CN106525655A - A device and method for gas-liquid injection simulated oil displacement and fluid performance measurement - Google Patents

Abstract

The invention provides a device and method for gas-liquid injection simulation of oil displacement and fluid performance measurement. The device includes a model system for simulating reservoirs, an injection system for injecting displacement medium into the model system, and metering and collection of effluent from the model system. The effluent metering collection system and the measurement system for obtaining fluid properties in the core, the measurement system includes: a first mass flow meter and a first visible capillary, a second mass flow meter and a second visible capillary. The device of the present invention measures the fluid form and kinematic viscosity of the fluid before entering the rock core, in different layers and different positions in the rock core, and after flowing out of the rock core by setting a visible capillary, a mass flow meter and a differential pressure sensor, which is helpful for analyzing the injected fluid or The movement state and speed of the injected fluid mixed with crude oil in the formation provide technical support for the study of fluid migration laws and oil displacement mechanisms; the flow velocity and flow rate of gas, liquid or gas-liquid mixture fluids are accurately measured by mass flowmeters.

Description

A device and method for gas-liquid injection simulated oil displacement and fluid performance measurement

technical field

The invention belongs to the field of petroleum engineering and process technology, and specifically relates to a device and method for simulated oil displacement by gas-liquid injection, which is suitable for laboratory environments and can realize gas-liquid injection alternately or simultaneously. The simulated oil displacement device and method can also directly Realize the measurement of fluid properties.

Background technique

Petroleum is a non-renewable energy source, and economically and effectively developing existing oil fields is an eternal subject. Water flooding can increase the recovery rate by 1/3-1/5. All major oil fields in my country are in the late stage of water flooding, but more than half of the geological reserves of oil still remain underground. It is necessary to carry out effective tertiary oil recovery technology, which can make my country Oil production increased by 10%-20%. Chemical flooding technology is the most widely used and most mature technology in tertiary oil recovery, and the results of physical simulation flooding experiments are the main basis for judging whether chemical flooding can be applied in the field.

At present, physical simulation oil flooding experimental devices are mainly designed for the needs and characteristics of polymer flooding, ASP flooding or gas flooding experiments, while there are few physical simulation oil flooding devices specially designed for gas-liquid alternate injection, and most of them are made of The modification of the above devices has problems such as large pressure fluctuations when gas-liquid alternates, and inaccurate gas flow measurement.

Contents of the invention

The object of the present invention is to solve the above problems and provide a gas-liquid injection simulated oil displacement and fluid performance measurement device suitable for laboratory environment, which can realize gas-liquid injection alternately or simultaneously.

Above-mentioned purpose of the present invention is achieved by the following technical solutions:

A gas-liquid injection simulated oil displacement and fluid performance measurement device, including a model system for simulating reservoirs, an injection system for injecting displacement media into the model system, and an effluent metering and acquisition system for metering and collecting the effluent of the model system, the The model system includes a core holder (A), and also includes a measurement system for obtaining fluid properties in the core, and the measurement system includes:

The first mass flowmeter (H1) and the first visual capillary (G5), the two are connected in series at the core holder inlet (A1) end of the core holder (A), the first mass flowmeter (H1) The inlet end is provided with a first pressure sensor (P1); the inlet end of the first mass flow meter (H1) is connected to the injection system;

The second mass flow meter (H2) and the second visual capillary (G6), both are connected in series to the core holder outlet (A8) of the core holder (A) through the pneumatic valve (K24), and the core fluid collection The points (A2-A7) are respectively connected to the inlet port of the second mass flowmeter (H2) through the pneumatic valve (K18-K23), and the inlet port of the second mass flowmeter (H2) is provided with the fifth pressure sensor (P7); the second The outlet end of the visual capillary (G6) is connected to the effluent metering collection system.

The above-mentioned gas-liquid is injected into the simulated oil displacement and fluid performance measurement device, and the effluent metering and collection system includes a first back pressure valve (B1), a second back pressure valve (B2), a pneumatic valve (K3), a pneumatic valve (K25 ) and the oil-gas-water metering device (D), the outlet end of the second visible capillary (G6) is connected to the oil-gas-water metering device (D) through the second back pressure valve (B2) and the pneumatic valve (K25) sequentially, and the core is clamped The outlet (A8) of the core holder (A) is connected to the oil, gas and water metering device (D) through the first back pressure valve (B1) and the pneumatic valve (K3) in sequence.

The above-mentioned gas-liquid is injected into the simulated oil displacement and fluid performance measurement device, the first visible capillary (G5) is located at the core holder inlet (A1) end of the core holder (A) and connected to the pipeline, along the first A first light source (G3) is arranged on one side parallel to the length direction of the visible capillary (G5), and a first high-power camera (G7) is arranged on the other side, and a parallel connection between the entrance and the outlet of the first visible capillary (G5) is provided. The first differential pressure sensor (P5) is used to measure the pressure difference between the inlet and outlet of the first visible capillary (G5).

The above-mentioned gas-liquid is injected into the device for simulating oil displacement and fluid performance measurement, and the second visible capillary (G6) is located at the end of the outlet (A8) of the core holder and connected to the pipeline, parallel to the length direction of the second visible capillary (G6). One side is provided with a second light source (G4), the other side is provided with a second high-power camera (G8), and a second differential pressure sensor (P6) is connected in parallel between the inlet and outlet of the second visible capillary (G6).

The above-mentioned gas-liquid injection into the device for simulating oil displacement and fluid performance measurement, the injection system includes a gas injection system for injecting gas into the model system and a liquid injection system for injecting liquid into the model system.

The above-mentioned gas-liquid injection simulates oil displacement and fluid performance measurement device, and the gas injection system includes:

A first gas piston container L1 and a second gas piston container L2 connected in parallel, wherein,

The upper opening of the first gas piston container (L1) is provided with a pneumatic valve (K10) and a third pressure sensor (P3) for measuring the internal gas pressure of the first gas piston container (L1). The upper opening of (L1) is connected to the first emptying pipe (U1) through the pneumatic valve (K11); the lower opening of the first gas piston container (L1) is connected to the second constant pressure and constant speed pump through the pneumatic valve (K14) (R2), connected to the third liquid receiving container (F3) through a pneumatic valve (K16);

The upper opening of the second gas piston container (L2) is provided with a pneumatic valve (K9) and a fourth pressure sensor (P4) for measuring the internal gas pressure of the second gas piston container (L2), and the second gas piston container (L2 ) through the pneumatic valve (K12) and the second emptying pipe (U2); the lower end of the second gas piston container (L2) is connected to the third constant pressure constant speed pump (R3) through the pneumatic valve (K13) ), connected to the third liquid receiving container (F3) through a pneumatic valve (K17);

A high-pressure gas cylinder (N) for storing high-pressure gas, the high-pressure gas cylinder (N) is connected to a gas booster pump (M) through a pneumatic valve (K8), and the gas booster pump (M) is connected to a gas booster pump (M) through a pneumatic valve (K7) is connected to the junction of pneumatic valve (K9) and pneumatic valve (K10), and the junction of pneumatic valve (K7, K9, K10) is connected to the inlet of the first mass flow meter (H1) through pneumatic valve (K6) end.

The above-mentioned gas-liquid injection simulated oil displacement and fluid performance measurement device, the liquid injection system includes a liquid piston container (E), and the upper end inlet of the liquid piston container (E) is provided with a device for measuring the liquid piston container (E). The second pressure sensor (P2) for liquid pressure, the upper opening of the liquid piston container (E) is respectively connected to the first liquid receiver (F1) via a pneumatic valve (K2) and to the first mass flow rate via a pneumatic valve (K5). The inlet end of the gauge (H1); the lower opening of the liquid piston container (E) is connected to the first constant pressure constant speed pump (R1) through the pneumatic valve (K4), and is connected to the second liquid receiving port through the pneumatic valve (K15). Containers (F2) are connected.

