50 results about "Polymer flood" patented technology

This invention discloses a demulsifier for polymer flooding crude oil produced fluids, its preparation method, and its application, belonging to the field of chemical additives for petrochemicals. The technical solution includes a main agent, an auxiliary agent, a penetrant, and water; the main agent is a polyene-polyamine block polyether, the auxiliary agent is a triethanolamine block polyether quaternary ammonium salt, and the penetrant is selected from at least one of methanol, ethanol, ethylene glycol, and diethylene glycol butyl ether; in the demulsifier, the ratio of the main agent to the auxiliary agent is 4-9:1, the amount of penetrant is 30% of the total amount of the main agent and auxiliary agent, and the amount of water is 70% of the total amount of the main agent and auxiliary agent. This invention, applied to demulsification of polymer flooding crude oil produced fluids, features high demulsification efficiency and rapid demulsification effect.

The application provides a device and method for simulating low-efficiency water drive thick oil viscosity reduction composite drive enhanced oil recovery, which comprises an injection system, a three-dimensional large-size sand filling model, a multi-well back pressure measurement and control system and a multi-well flow metering system. The injection system is connected to the three-dimensional large-size sand filling model, and fluid is injected into the three-dimensional large-size sand filling model which can simulate well pattern mode. The multi-well back pressure measurement and control system is connected to the three-dimensional large-size sand filling model, and the formation pressure is set. The multi-well flow metering system is connected to the three-dimensional large-size sand filling model, and the output fluid is metered. The device and method for simulating low-efficiency water drive thick oil viscosity reduction composite drive enhanced oil recovery can meet the enhanced oil recovery experiments of water drive, polymer drive, viscosity reduction drive, viscosity reduction composite drive and the like of three-dimensional large-scale heterogeneous reservoir models under different well pattern modes, and has important significance for the enhanced oil recovery of low-efficiency water drive thick oil reservoirs.

The invention discloses a polymer mother liquor device capable of accelerating curing speed, and belongs to the technical field of tertiary oil recovery. The device comprises a curing tank and multiple stages of stripping plates arranged in the tank, the stripping plates comprise a first stripping plate, a second stripping plate and a third stripping plate, and the curing tank is divided into a lower cavity, a middle lower cavity, a middle upper cavity and an upper cavity in the axial direction; through holes with different diameters are formed in the stripping plates, the diameters of the through holes in the upper layer are smaller than those of the through holes in the lower layer, and the stripping plates are used for graded stripping of polymer particles with different swelling degrees; a stirrer and a cleaner positioned above the stripping plate are arranged in the curing tank, so that blockage is prevented, and dissolution is promoted. Through multi-stage stripping and partition stirring, the device effectively increases the specific surface area of a polymer, accelerates dissolution, reduces fisheye generation, remarkably shortens the curing time, improves the solution uniformity, and is suitable for the mother liquor curing procedure in the polymer flooding oil extraction process.

This invention belongs to the field of petrochemical new materials technology, specifically relating to a novel oil displacement agent and its preparation method. The novel oil displacement agent comprises the following raw materials in parts by weight: 3-7 parts of either acrylic acid or methacrylic acid, 20-30 parts of acrylamide, 1.1-2.3 parts of octadecyl acrylate, 10-21 parts of polymeric oil, 1-3 parts of emulsifier, 0.05-0.08 parts of initiator, and 1.7-2.4 parts of phase inverting agent. The oil displacement agent provided by this invention is suitable for 5-50 mD low-to-medium permeability reservoirs, does not cause pore throat blockage, can be mixed online without human intervention, effectively improves the oil-water mobility ratio, enhances oil washing efficiency, and significantly improves crude oil recovery. It is suitable for fracture network fracturing of continental sedimentary unconventional oil and gas reservoirs and the development of low-to-medium permeability reservoirs, solving the problems of difficult injection, easy blockage, and high cost of traditional polymer flooding.

