CN113514607A

CN113514607A - Device and method for evaluating performance of microemulsion for oil displacement

Info

Publication number: CN113514607A
Application number: CN202110456231.3A
Authority: CN
Inventors: 周亚洲; 杨文斌; 殷代印; 王东琪; 张承丽
Original assignee: Northeast Petroleum University
Current assignee: Northeast Petroleum University
Priority date: 2021-04-26
Filing date: 2021-04-26
Publication date: 2021-10-19
Anticipated expiration: 2041-04-26
Also published as: CN113514607B

Abstract

The invention relates to a device and a method for evaluating the performance of microemulsion for oil displacement, wherein the device for evaluating the performance of the microemulsion for oil displacement comprises an injection system, a mixing system and a measuring system; the mixing system comprises a visual container, a first constant-speed constant-pressure pump, a first piston container, an oil-water mixing device and a porous medium; the top of the visual container is connected with a first valve and a first pressure gauge through pipelines, the first valve is connected with a first quick connector, and the bottom of the visual container is connected with a second quick connector through a pipeline and a second valve; the middle part of the side face of the visual container is vertically connected with the rotating shaft, one end of the rotating shaft is connected with the first motor, the other end of the rotating shaft is connected with the second motor, and the visual container can rotate or vibrate around the rotating shaft. The invention can fully mix the water phase and the oil phase to form more stable microemulsion under the condition of simulating the oil reservoir, and the mixing system can measure the type of the microemulsion, the volume of the microemulsion, the stability of the microemulsion, the volume of the water phase in the microemulsion and the interfacial tension of the middle-phase microemulsion under the condition of simulating the oil reservoir.

Description

Device and method for evaluating performance of microemulsion for oil displacement

The technical field is as follows:

the invention belongs to the technical field of petroleum engineering and tertiary oil recovery, and particularly relates to a device and a method for evaluating the performance of a microemulsion for oil displacement.

Background art:

the low-permeability oil and gas resource amount of China accounts for more than 60% of the total remaining oil resource amount, and the reasonable and efficient development of the low-permeability oil reservoir has important significance on the sustainable development of oil and gas of China. The outstanding problem of low permeability reservoir development is that the water content rises quickly and the yield decreases quickly. When the low-permeability oil reservoir reaches the stage of medium and high water content, the application of chemical flooding enhanced recovery methods such as polymer flooding, polymer flooding binary flooding, ternary combination flooding and the like which take polymers as fluidity control is restricted due to fine pore throats. Indoor experiments and field experiments of domestic and external surfactant flooding show that if a surfactant system with high concentration or good emulsifying property is injected, a surfactant solution flows in an oil layer to form emulsification entrainment, microemulsion flooding occurs, the fluidity control can be realized by depending on the viscosity of microemulsion and the Jamin effect of droplets, the oil displacement efficiency can be improved by depending on the low interfacial tension of the surfactant solution, and the surfactant system can become an effective means for further improving the recovery ratio of a low-permeability oil reservoir. With the development of surfactants with ultralow interfacial tension, high temperature resistance, high salinity and high emulsifying property, the cost of chemical agents for microemulsion flooding is continuously reduced, and the method becomes the key point of the research of improving the recovery ratio of chemical flooding.

The microemulsion flooding needs to evaluate the emulsifying property of the surfactant, at present, the disclosed microemulsion preparation device is mainly a glass tubule, and the microemulsion is prepared in a mechanical or hand-operated mode, and the type, volume and stability of the microemulsion are observed. But the microemulsion type, volume and stability under reservoir conditions cannot be measured. The microemulsion oil displacement evaluation method mainly comprises a physical simulation oil displacement method and a microscopic oil displacement method, wherein the physical simulation oil displacement device adopts a natural rock core, an artificial rock core or sand filling to evaluate the oil displacement effect of the microemulsion. But the device can not observe the micro-flow characteristics of oil and water in the microemulsion flooding, and has large injection pressure fluctuation range and larger actual difference with an oil reservoir due to low experimental back pressure control precision. The microcosmic oil displacement device adopts a microcosmic visual etched glass model to observe the flowing conditions of microemulsion, oil and water in microemulsion injection in real time. But cannot measure the dynamic and static images of the microcosmic oil displacement of the rock core under the oil reservoir condition. Therefore, the existing microemulsion performance evaluation device and method cannot prepare and measure the type, volume and stability of the microemulsion under the oil reservoir condition, and cannot measure the microscopic oil displacement mechanism of the microemulsion in the core under the oil reservoir condition.

The invention content is as follows:

the invention aims to provide a microemulsion performance evaluation device for oil displacement, which is used for solving the problems that the existing microemulsion performance evaluation device can not prepare and measure the type, volume and stability of microemulsion under the oil reservoir condition and can not measure the microcosmic oil displacement mechanism of the microemulsion in a rock core under the oil reservoir condition; the invention also aims to provide a method for evaluating the performance of the oil displacement microemulsion by using the device for evaluating the performance of the oil displacement microemulsion.

The technical scheme adopted by the invention for solving the technical problems is as follows: a microemulsion performance evaluation device for oil displacement comprises an injection system ZS, a mixing system HS and a measuring system CS; the mixing system HS comprises a visual container A, a constant-speed constant-pressure pump C1, a piston container D, an oil-water mixing device J and a porous medium H; the top of the visible container A is connected with a first valve T1 and a first pressure gauge P1 through pipelines, a first valve T1 is connected with a first quick connector E1, and the bottom of the visible container A is connected with a second quick connector E2 through pipelines and a second valve T2; the top of the first piston container D is connected with a quick joint III E3 through a pipeline and a valve III T3, and the bottom of the first piston container D is connected with a constant-speed constant-pressure pump I C1 through a pipeline; the inlet end of the porous medium H is connected with a valve seven T7 through a pipeline, the outlet end of the porous medium H is connected with an oil-water mixing device J through a pipeline, and the oil-water mixing device J is connected with a quick connector four E4 through a pipeline; the middle part of the side surface of the visual container A is vertically connected with a rotating shaft B, one end of the rotating shaft B is connected with a first motor B1, the other end of the rotating shaft B is connected with a second motor B2, and the visual container A can rotate or vibrate around the rotating shaft B;

the side face of the visible container A is a visible container wall A1, a visible container window A2 is arranged on the visible container wall A1, a first triangular prism A5 is arranged outside the visible container window A2, one face of the first triangular prism A5 is overlapped with the visible container window A2, a first light source A3 is arranged outside one of the other two faces of the first triangular prism A5, and a first microscope camera A4 is arranged outside the other two faces of the first triangular prism A5; the first light source A3 is in sliding connection with the first light source sliding track A7, and the first microscope camera A4 is in sliding connection with the first microscope camera sliding track A6; the visible container A is internally provided with a first electrode group A8 and a second electrode group A9, the first electrode group A8 is connected through an electrode group connecting wire A10, and the second electrode group A9 is connected through an electrode group connecting wire A11.

The measuring system CS in the scheme comprises a microscopic visual device M, a micropore device N, a visual piston container K and a constant-speed constant-pressure pump four C4; the inlet of the microscopic visual device M is connected with a quick coupling seven E7 through a pipeline and a valve eight T8, and the outlet of the microscopic visual device M is connected with a valve nine T9 through a pipeline; the inlet of the micropore device N is connected with a quick connector seven E7 through a pipeline and a valve ten T10, and the outlet of the micropore device N is connected with a valve eleven T11 through a pipeline; the top of the visual piston container K is connected with a valve nine T9 and a valve eleven T11 through pipelines, and the bottom of the visual piston container K is connected with a constant-speed constant-pressure pump four C4 through pipelines.

