Reservoir supercritical carbon dioxide fracturing soaking production simulation method and device

Abstract

The invention relates to the technical field of oilfield development, in particular to a reservoir supercritical carbon dioxide fracturing soaking production simulation method and device. Well cementation is simulated; fracturing simulation: placing the core sample subjected to well cementation in a core holder, applying axial pressure and confining pressure to the core sample, simulating stratum triaxial stress at a required temperature, obtaining initial experimental data of the core sample at the moment, injecting supercritical carbon dioxide into the core sample through a shaft, and obtaining experimental data during core fracturing; soaking is simulated, and the core sample enters a soaking stage after being fractured; carrying out production simulation, enabling the core sample to enter a flowback stage under a specific return pressure condition, and recording experimental data of the core sample in the flowback stage; and performing three-dimensional imaging analysis. According to the method, the spatial distribution of the crude oil after the supercritical carbon dioxide fracturing of the unconventional reservoir can be monitored in real time, and the characteristics of the cracks formed after the fracturing and the crude oil recovery capacity are quantitatively evaluated.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield development, and relates to a reservoir supercritical carbon dioxide fracturing well soaking production simulation method and device. Background Art

[0002] my country's unconventional resources are widely distributed and have great development value. However, the reservoir porosity and permeability are poor, and it is necessary to improve the permeability of reservoir oil and gas through fracturing to achieve economic crude oil production. Compared with conventional hydraulic fracturing, supercritical carbon dioxide has the advantages of reducing fracture pressure and forming complex fracture networks. It is an effective means to efficiently utilize carbon dioxide and reduce the atmospheric content of greenhouse gases.

[0003] Compared with water, carbon dioxide has a lower viscosity and can effectively act on the deep reservoir, thereby effectively mobilizing crude oil in the deep reservoir. At the same time, carbon dioxide can dissolve in crude oil, reduce its viscosity, and improve the flowability of crude oil, which has the ability to efficiently develop unconventional reservoirs. At present, the physical simulation methods for the degree of crude oil utilization after fracturing are all carried out around the reservoir matrix core. There is no physical simulation device for integrated fracturing-well replacement-well production, which makes it difficult to effectively evaluate the utilization characteristics of crude oil after supercritical carbon dioxide fracturing. Summary of the invention

[0004] The present invention provides a reservoir supercritical carbon dioxide fracturing soaking well production simulation method and device, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problem that the existing physical simulation method for the degree of crude oil production after fracturing cannot effectively evaluate the production characteristics of crude oil after supercritical carbon dioxide fracturing.

[0005] One of the technical solutions of the present invention is achieved by the following measures: A reservoir supercritical carbon dioxide fracturing well production simulation method is carried out according to the following steps: The first step is core preparation. A wellbore is drilled axially in the center of the core sample. The drilled core sample is washed with oil, dried, and vacuumed to saturate with crude oil. The second step is to simulate cementing, placing the wellbore in the borehole and fixing it with a fixing glue, and the cementing is completed after the fixing glue solidifies; The third step is fracturing simulation. The cemented core sample is placed in a core holder and axial pressure and confining pressure are applied to the core sample to simulate the triaxial stress of the formation at the required temperature to obtain the initial experimental data of the core sample. Then, supercritical carbon dioxide is injected into the core sample through the wellbore to obtain the experimental data of the core fracturing. The fourth step is to simulate the well shut-in, and the core sample enters the well shut-in stage after fracturing; The fifth step is production simulation. Under specific back pressure conditions, the core samples enter the flowback stage and the experimental data of the core samples in the flowback stage are recorded. The sixth step is three-dimensional imaging analysis. After the production simulation is completed, the core samples are taken out and CT scanned to obtain three-dimensional imaging of the cracks formed by fracturing.

[0006] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: In the first step above, the core sample is cylindrical, with a diameter of 30 mm to 50 mm and a length of 60 mm to 100 mm, and the core drilling diameter is 5 mm to 10 mm and the depth is 30 mm to 50 mm.

[0007] In the third step, the confining pressure and the axial pressure are 0 to 30 MPa, and the temperature is 34°C to 90°C.

[0008] In the third step above, supercritical carbon dioxide is injected into the core sample at a constant flow rate of 5cc / min to 30cc / min. The injection pressure is monitored during the injection of supercritical carbon dioxide. When the injection pressure suddenly drops, it indicates that the core is fractured and the supercritical carbon dioxide injection is stopped.

[0009] In the third and fifth steps above, the experimental data include: T2 spectrum, 1D frequency coding and two-dimensional crude oil distribution.

[0010] In the fourth step above, the soaking stage is from 1 day to 7 days.