A method for establishing tracking and adjustment charts for injection and production wells during the recovery phase of polymer flooding in Class III oil reservoirs addresses the issue that existing polymer flooding tracking and adjustment technologies for Class I oil reservoirs are unsuitable for Class III reservoirs. The method includes establishing adjustment charts for injection and production wells. The injection well adjustment chart is established by using the injection well's fluid absorption thickness as the length of a rectangle (40-100 mm) and the maximum relative fluid absorption of a single layer as the width of a rectangle (0-100 mm). The chart is divided into four zones: a fracturing zone, a subdivision adjustment zone, a enrichment zone, and a rational zone. The production well adjustment chart is established by using the production well's stage of production as the length of a rectangle (0-35 mm) and the water cut as the width of a rectangle (60-100 mm). The chart also includes four zones: a fracturing zone, a rational zone, a enrichment zone, and a fracturing and water shut-off zone.

The application discloses a preparation method of a flexible intelligent liquid crystal polymer driver and relates to the technical field of liquid crystal polymer materials, and comprises the following steps: step one, configuring a liquid crystal mixture: one or more liquid crystal polymer monomers and a photoinitiator are mixed, and after being heated and melted, the mixture is uniformly shaken and stirred to obtain the liquid crystal mixture; step two, preparing a liquid crystal box: a liquid crystal box with a main body 90-degree twist orientation and one end structured orientation is prepared; step three, preparing a long-strip liquid crystal polymer film driver; and step four, driving and optically regulating the long-strip liquid crystal polymer film driver; the liquid crystal polymer driver prepared by the method has optical microstructures, can be bent and deformed under thermal field stimulation, and can also be regulated for light beam deflection to generate self-driven, self-feedback and self-sustaining dynamic optical function effects.

The invention discloses a method for improving oil extraction speed through combination of fault block oil reservoir water drive encryption and polymer flooding, relates to the technical field of oil field development, and solves the problems of poor development effect and low oil extraction speed due to economic limitation of a long-well-section oil reservoir which can only adopt one set of well pattern. The method comprises the following steps: S1, preferably selecting an implementation block according to polymer flooding application conditions; s2, implementing block water flooding and polymer flooding collaborative well pattern reconstruction; s3, implementing block water-driven three-dimensional potential tapping; s4, performing an indoor physical model experiment, and screening polymer products suitable for implementation of blocks; s5, implementing block injection parameter optimization; and S6, block selective machine injection is implemented, and the comprehensive mining effect is improved. According to the method for improving the oil extraction speed by combining water drive and polymer drive of the fault block oil reservoir, the development thought that water drive and polymer drive are combined is adopted, after water drive encryption and well pattern reconstruction are conducted on the basis of meeting the polymer drive requirement, three-dimensional potential tapping is conducted on the basis of current water drive, then polymer drive development is conducted in good time, and the oil extraction speed of the oil reservoir is improved.

The invention discloses ferrous ion resistant polyacrylamide as well as a preparation method and application thereof, and relates to the field of polymer preparation of oil field polymer flooding. In order to overcome the viscosity reduction effect of metal ions on a polyacrylamide solution, the polyacrylamide polymer prepared by the invention is prepared from the following raw materials: acrylamide (AM), acrylic acid (AA), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), N, N-dimethyl octadecyl allyl ammonium chloride (DMAAC-18), alkali, a salt-resistant ferrous ion-resistant hydrophobic monomer and deionized water. The ferrous ion tolerance range of the ferrous ion-resistant polyacrylamide is 0-80 mg / L, meanwhile, the salt tolerance reaches 100000 mg / L, the calcium magnesium reaches 10000 mg / L, and the ferrous ion-resistant polyacrylamide can be applied to oil field development polymer flooding, polymer profile control flooding, profile control and other recovery ratio increasing measures.

The utility model relates to the technical field of chemical separation, in particular to an oil-water purification device for ternary and polymer flooding produced liquid. According to the oil-water purification device for the ternary and polymer flooding produced liquid, through the separation assembly in the inclined plate, especially the combination of an inclined limiting block, a pushing cross rod, an isolation block and a filter plate, the device can efficiently and preliminarily separate an oil-water mixture, and the inclined design is beneficial to utilizing the gravity effect; oil and water can be layered more easily according to density difference, separated water can be quickly guided to the outside of the device through the arrangement of a plastic slope, the water is prevented from being accumulated in the device and affecting the separation effect, the transfer box is designed to be used for collecting an oil-water mixture subjected to preliminary separation, and the oil-water separation efficiency is improved. Further purification treatment is carried out through the oil-water adsorption layer, and oil remaining in water can be efficiently adsorbed and removed through the use of the oil-water adsorption layer, especially the close fit design of the oil-water adsorption layer and the inclined knife edge, so that the purification efficiency is improved.