In the scheme, the microscopic visual device M comprises a microscopic visual device outer wall M1, a microscopic visual device window I M21, a transparent rubber sleeve M3, a light source III M5, a microscope camera III M6, a triangular prism III M7 and a ring pressure pump M10; a transparent rubber sleeve M3 is arranged inside the outer wall M1 of the microscopic visual device, a transparent annular hydraulic liquid M9 is arranged between the outer wall M1 of the microscopic visual device and the transparent rubber sleeve M3, a rock core M4 is wrapped inside the transparent rubber sleeve M3, and the transparent annular hydraulic liquid M9 is connected with an annular pressure pump M10 through a pipeline; a first microscopic visual device window M21 is arranged on the outer wall M1 of the microscopic visual device, a triangular prism tri-M7 is arranged outside the first microscopic visual device window M21, one surface of the triangular prism tri-M7 is overlapped with the first microscopic visual device window M21, a light source tri-M5 is arranged outside one of the other two surfaces of the triangular prism tri-M7, and a microscope camera tri-M6 is arranged outside the other two surfaces of the triangular prism tri-M7.

In the scheme, the outer wall M1 of the microscopic visual device is also provided with a microscopic visual device window two M22, a microscopic visual device window three M23 and/or a microscopic visual device window four M24; the light source three M5, the microscope camera three M6 and the triangular prism three M7 are respectively connected with a rotating bracket M8, the rotating bracket M8 can rotate around the outer wall M1 of the microscopic visual device, and the rotating bracket M8 can also horizontally move on the outer wall M1 of the microscopic visual device.

In the scheme, the side face of the visual piston container K is a visual piston container wall K1, a visual piston container window K2 is arranged on the visual piston container wall K1, a triangular prism second K5 is arranged outside the visual piston container window K2, one face of the triangular prism second K5 coincides with the visual piston container window K2, a light source second K3 is arranged outside one face of the other two faces of the triangular prism second K5, a microscope camera second K4 is arranged outside the other two faces of the triangular prism second K5, the light source second K3 is in sliding connection with the light source second sliding track K7, and the microscope camera second K4 is in sliding connection with the microscope camera second sliding track K6.

In the scheme, the injection system ZS comprises a piston container II F, a piston container III G, a constant-speed constant-pressure pump II C2 and a constant-speed constant-pressure pump III C3; the top of the second piston container F is connected with a fifth valve T5, a sixth valve T6, a seventh valve T7 and a second pressure gauge P2 through a pipeline and a fourth valve T4, and the bottom of the second piston container F is connected with a second constant-speed and constant-pressure pump C2 through a pipeline; the top of the piston container III G is connected with a valve IV T4, a valve VI T6, a valve VII T7 and a pressure gauge II P2 through a pipeline and a valve V T5, and the bottom of the piston container III G is connected with a constant-speed and constant-pressure pump III C3 through a pipeline; the valve six T6 is connected with the quick connector six E6 through a pipeline, and the valve seven T7 is connected with the porous medium H through a pipeline.

In the scheme, the micropore medium in the micropore device N is one or more of a rock core, a micropore filter membrane and a micropore metal net; the oil-water mixing device J is one or more of a homogenizer, an ultrasonic mixing device and a high-speed stirrer; the porous medium H is a screen or a porous plate; core M4 is one of a natural core, an artificial core, and a beret core.

In the scheme, an injection system ZS, a mixing system HS and a measurement system CS are arranged in a thermostat R; the light source A3, the microscope camera A4, an electrode group connecting line A10, an electrode group two connecting line A11, a motor B1, a motor B2, a constant-speed constant-pressure pump C1, a constant-speed constant-pressure pump C2, a constant-speed constant-pressure pump C3, a constant-speed constant-pressure pump C4, an oil-water phase mixing device J, a light source B K3, a microscope camera B K4, a light source III M5, a microscope camera III M6, a ring pressure pump M10, a pressure gauge P1, a pressure gauge II P2 and a thermostat R are electrically connected with the computer L.

A method for evaluating the performance of the microemulsion for oil displacement by adopting the microemulsion performance evaluation device for oil displacement of the scheme comprises the following steps:

opening a constant temperature box R to raise the temperature to the temperature required by the experiment, closing all valves, filling gas with the pressure required by the experiment into the upper part of a piston container I, filling a water phase solution for forming microemulsion into the upper part of a piston container II F, and filling an oil phase solution for forming microemulsion into the upper part of a piston container III G;

step two, connecting a first quick joint E1 and a third quick joint E3, connecting a second quick joint E2 and a fourth quick joint E4, opening a first valve T1 and a third valve T3, setting a first constant-pressure pump C1 to work in a constant-pressure mode, preparing microemulsion pressure by taking constant pressure as an experimental requirement, and starting a first constant-pressure pump C1;

step three, setting a second constant-speed constant-pressure pump C2 and a third constant-speed constant-pressure pump C3 to work in a constant-speed mode, wherein the constant speed is the speed required by the experiment, starting the second constant-speed constant-pressure pump C2 and the third constant-speed constant-pressure pump C3, opening a valve four T4, a valve five T5 and a valve seven T7, and when the reading of a second pressure gauge P2 is the same as that of the first pressure gauge P1, opening a valve two T2;

step four, the water phase solution in the piston container II F and the oil phase solution in the piston container III G enter a porous medium H and an oil-water mixing device J through pipelines and enter a visual container A, when the injection amount of the water phase solution in the piston container II F and the oil phase solution in the piston container III G meets the experimental requirements, the constant-speed constant-pressure pump I C1, the constant-speed constant-pressure pump II C2 and the constant-speed constant-pressure pump III C3 are closed, all valves are closed, the connection between the quick connector I E1 and the quick connector III E3 is disconnected, and the connection between the quick connector II E2 and the quick connector IV E4 is disconnected;

step five, setting the working mode of the motor I B1 and/or the motor II B2 as rotation or vibration according to the experimental requirements, and starting the motor I B1 and/or the motor II B2 until the experimental requirements time to obtain a microemulsion solution;

sixthly, starting a first light source A3 and a first microscope camera A4, controlling the first light source A3 and the first microscope camera A4 to move on a sliding track through a computer L, shooting the heights and the position relation of the microemulsion, the oil phase and the water phase in the visible container A through a first triangular prism A5 and a visible container window A2, judging the type of the microemulsion, calculating the volume of the microemulsion, the volume of the water phase and the volume of the oil phase, calculating the interfacial tension of the middle-phase microemulsion, and shooting microscopic images of the microemulsion at different positions; according to the time interval required by the experiment, a computer L controls a light source A3 and a microscope camera A4 to shoot the height, the position relation and the microscopic image of the microemulsion, the oil phase and the water phase in the visible container A until the experiment is finished;

seventhly, opening the first electrode group A8 and the second electrode group A9, controlling different electrode pairs on a first electrode group connecting line A10 and a second electrode group connecting line A11 through a computer L to measure the conductivity of the microemulsion, and calculating the volume of the water phase in the microemulsion; the volume of the aqueous phase in the microemulsion was calculated by measuring the conductivity of the microemulsion by controlling the different electrode pairs on the electrode set one line a10 and the electrode set two line a11 by the computer L at the time intervals required by the experiment.

The other method for evaluating the performance of the microemulsion for oil displacement by adopting the microemulsion performance evaluation device for oil displacement comprises the following steps:

step one, when the microemulsion is an upper phase microemulsion or a middle phase microemulsion, connecting a first quick joint E1 and a third quick joint E3, connecting a second quick joint E2 and a sixth quick joint E6, and setting a first constant-speed and constant-pressure pump C1 to work in a constant-speed mode, wherein the constant speed is the speed required by the experiment, a second constant-speed and constant-pressure pump C2 works in a constant-pressure mode, and the constant pressure is a pressure value P1 of a pressure gauge. Opening a first valve T1, a second valve opening T2, a third valve T3, a fourth valve T4 and a sixth valve T6, starting a first constant-speed constant-pressure pump C1 and a second constant-speed constant-pressure pump C2, and allowing the aqueous phase solution in the visible container A to flow into the upper part of a second piston container F; when all the water phase solution in the visible container A flows into the upper part of the piston container II F, the constant-speed constant-pressure pump I C1 and the constant-speed constant-pressure pump II C2 are closed, the valve I T1, the valve II T2, the valve III T3, the valve IV T4 and the valve VI T6 are closed, and the quick joint II E2 and the quick joint VI E6 are disconnected; when the microemulsion is a lower phase microemulsion or a single phase microemulsion, the operation of the first step is not needed;