The above-mentioned gas-liquid is injected into the simulated oil displacement and fluid performance measurement device, the core holder (A), the first back pressure valve (B1), the second back pressure valve (B2), the oil, gas and water metering device (D), Liquid piston container (E), liquid receiving container (F1), first mass flow meter (H1), second mass flow meter (H2), first gas piston container (L1), second gas piston container (L2) and Both the first light-tight box (G1) and the second light-tight box (G2) are placed in the thermostatic box (Q).

The above-mentioned gas-liquid is injected into the simulated oil displacement and fluid performance measurement device, the first mass flowmeter (H1), the second mass flowmeter (H2), the pneumatic valve (K1-K25), each pressure sensor (P1-P4, P7), each differential pressure sensor (P4, P5), constant temperature box (Q), each constant pressure and constant speed pump (R1-R3), the first light source (G3), the second light source (G4), the first high-power camera ( G7), the second high power camera (G8), and the gas booster pump M are all electrically connected to the computer (W).

The present invention also provides a gas-liquid injection simulated oil displacement and a method for measuring fluid performance. The method uses the above-mentioned gas-liquid injection simulated oil displacement and fluid performance measurement device to perform a gas-liquid injection simulated oil displacement experiment and measure the fluid performance in the core. Include the following steps:

Step 1: Put the three-layer heterogeneous oil-bearing core into the core holder (A), put the liquid into the liquid piston container (E), and the gas type in the high-pressure gas cylinder (N) meets the requirements of the simulated oil displacement experiment. Design, the pistons in the first gas piston container (L1) and the second gas piston container (L2) are located at the top, all pneumatic valves are closed, and the computer (W) controls the thermostat (Q) to heat up to the pre-simulation oil displacement experiment. Set the temperature; the computer (W) controls the opening of the first light source (G3) and the second light source (G4), and controls the opening of the first high-power camera (G7) and the second high-power camera (G8);

Step 2: The computer (W) controls the opening of the pneumatic valves (K8, K7, K10, K16), and the gas in the high-pressure cylinder (N) enters the first stage through the gas booster pump (M) and the pneumatic valves (K8, K7, K10). In a gas piston container (L1), when the piston in the first gas piston container (L1) is pushed to the bottom, the computer (W) controls the pneumatic valves (K10, K16) to close; the computer (W) controls the pneumatic valves (K9, K17) is opened, the gas in the high-pressure cylinder (N) enters the second gas piston container (L2) through the booster pump (M) and the pneumatic valve (K8, K7, K9), when the second gas piston container (L2) The piston in the cylinder is pushed to the bottom, and the computer (W) controls the pneumatic valves (K8, K7, K9, K17) to close;

Step 3: Set the pressure value of the first back pressure valve (B1) according to the back pressure designed in the simulated oil displacement experiment, the computer (W) controls the opening of the pneumatic valves (K4, K13, K14), and the computer (W) controls the first constant The pressure and constant speed pump (R1), the second constant pressure and constant speed pump (R2) and the third constant pressure and constant speed pump (R3) respectively control the liquid piston container (E), the first gas piston container (L1), the second gas The piston container (L2) is pressurized, when the pressure value of the second pressure sensor (P2), the third pressure sensor (P3) or the fourth pressure sensor (P4) is equal to the pressure value of the first back pressure valve (B1), The computer (W) controls the corresponding constant pressure constant speed pump to stop;

Step 4: Inject the oil-displacing medium into the oil-bearing core in the core holder (A) by means of alternate gas-liquid injection or simultaneous gas-liquid injection. During the injection process, the computer (W) passes through the first high-power camera (G7) and the first light source (G3) to observe the flow state of the gas, liquid or gas-liquid mixture, and at the same time combine the values of the first mass flow meter (H1) and the first differential pressure sensor (P5) to calculate the flow rate of the gas, liquid or gas-liquid mixture Kinematic viscosity; the computer (W) controls one of the pneumatic valves (K18-K24) to open, and sets the pressure of the back pressure valve (B2) equal to the pressure value of the fifth pressure sensor (P7), through the second high-power camera (G8) And the second light source (G4) can observe the fluid flow state corresponding to the three-layer heterogeneous core fluid collection point (A2-A7) and the core holder outlet (A8), also combined with the second mass flowmeter (H2) and the first The numerical value of the second pressure difference sensor (P6) calculates the kinematic viscosity of the fluid at the collection point until the injection time designed for the simulated oil displacement experiment is met.

In the above gas-liquid injection simulated oil displacement and fluid performance measurement method, the gas-liquid simultaneous injection method in step 4 includes the following steps:

The computer (W) controls the opening of the pneumatic valves (K3, K5, K6, K10), and the computer (W) controls the first constant-pressure constant-speed pump (R1) and the second constant-pressure constant-speed pump (R2) to simulate oil displacement experimental design The gas-liquid ratio and injection speed are used to inject liquid and gas. When the injection time of the simulated oil displacement experiment is met, the computer (W) controls the pneumatic valves (K3, K5, K6, K10) to close and stop the first constant pressure and constant speed pump. (R1) and the second constant pressure and constant speed pump (R2); during the experiment, the computer (W) records the pressure value of the first pressure sensor (P1) and the flow rate and injection time of the first mass flow meter (H1) foam fluid , and record the volume of oil, gas and water in the oil, gas and water metering device (D) in real time.

In the above gas-liquid injection simulated oil displacement and fluid performance measurement method, the gas-liquid alternate injection method in step 4 includes the following steps alternately:

(1) When liquid is injected, the computer (W) controls the opening of the pneumatic valves (K3, K4, K5), and the computer (W) controls the first constant pressure and constant speed pump (R1) to inject the liquid at a constant speed designed for the simulated oil flooding experiment , when the injection time designed for the simulated oil displacement experiment is met, the computer (W) controls the pneumatic valve (K5) to close, and stops the first constant-pressure constant-speed pump (R1); the computer (W) simultaneously records the first time when the liquid is injected The value of the pressure sensor (P1), the liquid injection time and speed, the liquid injection speed measured by the first mass flow meter (H1) corrects the injection speed recorded by the first constant pressure constant speed pump (R1);

During the liquid injection process, the computer (W) simultaneously controls the pneumatic valves (K13, K14) to open, and respectively compares the pressure values of the third pressure sensor (P3), the fourth pressure sensor (P4) with the first pressure sensor (P1) The size of the pressure value, that is, when the pressure value of the third pressure sensor (P3) is greater than the pressure value of the first pressure sensor (P1), the computer (W) controls the pneumatic valve (K11) to open, and the gas is discharged from the first exhaust pipe (U1) discharge until the pressure value of the third pressure sensor (P3) is equal to the pressure value of the first pressure sensor (P1), close the pneumatic valve (K11); when the pressure value of the third pressure sensor (P3) is less than the first When the pressure value of the pressure sensor (P1), the computer (W) controls the second constant pressure constant speed pump (R2) to pressurize the first gas piston container (L1), until the pressure value of the third pressure sensor (P3) is equal to the first Until the pressure value of the first pressure sensor (P1), stop the pressurization of the second constant pressure constant speed pump (R2); similarly, when the pressure value of the fourth pressure sensor (P4) is greater than the pressure value of the first pressure sensor (P1), The computer (W) controls the pneumatic valve (K12) to open, and the gas is discharged from the second exhaust pipe (U2) until the pressure value of the fourth pressure sensor (P4) is equal to the pressure value of the first pressure sensor (P1), and the pneumatic valve is closed. Valve (K12); when the pressure value of the fourth pressure sensor (P4) was less than the pressure value of the first pressure sensor (P1), the computer (W) controlled the third constant pressure constant speed pump (R3) to the second gas piston container (L2) Pressurize until the pressure value of the fourth pressure sensor (P4) is equal to the pressure value of the first pressure sensor (P1), stop the third constant pressure constant speed pump (R3) to pressurize until the liquid is injected;

