reservoir, the oil displacement efficiency, the storage capacity and the injection parameters can be adjusted and controlled according to the real-time dynamic state of the oil reservoir. And the operating parameters of each unit are dynamically adjusted, so that the optimal balance between the CO2 oil displacement efficiency and the storage capacity is realized, and the crude oil recovery rate of the low-permeability reservoir is improved.

This application discloses a composite oil displacement system and its preparation method, belonging to the field of oilfield development technology. The composite oil displacement system provided in this application includes rhamnolipin and betaine surfactant, wherein the rhamnolipin is a biosurfactant obtained by culturing *Pseudomonas aeruginosa*. Both the rhamnolipin biosurfactant and the betaine surfactant are heat- and salt-resistant; therefore, the composite oil displacement system prepared using the rhamnolipin biosurfactant and the betaine surfactant has good compatibility with high-temperature, high-salinity reservoirs, meaning it is suitable for such reservoirs. Therefore, it can significantly improve the oil displacement effect in high-temperature, high-salinity reservoirs.

The invention provides an in-situ emulsion surfactant optimization method, and belongs to the technical field of oil and gas field development engineering, and the method comprises the following steps: S1, constructing an emulsion in-situ generated droplet property characterization device; s2, injecting the simulated oil and the surfactant solution into an emulsion in-situ generated droplet property characterization device at a constant speed, preparing an emulsion, and injecting the simulated oil and the surfactant solution at a preset flow ratio and a preset speed; s3, observing the type of the emulsion, and measuring the particle size and the contact angle of the emulsion; and S4, repeating the steps S2 to S3, comparing the emulsifying properties of the surfactants according to types and concentrations, and preferably selecting the type and concentration of the oil displacement surfactant suitable for reservoir in-situ oil. According to the method, the process that in-situ emulsion generates liquid drops under the reservoir condition is simulated, the properties of the liquid drops of the in-situ emulsion are quantitatively represented, and the surfactant suitable for the reservoir is preferably selected.

The application discloses a kind of polymer oil displacement agent for carbonate fractured-vug type reservoir and preparation method thereof, step 1, with acetone and ethanol mixed solution as solvent, N, N-dimethylpropylene diamine, diethyl ether and perfluorinated nonanoic acid are added into acetone-ethanol mixed solution, after complete reaction, chloropropene is added, continue to react, after reaction is finished, solvent is removed by evaporation, to obtain fluorocarbon cation hydrophobic monomer CF-1;Step 2, white oil, emulsifier Span80 and Tween80 with mass ratio of 35-45:1-3:1-2 are mixed uniformly to obtain oil phase;AM, sodium p-styrenesulfonate and fluorocarbon cation hydrophobic monomer CF-1 are dissolved in deionized water, sodium bisulfite is added, and stirred uniformly to obtain aqueous solution;The aqueous solution is added to the oil phase to obtain a uniform emulsion, ammonium persulfate is added, and the polymer oil displacement agent is obtained by reaction. It has higher temperature resistance and salt resistance, and greatly reduces the adsorption of carbonate reservoir on the oil displacement agent.

The invention discloses an oil-displacing agent based on zirconium oxide nanosheets and a preparation method of the oil-displacing agent. The oil displacement agent comprises the following components in parts by mass: 0.2-1 part of zirconium oxide nanosheets, 10-30 parts of a surfactant and 5000-10000 parts of water, the size range of the zirconium oxide nanosheet is 200 to 300 nm. The two-dimensional zirconium oxide nanosheet is prepared by utilizing a green substitute solvent-ionic liquid assisted alcohol solvothermal method, the synthesis method is simple, convenient, effective and green, and the size of the product is controllable. The zirconium oxide material has the characteristic of changing rock wettability, and can be used as a metal oxide nano material to improve the viscosity of the prepared nanofluid, reduce the fluidity ratio, generate structural separation pressure on the interface of crude oil and reservoir rock and realize efficient stripping of retained crude oil, thereby greatly improving the recovery efficiency.