CN116241247B - Experimental device and method for simulating multi-well collaborative multi-period flooding-swallowing coupling - Google Patents

Abstract

The invention relates to the technical field of unconventional oil and natural gas exploration and development, and specifically relates to an experimental device and method for simulating multi-well coordinated multi-period flooding-swallowing coupling, including a high-pressure automatic pump, a first valve, a carbon dioxide sampler, and a formation crude oil mixer. Sample container, four-way valve, vacuum pump, thermostat, first pressure gauge, first coupling unit, second pressure gauge, second coupling unit, third pressure gauge and metering unit. This invention carries out inter-well interference analysis based on the theory of enhanced recovery, overcomes the limitations of conventional CO ₂ huff and puff on the degree of reservoir development and the shortcomings of the dual-core flooding-thrust coupling device that ignores inter-well interference, and also considers the impact of inter-well interference. , simulating the effect of multi-well collaborative multi-period flooding-swallowing coupling oil increase under real reservoir conditions, solving the problem that existing experimental devices do not consider the impact of inter-well interference caused by changes in the working system of adjacent wells during the gas injection process on multi-well collaborative The problem of large errors caused by drive-swallow coupling experimental results.

Description

Experimental device and method for simulating multi-well collaborative multi-period flooding-swallowing coupling

Technical field

The invention relates to the technical field of unconventional oil and natural gas exploration and development, and in particular to an experimental device and method for simulating multi-well collaborative multi-period flooding-swallowing coupling.

Background technique

In 2021, my country's crude oil dependence on foreign countries will reach 73%, and the efficient development of oil and gas resources has become a major need for the national energy strategy. my country's low-permeability tight oil reservoirs are abundant in reserves, accounting for more than 2/3 of the country's oil reserves. They have huge development potential. How to supplement formation energy has become a difficulty in the development of this type of oil reservoirs. Water flooding can effectively supplement formation deficits, but due to the high injection pressure and strong water sensitivity of the reservoir, it is difficult to effectively displace crude oil. Especially in recent years, as the proportion of low-permeability tight oil and gas resources has increased year by year, researchers have found that it is difficult to establish an effective displacement pressure system for water flooding in ultra-low permeability reservoirs, and related work on improving oil recovery is particularly important. A large number of indoor experimental studies have shown that CO ₂ has the functions of expanding energy and reducing viscosity through extraction. The implementation of CO ₂ huff and puff in mines can effectively solve the problem of "no injection, no production, and oil production speed" in the water flooding development process of ultra-low permeability reservoirs. low, low recovery rate” problem. However, conventional CO ₂ huff and puff mode is mainly based on synchronous huff and puff, lack of coordination between well groups, limited range of single well huff and puff, and low reservoir utilization. Therefore, an experimental device and method for simulating multi-well collaborative multi-period flooding-swallowing coupling are proposed. Through alternate throughput and puffing, the well group realizes that the same well can be both an injection well and a production well, giving full play to the synergistic effect of "injection-flooding-stew-production" to further improve the utilization of reserves between wells.

Deng Zhenlong et al. (2022) designed a dual-core CO ₂ flooding-swallowing coupling experiment to compare and analyze the enhanced oil recovery effect under different injection and production parameters. Chen et al. (2022) designed a supercritical carbon dioxide displacement experimental device. Three methods of continuous gas injection, synchronous gas injection and asynchronous gas injection were simulated. However, they all ignored the influence of the unstable pressure field formed between wells during multi-well gas injection on the oil displacement effect. Kong et al. (2016) have emphasized that inter-well interference will significantly affect the oil production of adjacent wells when studying multi-well collaborative flooding-swallowing coupling technology.

However, in the traditional multi-well collaborative flooding-swallowing coupling experimental device, the gas injection experiment is only carried out for one well or even two wells in the formation to complete the multi-well collaborative flooding-swallowing coupling simulation. When discussing the impact of adjacent wells, we did not consider the large error caused by inter-well interference caused by changes in the working system of adjacent wells during the gas injection process on the results of multi-well collaborative flooding-swallowing coupling experiments. However, the inter-well interference under real formation conditions is not considered. The impact cannot be ignored, thus reducing recovery.