(2) When injecting gas, the computer (W) controls the opening of the pneumatic valves (K3, K6, K10), and the computer (W) controls the second constant pressure and constant speed pump (R2) to inject gas at the speed designed for the simulated oil displacement experiment. After satisfying the injection time designed for the simulated oil displacement experiment, the computer (W) controls the pneumatic valves (K6, K10) to close and stops the second constant pressure and constant speed pump (R2); the computer (W) records the first pressure sensor when the gas is injected The value of (P1), gas injection rate and time, the gas injection rate measured by the first mass flow meter (H1) corrects the injection rate recorded by the second constant pressure constant speed pump (R2);

During the gas injection process, the computer (W) compares the pressure value of the fourth pressure sensor (P4) with the pressure value of the first pressure sensor (P1), when the pressure value of the fourth pressure sensor (P4) is greater than the first pressure The pressure value of the sensor (P1), the computer (W) controls the pneumatic valve (K12) to open, and the gas is discharged from the second emptying pipe (U2), until the pressure value of the fourth pressure sensor (P4) is equal to the pressure value of the first pressure sensor (P1 ), close the pneumatic valve (K12); when the pressure value of the fourth pressure sensor (P4) is less than the pressure value of the first pressure sensor (P1), the computer (W) controls the third constant pressure constant speed pump (R3 ) Pressurize the second gas piston container (L2) until the pressure value of the fourth pressure sensor (P4) is equal to the pressure value of the first pressure sensor (P1), stop the third constant pressure constant speed pump (R3) pressurization , until the gas injection is completed, or when the gas volume in the first gas piston container (L1) is used up, the computer (W) controls the pneumatic valve (K9) to open, controls the pneumatic valve (K10) to close and stops the second constant pressure constant speed The pump (R2), the computer (W) controls the third constant pressure constant speed pump (R3) to continue injecting gas at the same speed designed for the simulated oil flooding experiment, and when the injection time of the simulated oil flooding experiment design is satisfied, the computer W controls the pneumatic Valves (K6, K9) close and stop the third constant pressure constant speed pump (R3);

During the gas injection process, the computer (W) compares the pressure value of the second pressure sensor (P2) with the pressure value of the first pressure sensor (P1) at the same time, when the pressure value of the second pressure sensor (P2) is greater than the first When the pressure value of the pressure sensor (P1) is reached, the computer (W) controls the pneumatic valve (K2) to open and discharge excess liquid into the first liquid receiving container (F1) until the pressure value of the second pressure sensor (P2) is equal to the first Close the pneumatic valve (K2) until the pressure value of the pressure sensor (P1); when the pressure value of the second pressure sensor (P2) is lower than the pressure value of the first pressure sensor (P1), the computer (W) controls the first constant pressure constant The speed pump (R1) pressurizes the liquid piston container (E) until the pressure value of the second pressure sensor (P2) is equal to the pressure value of the first pressure sensor (P1), then the first constant pressure constant speed pump (R1) is stopped , until the gas injection is complete.

By adopting the above technical scheme, the technical effect of the present invention is: the device of the present invention can observe the flow of fluid before entering the rock core, in different layers and different positions in the rock core, and after flowing out of the rock core by setting a visible capillary, a mass flow meter and a differential pressure sensor. Fluid form and kinematic viscosity can directly measure fluid properties while simulating oil displacement, which is helpful to analyze the movement state and speed of injected fluid or injected fluid mixed with crude oil in the formation. The mechanism provides technical support; through the second and third constant speed and constant pressure pumps, the pressure of the gas injected into the first gas piston container and the second gas piston container is controlled in real time, so that the gas is injected into the first gas piston container and the second gas piston container The pressure is the same as the injection pressure at the inlet of the core holder, which realizes stable gas injection pressure and high control precision during the gas-liquid injection process; the pressure of the liquid injected into the liquid piston container is controlled in real time by the first constant speed and constant pressure pump, so that the liquid piston The pressure of the liquid injected in the container is the same as the injection pressure at the inlet of the core holder, which realizes the stable liquid injection pressure and high control precision during the gas-liquid injection process; the flow rate and flow rate of gas, liquid or gas-liquid mixture fluid are accurately measured by the mass flow meter .

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the present invention.

The reference signs in the figure represent:

A: core holder, A1: core holder inlet, A8: core holder outlet. A2-A7: core fluid collection points;

B1: first back pressure valve, B2: second back pressure valve; D: oil, gas and water metering device; G1: first light-tight sealing box, G2: second light-tight sealing box; G3: first light source, G4 : the second light source; G5: the first visible capillary, G6: the second visible capillary; G7: the first high-power camera, G8: the second high-power camera; H1: the first mass flow meter, H2: the second mass flow meter ;

E: liquid piston container; F1: first liquid receiver, F2: second liquid receiver, F3: third liquid receiver; K1-K25: pneumatic valve; L1: first gas piston container, L2: second gas Piston container; M: gas booster pump; N: high pressure cylinder; U1: first emptying pipe, U2: second emptying pipe; P1: first pressure sensor, P2: second pressure sensor, P3: third Pressure sensor, P4: fourth pressure sensor; P5: first differential pressure sensor, P6: second differential pressure sensor; P7: fifth pressure sensor; Q: constant temperature box;

R1: the first constant pressure and constant speed pump, R2: the second constant pressure and constant speed pump, R3: the third constant pressure and constant speed pump; W: computer.

detailed description

The gas-liquid injection simulated oil displacement and fluid performance measurement device and method of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Gas-liquid injection simulated oil displacement and fluid performance measurement device

As shown in Figure 1, it is the embodiment of the gas-liquid injection simulated oil displacement and fluid performance measurement device of the present invention, which is a kind of simulation and measurement device suitable for laboratory environment (thick line represents physical pipeline connection, thin line Indicates the electrical connection), including the model system for simulating the oil reservoir, the gas injection system for injecting gas into the model system, the liquid injection system for injecting liquid into the model system, the effluent metering and acquisition system for metering and collecting the effluent of the model system, and the A measurement system for obtaining fluid properties in rock cores, wherein:

The model system in this embodiment is the core holder A used to make rock core samples of different oil levels and as a container for placing samples. It has a core holder inlet connected to the gas injection system, liquid injection system and measurement system. A1, the outlet A8 of the core holder connected to the measurement system. The cores placed in the core holder A are the upper, middle and lower layers of heterogeneous cores. The three layers of heterogeneous cores share the same core holder inlet A1 to inject fluid and the same core holder outlet A8 to produce fluid. For each layer of the heterogeneous core in the middle and lower three layers, core fluid collection points A2-A7 are set at one-third of the core length direction, which are used to assist in the study of fluid migration laws and oil displacement mechanisms.