secondly, selecting a core according to the experiment requirement, measuring the appearance size and the volume of saturated water of the core, filling the saturated water core into a transparent rubber sleeve M3 of a microscopic visual device M, and injecting transparent ring pressure liquid M9 between an outer wall M1 of the microscopic visual device and a transparent rubber sleeve M3 through a ring pressure pump M10 to ensure that the ring pressure of the core reaches the experiment requirement pressure;

step three, discharging upper liquid of the piston container II F, filling oil displacement experiment water, similarly discharging upper liquid of the piston container III G, and filling an oil sample for rock core saturated oil; connecting a quick joint six E6 and a quick joint seven E7, setting a constant-speed constant-pressure pump three C3 to work in a constant-speed mode, wherein the constant speed is the saturated oil speed required by the experiment, setting a constant-speed constant-pressure pump four C4 to work in a constant-pressure mode, and the constant pressure is the pressure required by the experiment; opening a valve five T5, a valve six T6, a valve eight T8 and a valve nine T9, starting a constant-speed constant-pressure pump three C3 and a constant-speed constant-pressure pump four C4, enabling oil in a piston container three G to enter a rock core, closing the constant-speed constant-pressure pump three C3 and the constant-speed constant-pressure pump four C4, closing the valve five T5, the valve six T6, the valve eight T8 and the valve nine T9 and disconnecting a quick joint six E6 and a quick joint seven E7 when the oil saturation of the rock core meets the experimental requirements; discharging the liquid on the upper part of the visible piston container K to enable the piston to be positioned at the top;

step four, connecting a quick joint II E2 and a quick joint seven E7, setting a constant-speed constant-pressure pump I C1 to work in a constant-speed mode, wherein the constant speed is the speed of injecting the microemulsion required by the experiment, setting a constant-speed constant-pressure pump IV C4 to work in a constant-pressure mode, and setting the constant pressure as the pressure required by the experiment; opening a first valve T1, a second valve opening T2, a third valve T3, an eighth valve T8 and a ninth valve T9, opening a first constant-speed constant-pressure pump C1, a fourth constant-speed constant-pressure pump C4, a second light source K3, a second microscope camera K4, a third light source M5 and a third microscope camera M6, enabling the micro-emulsion in the visual container A to enter the rock core, displacing oil in the rock core, enabling the produced oil and water to flow into the visual piston container K, recording a first pressure value P1 of a pressure gauge, closing the first constant-speed constant-pressure pump C1 and the fourth constant-pressure pump C4 when the injection amount of the micro-emulsion meets the experimental requirement, and closing the first valve T1, the second valve opening T2, the third valve T3, the eighth valve T8 and the ninth valve T9;

and step five, in the process of displacing the oil in the rock core by the microemulsion, shooting a dynamic and static microscopic image of the microemulsion displacement oil by a computer L through a triangular prism M7 and a microscopic visual device window M21 by using a light source three M5 and a microscope camera three M6. Adjusting the rotary support M8 to enable the microscope camera III M6 to shoot dynamic and static microscopic images of the microemulsion displacement oil at different positions in the same window and at different window positions; similarly, in the process of displacing oil in the rock core by the microemulsion, according to the time interval required by the experiment, the computer L controls the light source II K3 and the microscope camera II K4 to move on the sliding track, the volume of the oil and the volume of the water entering the visible piston container K are shot through the triangular prism II K5 and the visible piston container window K2, and meanwhile, the microscope camera II K4 shoots microscopic images of the oil and the water at different positions until the experiment is finished;

and step six, closing all valves, closing the power supply and ending the experiment.

The invention has the following beneficial effects:

1. the injection system can inject water phase and oil phase which form microemulsion into the mixing system under the condition of simulating oil reservoir, and can also inject oil and water into the measuring system. The mixing system can be used for simulating the oil reservoir condition, under the cooperation of the injection system, the water phase and the oil phase can be fully mixed to form the microemulsion through the porous medium and the oil-water mixing device, the motor drives the water phase and the oil phase in the visible container to rotate or vibrate, the water phase and the oil phase are further fully mixed to form the more stable microemulsion, and meanwhile, the mixing system can be used for measuring the type of the microemulsion, the volume of the microemulsion, the stability of the microemulsion, the volume of the water phase in the microemulsion and the interfacial tension of the middle-phase microemulsion under the simulated oil reservoir condition.

2. The measuring system adopts the cooperation of the microscopic visual device, the visual piston container and the constant-speed constant-pressure pump, so that the back pressure control accuracy of the experiment is improved, the precision is improved, and the back pressure control precision is consistent with the pressure control precision of the constant-speed constant-pressure pump; the method realizes the accurate simulation of oil reservoir conditions to shoot the micro oil displacement dynamic and static images of the microemulsion in the natural rock core, provides a basis for the micro oil displacement mechanism of the microemulsion, and can accurately obtain the macro oil displacement effect data of the microemulsion.

Drawings

FIG. 1 is a schematic structural diagram of a microemulsion performance evaluation device for oil displacement according to the present invention;

FIG. 2 is a schematic top view of a visual container according to the present invention;

FIG. 3 is a schematic side view of a visual container according to the present invention;

FIG. 4 is a schematic view of the electrode structure inside the visible container according to the present invention;

FIG. 5 is a schematic view of the inlet end side view of the micro-visualization device of the present invention;

FIG. 6 is a schematic side view of a viewing window of the micro-visualization device of the present invention;

FIG. 7 is a schematic top view of the micro-visualization device of the present invention;

FIG. 8 is a schematic top view of a visual piston container according to the present invention;

FIG. 9 is a side view of the piston container of the present invention.

In the figure: ZS: injection system, HS: hybrid system, CS: a measurement system;

wherein A: visual container, a 1: visual container wall, a 2: visual container window, a 3: light source one, a 4: first microscope camera, a 5: triangular prism one, a 6: microscope camera-slide rail, a 7: light source-slide rail, A8: electrode group one, a 9: electrode group two, a 10: electrode group-connection line, a 11: connecting line of electrode group two, B: rotating shaft, B1: motor one, B2: motor two, C1: constant-speed constant-pressure pump one, C2: constant-speed constant-pressure pump two, C3: constant-speed constant-pressure pump three, C4: a constant-speed constant-pressure pump IV: piston container one, E1-E7: quick joint one-quick joint seven, F: piston container two, G: piston container three, H: porous media, J: oil-water mixing device, K: visual piston container, K1: visual piston container wall, K2: visual piston container window, K3: light source two, K4: second microscope camera, K5: triangular prism two, K6: second slide rail of microscope camera, K7: light source two sliding rail, L: computer, M: microscopic visualization device, M1: microscopic visualization device outer wall, M21: microscopic visualization device window one, M22: microscopic visualization device window two, M23: microscopic visualization device window three, M24: microscopic visualization device window four, M3: transparent rubber sleeve, M4: core, M5: light source three, M6: microscope camera three, M7: triangular prism three, M8: rotating bracket, M9: transparent ring-pressing liquid, M10: ring pressure pump, N: microwell device, P1: pressure gauge one, P2: pressure gauge two, R: oven, T1-T11: valve one-valve eleven.

Detailed Description

The invention is further described with reference to the accompanying drawings in which:

example 1:

as shown in figure 1, the evaluation device for the performance of the microemulsion for oil displacement comprises an injection system ZS, a mixing system HS and a measurement system CS, wherein a solid line represents physical pipeline connection, and a dotted line represents electric connection.

(1) Injection system ZS

The injection system ZS comprises a piston container II F, a piston container III G, a constant-speed constant-pressure pump II C2 and a constant-speed constant-pressure pump III C3; the top of the piston container II F is connected with a valve five T5, a valve six T6, a valve seven T7 and a pressure gauge II P2 through a pipeline and a valve four T4, and the bottom of the piston container II F is connected with a constant-speed and constant-pressure pump II C2 through a pipeline; the top of the piston container III G is connected with a valve IV T4, a valve VI T6 and a valve VII T7 through pipelines and a valve V T5, and a pressure gauge II P2, and the bottom of the piston container III G is connected with a constant-speed and constant-pressure pump III C3 through pipelines; the valve six T6 is connected with the quick connector six E6 through a pipeline, and the valve seven T7 is connected with the porous medium H through a pipeline. The piston container II F, the piston container III G, the constant-speed constant-pressure pump II C2, the constant-speed constant-pressure pump III C3 and related pipelines, valves and quick joints are all resistant to pressure of 40 MPa; the injection system can simulate the oil reservoir condition and inject the water phase and the oil phase which form the microemulsion into the mixing system, and can also inject oil, water, oil displacement agent and the like into the measuring system.