This invention discloses a heat-resistant, high-salt-resistant, highly surface-active polymerizable macromonomer and its preparation method. The structure of the heat-resistant, high-salt-resistant, highly surface-active polymerizable macromonomer is shown in Formula I, R 1 C2-C with a carbon-carbon double bond at the end 16 Hydrocarbon chain, R 2 It is an alkylene group, R 3 R 4 It is a C1-C3 alkyl group; R 5 The monomers are selected from tert-butyl, n-butyl, and benzyl; the number of C2H4O atoms p = 1 to 6. The method for preparing the temperature-resistant and high-salt-resistant polymerizable macromonomer of this invention uses widely available raw materials, is safe, simple, and easy to operate. Temperature can be precisely controlled, and the reaction is highly efficient. The high-surface-active, temperature-resistant, and high-salt-resistant polymerizable macromonomer prepared by this invention can self-polymerize and copolymerize with acrylamide. The resulting polymer oil displacement agent exhibits high surface activity and good salt resistance.

This invention discloses a dynamic monitoring method for polymer flooding reservoir plugging based on multi-point pressure measurement. The method includes: uniformly setting multiple pressure measurement points along the axial direction of a sand-filled model; experimental system setup and debugging; multi-stage displacement experiments and pressure monitoring, sequentially performing water flooding, polymer flooding, and subsequent water flooding; experimental data acquisition, identifying pressure surge events; core plugging dynamic characteristic analysis, identifying pressure surge processes during subsequent water flooding, and analyzing the maximum amplitude of each pressure surge, pressure surge interval, first surge pressure measurement point, core response pressure measurement point, pressure coverage area, surge coverage, and core pressure measurement point migration trajectory; outputting plugging dynamic monitoring results, integrating and analyzing the results, and generating a chart of the core plugging migration trajectory during the subsequent water flooding stage of polymer flooding. This application can achieve synchronous and accurate acquisition of pressure data from different locations in polymer flooding reservoir cores, and can comprehensively capture the spatial distribution characteristics and dynamic evolution laws of core plugging.

This invention discloses a method for adjusting injection parameters in horizontal wells with limited wellhead pressure rise. The method includes determining injection capacity evaluation indicators, influencing factors, and the number of levels for each influencing factor; numerically simulating and fitting a single-factor functional relationship to determine the water-polymer injection pressure ratio; obtaining an injection capacity prediction formula under multi-factor conditions using multivariate composite nonlinear regression; fitting parameters to the injection capacity prediction formula using the minimum sum of squared errors method; obtaining calculation formulas for injection rate and polymer viscosity based on the injection capacity prediction formula; calculating the maximum injection rate and maximum polymer viscosity under limited wellhead injection pressure rise conditions; and obtaining the optimal parameters for pressure constraints using the SLSQP algorithm. This application is applicable to polymer flooding development scenarios with limited wellhead injection pressure rise, balancing development efficiency and production safety, and providing technical support for chemical flooding injection.

The invention discloses a composite oil displacement system and a preparation method thereof, and belongs to the technical field of oilfield development. The composite oil displacement system provided by the invention mainly comprises polyacrylamide and a viscoelastic body, the viscoelastic body is carried by utilizing the tackifying and suspending capabilities of polyacrylamide, the viscosity of the system can be increased by 1-2 times on the basis of single polyacrylamide, the viscoelasticity of the system is greatly increased, and compared with a polymer oil displacement system, the composite oil displacement system has the advantages that the viscosity of the system is increased by 1-2 times; and the oil field recovery ratio can be effectively improved. Compared with a polymer / surfactant oil displacement system, the cost of the system can be reduced by about 55%. Therefore, the composite oil displacement system provided by the invention not only can improve the recovery efficiency of an oil field, but also has relatively low cost.