The gas injection system in this embodiment includes a high-pressure gas cylinder N for storing high-pressure gas, and a first gas piston container L1 and a second gas piston container L2 connected in parallel. The upper end opening of the first gas piston container L1 is provided with a second Three pressure sensors P3 are used to measure the gas pressure inside the first gas piston container L1; the upper opening of the first gas piston container L1 communicates with the first emptying pipe U1 through the pneumatic valve K11 to discharge gas and reduce the first The pressure of the gas in the gas piston container L1; the upper opening of the first gas piston container L1 is also provided with a pneumatic valve K10, which is used to control the communication between the first gas piston container L1 and other components; the lower end opening of the first gas piston container L1 connected to the second constant pressure and constant speed pump R2 through the pneumatic valve K14, and connected to the third liquid receiving container F3 through the pneumatic valve K16, and the third liquid receiving container F3 is used to receive the lower part of the piston in the first and second gas piston containers Liquid, allowing the gas piston container to be filled with high pressure gas.

Similarly, the upper opening of the second gas piston container L2 is provided with a fourth pressure sensor P4 for measuring the gas pressure inside the second gas piston container L2; The two emptying pipes U2 are connected to each other, and are used to discharge gas and reduce the pressure of the gas in the second gas piston container L2; the upper opening of the second gas piston container L2 is also provided with a pneumatic valve K9, which is used to control the second gas piston container The communication between L2 and other components; the lower end opening of the second gas piston container L2 is connected to the third constant pressure and constant speed pump R3 through the pneumatic valve K13, connected to the third liquid receiving container F3 through the pneumatic valve K17, and the third constant pressure and constant speed pump R3. The pump R3 is used to control the gas flow rate and pressure in the second gas piston container L2.

The high-pressure gas cylinder N is connected to a gas booster pump M through a pneumatic valve K8. The gas booster pump M is used to increase the gas pressure. It is connected to the junction of the pneumatic valve K9 and the pneumatic valve K10 through the pneumatic valve K7. The pneumatic valve K7, The junction of K9 and K10 is connected to the inlet port of the first mass flow meter H1 through the pneumatic valve K6.

The liquid injection system in this embodiment includes a liquid piston container E, the upper end of the liquid piston container E is provided with a second pressure sensor P2 for measuring the pressure of the liquid in the liquid piston container E, the upper end of the liquid piston container E is open The first liquid receiver F1 is connected to the first liquid receiver F1 through the pneumatic valve K2 and connected to the inlet port of the first mass flow meter H1 through the pneumatic valve K5 respectively. The first liquid receiver F1 is used to receive the liquid in the liquid piston container E. The lower end opening of the liquid piston container E is connected to the first constant pressure and constant speed pump R1 through the pneumatic valve K4, and connected to the second liquid receiving container F2 through the pneumatic valve K15, wherein the first constant pressure and constant speed pump R1 controls the liquid piston container E The flow rate and pressure of the liquid in the liquid, the second liquid receiving container F2 receives the liquid in the lower part of the piston in the liquid piston container E.

The measurement system in this embodiment includes a first mass flowmeter H1, a second mass flowmeter H2, a first visible capillary G5 and a second visible capillary G6, wherein the first mass flowmeter H1 and the first visible capillary G5 is connected in series to the core holder inlet A1 end of the core holder A, the first pressure sensor P1 is arranged at the inlet end of the first mass flowmeter H1, and the inlet end of the first mass flowmeter H1 is connected to the gas injection system And liquid injection system, used to measure the flow rate of injected gas, liquid or gas-liquid mixture, the first pressure sensor P1 measures the pressure at the inlet port of the first mass flowmeter H1; the second mass flowmeter H2 and the second visual capillary G6 pass through the pneumatic The valve K24 is connected in series to the core holder outlet A8 of the core holder A, and the core fluid collection points A2-A7 are respectively connected to the inlet port of the second mass flowmeter H2 through the pneumatic valves K18-K23, and the second mass flowmeter The fifth pressure sensor P7 is set at the inlet end of H2, and the second mass flow meter H2 is used to measure the flow rate of gas, liquid or gas-liquid mixture flowing out of the core fluid collection point. The outlet end of the second visible capillary G6 is connected to the effluent metering collection system.

The first visible capillary G5 is located at the entrance A1 of the core holder A of the core holder A and is connected to the pipeline (the visible capillary is not set on the pipeline, it is a separate device connected to the pipeline), along the first visible A first light source G3 is provided on one side parallel to the length direction of the visual capillary G5, a first high-power camera G7 is provided on the other side, and a first differential pressure sensor P5 is connected in parallel between the inlet and outlet of the first visible capillary G5 for Measure the pressure difference between the inlet and outlet of the first visible capillary G5, the first visible capillary G5, the first light source G3, the first high-power camera G7 and the first differential pressure sensor P5 are all placed in the first light-tight sealed box In the box of G1, the purpose is to avoid external light interference, make the camera shooting more clear and stable, keep the temperature constant, and improve the measurement accuracy; similarly, the second visible capillary G6 is located at the side of the core holder outlet A8 and connected with the pipeline, along the second One side parallel to the length direction of the visible capillary G6 is provided with a second light source G4, and the other side is provided with a second high-power camera G8, and a second differential pressure sensor P6 is connected in parallel between the inlet and outlet of the second visible capillary G6. The two visible capillaries G6, the second light source G4, the second high-power camera G8 and the second differential pressure sensor P6 are all in the light-tight sealed box G2.

The effluent metering and collection system in this embodiment includes a first back pressure valve B1, a second back pressure valve B2, a pneumatic valve K3, a pneumatic valve K25 and an oil, gas and water metering device D, and the outlet end of the second visual capillary G6 passes through the The second back pressure valve B2 and the pneumatic valve K25 are connected to the oil, gas and water metering device D, and the outlet A8 of the core holder A of the core holder A is connected to the oil, gas and water metering device D through the first back pressure valve B1 and the pneumatic valve K3 in turn, The first back pressure valve B1 and the second back pressure valve B2 are used to control the outlet pressure of the core holder outlet A8 and the second visible capillary G6 respectively, and the oil, gas and water metering device D is used to measure oil, gas and water at different times Extracted volume.

Core holder A, first back pressure valve B1, second back pressure valve B2, oil, gas and water metering device D, liquid piston container E, liquid receiving container F1, first mass flow meter H1, second mass flow meter H2, The first gas piston container L1, the second gas piston container L2, the first light-tight box G1 and the second light-tight box G2 are all placed in the constant temperature box Q, the purpose is to keep the temperature of the injected fluid constant during the experiment, and improve the temperature of the experiment. Accuracy, the heating temperature range of the incubator is 25°C-200°C. And other components are not put into the incubator Q in order to prevent the aging of the instrument and improve the service life and safety of the instrument.

First mass flowmeter H1, second mass flowmeter H2, pneumatic valves K1-K25, pressure sensors P1-P6, constant temperature box Q, constant pressure and constant speed pumps R1-R3, first light source G3, second light source G4 , the first high-power camera G7, the second high-power camera G8, and the gas booster pump M are all electrically connected to the computer W, and the computer W collects the data of the corresponding components, sets the parameters of the corresponding components, and controls the execution of the corresponding components.