(2) Hybrid system HS

The mixing system HS comprises a visual container A, a constant-speed constant-pressure pump C1, a piston container D, an oil-water mixing device J and a porous medium H; the top of the visual piston container A is connected with a first valve T1 and a first pressure gauge P1 through pipelines, the first valve T1 is connected with a first quick connector E1, and the bottom of the visual piston container A is connected with a second quick connector E2 through pipelines and a second valve T2; the top of the first piston container D is connected with a quick joint III E3 through a pipeline and a valve III T3, and the bottom of the first piston container D is connected with a constant-speed constant-pressure pump I C1 through a pipeline; the inlet end of the porous medium H is connected with a valve seven T7 through a pipeline, the outlet end of the porous medium H is connected with an oil-water mixing device J through a pipeline, and the oil-water mixing device J is connected with a quick connector four E4 through a pipeline. The visible container A, the constant-speed constant-pressure pump C1, the piston container D, the oil-water mixing device J, the porous medium H and related pipelines, valves and quick connectors all resist pressure of 40 MPa. The visible container A has an inner diameter of 0.5-3 cm and a height of 20-50 cm.

As shown in fig. 2 and 3, the visual container a is cylindrical, the middle of the side surface of the visual container a is vertically connected with the rotating shaft B, one end of the rotating shaft B is connected with the first motor B1, the other end of the rotating shaft B is connected with the second motor B2, and the first motor B1 and/or the second motor B2 can drive the rotating shaft B and the visual container a to rotate or vibrate. The rotation speed of the visual container A can be 1-120 r/min; the vibration frequency of the visual container A can be 1-100 times/min, and the amplitude can be 0.5-2 cm. The existence of high-pressure gas in the visible container A is beneficial to the formation of stable microemulsion by rotation or vibration of the aqueous phase solution and the oil phase solution.

The side face of the visible container A is a visible container wall A1, a visible container window A2 is arranged on the visible container wall A1, a first triangular prism A5 is arranged outside the visible container window A2, one face of the first triangular prism A5 is overlapped with a visible piston container window A2, a first light source A3 is arranged outside one of the other two faces of the first triangular prism A5, and a first microscope camera A4 is arranged outside the other two faces of the first triangular prism A5. The first light source A3 is connected with the first light source sliding track A7 in a sliding way, and the first light source A3 can move on the first light source sliding track A7; the first microscope camera a4 is slidably connected to the first microscope camera sliding rail a6, and the first microscope camera a4 can move on the first microscope camera sliding rail a 6. Light emitted by the first light source A3 vertically irradiates one side face of the first triangular prism A5, light irradiates the visual container window A2 through the first triangular prism A5, and the first microscope camera A4 vertically irradiates the other side face of the first triangular prism A5 to shoot dynamic and static images of oil phase, water phase or microemulsion in the visual container window A2.

The placing directions of the first triangular prism A5, the first microscope camera sliding track A6 and the first light source sliding track A7 are the same as the direction of the visual container window A2. The visible container window A2 has a length of 0.2-1 cm and a width of the distance from the bottom to the top of the visible container A. The length of the triangular prism A5, the microscope camera sliding track A6 and the light source sliding track A7 is the same as the length of the visual container window A2.

As shown in fig. 4, the visible container a has a first electrode group A8 and a second electrode group a9 inside, the first electrode group A8 is connected by a first electrode group connecting line a10, and the second electrode group a9 is connected by a second electrode group connecting line a 11.

The oil-water mixing device J can be one or more of a homogenizer, an ultrasonic mixing device or a high-speed stirrer, the speed of the homogenizer is 5000-.

The porous medium H can be a screen or a perforated plate, the aperture of the screen or the perforated plate is 1-50 μm, and the type and the porosity of the porous medium H are selected according to the experimental requirements.

The mixing system HS can enable the water phase and the oil phase to be fully mixed to form the microemulsion through the oil-water mixing device under the condition of simulating an oil reservoir and under the cooperation of the injection system, the motor drives the water phase and the oil phase in the visible container to rotate or vibrate, the water phase and the oil phase are further fully mixed to form the more stable microemulsion, and meanwhile, the mixing system can measure the types of the microemulsion, the volume of the microemulsion, the stability of the microemulsion, the volume of the water phase in the microemulsion, the interfacial tension of the middle-phase microemulsion and the like under the condition of simulating the oil reservoir.

(3) Measurement system CS

The measuring system CS comprises a microscopic visual device M, a micropore device N, a visual piston container K and a constant-speed constant-pressure pump four C4; the inlet of the microscopic visual device M is connected with a quick coupling seven E7 through a pipeline and a valve eight T8, and the outlet of the microscopic visual device M is connected with a valve nine T9 through a pipeline. The inlet of the microporous device N is connected with a quick connector seven E7 through a pipeline and a valve ten T10, and the outlet of the microporous device N is connected with a valve eleven T11 through a pipeline. The top of the visual piston container K is connected with a valve nine T9 and a valve eleven T11 through pipelines, and the bottom of the visual piston container K is connected with a constant-speed constant-pressure pump four C4 through pipelines. The microscopic visual device M, the micropore device N, the visual piston container K, the constant-speed constant-pressure pump four C4 and related pipelines, valves and quick joints are all resistant to pressure of 40 MPa. The inner diameter of the visible piston container K is 0.5-3 cm, and the height is 20-50 cm.

As shown in fig. 5, 6 and 7, the micro visualization device M comprises a micro visualization device outer wall M1, a micro visualization device window one M21, a transparent rubber sleeve M3, a light source three M5, a microscope camera three M6, a triangular prism three M7 and a ring pressure pump M10; transparent rubber sleeve M3 is arranged inside the outer wall M1 of the microscopic visual device, the microscopic visual device M and the transparent rubber sleeve M3 are both cylindrical, transparent annular pressure liquid M9 is arranged between the outer wall M1 of the microscopic visual device and the transparent rubber sleeve M3, a rock core M4 is wrapped inside the transparent rubber sleeve M3, and the transparent annular pressure liquid M9 is connected with an annular pressure pump M10 through a pipeline. The transparent annular hydraulic fluid M10 may be water or colorless oil, or the like. The core M4 can be natural core, artificial core or Bailey core, with diameter of 1-4 cm and length of 2-15 cm. The transparent rubber sleeve has an inner diameter of 1-4 cm and a length of 5-18 cm.

A first microscopic visual device window M21 is arranged on an outer wall M1 of a microscopic visual device M side surface microscopic visual device M, a triangular prism tri-M7 is arranged outside the first microscopic visual device window M21, one surface of the triangular prism tri-M7 is overlapped with the first microscopic visual device window M21, a light source tri-M5 is arranged outside one of the other two surfaces of the triangular prism tri-M7, and a microscope camera tri-M6 is arranged outside the other surface of the other two surfaces of the triangular prism tri-M7.

The outer wall M1 of the micro visual device on the side surface of the micro visual device M can be uniformly provided with four observation windows, namely a micro visual device window I M21, a micro visual device window II M22, a micro visual device window III M23 and a micro visual device window IV M24.

The light source three M5, the microscope camera three M6 and the triangular prism three M7 are respectively connected with the rotating bracket M8, the rotating bracket M8 can rotate around the outer wall M1 of the microscopic visual device, so that the triangular prism three M7 is respectively superposed with the microscopic visual device window one M21, the microscopic visual device window two M22, the microscopic visual device window three M23 or the microscopic visual device window four M24, and the microscopic images corresponding to different windows are shot. The rotary support M8 can also move horizontally on the outer wall M1 of the micro visual device to take micro images of different positions in the same window.