The invention provides a photo-thermal activated epoxy shape memory polymer and a preparation method thereof, and belongs to the technical field of functional materials. The preparation method comprises the following steps: uniformly dispersing carboxylated multi-walled carbon nanotubes in a system containing epoxy resin and an organic solvent according to a certain addition ratio, adding a curing agent, mixing, pouring, and curing to obtain the shape memory polymer. The polymer has high glass transition temperature, high tensile strength and good toughness, and can realize rapid shape recovery under the irradiation of near-infrared light. The invention also provides a method for driving the shape memory polymer to recover the shape, and the shape of the deformed shape memory polymer can be recovered only in 30-100 seconds under the action of a thermal activation mode or an infrared light irradiation activation mode. The problems that a traditional epoxy shape memory polymer is single in driving mode, and mechanical performance and driving performance are difficult to consider at the same time are solved, and the method has wide application prospects in the fields of intelligent driving and precise control.

Examples of the present disclosure provide a method and a device for determining a displaceable unit developable by polymer flooding, a medium, and a processor, which belong to the technical field of petroleum development. The method includes: obtaining a plurality of core samples in a working area and relative permeability experiment data of the core samples, and obtaining a fitting function of water saturation parameters and water cut parameters in the working area according to the relative permeability experiment data; calculating a corresponding water saturation parameter threshold interval according to the fitting function and a preset water cut parameter threshold interval, and calculating a deep lateral resistivity parameter threshold interval corresponding to the water saturation parameter; and obtaining acoustic time difference parameter curves and deep lateral resistivity parameter curves at different depth positions, and determining the displaceable unit developable by polymer flooding according to whether a deep lateral resistivity parameter and an acoustic time difference parameter simultaneously fall into corresponding parameter threshold intervals at each depth position. According to the method for determining a displaceable unit developable by polymer flooding in the present application, the displaceable unit developable by polymer flooding can be found from a developed reservoir.

The invention relates to the technical field of oil layer injection stopping and polymer injection stopping opportunity prediction, in particular to a special geological condition oil layer injection stopping and polymer injection stopping opportunity prediction system which comprises an industrial data acquisition module used for acquiring industrial bottom hole flowing pressure data of an injection well and an adjacent production well and industrial water content data of produced liquid in real time; the industrial data processing module is used for constructing the displacement failure degree of the injection well and representing the significance of the failure of the polymer displacement mechanism of the injection well in the acquisition period; and the polymer injection stopping opportunity prediction module is used for judging whether the current acquisition period reaches the polymer injection stopping opportunity in the polymer oil displacement process or not by utilizing the displacement failure degree predicted in the next acquisition period and the industrial water content data of all the adjacent production wells of the injection well. According to the method, opportunity prediction is carried out by fully considering the actual oil displacement state change of polymer oil displacement, so that the polymer injection stopping opportunity of an oil layer under special geological conditions is optimized more reasonably.

The invention discloses an oil displacement polymer solution analysis method, device and equipment and a storage medium, and the method comprises the steps that when a polymer solution is injected into a stratum through a polymer injection well, solution parameters of the polymer solution in the polymer injection well are obtained, and the solution parameters comprise the volume coefficient and the injection amount of the polymer solution; physical parameters of the stratum are obtained, wherein the physical parameters comprise the effective permeability and the effective thickness of the stratum; when injection of the polymer solution is stopped, acquiring pressure drop data in the polymer injection well in real time; according to the solution parameters, the physical parameters and the pressure drop data, the real-time viscosity of the polymer solution in the oil displacement process of the stratum is determined. According to the technical scheme provided by the invention, the viscosity of the polymer solution in the stratum at different times can be accurately calculated during migration and propulsion of the polymer solution entering the stratum for oil displacement, and a basis is provided for evaluating the polymer flooding effect, formulating and adjusting a polymer flooding scheme and improving the polymer flooding recovery ratio.