The above components form the gas-liquid injection simulated oil displacement and fluid performance measuring device of the present invention according to the above-mentioned connection relationship. In the device, each component that contacts the gas medium and/or liquid medium and the pipelines connecting the components are all resistant to acid and alkali corrosion. And the withstand pressure is above 50MPa; the first mass flowmeter H1 and the second mass flowmeter H2 can choose Foxboro's products, which can measure the mass flow of gas phase, liquid phase and gas-liquid two-phase, the first visible capillary G5 and the second visible capillary G6 can be made of sapphire, with a pressure resistance of more than 50MPa and a temperature resistance of more than 200°C; the volume of the first gas piston container L1 and the second gas piston container L2 is 2000mL or 3000mL. The core pore volume is selected according to the core pore volume. If the core pore volume is less than 200mL, 2000mL is selected. If the core pore volume is greater than 200mL, 3000mL is selected. The volume of the liquid piston container E is 500mL or 1000mL, which is selected according to the core pore volume in the core holder. If the pore volume is less than 200mL, 500mL is selected, and if the core pore volume is greater than 200mL, 1000mL is selected.

Gas-liquid injection simulated oil displacement and fluid performance measurement method

The above-mentioned device can be used to carry out gas-liquid injection simulated oil displacement experiments and to measure the fluid performance in the core. The specific gas-liquid injection simulated oil displacement and fluid performance measurement methods include the following steps:

Step 1: Put the three-layer heterogeneous oil-bearing core into the core holder A, put the liquid into the liquid piston container E, and the gas type in the high-pressure gas cylinder N meets the design of the experiment, the first gas piston container L1 and the second gas piston container The piston in the gas piston container L2 is at the top, all pneumatic valves are closed, and the computer W controls the thermostat Q to be heated to the experimental preset temperature; the computer W controls the first light source G3 and the second light source G4 to be turned on, and controls the first high-magnification The camera G7 and the second high-power camera G8 are turned on and record images of the fluid in the capillary during the whole experiment (to obtain the flow state of the fluid).

Step 2: The computer W controls the opening of the pneumatic valves K8, K7, K10, and K16, and the gas in the high-pressure cylinder N enters the first gas piston container L1 through the gas booster pump M and the pneumatic valves K8, K7, and K10. The piston in the gas piston container L1 is pushed to the bottom, the computer W controls the closing of the pneumatic valves K10 and K16; the computer W controls the opening of the pneumatic valves K9 and K17, and the gas in the high-pressure cylinder N passes through the booster pump M and the pneumatic valves K8 and K7 , K9 into the second gas piston container L2, when the piston in the second gas piston container L2 is pushed to the bottom, the computer W controls the pneumatic valves K8, K7, K9, K17 to close.

Step 3: Set the pressure value of the first back pressure valve B1 according to the back pressure designed in the simulated oil displacement experiment, the computer W controls the opening of the pneumatic valves K4, K13, and K14, and the computer W controls the first constant pressure and constant speed pump R1, the second The constant pressure and constant speed pump R2 and the third constant pressure and constant speed pump R3 pressurize the liquid piston container E, the first gas piston container L1 and the second gas piston container L2 respectively, when the second pressure sensor P2 and the third pressure sensor P3 Or when the pressure value of the fourth pressure sensor P4 is equal to the pressure value of the first back pressure valve B1, the computer W controls the corresponding constant pressure constant speed pump to stop.

Step 4: Inject the oil-displacing medium into the oil-bearing core in the core holder A by using the gas-liquid alternate injection method or the gas-liquid simultaneous injection method. During the injection process, the computer W passes the first high-power camera G7 and the first light source G3 Observe the flow state of gas, liquid or gas-liquid mixture, and combine the value of the first mass flowmeter H1 (fluid flow rate before entering the core) and the value of the first differential pressure sensor P5 (the differential pressure at both ends of the first visible capillary G5) to calculate Kinematic viscosity of gas, liquid or gas-liquid mixture; computer W controls one of pneumatic valve K18-K24 to open, and the pressure of setting back pressure valve B2 is equal to the pressure value of the fifth pressure sensor P7 (core fluid collection point A2-A7 The pressure after flowing out of the core at any collection point), through the second high-power camera G8 and the second light source G4 to observe the fluid flow state corresponding to the three-layer heterogeneous core fluid collection points A2-A7 and the outlet A8 of the core holder, When measuring the fluid properties of the core holder outlet A8, it is necessary to close the pneumatic valve K3, and also combine the second mass flowmeter H2 (fluid flow rate after flowing out of the core) and the second differential pressure sensor P6 value (the two ends of the second visible capillary G6 differential pressure) to calculate the kinematic viscosity of the fluid at the collection point until the injection time designed for the simulated oil displacement experiment is met.

The gas-liquid simultaneous injection method in step 4 includes the following steps:

The computer W controls the opening of the pneumatic valves K3, K5, K6, and K10, and the computer W controls the first constant-pressure constant-speed pump R1 and the second constant-pressure constant-speed pump R2 to simulate the gas-liquid ratio and injection speed designed in the oil displacement experiment. Gas, when the injection time of the simulated oil displacement experiment design is satisfied, the computer W controls the pneumatic valves K3, K5, K6, and K10 to close and stop the first constant-pressure constant-speed pump R1 and the second constant-pressure constant-speed pump R2; The central computer W records the pressure value of the first pressure sensor P1 and the flow rate and injection time of the foam fluid of the first mass flowmeter H1, and records the volume of oil, gas and water in the oil, gas and water metering device D in real time.

The gas-liquid alternate injection method in step 4 includes the following steps carried out alternately:

(1) When injecting the liquid, the computer W controls the opening of the pneumatic valves K3, K4, and K5, and the computer W controls the first constant-pressure constant-speed pump R1 to inject the liquid at a constant speed designed for the simulated oil displacement experiment. After the injection time, the simulated oil displacement computer W controls the pneumatic valve K5 to close and stops the first constant pressure and constant speed pump R1; the computer W simultaneously records the value of the first pressure sensor P1 when the liquid is injected, and the liquid injection time and speed (injection volume = injection time × injection speed), the computer W corrects the injection speed recorded by the first constant pressure and constant speed pump R1 through the liquid injection speed measured by the first mass flowmeter H1 to ensure the accuracy of the injection speed.

During the liquid injection process, the computer W simultaneously controls the pneumatic valves K13 and K14 to open, and respectively compares the pressure values of the third pressure sensor P3 and the fourth pressure sensor P4 with the pressure value of the first pressure sensor P1, that is, when the third When the pressure value of the pressure sensor P3 is greater than the pressure value of the first pressure sensor P1, the computer W controls the opening of the pneumatic valve K11, and the gas is discharged from the first emptying pipe U1 until the pressure value of the third pressure sensor P3 is equal to that of the first pressure sensor P1 close the pneumatic valve K11; when the pressure value of the third pressure sensor P3 is lower than the pressure value of the first pressure sensor P1, the computer W controls the second constant pressure and constant speed pump R2 to pressurize the first gas piston container L1 , until the pressure value of the third pressure sensor P3 is equal to the pressure value of the first pressure sensor P1, stop the second constant pressure constant speed pump R2 pressurization; similarly, when the pressure value of the fourth pressure sensor P4 is greater than the pressure value of the first pressure sensor P1 The computer W controls the pneumatic valve K12 to open, and the gas is discharged from the second exhaust pipe U2 until the pressure value of the fourth pressure sensor P4 is equal to the pressure value of the first pressure sensor P1, and the pneumatic valve K12 is closed; when the fourth pressure sensor P4 is equal to the pressure value of the first pressure sensor P1 When the pressure value of the pressure sensor P4 is lower than the pressure value of the first pressure sensor P1, the computer W controls the third constant pressure constant speed pump R3 to pressurize the second gas piston container L2 until the pressure value of the fourth pressure sensor P4 is equal to the first Stop the third constant pressure and constant speed pump R3 to pressurize until the pressure value of the pressure sensor P1 is reached until the liquid injection is completed.