Contents of the invention

The purpose of the present invention is to provide an experimental device and method for simulating multi-well collaborative multi-period flooding-swallowing coupling, aiming to solve the problem that the existing experimental device does not consider the inter-well interference caused by changes in the working system of adjacent wells during the gas injection process. The problem of large errors caused by multi-well collaborative flooding-swallowing coupling experimental results.

In order to achieve the above object, in the first aspect, the present invention provides an experimental device for simulating multi-well collaborative multi-period flooding-swallowing coupling, including a high-pressure automatic pump, a first valve, a carbon dioxide sampler, a formation crude oil sampler, and four A through valve, a vacuum pump, a thermostat, a first pressure gauge, a first coupling unit, a second pressure gauge, a second coupling unit, a third pressure gauge and a metering unit; the first valve is connected to the high-pressure automatic pump, so The carbon dioxide sampler is connected to the first valve and to port a of the four-way valve. The formation crude oil sampler is connected to the first valve and to port b of the four-way valve. connection, the vacuum pump is connected to the d port of the four-way valve, the first pressure gauge is connected to the c port of the four-way valve, and the first coupling unit is disposed away from the first pressure gauge. On one side of the four-way valve, the second pressure gauge is disposed on the side of the first coupling unit away from the first pressure gauge, and the second coupling unit is disposed on the side of the second pressure gauge away from the first pressure gauge. On one side of a coupling unit, the third pressure gauge is disposed on the side of the second coupling unit away from the second pressure gauge, and the metering unit is disposed on the third pressure gauge away from the second coupling unit. On one side of the unit, the carbon dioxide sampler, the formation crude oil sampler, the four-way valve, the first pressure gauge, the first coupling unit, the second pressure gauge, the third The second coupling unit and the third pressure gauge are both located in the thermostatic box.

Wherein, the first coupling unit includes a first core holder and a first confining pressure pump. The first core holder is connected to the first pressure gauge and is located in the thermostatic box. A confining pressure pump is connected to the first core holder and located outside the thermostatic box.

Wherein, the second coupling unit includes a second core holder, a third core holder, a second confining pressure pump and a third confining pressure pump. The second core holder and the third core holder The holders are connected in parallel and are located in the thermostatic box, and the second pressure gauge and the third pressure gauge are connected on both sides of the parallel second core holder and the third core holder. , the second confining pressure pump is connected to the second core holder and is located outside the constant temperature box, and the third confining pressure pump is connected to the third core holder and is located in the constant temperature box. outside the box.

Wherein, the metering unit includes a second valve, a back pressure valve, a separator, a gas meter and a back pressure pump. The second valve, the back pressure valve, the separator and the gas meter are all connected in sequence. It is located outside the thermostatic box, and the second valve is connected to the third pressure gauge. The back pressure pump is connected to the back pressure valve and is located on one side of the back pressure valve.

In a second aspect, the present invention provides an experimental method for simulating multi-well collaborative multi-period flooding-swallowing coupling, which includes the following steps: S1 checks the tightness of the experimental device for simulating multi-well collaborative multi-cycle flooding-swallowing coupling; S2 selects the core A. After core B and core C are washed and dried, they are placed in the first core holder, the second core holder and the third core holder respectively. The thermostat simulates the formation temperature of 106°C; connect the four-way valve Ports d and c of the four-way valve, close the second valve, and evacuate the core; then connect ports b and c of the four-way valve, open the second valve, and push the formation crude oil in the formation crude oil sampler through the high-pressure automatic pump to saturate the core Crude oil; S3 is connected to the a and c ports of the four-way valve, set the high-pressure automatic pump pressure to be constant, push the carbon dioxide in the carbon dioxide sampler until the first pressure gauge and the high-pressure automatic pump pressure are the same, close the c port of the four-way valve, Stew the well for 12 hours, simulate core A gas injection and stew the well; S4 increases the inlet pressure of the first core holder, closes the c port of the four-way valve, opens the second valve, reduces the pressure in stages, and records the indication of the second pressure gauge. Change, use a separator to measure the oil production of core A, use a gas meter to measure the gas production of core A, and simulate the flooding-swallowing coupling of core A; S5 reverses the positions of the first coupling unit and the second coupling unit; S6 connects the four-way valve Ports a and c, set the high-pressure automatic pump pressure to be constant, push the carbon dioxide in the carbon dioxide sampler until the first pressure gauge and the high-pressure automatic pump pressure are the same, close port c of the four-way valve, let the well simmer for 12 hours, simulate core B, C injects gas to stew the well; S7 increases the inlet pressure of the second core holder and the third core holder, closes the c port of the four-way valve, opens the second valve, reduces the pressure in stages, and records the value of the second pressure gauge. The display changes, using a separator to measure the oil production of core B and core C, and using a gas meter to measure the gas production of core B and core C, simulating the flooding-swallowing coupling of cores B and C; S8 repeats steps S3 to S7 to the preset number of times, Calculate the recovery degree of multi-cycle flooding and swallowing coupling respectively.