The invention relates to a poly surfactant for oil displacement and a preparation method thereof, and relates to the technical field of high polymer materials, the preparation method comprises the following steps: (1) reacting palmitic acid, N, N-dimethyl trimethylene diamine and chloroethyl acrylate to obtain a cationic surfactant; (2) adding acrylamide, acrylic acid, a cationic surfactant, 2-acrylamide-2-methylpropanesulfonic acid, tetrahydrofurfuryl acrylate, 4-hydroxybutyl vinyl ether, a dispersing agent, a molecular weight regulator and a pH regulator into a composite solvent, and uniformly mixing to obtain a polymerization solution; and (3) introducing nitrogen into the polymerization solution, and then adding an initiator to initiate a polymerization reaction to obtain the surfactant polymer for oil displacement. The prepared polymer surfactant for oil displacement has good water solubility and tackifying performance, excellent salt resistance, temperature resistance and shearing resistance and excellent interfacial activity, has the capabilities of oil displacement of a surfactant and oil displacement of a polymer at the same time, and can improve the efficiency of on-site construction.

This invention relates to the field of oilfield chemical technology, and discloses a low-molecular-weight, high-viscosity ternary polymer flooding agent, its preparation process, and its application. The low-molecular-weight, high-viscosity ternary polymer flooding agent comprises the following raw materials by weight: simulated formation water: 986.2-995.9 g; sodium thiocyanate: 0.2-1.2 g; partially hydrolyzed polyacrylamide: 1.0-3.0 g; dodecyl hydroxypropyl sulfobetaine: 2.0-6.0 g; sodium salicylate: 0.9-3.6 g. The simulated formation water is prepared from deionized water, sodium chloride, calcium chloride, and magnesium chloride. Sodium thiocyanate is added to the simulated formation water to obtain a basic conditioning fluid; partially hydrolyzed polyacrylamide is added to obtain a polymer-based fluid; dodecyl hydroxypropyl sulfobetaine is added to obtain a mixed solution; and sodium salicylate is added to induce a rheological property transformation. This invention constructs a double interpenetrating network structure, solving the problems of insufficient viscosity enhancement and poor plugging.

The application relates to the technical field of polymer flooding filtering, and discloses a portable mother liquor inlet filter for polymer flooding, which comprises a base, the top end of the base is fixedly connected with a filtering barrel, the left side of the filtering barrel is fixedly connected with a liquid inlet, the right side of the filtering barrel is fixedly connected with a liquid outlet, the top end of the filtering barrel is provided with a gland assembly, the inside of the filtering barrel is provided with a filtering assembly, the inside of the filtering assembly is provided with three self-cleaning assemblies, the bottom side of the self-cleaning assembly is provided with a self-adapting assembly, and the inside of the filtering assembly is provided with three buckle assemblies; the gland assembly comprises an embedded ring which is placed at the top end of the filtering barrel. Through cooperation of the embedded ring, a sealing ring and a clamp ring, the technical effect that the filter gland can be conveniently disassembled and installed is achieved. Compared with the technical scheme in the prior art which needs to disassemble multiple screws and repeatedly process a sealing rubber ring, the application greatly reduces the operation steps in the cleaning process.

This invention discloses a novel method and system for evaluating the enrichment effect of crude oil in polymer flooding. The method includes: acquiring basic data during the polymer flooding process based on a physical simulation experiment using sand-filled pipes; calculating, based on the basic data, peak significance index, front steepness index, mobility contrast index, pressure anomaly index, water-bearing disturbance intensity index, and oil wall stability advancement coefficient; calculating the comprehensive evaluation index of the oil wall based on the above indicators; and determining the level of the oil wall's development and migration effect based on the values. This invention overcomes the limitations of traditional single saturation peak evaluation by integrating multi-dimensional indicators and applying stability constraints. It can comprehensively, quantitatively, and stably reflect the enrichment degree, morphological characteristics, dynamic response, and advancement state of the oil wall, providing a unified and objective decision-making basis for optimizing polymer flooding schemes.