As shown in fig. 8 and 9, the side surface of the visible piston container K is a visible piston container wall K1, a visible piston container window K2 is arranged on the visible piston container wall K1, a triangular prism two K5 is arranged outside the visible piston container window K2, one surface of the triangular prism two K5 is overlapped with the visible piston container window K2, a light source two K3 is arranged outside one surface of the other two surfaces of the triangular prism two K5, and a microscope camera two K4 is arranged outside the other surface of the other two surfaces of the triangular prism two K5. The second light source K3 is in sliding connection with the second light source sliding track K7, the second light source K3 can move on the second light source sliding track K7, the second microscope camera K4 is in sliding connection with the second microscope camera sliding track K6, and the second microscope camera K4 can move on the second microscope camera sliding track K6.

The visual piston container window K2, the triangular prism II K5, the light source II sliding track K7 and the microscope camera II sliding track K6 are in the same direction as the visual piston container K. The length of the visual piston container window K2 is the distance between the bottom surface and the top surface of the interior of the visual piston container K, and the width is 0.5-2 cm. The lengths of the triangular prism II K5, the light source II sliding track K7 and the microscope camera II sliding track K6 are the same as the length of the visual piston container window K2.

The micropore medium in the micropore device N can be one or more of a rock core, a micropore filter membrane and a micropore metal net, and the aperture of the micropore medium is 0.2-20 μm.

The measuring system adopts a microscopic visual device, a visual piston container and a constant-speed constant-pressure pump to be matched for use, so that the back pressure accuracy is improved, the control precision is improved, and the back pressure control precision is consistent with the pressure control precision of the constant-speed constant-pressure pump; the method realizes the accurate simulation of oil reservoir conditions to shoot the micro oil displacement dynamic and static images of the microemulsion in the natural rock core, provides a basis for the micro oil displacement mechanism of the microemulsion, and can accurately obtain the macro oil displacement effect data of the microemulsion.

The light source one A3, the light source two K3 and the light source three M5 are LED lamps, halogen lamps or mercury lamps, and the microscope camera one a4, the microscope camera two K4 and the microscope camera three M6 are leca DMC6200, leca 5400 or leca FLEXACAMC 1.

The injection system ZS, the mixing system HS and the measurement system CS are located in a thermostat R, which can be at a temperature of 25-120 ℃.

The computer system comprises a light source I3, a microscope camera I A4, an electrode group connecting line A10, an electrode group two connecting line A11, a motor I B1, a motor II B2, a constant-speed constant-pressure pump I C1, a constant-speed constant-pressure pump II C2, a constant-speed constant-pressure pump III C3, a constant-speed constant-pressure pump IV C4, an oil-water phase mixing device J, a light source II K3, a microscope camera II K4, a light source III M5, a microscope camera III M6, a ring pressure pump M10, a pressure gauge I P1, a pressure gauge II P2 and a thermostat R, wherein the computer L is electrically connected with the light source I A4, the microscope camera III M6, the thermostat R and the computer L can realize automatic control recording of the computer P.

Example 2:

the method for evaluating the performance of the microemulsion for oil displacement, which adopts the microemulsion performance evaluation device to prepare the microemulsion, comprises the following steps:

the method comprises the following steps of firstly, turning on a power supply, turning on a computer L, turning on a thermostat R, raising the temperature to the temperature required by an experiment, turning off all valves, filling gas with the pressure required by the experiment into the upper part of a piston container I D, filling a water phase solution for forming the microemulsion into the upper part of a piston container II F, and filling an oil phase solution for forming the microemulsion into the upper part of a piston container III G.

And step two, connecting a first quick joint E1 and a third quick joint E3, connecting a second quick joint E2 and a fourth quick joint E4, opening a first valve T1 and a third valve T3, setting a first constant-speed constant-pressure pump C1 to work in a constant-pressure mode, preparing microemulsion pressure by taking constant pressure as an experimental requirement, and starting the first constant-speed constant-pressure pump C1 manually or through a computer L.

And step three, manually or through a computer L, setting the second constant-speed constant-pressure pump C2 and the third constant-speed constant-pressure pump C3 to work in a constant-speed mode, wherein the constant speed is the speed required by the experiment, starting the second constant-speed constant-pressure pump C2 and the third constant-speed constant-pressure pump C3, opening a valve four T4, a valve five T5 and a valve seven T7, and when the reading of the second pressure gauge P2 is the same as that of the first pressure gauge P1, starting the valve two T2.

And step four, enabling the water phase solution in the piston container II F and the oil phase solution in the piston container III G to enter a porous medium H through pipelines to filter impurities, then enabling the water phase solution and the oil phase solution in the piston container III G to enter a visible container A through pipelines to form micro-emulsion, enabling the micro-emulsion and the surplus water phase solution or/and oil phase solution to enter the visible container A through pipelines, manually or through a computer L, closing the constant-speed constant-pressure pump I C1, the constant-speed constant-pressure pump II C2 and the constant-speed constant-pressure pump III C3, closing all valves, disconnecting the quick connector I E1 from the quick connector III E3, and disconnecting the quick connector II E2 from the quick connector IV E4 when the injection amount of the water phase solution in the piston container II F and the oil phase solution in the piston container III G meets the experimental requirements.

And step five, setting the working mode of the first motor B1 and/or the second motor B2 to be rotation or vibration manually or through a computer L according to the experimental requirements, starting the first motor B1 and/or the second motor B2 until the experimental requirement time, and enabling the water phase solution and the oil phase solution in the visible container A to form stable microemulsion through the first motor B1 and/or the second motor B2 in the presence of high-pressure gas to prepare the microemulsion solution.

Example 3:

a method for evaluating the performance of microemulsion for displacing oil adopts the microemulsion performance evaluating device to evaluate the performance of microemulsion, wherein the performance of microemulsion comprises the types of microemulsion, the volume of microemulsion, the stability of microemulsion, the volume of aqueous phase in microemulsion, the interfacial tension of intermediate-phase microemulsion and the like, and the method for evaluating the performance of microemulsion comprises the following steps:

the method comprises the steps of firstly, turning on a first light source A3 and a first microscope camera A4, controlling the first light source A3 and the first microscope camera A4 to move on a sliding track through a computer L, shooting the height and position relation of microemulsion, oil phase and water phase in a visible container A through a first triangular prism A5 and a visible container window A2, judging the type of the microemulsion, calculating the volume of the microemulsion, the volume of the water phase or/and the volume of the oil phase, calculating the interfacial tension of the microemulsion in the phase, and shooting microscopic images of the microemulsion at different positions.

The microemulsion type is determined by the fact that when the microemulsion is at the bottom, the microemulsion is an oil-in-water microemulsion (Winsor i), when the microemulsion is at the top, the microemulsion is a water-in-oil microemulsion (Winsor ii), when the microemulsion is at the middle, the microemulsion is a medium-phase microemulsion (Winsor iii), and when all solutions are microemulsions, the microemulsion is a single-phase microemulsion (Winsor iv). When the microemulsion is the middle-phase microemulsion, the interfacial tension of the middle-phase microemulsion can be calculated by using a Huh equation according to the oil-water solubilization index.

And step two, controlling a light source A3 and a microscope camera A4 by a computer L to shoot the height and position relation of the microemulsion, the oil phase and the water phase in the visible container A according to the time interval required by the experiment, shooting microscopic images of the microemulsion at different positions until the experiment is finished, and determining the stability of the microemulsion according to the volume change of the microemulsion at different times.

And step three, opening the electrode group I A8 and the electrode group II A9, controlling different electrode pairs on a connecting line A10 of the electrode group and a connecting line A11 of the electrode group to measure the conductivity of the microemulsion through the computer L, and calculating to obtain the volume of the water phase in the microemulsion by combining the positions of the microemulsion.

And step four, controlling different electrode pairs on a connecting line A10 of the electrode group and a connecting line A11 of the electrode group to measure the conductivity of the microemulsion through a computer L according to the time interval required by the experiment, and calculating to obtain the water phase volume in the microemulsion at different times.