An experimental device of the present invention that simulates multi-well collaborative multi-period flooding-swallowing coupling. Experiments are conducted through the experimental device of the present invention that simulates multi-well collaborative multi-period flooding-swallowing coupling. Interwell interference analysis is carried out based on the theory of enhanced oil recovery. , overcoming the limitations of conventional CO ₂ huff and puff on the degree of reservoir utilization and the shortcomings of the dual core flooding-thrust coupling device that ignores inter-well interference, and at the same time improves the utilization of low-permeability reservoirs outside fractures by asynchronous injection and production between fractures in the same well. This invention considers the influence of inter-well interference and simulates the multi-well collaborative multi-period flooding-swallowing coupling oil increasing effect under real reservoir conditions, and the obtained results are more reasonable and reliable. By replacing the core in the coupling unit, it can be used to study the impact of core heterogeneity on the oil displacement effect. In addition to carrying out flooding-swallowing coupling experiments, water flooding, gas flooding, chemical flooding and CO ₂ storage experiments that consider inter-well interference can also be carried out. It has wide application value and solves the problem that existing experimental equipment does not consider gas injection. During the process, inter-well interference caused by changes in the working system of adjacent wells caused large errors in the results of multi-well collaborative flooding-swallowing coupling experiments.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of the first stage of an experimental device for simulating multi-well collaborative multi-period flooding-swallowing coupling provided by the present invention.

Figure 2 is a schematic structural diagram of the second stage of an experimental device for simulating multi-well collaborative multi-period flooding-swallowing coupling provided by the present invention.

Figure 3 is a production flow chart simulating multi-well collaborative multi-cycle flooding-swallowing coupling.

Figure 4 is a flow chart of an experimental method for simulating multi-well collaborative multi-period flooding-swallowing coupling provided by the present invention.

1-High-pressure automatic pump, 2-Carbon dioxide sampler, 3-Form crude oil sampler, 4-Vacuum pump, 5-Thermostatic box, 6-First coupling unit, 7-Second coupling unit, 8-First core clamp holder, 9-second core holder, 10-third core holder, 11-first confining pressure pump, 12-second confining pressure pump, 13-third confining pressure pump, 14-back pressure pump , 15-back pressure valve, 16-separator, 17-gas meter, 18-first pressure gauge, 19-second pressure gauge, 20-third pressure gauge, 21-four-way valve, 22-first valve, 23-Second valve.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and are not to be construed as limiting the present invention.

Please refer to Figures 1 to 2. In the first aspect, the present invention provides an experimental device for simulating multi-well coordinated multi-cycle flooding-swallowing coupling, including a high-pressure automatic pump 1, a first valve 22, a carbon dioxide sampler 2, and formation crude oil. Sample dispenser 3, four-way valve 21, vacuum pump 4, thermostat 5, first pressure gauge 18, first coupling unit 6, second pressure gauge 19, second coupling unit 7, third pressure gauge 20 and metering unit; The first valve 22 is connected to the high-pressure automatic pump 1. The carbon dioxide sampler 2 is connected to the first valve 22 and to port a of the four-way valve 21. The formation crude oil sampler The device 3 is connected to the first valve 22 and to the b port of the four-way valve 21, the vacuum pump 4 is connected to the d port of the four-way valve 21, and the first pressure gauge 18 is connected to the The c port of the four-way valve 21 is connected, the first coupling unit 6 is disposed on the side of the first pressure gauge 18 away from the four-way valve 21, and the second pressure gauge 19 is disposed on the first coupling The unit 6 is on the side away from the first pressure gauge 18, the second coupling unit 7 is disposed on the side of the second pressure gauge 19 away from the first coupling unit 6, and the third pressure gauge 20 is disposed on The metering unit is disposed on the side of the second coupling unit 7 away from the second pressure gauge 19 and the third pressure gauge 20 on the side away from the second coupling unit 7. The carbon dioxide sampling unit 2, the formation crude oil sampler 3, the four-way valve 21, the first pressure gauge 18, the first coupling unit 6, the second pressure gauge 19, the second coupling unit 7 and the third pressure gauge 20 are located in the thermostatic box 5 .