This invention provides a method and system for calculating development indicators of polymer flooding reservoirs, belonging to the field of reservoir engineering. The method includes: initializing the split flow rate data of each oil layer and the split flow rate data of the flow tubes based on the seepage characteristics of the polymer flooding reservoir at different development stages, the initial flow tube distribution data corresponding to the target well network, and the initial oil layer data of the target well network, to obtain an initial state; based on the initial state, determining the split flow rate data of each oil layer and the split flow rate data of the flow tubes at each moment during the water injection process, starting from the start of water injection; updating the displacement process leading edge distance data and development indicator data for characterizing the development status of the displacement process of the target well network in real time according to the split flow rate data of each oil layer and the split flow rate data of the flow tubes at each moment during the water injection process; and stopping water injection when the water injection status data of the target well network reaches a preset stopping condition. This method reduces the computational difficulty while accurately calculating the development dynamics of the target well network.

The invention relates to the technical field of oil and gas field development, in particular to an evaluation method and device for determining residual potential of a block after polymer displacement. The method comprises the following steps: determining a post-displacement block of a target polymer, and obtaining geological factor parameters and development factor parameters of the post-displacement block of the target polymer; the weights of the geological factor parameters and the development factor parameters are obtained through calculation; normalizing the geological factor parameters and the development factor parameters; according to the geological factor parameter weight, the development factor parameter weight, and the geological factor parameter and the development factor parameter after normalization processing, calculating a comprehensive evaluation score of the block after polymer displacement by adopting a residual potential evaluation model of the block after polymer displacement; and sorting the comprehensive evaluation scores, and quantitatively evaluating the residual potential of the block after displacement of the target polymer. According to the method and the device provided by the invention, the potential of the block after displacement of each polymer is effectively evaluated and distinguished, and the residual replacement potential of each block is determined.

The present application relates to ground intelligent layered polymer injection and water injection anti-sticking pipe column, including inner tube injection manifold, outer tube injection manifold, small tubing hanger, large tubing hanger, outer layer large tubing, inner layer small tubing;Small tubing hanger connects inner layer small tubing, and suspends and fixes inner layer small tubing on Christmas tree, and inner tube injection manifold is connected with small tubing hanger;Large tubing hanger connects outer layer large tubing, and suspends and fixes outer layer large tubing on Christmas tree, and outer tube injection manifold is connected with large tubing hanger;Inner tube injection manifold is fixedly connected with inner tube intelligent control valve and upper layer pressure gauge, and outer tube injection manifold is fixedly connected with outer tube intelligent control valve and lower layer pressure gauge;Inner tube intelligent control valve and outer tube intelligent control valve are all communicated with host computer through communication module;The present application can realize injection optimization adjustment of each layer according to the production dynamic of monitoring in time, improves polymer flooding or water flooding development effect.

This invention provides a novel multi-element heavy oil recovery process combining gas injection and oil displacement agents, relating to the field of oilfield production technology. It includes the following steps: S1: CO2 pre-injection into the injection well, with an injection volume of 0.1-0.3 PV; S2: Injection of nanoparticle foaming agent, with an injection volume of 0.3-0.6 PV; S3: Injection of N2, with an injection volume of 0.2-0.4 PV; wherein, the nanoparticle foaming agent comprises a polymer oil displacement agent, a composite surfactant, nanoparticles, and a CO2 / N2 mixture. First, carbon dioxide is injected to dissolve and reduce viscosity, improving permeability. Then, the polymer oil displacement agent, composite surfactant, nanoparticles, and the mixed gas are co-injected to form stable foam and synergistically displace the oil. In the subsequent displacement stage, nitrogen is injected to replenish energy, prevent gas channeling, and drive the foam to areas where it has not affected the crude oil. This multi-element heavy oil recovery process is suitable for the development of high-temperature, high-salinity heavy oil reservoirs.