Example 4:

the method for evaluating the performance of the microemulsion for oil displacement by adopting the microemulsion performance evaluation device comprises the following steps of:

step one, when the microemulsion is an upper phase microemulsion or a middle phase microemulsion, connecting a first quick joint E1 and a third quick joint E3, connecting a second quick joint E2 and a sixth quick joint E6, setting a first constant-speed constant-pressure pump C1 to work in a constant-speed mode manually or through a computer L, wherein the constant speed is the speed required by an experiment, the second constant-speed constant-pressure pump C2 works in a constant-pressure mode, and the constant pressure is the pressure value of a first pressure gauge P1. Opening a first valve T1, a second valve opening T2, a third valve T3, a fourth valve T4 and a sixth valve T6, manually or through a computer L, opening a first constant-speed constant-pressure pump C1 and a second constant-speed constant-pressure pump C2, and enabling the aqueous phase solution in the visible container A to flow into the upper part of a second piston container F; when the water phase solution in the visible container A completely flows into the upper part of the piston container II F, the constant-speed constant-pressure pump I C1 and the constant-speed constant-pressure pump II C2 are closed manually or through a computer L, a valve II T2, a valve IV T4 and a valve VI T6 are closed, and the connection of a quick joint II E2 and a quick joint VI E6 is disconnected; when the microemulsion is a lower phase microemulsion or a single phase microemulsion, the operation of the step one is not required.

And step two, filling a micropore medium required by an experiment into the micropore device N, enabling a piston in the visible piston container K to be positioned at the top, connecting a quick joint II E2 and a quick joint III E7, and setting a constant-speed constant-pressure pump I C1 to work in a constant-speed mode manually or through a computer L, wherein the constant speed is the speed required by the experiment, the constant-speed constant-pressure pump IV C4 works in a constant-pressure mode, and the constant pressure is the pressure required by the experiment.

And step three, opening a valve II T2, a valve ten T10 and a valve eleven T11, manually or through a computer L, starting a constant-speed constant-pressure pump I C1, a constant-speed constant-pressure pump IV C4, a light source II K3 and a microscope camera II K4, allowing the microemulsion in the visual container A to pass through a micropore device N and enter a visual piston container K, and recording a pressure value P1 of a pressure gauge I until the injection amount or the injection pressure of the microemulsion reaches the experimental requirements. And manually or through a computer L, closing the first constant-speed constant-pressure pump C1 and the fourth constant-speed constant-pressure pump C4, and closing a valve I T1, a valve II T2, a valve III T3, a valve ten T10 and a valve eleven T11. The pressure of the microemulsion passing through the micropore medium is the capacity of passing through the micropore medium, and the pressure value is the difference value between a pressure gauge P1 pressure value and a constant-speed constant-pressure pump four C4 constant pressure.

And step four, in the process that the microemulsion flows through the micropore device N, the computer L controls the light source II K3 and the microscope camera II K4 to move on the sliding track, the height and the position relation of the microemulsion, the oil phase and the water phase entering the visible piston container K is shot through the triangular prism II K5 and the visible piston container window K2, the type and the volume of the microemulsion are judged, and meanwhile, microscopic images of the microemulsion at different positions are shot until the experiment is finished.

Example 5:

a method for evaluating the performance of microemulsion for oil displacement comprises the following steps:

step one, when the microemulsion is an upper phase microemulsion or a middle phase microemulsion, connecting a first quick joint E1 and a third quick joint E3, connecting a second quick joint E2 and a sixth quick joint E6, setting a first constant-speed constant-pressure pump C1 to work in a constant-speed mode manually or through a computer L, wherein the constant speed is the speed required by an experiment, the second constant-speed constant-pressure pump C2 works in a constant-pressure mode, and the constant pressure is a pressure value P1 of a pressure gauge. Opening a first valve T1, a second valve opening T2, a third valve T3, a fourth valve T4 and a sixth valve T6, manually or through a computer L, opening a first constant-speed constant-pressure pump C1 and a second constant-speed constant-pressure pump C2, and enabling the aqueous phase solution in the visible container A to flow into the upper part of a second piston container F; when all the water phase solution in the visual container A flows into the upper part of the piston container II F, the constant-speed constant-pressure pump I C1 and the constant-speed constant-pressure pump II C2 are closed manually or through a computer L, a valve I T1, a valve II T2, a valve III T3, a valve IV T4 and a valve VI T6 are closed, and the connection of a quick joint II E2 and a quick joint VI E6 is disconnected; when the microemulsion is a lower phase microemulsion or a single phase microemulsion, the operation of the step one is not required.

And secondly, selecting a core according to the experimental requirements, measuring the appearance size and the volume of saturated water of the core, filling the saturated water core into a transparent rubber sleeve M3 of the microscopic visual device M, and injecting transparent annular pressure liquid M9 between an outer wall M1 of the microscopic visual device and the transparent rubber sleeve M3 through an annular pressure pump M10 to ensure that the annular pressure of the core reaches the experimental required pressure.

And step three, discharging liquid on the upper part of a piston container II F, filling experimental water, similarly discharging liquid on the upper part of a piston container III G, filling an oil sample for saturated oil of the rock core, connecting a quick joint VI E6 and a quick joint VII E7, setting a constant-speed constant-pressure pump III C3 to work in a constant-speed mode manually or through a computer L, wherein the constant speed is the saturated oil speed required by the experiment, the constant-speed constant-pressure pump IV C4 works in a constant-pressure mode, and the constant pressure is the pressure required by the experiment. Opening a valve five T5, a valve six T6, a valve eight T8 and a valve nine T9, manually or through a computer L, opening a constant-speed constant-pressure pump three C3 and a constant-speed constant-pressure pump four C4, enabling oil in a piston container three G to enter a rock core, closing the constant-speed constant-pressure pump three C3 and the constant-speed constant-pressure pump four C4, closing the valve five T5, the valve six T6, the valve eight T8 and the valve nine T9 and disconnecting the quick joint six E6 and the quick joint seven E7 when the oil saturation of the rock core meets the experimental requirements. And discharging the liquid on the visible piston container K to enable the piston to be positioned at the top.

And step four, connecting the quick joint II E2 and the quick joint seven E7, manually or by a computer L, setting the constant-speed constant-pressure pump I C1 to work in a constant-speed mode, wherein the constant speed is the speed of injecting the microemulsion according to the experimental requirement, and the constant-speed constant-pressure pump IV C4 works in a constant-pressure mode, and the constant pressure is the pressure required by the experiment. Opening a first valve T1, a second valve opening T2, a third valve T3, an eighth valve T8 and a ninth valve T9, manually or through a computer L, opening a first constant-speed constant-pressure pump C1, a fourth constant-speed constant-pressure pump C4, a second light source K3, a second microscope camera K4, a third light source M5 and a third microscope camera M6, allowing the micro-emulsion in a visual container A to enter a rock core, displacing oil in the rock core, allowing the produced oil and water to flow into the visual piston container K, recording a first pressure value P1 of a pressure gauge, closing the first constant-pressure pump C1 and the fourth constant-pressure pump C4 when the injection amount of the micro-emulsion meets the experimental requirements, and closing the first valve T1, the second valve opening T2, the third valve T3, the eighth valve T8 and the ninth valve T9.

And step five, in the process of displacing the oil in the rock core by the microemulsion, shooting a dynamic and static microscopic image of the microemulsion displacement oil by a computer L through a triangular prism M7 and a microscopic visual device window M21 by using a light source three M5 and a microscope camera three M6. By adjusting the rotating support M8, the microscope camera III M6 shoots dynamic and static microscopic images of the microemulsion displacement oil at different positions in the same window and different window positions. And in the process of displacing the oil in the rock core by the microemulsion, according to the time interval required by the experiment, the computer L controls the light source II K3 and the microscope camera II K4 to move on the sliding track, the volume of the oil and the volume of the water entering the visible piston container K are shot through the triangular prism II K5 and the visible piston container window K2, and meanwhile, the microscope camera II K4 shoots microscopic images of the oil and the water at different positions until the experiment is finished.

In addition, if other special requirements exist in the experiment, the microemulsion evaluation device and method can be adjusted according to actual conditions so as to meet the experiment requirements.

It will be understood by those skilled in the art that these examples or embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention, and that various equivalent modifications and changes may be made to the present invention without departing from the spirit of the present disclosure.