Specifically, after core A, core B and core C are selected, washed and dried, core A is placed in the first coupling unit 6 , and core B and core C are placed in the second coupling unit 7 . Connect the d and c ports of the four-way valve 21, close the second valve 23, and evacuate the core. Then connect the b and c ports of the four-way valve 21, open the second valve 23, and push the formation crude oil in the formation crude oil sampler 3 through the high-pressure automatic pump 1 to saturate the core with crude oil. Connect ports a and c of the four-way valve 21, set the pressure of the high-pressure automatic pump 1 to be constant, push the carbon dioxide in the carbon dioxide sampler 2 until the pressure of the first pressure gauge 18 is the same as that of the high-pressure automatic pump 1, close the four-way valve 21 c port, simmer the well for 12 hours, and simulate core A for gas injection and simmering. Increase the inlet pressure of the first coupling unit 6, close the c port of the four-way valve 21, open the second valve 23, reduce the pressure in stages, record the changes in the reading of the second pressure gauge 19, and use the separator 16 to measure the oil production of core A The gas volume meter 17 is used to measure the gas production volume of core A, and the flooding-swallowing coupling of core A is simulated. The positions of the first coupling unit 6 and the second coupling unit 7 are reversed. Connect ports a and c of the four-way valve 21, set the pressure of the high-pressure automatic pump 1 to be constant, push the carbon dioxide in the carbon dioxide sampler 2 until the pressure of the first pressure gauge 18 is the same as that of the high-pressure automatic pump 1, close the four-way valve 21 Port c, simmer the well for 12 hours, and simulate cores B and C for gas injection and simmering. Increase the inlet pressure of the second coupling unit 7 and the third core holder 10, close the c port of the four-way valve 21, open the second valve 23, reduce the pressure in stages, and record the change in the indication of the second pressure gauge 19, The separator 16 is used to measure the oil production of core B and core C, and the gas meter 17 is used to measure the gas production of core B and core C to simulate the flooding-swallowing coupling of cores B and C. Repeat the above operation to the preset number of times, calculate the recovery degree of multi-cycle flooding-thrust coupling respectively, and conduct inter-well interference analysis based on the enhanced recovery theory, overcoming the limitations of conventional CO ₂ huff and puff on the degree of reservoir production and dual core flooding The -Thon coupling device ignores the shortcomings of interference between wells, and at the same time improves the utilization of low permeability reservoirs outside fractures by asynchronous injection and production between fractures in the same well. This invention considers the influence of inter-well interference and simulates the multi-well collaborative multi-period flooding-swallowing coupling oil increasing effect under real reservoir conditions, and the obtained results are more reasonable and reliable. By replacing the core in the coupling unit, it can be used to study the impact of core heterogeneity on the oil displacement effect. In addition to carrying out flooding-swallowing coupling experiments, water flooding, gas flooding, chemical flooding and CO ₂ storage experiments that consider inter-well interference can also be carried out. It has wide application value and solves the problem that existing experimental equipment does not consider gas injection. During the process, inter-well interference caused by changes in the working system of adjacent wells caused large errors in the results of multi-well collaborative flooding-swallowing coupling experiments.