(2) When injecting gas, the computer W controls the pneumatic valves K3, K6, and K10 to open, and the computer W controls the second constant-pressure constant-speed pump R2 to inject gas at the speed designed for the simulated oil displacement experiment. After a period of time, the simulated oil displacement computer W controls the pneumatic valves K6 and K10 to close and stops the second constant pressure and constant speed pump R2; the computer W records the value of the first pressure sensor P1, the gas injection speed and time when the gas is injected, and the computer W passes through The gas injection rate measured by the first mass flow meter H1 corrects the injection rate recorded by the second constant pressure constant speed pump R2 to ensure the accuracy of the injection rate.

During the gas injection process, the computer W compares the pressure value of the fourth pressure sensor P4 with the pressure value of the first pressure sensor P1, and when the pressure value of the fourth pressure sensor P4 is greater than the pressure value of the first pressure sensor P1, the computer W Control the opening of the pneumatic valve K12, and the gas is discharged from the second emptying pipe U2 until the pressure value of the fourth pressure sensor P4 is equal to the pressure value of the first pressure sensor P1, then close the pneumatic valve K12; when the pressure value of the fourth pressure sensor P4 If the pressure value of the first pressure sensor P1 is lower than the pressure value of the first pressure sensor P1, the computer W controls the third constant pressure constant speed pump R3 to pressurize the second gas piston container L2 until the pressure value of the fourth pressure sensor P4 is equal to the pressure value of the first pressure sensor P1 , stop the third constant pressure and constant speed pump R3 to pressurize until the gas injection is complete, or when the gas volume in the first gas piston container L1 is used up, the computer W controls the opening of the pneumatic valve K9, controls the closing of the pneumatic valve K10 and stops the second The constant pressure and constant speed pump R2, the computer W controls the third constant pressure and constant speed pump R3 to continue injecting gas at the same speed required by the simulated oil flooding experiment. When the gas injection time meets the requirements of the simulated oil flooding experiment, the computer W automatically controls the pneumatic valve K6 , K9 closes and stops the third constant-pressure constant-speed pump R3.

During the gas injection process, the computer W simultaneously compares the pressure value of the second pressure sensor P2 with the pressure value of the first pressure sensor P1, and when the pressure value of the second pressure sensor P2 is greater than the pressure value of the first pressure sensor P1, The computer W controls the opening of the pneumatic valve K2, discharges excess liquid into the first liquid receiving container F1, and closes the pneumatic valve K2 until the pressure value of the second pressure sensor P2 is equal to the pressure value of the first pressure sensor P1; when the second pressure sensor The pressure value of P2 is less than the pressure value of the first pressure sensor P1, the computer W controls the first constant pressure and constant speed pump R1 to pressurize the liquid piston container E until the pressure value of the second pressure sensor P2 is equal to the pressure of the first pressure sensor P1 value, stop the first constant pressure and constant speed pump R1 until the gas injection is complete.

In gas-liquid injection simulated oil displacement and fluid performance measurement method, the core inlet pressure is stable, the flow rate is constant, and there is no fluctuation when the gas-liquid is alternately injected. Mass flow meters can measure the flow rate of trace gases, liquids, and gas-liquid mixtures.

The fluid performance parameters obtained in the gas-liquid injection simulated oil displacement and fluid performance measurement methods include: fluid state (recorded by the first high-power camera G7 and the second high-power camera G8 in the above step four), fluid velocity (in step four by the first high-power camera G8) A mass flow meter H1 and a second mass flow meter H2 record), fluid kinematic viscosity (calculated using the following formula in step 4), pressure (recorded by the first pressure sensor P1 and the fifth pressure sensor P7).

Kinematic viscosity is calculated by the formula Poiseuille's law. The formula for calculating fluid kinematic viscosity is:

In the formula, μ is the viscosity of the fluid, Q is the flow rate of the fluid, L is the length of the visible capillary, r is the radius of the visible capillary, ΔP is the differential pressure at both ends of the visible capillary, and K is the constant of the visible capillary.

The gas-liquid injection simulated oil displacement and fluid performance measurement methods can obtain the flow properties of the injected liquid and the outlet liquid of the core holder. The core holder sets six fluid collection points A2-A7 in the upper, middle and lower layers, which can measure the properties of fluids in different positions in the same layer and the properties of fluids in the same positions in different layers. The fluid properties of the fluid at different positions and layers in the core can be determined. If the core contains oil, the effect of the oil on the fluid properties at different locations can be determined.

The fluid performance data obtained above can be used to study the oil displacement mechanism (see the experimental verification section).

In addition, if there are other special requirements for the experiment, the injection process can be adjusted according to the actual situation to meet the experimental requirements.

Experimental verification

The experimental temperature is 45°C, the permeability of the upper, middle and lower layers of the core is 200, 800, and 1000md respectively, the pore volume of the core is 256mL, and the oil saturation is 71%. 1:1, carbon dioxide gas injection rate 0.9mL/min, foaming agent injection rate 0.9mL/min, injection time 72min, foaming agent composition: sulfobetaine silicon surfactant 0.5wt%, dodecyl di Methyl oxidation is 0.2wt%, partially hydrolyzed polyacrylamide (molecular weight is 16.6 million, hydrolysis degree is 23%) is 0.1wt%, and the balance is water. The first visible capillary G5 and the second visible capillary G6 have a length of 80 cm, an inner diameter of 1 mm, and a visible capillary constant K of 0.756.

Table 1. Parameter table of simulated oil displacement experiment

Analyzing the flow state and viscosity parameters of the fluid at different times and locations in the core provides a basis for analyzing the oil displacement mechanism. The viscosity of the fluid at collection points A4 and A7 changes greatly with time, and oil-containing foam is observed, indicating that the foam near these two points has formed an effective displacement, and the oil near these two points has been displaced, indicating that the foam is in the The medium-high permeability layer forms an effective displacement. After 40 minutes of injection, the viscosity at the A2 collection point was low, and a small amount of oily foam was observed, indicating that the foam in the low-permeability layer did not form effective displacement, and other displacement methods were needed to improve the displacement efficiency of the low-permeability layer. At 70 minutes after injection, the viscosity of the A8 collection point was low, and only a small amount of oily foam was observed, indicating that the foaming agent had a large adsorption loss in the core and the oil resistance of the foam was poor, so it is necessary to increase the oil resistance of the foaming agent and the injection time.

Those skilled in the art should understand that these examples or implementations are only for illustrating the present invention and not limiting the scope of the present invention, and various equivalent variations and modifications to the present invention belong to the disclosure content of the present invention.