Claims

1. A microemulsion performance evaluation device for oil displacement comprises an injection system (ZS), a mixing system (HS) and a measurement system (CS); the mixing system (HS) comprises a visual container (A), a constant-speed constant-pressure pump I (C1), a piston container I (D), an oil-water mixing device (J) and a porous medium (H); the top of the visual container (A) is connected with a first valve (T1) and a first pressure gauge (P1) through pipelines, the first valve (T1) is connected with a first quick connector (E1), and the bottom of the visual container (A) is connected with a second quick connector (E2) through pipelines and a second valve (T2); the top of the piston container I (D) is connected with a quick joint III (E3) through a pipeline and a valve III (T3), and the bottom of the piston container I (D) is connected with a constant-speed constant-pressure pump I (C1) through a pipeline; the inlet end of the porous medium (H) is connected with a valve seven (T7) through a pipeline, the outlet end of the porous medium (H) is connected with an oil-water mixing device (J) through a pipeline, and the oil-water mixing device (J) is connected with a quick connector four (E4) through a pipeline; the method is characterized in that: the middle part of the side surface of the visual container (A) is vertically connected with a rotating shaft (B), one end of the rotating shaft (B) is connected with a motor I (B1), the other end of the rotating shaft (B) is connected with a motor II (B2), and the visual container (A) can rotate or vibrate around the rotating shaft (B);

the side face of the visual container (A) is a visual container wall (A1), a visual container window (A2) is arranged on the visual container wall (A1), a first triangular prism (A5) is arranged outside the visual container window (A2), one face of the first triangular prism (A5) is overlapped with the visual container window (A2), a first light source (A3) is arranged outside one face of the other two faces of the first triangular prism (A5), and a first microscope camera (A4) is arranged outside the other face of the other two faces of the first triangular prism (A5); the first light source (A3) is connected with the first light source sliding rail (A7) in a sliding way, and the first microscope camera (A4) is connected with the first microscope camera sliding rail (A6) in a sliding way; the visible container (A) is internally provided with a first electrode group (A8) and a second electrode group (A9), the first electrode group (A8) is connected through an electrode group connecting line (A10), and the second electrode group (A9) is connected through an electrode group connecting line (A11).

2. The microemulsion performance evaluation device for oil displacement according to claim 1, wherein the measuring system (CS) comprises a microscopic visual device (M), a micropore device (N), a visual piston container (K) and a constant-speed constant-pressure pump four (C4); the inlet of the microscopic visual device (M) is connected with a quick coupling seven (E7) through a pipeline and a valve eight (T8), and the outlet of the microscopic visual device (M) is connected with a valve nine (T9) through a pipeline; the inlet of the micropore device (N) is connected with a quick connector seven (E7) through a pipeline and a valve ten (T10), and the outlet of the micropore device (N) is connected with a valve eleven (T11) through a pipeline; the top of the visual piston container (K) is connected with a valve nine (T9) and a valve eleven (T11) through pipelines, and the bottom of the visual piston container (K) is connected with a constant-speed constant-pressure pump four (C4) through pipelines.

3. The microemulsion performance evaluation device for oil displacement according to claim 2, wherein the microscopic visual device (M) comprises a microscopic visual device outer wall (M1), a microscopic visual device window I (M21), a transparent rubber sleeve (M3), a light source III (M5), a microscope camera III (M6), a triangular prism III (M7) and a ring pressure pump (M10); a transparent rubber sleeve (M3) is arranged inside the outer wall (M1) of the microscopic visual device, transparent annular pressure liquid (M9) is arranged between the outer wall (M1) of the microscopic visual device and the transparent rubber sleeve (M3), a rock core (M4) is wrapped inside the transparent rubber sleeve (M3), and the transparent annular pressure liquid (M9) is connected with an annular pressure pump (M10) through a pipeline; the micro visual device comprises a micro visual device outer wall (M1), a micro visual device window I (M21) is arranged on the micro visual device outer wall (M1), a triangular prism III (M7) is arranged outside the micro visual device window I (M21), one surface of the triangular prism III (M7) is overlapped with the micro visual device window I (M21), a light source III (M5) is arranged outside one surface of the other two surfaces of the triangular prism III (M7), and a microscope camera III (M6) is arranged outside the other surface of the other two surfaces of the triangular prism III (M7).

4. The microemulsion performance evaluation device for oil displacement according to claim 3, wherein the micro-visual device outer wall (M1) is further provided with a micro-visual device window two (M22), a micro-visual device window three (M23) and/or a micro-visual device window four (M24); the light source III (M5), the microscope camera III (M6) and the triangular prism III (M7) are respectively connected with the rotating bracket (M8), the rotating bracket (M8) can rotate around the outer wall (M1) of the microscopic visual device, and the rotating bracket (M8) can also horizontally move on the outer wall (M1) of the microscopic visual device.

5. The microemulsion performance evaluation device for oil displacement according to claim 4, wherein the side of the visible piston container (K) is a visible piston container wall (K1), a visible piston container window (K2) is arranged on the visible piston container wall (K1), a triangular prism II (K5) is arranged outside the visible piston container window (K2), one surface of the triangular prism II (K5) is overlapped with the visible piston container window (K2), a light source II (K3) is arranged outside one surface of the other two surfaces of the triangular prism II (K5), a microscope camera II (K4) is arranged outside the other surface of the other two surfaces of the triangular prism II (K5), the light source II (K3) is in sliding connection with the light source II sliding track (K7), and the microscope camera II (K4) is in sliding connection with the microscope camera II sliding track (K6).

6. The microemulsion performance evaluation device for oil displacement according to claim 5, wherein the injection system (ZS) comprises a piston container II (F), a piston container III (G), a constant-speed constant-pressure pump II (C2) and a constant-speed constant-pressure pump III (C3); the top of the piston container II (F) is connected with a valve five (T5), a valve six (T6), a valve seven (T7) and a pressure gauge II (P2) through a pipeline and a valve four (T4), and the bottom of the piston container II (F) is connected with a constant-speed and constant-pressure pump II (C2) through a pipeline; the top of the piston container III (G) is connected with a valve IV (T4), a valve VI (T6), a valve VII (T7) and a pressure gauge II (P2) through a pipeline and a valve V (T5), and the bottom of the piston container III (G) is connected with a constant-speed constant-pressure pump III (C3) through a pipeline; the valve six (T6) is connected with the quick connector six (E6) through a pipeline, and the valve seven (T7) is connected with the porous medium (H) through a pipeline.

7. The microemulsion performance evaluation device for oil displacement according to claim 6, wherein the micropore medium inside the micropore device (N) is one or more of a rock core, a microfiltration membrane and a micropore metal mesh; the oil-water mixing device (J) is one or more of a homogenizer, an ultrasonic mixing device and a high-speed stirrer; the porous medium (H) is a screen or a porous plate; the core (M4) is one of a natural core, an artificial core, and a beret core.

8. The microemulsion performance evaluation device for oil displacement according to claim 7, wherein the injection system (ZS), the mixing system (HS) and the measurement system (CS) are in a thermostat (R); the microscope camera comprises a light source I (A3), a microscope camera I (A4), an electrode group connecting line (A10), an electrode group II connecting line (A11), a motor I (B1), a motor II (B2), a constant-speed constant-pressure pump I (C1), a constant-speed constant-pressure pump II (C2), a constant-speed constant-pressure pump III (C3), a constant-speed constant-pressure pump IV (C4), an oil-water phase mixing device (J), a light source II (K3), a microscope camera II (K4), a light source III (M5), a microscope camera III (M6), a ring pressure pump (M10), a pressure gauge I (P1), a pressure gauge II (P2) and a thermostat (R) which are electrically connected with a computer (L).