Further, the first coupling unit 6 includes a first core holder 8 and a first confining pressure pump 11. The first core holder 8 is connected to the first pressure gauge 18 and is located at the constant temperature In the box 5 , the first confining pressure pump 11 is connected to the first core holder 8 and is located outside the thermostatic box 5 . The second coupling unit 7 includes a second core holder 9, a third core holder 10, a second confining pressure pump 12 and a third confining pressure pump 13. The second core holder 9 and the The third core holder 10 is connected in parallel and is located in the thermostatic box 5 , and the second pressure gauge 19 and the third pressure gauge 20 are connected to the second core holder 9 and the parallel connection. On both sides of the third core holder 10, the second confining pressure pump 12 is connected to the second core holder 9 and is located outside the thermostatic box 5. The third confining pressure pump 13 is connected to the second confining pressure pump 12. The third core holder 10 is connected and located outside the thermostatic box 5 . The metering unit includes a second valve 23, a back pressure valve 15, a separator 16, a gas meter 17 and a back pressure pump 14. The second valve 23, the back pressure valve 15, the separator 16 and the The gas meters 17 are connected in sequence and are located outside the thermostatic box 5 , and the second valve 23 is connected to the third pressure gauge 20 , and the back pressure pump 14 is connected to the back pressure valve 15 and located there. One side of the back pressure valve 15.

Specifically, the first core holder 8, the second core holder 9 and the third core holder 10 are respectively used to fix core A, core B and core C. The first enclosure The pressure pump 11, the second confining pressure pump 12 and the third confining pressure pump 13 are respectively used to control the confining pressure of the first core holder 8, the second core holder 9 and the third core holder 10. , the second valve 23 is used to realize the connection between the first coupling unit 6 or the second coupling unit 7 and the separator 16, and the back pressure valve 15 can avoid the backflow of gas and oil. , the separator 16 is used to measure oil production, the gas meter 17 is used to measure gas production, and the back pressure pump 14 is used to control the back pressure of the back pressure valve.

Please refer to Figures 1 to 4. In a second aspect, the present invention provides an experimental method for simulating multi-well collaborative multi-period flooding-swallowing coupling, including the following steps: S1 Check the experiment of simulating multi-well collaborative multi-cycle flooding-swallowing coupling The tightness of the device.

Specifically, keep the device pressure constant at 37MPa. If the system pressure change is less than 0.5% within 12 hours, it means that the device has good sealing and the experiment can be carried out. In step S1, the device pressure used to check the air tightness of the device is constant to the formation pressure.

S2 selects core A, core B and core C, wash and dry them, and put them into the first core holder 8, the second core holder 9 and the third core holder 10 respectively, and the incubator 5 simulates the formation temperature. 106℃. Connect the d and c ports of the four-way valve 21, close the second valve 23, and evacuate the core. Then connect the b and c ports of the four-way valve 21, open the second valve 23, and push the formation crude oil in the formation crude oil sampler 3 through the high-pressure automatic pump 1 to saturate the core with crude oil.

Specifically, the experimental device in step S2 simulates the original formation conditions of formation temperature and formation pressure.

S3 is connected to ports a and c of the four-way valve 21, sets the pressure of the high-pressure automatic pump 1 to be constant, pushes the carbon dioxide in the carbon dioxide sampler 2 until the pressure of the first pressure gauge 18 is the same as that of the high-pressure automatic pump 1, closes the four-way valve 21 c port, simmer the well for 12 hours, and simulate core A for gas injection and simmering.

Specifically, simulate the gas injection and stew of core A: connect ports a and c of the four-way valve 21, set the pump pressure P1 of the high-pressure automatic pump ₁ to 37MPa, and pump the carbon dioxide volume _V1 in the carbon dioxide sampler 2 until When the first pressure gauge 18 is the same as the pump pressure _P1 of the high-pressure automatic pump 1, close the c port of the four-way valve 21 and let the well simmer for 12 hours. The simulated production process is shown in Figure 3(a) and Figure 3(b).

S4 increases the inlet pressure of the first core holder 8, closes the c port of the four-way valve 21, opens the second valve 23, reduces the pressure in stages, records the change in the indication of the second pressure gauge 19, and uses the separator 16 to measure the core A gas production volume is measured using a gas meter 17 to simulate the flooding-swallowing coupling of core A.

Specifically, simulate core A flooding-swallowing coupling: increase the inlet pressure P _1-1 of the first core holder 8 to 37MPa, close the c port of the four-way valve 21, open the second valve 23, reduce the pressure in stages, and record The indication P _1-2 of the second pressure gauge 19 changes, the separator 16 is used to measure the oil production volume G _h1 of the core A, and the gas meter 17 is used to measure the gas production volume V _g1 of the core A.

S5 reverses the positions of the first coupling unit 6 and the second coupling unit 7 .

Specifically, the reconnection device was used to simulate the gas injection and well flooding-swallowing coupling process of cores B and C.