Claims (12)

1. A gas-liquid injection simulated oil displacement and fluid performance measurement device, including a model system for simulating reservoirs, an injection system for injecting displacement media into the model system, and an effluent metering and acquisition system for metering and collecting the effluent of the model system , the model system includes a core holder (A), characterized in that it also includes a measurement system for obtaining fluid properties in the core, and the measurement system includes: The first mass flowmeter (H1) and the first visual capillary (G5), the two are connected in series at the core holder inlet (A1) end of the core holder (A), the first mass flowmeter (H1) The inlet end is provided with a first pressure sensor (P1); the inlet end of the first mass flow meter (H1) is connected to the injection system; The second mass flow meter (H2) and the second visual capillary (G6), both are connected in series to the core holder outlet (A8) of the core holder (A) through the pneumatic valve (K24), and the core fluid collection The points (A2-A7) are respectively connected to the inlet port of the second mass flowmeter (H2) through the pneumatic valve (K18-K23), and the inlet port of the second mass flowmeter (H2) is provided with the fifth pressure sensor (P7); the second The outlet end of the visual capillary (G6) is connected to the effluent metering collection system. 2. The gas-liquid injection simulated oil displacement and fluid performance measuring device according to claim 1, characterized in that, the effluent metering and collection system comprises a first back pressure valve (B1), a second back pressure valve (B2) , pneumatic valve (K3), pneumatic valve (K25) and oil, gas and water metering device (D), the outlet end of the second visual capillary (G6) is connected to the The oil-gas-water metering device (D), the core holder outlet (A8) of the core holder (A) is connected to the oil-gas-water metering device (D) through the first back pressure valve (B1) and the pneumatic valve (K3) in sequence. 3. gas-liquid injection simulated oil displacement and fluid performance measuring device according to claim 2, is characterized in that, described first visible capillary (G5) is positioned at the rock core holder inlet (A) of rock core holder (A) A1) end and connected to the pipeline, a first light source (G3) is provided on one side parallel to the length direction of the first visible capillary (G5), a first high-power camera (G7) is provided on the other side, and the first visible capillary A first differential pressure sensor (P5) is connected in parallel between the inlet and outlet of (G5) to measure the pressure difference between the inlet and outlet of the first visible capillary (G5). 4. The gas-liquid injection simulated oil displacement and fluid performance measuring device according to claim 2 or 3, characterized in that, the second visible capillary (G6) is located at the end of the core holder outlet (A8) and is connected to the pipeline , a second light source (G4) is provided on one side parallel to the length direction of the second visible capillary (G6), a second high-power camera (G8) is provided on the other side, and the entrance and exit of the second visible capillary (G6) A second differential pressure sensor (P6) is connected in parallel between them. 5. The gas-liquid injection simulated oil displacement and fluid performance measurement device according to claim 4, wherein the injection system includes a gas injection system for injecting gas into the model system and a liquid injection system for injecting liquid into the model system. 6. The gas-liquid injection simulated oil displacement and fluid performance measuring device according to claim 5, wherein the gas injection system comprises: A first gas piston container L1 and a second gas piston container L2 connected in parallel, wherein, The upper opening of the first gas piston container (L1) is provided with a pneumatic valve (K10) and a third pressure sensor (P3) for measuring the internal gas pressure of the first gas piston container (L1). The upper opening of (L1) is connected to the first emptying pipe (U1) through the pneumatic valve (K11); the lower opening of the first gas piston container (L1) is connected to the second constant pressure and constant speed pump through the pneumatic valve (K14) (R2), connected to the third liquid receiving container (F3) through a pneumatic valve (K16); The upper opening of the second gas piston container (L2) is provided with a pneumatic valve (K9) and a fourth pressure sensor (P4) for measuring the internal gas pressure of the second gas piston container (L2), and the second gas piston container (L2 ) through the pneumatic valve (K12) and the second emptying pipe (U2); the lower end of the second gas piston container (L2) is connected to the third constant pressure constant speed pump (R3) through the pneumatic valve (K13) ), connected to the third liquid receiving container (F3) through a pneumatic valve (K17); A high-pressure gas cylinder (N) for storing high-pressure gas, the high-pressure gas cylinder (N) is connected to a gas booster pump (M) through a pneumatic valve (K8), and the gas booster pump (M) is connected to a gas booster pump (M) through a pneumatic valve (K7) is connected to the junction of pneumatic valve (K9) and pneumatic valve (K10), and the junction of pneumatic valve (K7, K9, K10) is connected to the inlet of the first mass flow meter (H1) through pneumatic valve (K6) end. 7. gas-liquid injection simulated oil displacement and fluid performance measuring device according to claim 5, is characterized in that, described liquid injection system comprises liquid piston container (E), and the upper end entrance of described liquid piston container (E) A second pressure sensor (P2) for measuring the liquid pressure in the liquid piston container (E) is provided, and the upper end opening of the liquid piston container (E) is respectively connected with the first liquid receiver (F1) through a pneumatic valve (K2) and through The pneumatic valve (K5) is connected to the inlet port of the first mass flow meter (H1); the lower end opening of the liquid piston container (E) is connected to the first constant-pressure constant-speed pump (R1) through the pneumatic valve (K4), and It is connected to the second liquid receiving container (F2) through a pneumatic valve (K15). 8. The gas-liquid injection simulated oil displacement and fluid performance measuring device according to claim 5 or 6, characterized in that, the core clamp (A), the first back pressure valve (B1), the second back pressure Valve (B2), oil, gas and water metering device (D), liquid piston container (E), liquid receiving container (F1), first mass flow meter (H1), second mass flow meter (H2), first gas piston container (L1), the second gas piston container (L2), and the first light-tight box (G1) and the second light-tight box (G2) are all placed in the thermostatic box (Q). 9. according to claim 5 or 6 described gas-liquid injection simulated oil flooding and fluid property measuring device, it is characterized in that, described first mass flow meter (H1), the second mass flow meter (H2), pneumatic valve ( K1-K25), each pressure sensor (P1-P4, P7), each differential pressure sensor (P4, P5), constant temperature box (Q), each constant pressure constant speed pump (R1-R3), the first light source (G3) , the second light source (G4), the first high-power camera (G7), the second high-power camera (G8), and the gas booster pump M are all electrically connected to the computer (W). 10. A gas-liquid injection simulated oil displacement and fluid performance measurement method, said method adopts the gas-liquid injection simulated oil displacement and fluid performance measurement device according to any one of claims 1 to 9 to carry out the gas-liquid injection simulated oil displacement experiment And measuring the fluid properties in the core, including the following steps: Step 1: Put the three-layer heterogeneous oil-bearing core into the core holder (A), put the liquid into the liquid piston container (E), and the gas type in the high-pressure gas cylinder (N) meets the requirements of the simulated oil displacement experiment. Design, the pistons in the first gas piston container (L1) and the second gas piston container (L2) are located at the top, all pneumatic valves are closed, and the computer (W) controls the thermostat (Q) to heat up to the pre-simulation oil displacement experiment. Set the temperature; the computer (W) controls the opening of the first light source (G3) and the second light source (G4), and controls the opening of the first high-power camera (G7) and the second high-power camera (G8); Step 2: The computer (W) controls the opening of the pneumatic valves (K8, K7, K10, K16), and the gas in the high-pressure cylinder (N) enters the first stage through the gas booster pump (M) and the pneumatic valves (K8, K7, K10). In a gas piston container (L1), when the piston in the first gas piston container (L1) is pushed to the bottom, the computer (W) controls the pneumatic valves (K10, K16) to close; the computer (W) controls the pneumatic valves (K9, K17) is opened, the gas in the high-pressure cylinder (N) enters the second gas piston container (L2) through the booster pump (M) and the pneumatic valve (K8, K7, K9), when the second gas piston container (L2) The piston in the cylinder is pushed to the bottom, and the computer (W) controls the pneumatic valves (K8, K7, K9, K17) to close; Step 3: Set the pressure value of the first back pressure valve (B1) according to the back pressure designed in the simulated oil displacement experiment, the computer (W) controls the opening of the pneumatic valves (K4, K13, K14), and