9. The method for evaluating the performance of the microemulsion for flooding by adopting the microemulsion performance evaluation device for flooding of claim 8 is characterized by comprising the following steps of:

opening a constant temperature box (R) to raise the temperature to the temperature required by the experiment, closing all valves, filling gas with the pressure required by the experiment into the upper part of a piston container I (D), filling a water phase solution for forming microemulsion into the upper part of a piston container II (F), and filling an oil phase solution for forming microemulsion into the upper part of a piston container III (G);

step two, connecting a first quick joint (E1) and a third quick joint (E3), connecting a second quick joint (E2) and a fourth quick joint (E4), opening a first valve (T1) and a third valve (T3), setting a first constant-speed constant-pressure pump (C1) to work in a constant-pressure mode, preparing microemulsion pressure by taking constant pressure as an experimental requirement, and starting the first constant-speed constant-pressure pump (C1);

step three, setting a second constant-speed constant-pressure pump (C2) and a third constant-speed constant-pressure pump (C3) to work in a constant-speed mode, wherein the constant speed is the speed required by the experiment, starting the second constant-speed constant-pressure pump (C2) and the third constant-speed constant-pressure pump (C3), opening a valve IV (T4), a valve V (T5) and a valve VII (T7), and when the reading of a second pressure gauge (P2) is the same as that of the first pressure gauge (P1), starting a valve II (T2);

step four, the water phase solution in the piston container II (F) and the oil phase solution in the piston container III (G) enter a porous medium (H) and an oil-water mixing device (J) through pipelines and enter a visual container (A), when the injection amount of the water phase solution in the piston container II (F) and the oil phase solution in the piston container III (G) meets the experimental requirements, a constant-speed constant-pressure pump I (C1), a constant-speed constant-pressure pump II (C2) and a constant-speed constant-pressure pump III (C3) are closed, all valves are closed, the connection between a quick connector I (E1) and the quick connector III (E3) is disconnected, and the connection between the quick connector II (E2) and the quick connector IV (E4) is disconnected;

step five, setting the working mode of the motor I (B1) and/or the motor II (B2) to be rotation or vibration according to the experimental requirements, and starting the motor I (B1) and/or the motor II (B2) until the experimental required time to obtain the microemulsion solution;

sixthly, turning on a first light source (A3) and a first microscope camera (A4), controlling the first light source (A3) and the first microscope camera (A4) to move on a sliding track through a computer (L), shooting the heights and the position relations of the microemulsion, the oil phase and the water phase in a visible container (A) through a triangular prism (A5) and a visible container window (A2), judging the type of the microemulsion, calculating the volume of the microemulsion, the volume of the water phase and the volume of the oil phase, calculating the interfacial tension of the microemulsion in the phase, and shooting microscopic images of the microemulsion at different positions; controlling a first light source (A3) and a first microscope camera (A4) to shoot the heights, the position relation and the microscopic images of the microemulsion, the oil phase and the water phase in the visible container (A) by the computer (L) according to the time interval required by the experiment until the experiment is finished;

seventhly, opening the first electrode group (A8) and the second electrode group (A9), controlling different electrode pairs on a first electrode group connecting line (A10) and a second electrode group connecting line (A11) by the computer (L) to measure the conductivity of the microemulsion, and calculating the volume of the water phase in the microemulsion; the volume of the aqueous phase in the microemulsion was calculated by measuring the conductivity of the microemulsion by controlling the different electrode pairs on the electrode set one line (a 10) and the electrode set two line (a 11) by the computer (L) at the time intervals required for the experiment.

10. The method for evaluating the performance of the microemulsion for flooding by adopting the microemulsion performance evaluation device for flooding of claim 8 is characterized by comprising the following steps of:

step one, when the microemulsion is an upper phase microemulsion or a middle phase microemulsion, connecting a first quick joint (E1) and a third quick joint (E3), connecting a second quick joint (E2) and a sixth quick joint (E6), setting a first constant-speed constant-pressure pump (C1) to work in a constant-speed mode, wherein the constant speed is the speed required by the experiment, a second constant-speed constant-pressure pump (C2) works in a constant-pressure mode, and the constant pressure is the pressure value of a first pressure gauge (P1); opening a first valve (T1), a second valve (T2), a third valve (T3), a fourth valve (T4) and a sixth valve (T6), starting a first constant-speed constant-pressure pump (C1) and a second constant-speed constant-pressure pump (C2), and enabling the water phase solution in the visible container (A) to flow into the upper part of a second piston container (F); when all the water phase solution in the visual container (A) flows into the upper part of the piston container II (F), the constant-speed constant-pressure pump I (C1) and the constant-speed constant-pressure pump II (C2) are closed, the valve I (T1), the valve II (T2), the valve III (T3), the valve IV (T4) and the valve VI (T6) are closed, and the quick joint II (E2) and the quick joint VI (E6) are disconnected; when the microemulsion is a lower phase microemulsion or a single phase microemulsion, the operation of the first step is not needed;

secondly, selecting a rock core according to the experiment requirement, measuring the appearance size and the saturated water volume of the rock core, filling the rock core with saturated water into a transparent rubber sleeve (M3) of a microscopic visual device (M), and injecting transparent annular pressure liquid (M9) between the outer wall (M1) of the microscopic visual device and the transparent rubber sleeve (M3) through an annular pressure pump (M10) to ensure that the annular pressure of the rock core reaches the experiment requirement pressure;

step three, discharging liquid on the upper part of the piston container II (F), filling oil displacement experiment water, similarly discharging liquid on the upper part of the piston container III (G), and filling an oil sample for rock core saturated oil; connecting a quick joint six (E6) and a quick joint seven (E7), setting a constant-speed constant-pressure pump three (C3) to work in a constant-speed mode, wherein the constant speed is the saturated oil speed required by the experiment, setting a constant-speed constant-pressure pump four (C4) to work in a constant-pressure mode, and the constant pressure is the pressure required by the experiment; opening a valve five (T5), a valve six (T6), a valve eight (T8) and a valve nine (T9), starting a constant-speed constant-pressure pump three (C3) and a constant-speed constant-pressure pump four (C4), enabling oil in a piston container three (G) to enter a rock core, closing the constant-speed constant-pressure pump three (C3) and the constant-speed constant-pressure pump four (C4), closing the valve five (T5), the valve six (T6), the valve eight (T8) and the valve nine (T9) when the oil saturation of the rock core meets the experimental requirements, and disconnecting the quick joint six (E6) and the quick joint seven (E7); discharging the liquid at the upper part of the visible piston container (K) to enable the piston to be positioned at the top;

step four, connecting a quick joint II (E2) and a quick joint VII (E7), setting a constant-speed constant-pressure pump I (C1) to work in a constant-speed mode, wherein the constant speed is the speed of injecting the microemulsion required by the experiment, and setting a constant-speed constant-pressure pump IV (C4) to work in a constant-pressure mode, and the constant pressure is the pressure required by the experiment; opening a first valve (T1), a second valve opening (T2), a third valve (T3), an eighth valve (T8) and a ninth valve (T9), opening a first constant-speed constant-pressure pump (C1), a fourth constant-speed constant-pressure pump (C4), a second light source (K3), a second microscope camera (K4), a third light source (M5) and a third microscope camera (M6), allowing a microemulsion in a visual container (A) to enter a rock core, displacing oil in the rock core, allowing produced oil and water to flow into the visual piston container (K), recording a first pressure gauge (P1) pressure value, and closing the first constant-pressure pump (C1) and the fourth constant-speed constant-pressure pump (C4) when the injection amount of the microemulsion reaches the experimental requirement, closing the first valve (T1), the second valve opening (T2), the third valve (T3), the eighth valve (T8) and the ninth valve (T9);

step five, in the process of displacing the oil in the rock core by the microemulsion, the computer (L) controls a light source III (M5) and a microscope camera III (M6) to shoot dynamic and static microscopic images of the microemulsion displacement oil through a triangular prism (M7) and a microscopic visual device window I (M21); adjusting the rotary bracket (M8) to enable the microscope camera III (M6) to shoot dynamic and static microscopic images of the microemulsion displacement oil at different positions in the same window and at different window positions; in the process of displacing oil in the rock core by the microemulsion, according to the time interval required by the experiment, the computer (L) controls a second light source (K3) and a second microscope camera (K4) to move on the sliding track, the volume of the oil and the volume of water entering a visible piston container (K) are shot through a second triangular prism (K5) and a visible piston container window (K2), and meanwhile, the second microscope camera (K4) shoots microscopic images of the oil and the water at different positions until the experiment is finished;