S6 is connected to ports a and c of the four-way valve 21, sets the pressure of the high-pressure automatic pump 1 to be constant, pushes the carbon dioxide in the carbon dioxide sampler 2 until the pressure of the first pressure gauge 18 is the same as that of the high-pressure automatic pump 1, closes the four-way valve 21 C port, simmer the well for 12 hours, and simulate cores B and C to inject gas and simmer the well.

Specifically, simulate the gas injection and stew of cores B and C: connect ports a and c of the four-way valve 21, set the pressure P1 of the high-pressure automatic pump ₁ to 37MPa, and pump the carbon dioxide volume V2 in the carbon dioxide sampler ₂ until When the first pressure gauge 18 is the same as the pump pressure _P1 of the high-pressure automatic pump 1, close the c port of the four-way valve 21 and let the well simmer for 12 hours. The simulated production process is shown in Figure 3(c) and Figure 3(d).

S7 increases the inlet pressure of the second core holder 9 and the third core holder 10, closes port c of the four-way valve 21, opens the second valve 23, reduces the pressure in stages, and records the indication of the second pressure gauge 19 The number changes, the separator 16 is used to measure the oil production of core B and core C, the gas meter 17 is used to measure the gas production of core B and core C, and the flooding-swallowing coupling of cores B and C is simulated.

Specifically, simulate the flooding-swallowing coupling of cores B and C: increase the inlet pressure P _1-1 of the second core holder 9 and the third core holder 10 to 37MPa, close port c of the four-way valve 21, and open The second valve 23 reduces the pressure in stages, records the changes in the indication P _1-2 of the second pressure gauge 19, uses the separator 16 to measure the oil production G _h2 of core B and core C, and uses the gas meter 17 to measure the oil production of core B and core C. C gas production V _g2 .

In the step S7, the first cycle fuel increase calculation model:

G _1-1 ＝G _h1 +G _h2

In the formula, G _1-1 is the oil production in the first period, in mL; G _h1 is the oil production in core A, in mL; G _h2 is the oil production in cores B and C, in mL.

Calculation model of CO ₂ storage rate in the first cycle:

In the formula, ζ is the CO ₂ storage rate in the first cycle; V _g1 is the gas production of core A, in mL; V _g2 is the gas production of cores B and C, in mL; the volume of carbon dioxide pumped for the first time is V ₁ , in unit mL; the volume of carbon dioxide pumped in for the second time is V ₂ in mL.

S8 repeats steps S3 to S7 to a preset number of times to calculate the recovery degree of multi-cycle drive-throat coupling respectively.

Specifically, in steps S4 and S7, as the injection-production pressure difference P _1-2 increases, the recovery factor in the flooding-cannulation coupling stage gradually increases. When the injection-production pressure difference is greater than the pressure difference between the formation pressure and the miscible pressure, the recovery rate growth begins to slow down, and the recovery rate per unit pressure difference will peak.

What is disclosed above is only a preferred embodiment of the experimental device and method for simulating multi-well coordinated multi-period flooding-swallowing coupling of the present invention. Of course, it cannot be used to limit the scope of the present invention. Those of ordinary skill in the art can understand that Implementing all or part of the processes of the above embodiments and making equivalent changes in accordance with the claims of the present invention still fall within the scope of the invention.

Claims (5)

1. An experimental device for simulating multi-well collaborative multi-cycle driving-decoupling is characterized in that,

the system comprises a high-pressure automatic pump, a first valve, a carbon dioxide sample preparation device, a stratum crude oil sample preparation device, a four-way valve, a vacuum pump, a constant temperature box, a first pressure gauge, a first coupling unit, a second pressure gauge, a second coupling unit, a third pressure gauge and a metering unit;

the first valve is connected with the high-pressure automatic pump, the four-way valve is provided with an a port, a b port, a c port and a d port, the carbon dioxide sample preparation device is connected with the first valve and is connected with the a port of the four-way valve, the stratum crude oil sample preparation device is connected with the first valve and is connected with the b port of the four-way valve, the vacuum pump is connected with the d port of the four-way valve, the first pressure gauge is connected with the c port of the four-way valve, the first coupling unit is arranged on one side, far away from the four-way valve, of the first coupling unit, the second coupling unit is arranged on one side, far away from the first coupling unit, of the second coupling unit, the third crude oil sample preparation device is arranged on one side, far away from the second pressure gauge, of the third pressure gauge is arranged on one side, far away from the second coupling unit, of the carbon dioxide sample preparation device, the second pressure gauge, the first coupling unit, the first pressure gauge, the second coupling unit and the first stratum sample preparation device.