The invention provides an ampholytic surfactant as well as a preparation method and application thereof, and belongs to the technical field of oilfield chemistry. The ampholytic surfactant comprises the following components in percentage by mass: 3-8% of a sulfonic acid-carboxylic acid type ampholytic surfactant main body, 1-3% of a gemini type organic silicon surfactant, 2-5% of a nonionic emulsifier, 4-7% of an environment-friendly organic scale inhibitor, 1-2% of a macromolecular foam stabilizer and the balance of water. According to the invention, the sulfonic acid-carboxylic acid type ampholytic surfactant main body and the gemini type organosilicon surfactant are compounded, ultralow interfacial tension (less than or equal to 10 <-3 > mN / m) can be still maintained under high salinity, and the environment-friendly organic scale inhibitor and the macromolecular foam stabilizer have a synergistic effect, so that inorganic scale blockage is prevented, the foam stability is enhanced, and the oil displacement efficiency is improved; and the whole system of the ampholytic surfactant has good compatibility, can be compounded with a polymer oil-displacing agent (such as HPAM) for use, and has no layering and precipitation phenomena.

This invention discloses a bio-depolymerase composite system for polymer deblocking in oilfields, its preparation method, and its application. For the first time, a ternary synergistic combination of bio-depolymerase, a sugar coenzyme, and an organic acid salt synergist is established. The bio-depolymerase specifically cleaves the main chain or side chain amide groups of polyacrylamide causing blockage in the formation; the sugar coenzyme participates in the enzymatic reaction and stabilizes the enzyme's active conformation, preventing enzyme inactivation under high temperature and high salt conditions; the organic acid salt synergist regulates the reaction microenvironment, chelates metal ions, and enhances the enzymatic reaction rate. The synergistic effect of these three components achieves mild, efficient, and low-residue degradation of various polymers during fracturing oil recovery, providing a green, low-damage, and efficient new technological approach for deep deblocking and increased production in polymer-driven oilfields.

This invention discloses a method for evaluating the degree of equilibrium displacement in multi-layered reservoirs. The evaluation method includes: Step S1: Constructing a geological model of the multi-layered reservoir based on geological data of its development; Step S2: Conducting numerical simulations of the multi-layered reservoir development to obtain the spatial distribution results of remaining oil during the ultra-high water-cut period; Step S3: Extracting characteristic parameters of grid cells and remaining oil data to construct an evaluation index system for the degree of equilibrium displacement in multi-layered reservoirs; Step S4: Conducting an evaluation of the degree of equilibrium displacement in multi-layered reservoirs. Based on the Theil index, a comprehensive evaluation of the degree of equilibrium displacement is performed on the inter-layer, intra-layer, and overall reservoir conditions, achieving a quantitative evaluation of the degree of equilibrium displacement in multi-layered polymer flooding reservoirs. The method is convenient and reliable.

The application discloses a kind of based on CT scanning and mercury injection data fusion core geometry model construction method, it is related to oil and gas field development technical field. Including: by three-dimensional CT scanning and image processing algorithm obtains core pore structure data;Through high-pressure mercury injection experiment obtains core pore throat size distribution data;Innovatively, three-dimensional core pore structure data and core pore throat size distribution data are fused, and pore-throat space mapping network is constructed by graph theory, to construct the core geometry model;And combining optimization algorithm dynamically adjusts pore throat size, verifies the core geometry model constructed.This application breaks through the limitation of traditional single experimental method, solves the problem of insufficient precision of core geometry model construction, and provides high-precision input for numerical simulation of fluid migration law in post-polymer flooding reservoir.The error of fluid flow simulation in COMSOL of the core geometry model constructed and experimental measurement result is controlled within ±5%, which is significantly better than traditional method.

The application discloses a phase-changeable polymer and a preparation method and application thereof. The phase-changeable polymer contains structural unit A, structural unit B and hydrolysable cross-linking structural unit C, wherein the hydrolysable cross-linking structural unit C contains anhydride bonds and ester bonds; the phase-changeable polymer has obvious thermal weight loss characteristic peaks between 550-650 DEG C. The phase-changeable polymer can be prepared into a polymer oil displacement agent, which can realize the transformation from a gel particle dispersed phase to a solution continuous phase under reservoir conditions, and finally realize the slow-release and viscosity increase in a deep reservoir, so that the gel plugging and flow diversion line near a wellbore is adjusted, the solution viscosity is increased in a far wellbore to expand the swept volume, and the oil displacement efficiency is improved, thereby greatly improving the utilization rate of the polymer and the oil displacement efficiency and improving the oil recovery rate.