the computer (W) controls the first constant The pressure and constant speed pump (R1), the second constant pressure and constant speed pump (R2) and the third constant pressure and constant speed pump (R3) respectively control the liquid piston container (E), the first gas piston container (L1), the second gas The piston container (L2) is pressurized, when the pressure value of the second pressure sensor (P2), the third pressure sensor (P3) or the fourth pressure sensor (P4) is equal to the pressure value of the first back pressure valve (B1), The computer (W) controls the corresponding constant pressure constant speed pump to stop; Step 4: Inject the oil-displacing medium into the oil-bearing core in the core holder (A) by means of alternate gas-liquid injection or simultaneous gas-liquid injection. During the injection process, the computer (W) passes through the first high-power camera (G7) and the first light source (G3) to observe the flow state of the gas, liquid or gas-liquid mixture, and at the same time combine the values of the first mass flow meter (H1) and the first differential pressure sensor (P5) to calculate the flow rate of the gas, liquid or gas-liquid mixture Kinematic viscosity; the computer (W) controls one of the pneumatic valves (K18-K24) to open, and sets the pressure of the back pressure valve (B2) equal to the pressure value of the fifth pressure sensor (P7), through the second high-power camera (G8) and the second light source (G4) to observe the fluid flow state corresponding to the three-layer heterogeneous core fluid collection points (A2-A7) and the outlet of the core holder (A8), also combined with the second mass flowmeter (H2) and the second The value of the differential pressure sensor (P6) calculates the kinematic viscosity of the fluid at the collection point until the injection time designed for the simulated oil displacement experiment is met. 11. gas-liquid injection simulated oil displacement and fluid performance measurement method according to claim 10, is characterized in that, the gas-liquid simultaneous injection mode in step 4 comprises the following steps: The computer (W) controls the opening of the pneumatic valves (K3, K5, K6, K10), and the computer (W) controls the first constant-pressure constant-speed pump (R1) and the second constant-pressure constant-speed pump (R2) to simulate oil displacement experimental design The gas-liquid ratio and injection speed are used to inject liquid and gas. When the injection time of the simulated oil displacement experiment is met, the computer (W) controls the pneumatic valves (K3, K5, K6, K10) to close and stop the first constant pressure and constant speed pump. (R1) and the second constant pressure and constant speed pump (R2); during the experiment, the computer (W) records the pressure value of the first pressure sensor (P1) and the flow rate and injection time of the first mass flow meter (H1) foam fluid , and record the volume of oil, gas and water in the oil, gas and water metering device (D) in real time. 12. The gas-liquid injection simulated oil displacement and fluid performance measurement method according to claim 10, wherein the gas-liquid alternate injection method in step 4 comprises the following steps carried out alternately: (1) When liquid is injected, the computer (W) controls the opening of the pneumatic valves (K3, K4, K5), and the computer (W) controls the first constant pressure and constant speed pump (R1) to inject the liquid at a constant speed designed for the simulated oil flooding experiment , when the injection time designed for the simulated oil displacement experiment is met, the computer (W) controls the pneumatic valve (K5) to close, and stops the first constant-pressure constant-speed pump (R1); the computer (W) simultaneously records the first time when the liquid is injected The value of the pressure sensor (P1), the liquid injection time and speed, the liquid injection speed measured by the first mass flow meter (H1) corrects the injection speed recorded by the first constant pressure constant speed pump (R1); During the liquid injection process, the computer (W) simultaneously controls the pneumatic valves (K13, K14) to open, and respectively compares the pressure values of the third pressure sensor (P3), the fourth pressure sensor (P4) with the first pressure sensor (P1) The size of the pressure value, that is, when the pressure value of the third pressure sensor (P3) is greater than the pressure value of the first pressure sensor (P1), the computer (W) controls the pneumatic valve (K11) to open, and the gas is discharged from the first exhaust pipe (U1) discharge until the pressure value of the third pressure sensor (P3) is equal to the pressure value of the first pressure sensor (P1), close the pneumatic valve (K11); when the pressure value of the third pressure sensor (P3) is less than the first When the pressure value of the pressure sensor (P1), the computer (W) controls the second constant pressure constant speed pump (R2) to pressurize the first gas piston container (L1), until the pressure value of the third pressure sensor (P3) is equal to the first Until the pressure value of the first pressure sensor (P1), stop the pressurization of the second constant pressure constant speed pump (R2); similarly, when the pressure value of the fourth pressure sensor (P4) is greater than the pressure value of the first pressure sensor (P1), The computer (W) controls the pneumatic valve (K12) to open, and the gas is discharged from the second exhaust pipe (U2) until the pressure value of the fourth pressure sensor (P4) is equal to the pressure value of the first pressure sensor (P1), and the pneumatic valve is closed. Valve (K12); when the pressure value of the fourth pressure sensor (P4) was less than the pressure value of the first pressure sensor (P1), the computer (W) controlled the third constant pressure constant speed pump (R3) to the second gas piston container (L2) Pressurize until the pressure value of the fourth pressure sensor (P4) is equal to the pressure value of the first pressure sensor (P1), stop the third constant pressure constant speed pump (R3) to pressurize until the liquid is injected; (2) When injecting gas, the computer (W) controls the opening of the pneumatic valves (K3, K6, K10), and the computer (W) controls the second constant pressure and constant speed pump (R2) to inject gas at the speed designed for the simulated oil displacement experiment. After satisfying the injection time designed for the simulated oil displacement experiment, the computer (W) controls the pneumatic valves (K6, K10) to close and stops the second constant pressure and constant speed pump (R2); the computer (W) records the first pressure sensor when the gas is injected The value of (P1), gas injection rate and time, the gas injection rate measured by the first mass flow meter (H1) corrects the injection rate recorded by the second constant pressure constant speed pump (R2); During the gas injection process, the computer (W) compares the pressure value of the fourth pressure sensor (P4) with the pressure value of the first pressure sensor (P1), when the pressure value of the fourth pressure sensor (P4) is greater than the first pressure The pressure value of the sensor (P1), the computer (W) controls the pneumatic valve (K12) to open, and the gas is discharged from the second emptying pipe (U2), until the pressure value of the fourth pressure sensor (P4) is equal to the pressure value of the first pressure sensor (P1 ), close the pneumatic valve (K12); when the pressure value of the fourth pressure sensor (P4) is less than the pressure value of the first pressure sensor (P1), the computer (W) controls the third constant pressure constant speed pump (R3 ) Pressurize the second gas piston container (L2) until the pressure value of the fourth pressure sensor (P4) is equal to the pressure value of the first pressure sensor (P1), stop the third constant pressure constant speed pump (R3) pressurization , until the gas injection is completed, or when the gas volume in the first gas piston container (L1) is used up, the computer (W) controls the pneumatic valve (K9) to open, controls the pneumatic valve (K10) to close and stops the second constant pressure constant speed The pump (R2), the computer (W) controls the third constant pressure constant speed pump (R3) to continue injecting gas at the same speed designed for the simulated oil flooding experiment, and when the injection time of the simulated oil flooding experiment design is satisfied, the computer W controls the pneumatic Valves (K6, K9) close and stop the third constant pressure constant speed pump (R3); During the gas injection process, the computer (W) compares the pressure value of the second pressure sensor (P2) with the pressure value of the first pressure sensor (P1) at the same time, when the pressure value of the second pressure sensor (P2) is greater than the first When the pressure value of the pressure sensor (P1) is reached, the computer (W) controls the pneumatic valve (K2) to open and discharge excess liquid into the first liquid receiving container (F1) until the pressure value of the second pressure sensor (P2) is equal to the first Close the pneumatic valve (K2) until the pressure value of the pressure sensor (P1); when the pressure value of the second pressure sensor (P2) is lower than the pressure value of the first pressure sensor (P1), the computer (W) controls the first constant pressure constant The speed pump (R1) pressurizes the liquid piston container (E) until the pressure value of the second pressure sensor (P2) is equal to the pressure value of the first pressure sensor (P1), then the first constant pressure constant speed pump (R1) is stopped , until the gas injection is complete.