2. The experimental apparatus for simulating multi-well collaborative multi-cycle drive-swallow coupling according to claim 1, wherein,

the first coupling unit comprises a first core holder and a first pressure surrounding pump, the first core holder is connected with the first pressure gauge and is positioned in the incubator, and the first pressure surrounding pump is connected with the first core holder and is positioned outside the incubator.

3. The experimental apparatus for simulating multi-well collaborative multi-cycle drive-swallow coupling according to claim 2, wherein,

the second coupling unit comprises a second core holder, a third core holder, a second confining pressure pump and a third confining pressure pump, wherein the second core holder and the third core holder are connected in parallel and are both positioned in the constant temperature box, the second pressure gauge and the third pressure gauge are connected to the two sides of the second core holder and the two sides of the third core holder in parallel, the second confining pressure pump is connected with the second core holder and is positioned outside the constant temperature box, and the third confining pressure pump is connected with the third core holder and is positioned outside the constant temperature box.

4. The experimental apparatus for simulating multi-well collaborative multi-cycle drive-swallow coupling according to claim 3, wherein,

the metering unit comprises a second valve, a back pressure valve, a separator, a gas meter and a back pressure pump, wherein the second valve, the back pressure valve, the separator and the gas meter are sequentially connected and are all positioned outside the constant temperature box, the second valve is connected with the third pressure meter, and the back pressure pump is connected with the back pressure valve and is positioned on one side of the back pressure valve.

5. An experimental method for simulating multi-well collaborative multi-cycle driving-swallowing coupling, which is applied to the experimental device for simulating multi-well collaborative multi-cycle driving-swallowing coupling as claimed in claim 4, and is characterized by comprising the following steps:

s1, checking the tightness of an experimental device for simulating multi-well collaborative multi-cycle driving-swallowing coupling;

s2, selecting a core A, a core B and a core C, cleaning and drying, and then respectively putting the selected core A, the core B and the core C into a first core holder, a second core holder and a third core holder, wherein an incubator simulates the stratum temperature to 106 ℃; d, c ports of the four-way valve are connected, the second valve is closed, and the core is vacuumized; then connecting ports b and c of the four-way valve, opening a second valve, pushing stratum crude oil in the stratum crude oil sample preparation device through a high-pressure automatic pump, and enabling the rock core to be saturated with the crude oil;

s3, connecting an a port and a c port of the four-way valve, setting the pressure of the high-pressure automatic pump to be constant, pushing carbon dioxide in the carbon dioxide sample preparation device until the pressure of the first pressure gauge is the same as that of the high-pressure automatic pump, closing the c port of the four-way valve, and stewing the well for 12 hours to simulate the gas injection and stewing of the core A;

s4, increasing the pressure of an inlet of the first core holder, closing a port c of the four-way valve, opening a second valve, reducing the pressure in stages, recording the number change of the second pressure gauge, measuring the oil production of the core A by using a separator, measuring the gas production of the core A by using a gas meter, and simulating the driving-swallowing coupling of the core A;

s5, exchanging the positions of the first coupling unit and the second coupling unit;

s6, connecting an a port and a c port of the four-way valve, setting the pressure of the high-pressure automatic pump to be constant, pushing carbon dioxide in the carbon dioxide sample preparation device until the pressure of the first pressure gauge is the same as that of the high-pressure automatic pump, closing the c port of the four-way valve, stewing the well for 12 hours, and simulating the core B, C gas injection and stewing the well;

s7, increasing inlet pressures of a second core holder and a third core holder, closing a C port of a four-way valve, opening the second valve, reducing the pressure in stages, recording the change of the number of a second pressure gauge, measuring oil production of a core B and a core C by using a separator, measuring gas production of the core B and the core C by using a gas meter, and simulating driving-swallowing coupling of the core B, C;

s8, repeating the steps S3-S7 to the preset times, and respectively calculating the extraction degree of the multi-period driving-swallowing coupling.