[0011] The second technical solution of the present invention is achieved by the following measures: a reservoir supercritical carbon dioxide fracturing soaking production simulation device, including a supercritical carbon dioxide component, a confining pressure loading component, a core clamping component and a data acquisition component, the core clamping component includes a core clamp and a recovery tank, the confining pressure loading component includes a fluorinated liquid storage tank and a first constant pressure and constant flow pump, the data acquisition component includes a nuclear magnetic resonance spectrometer and a computer, a fluorinated liquid pumping pipeline is fixedly connected between the first constant pressure and constant flow pump and the fluorinated liquid storage tank, a first fluorinated liquid pipeline is fixedly connected between the discharge end of the fluorinated liquid storage tank and the first feed end of the core clamp, and a second fluorinated liquid pipeline is fixedly connected between the first fluorinated liquid pipeline and the second feed end of the core clamp. A fluorinated liquid pipeline, a supercritical carbon dioxide pipeline is fixedly connected between the wellbore feed end on the right side of the core holder and the supercritical carbon dioxide assembly discharge end, a recovery pipeline is fixedly connected between the supercritical carbon dioxide pipeline and the recovery tank, a first pressure sensor is arranged on the core holder, a second pressure sensor is arranged on the first fluorinated liquid pipeline between the second fluorinated liquid pipeline and the core holder, a third pressure sensor is arranged on the second fluorinated liquid pipeline, a fourth pressure sensor is arranged on the supercritical carbon dioxide pipeline between the recovery pipeline and the core holder, and the first pressure sensor, the second pressure sensor, the third pressure sensor, the fourth pressure sensor and the nuclear magnetic resonance spectrometer are all connected to the computer for communication.

[0012] The following is a further optimization and / or improvement of the second technical solution of the above invention: The above-mentioned supercritical carbon dioxide assembly includes a supercritical carbon dioxide storage tank, a second constant pressure and constant flow pump and a carbon dioxide gas cylinder. A carbon dioxide pipeline is fixedly connected between the gas outlet end of the carbon dioxide gas cylinder and the gas inlet end of the supercritical carbon dioxide storage tank, a supercritical carbon dioxide pipeline is fixedly connected between the discharge end of the supercritical carbon dioxide storage tank and the feed end of the wellbore on the right side of the core clamp, a supercritical carbon dioxide pumping pipeline is fixedly connected between the supercritical carbon dioxide storage tank and the second constant pressure and constant flow pump, and a gas booster pump is fixedly installed on the carbon dioxide pipeline.

[0013] A first valve is fixedly installed on the carbon dioxide pipeline between the supercritical carbon dioxide storage tank and the gas booster pump, a second valve is fixedly installed on the supercritical carbon dioxide pipeline between the supercritical carbon dioxide storage tank and the recovery pipeline, a third valve and a back pressure valve are fixedly installed along the material flow direction of the recovery pipeline, a fourth valve is fixedly installed on the first fluorinated liquid pipeline between the second pressure sensor and the core clamp, a fifth valve is fixedly installed on the second fluorinated liquid pipeline between the third pressure sensor and the core clamp, and a sixth valve is fixedly installed on the first fluorinated liquid pipeline between the second fluorinated liquid pipeline and the fluorinated liquid storage tank.

[0014] The wellbore is made of Peek material, and includes a lower end that penetrates into the borehole and an upper end connected to the core holder. A fixing glue filling groove is provided on the outer side of the lower end of the wellbore from bottom to top, and an O-ring groove is provided on the outer side of the upper end of the wellbore.

[0015] The reservoir supercritical carbon dioxide fracturing soaking well production simulation method and device of the present invention can monitor the spatial distribution of crude oil after supercritical carbon dioxide fracturing in unconventional reservoirs in real time, and quantitatively evaluate the crack characteristics formed after fracturing and the crude oil recovery capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 This is a schematic diagram of the process flow of Example 11 of the present invention.

[0017] Attached Figure 1The codes are as follows: 1 is a core holder, 2 is a recovery tank, 3 is a fluorinated liquid storage tank, 4 is a first constant pressure and constant flow pump, 5 is a nuclear magnetic resonance spectrometer, 6 is a computer, 7 is a fluorinated liquid pumping pipeline, 8 is a first fluorinated liquid pipeline, 9 is a second fluorinated liquid pipeline, 10 is a supercritical carbon dioxide pipeline, 11 is a recovery pipeline, 12 is a first pressure sensor, 13 is a second pressure sensor, 14 is a third pressure sensor, 15 is a fourth pressure sensor, 16 is a supercritical carbon dioxide storage tank, 17 is a second constant pressure and constant flow pump, 18 is a carbon dioxide cylinder, 19 is a carbon dioxide pipeline, 20 is a supercritical carbon dioxide pumping pipeline, 21 is a gas booster pump, 22 is a first valve, 23 is a second valve, 24 is a third valve, 25 is a fourth valve, 26 is a fifth valve, 27 is a sixth valve, and 28 is a back pressure valve.

[0018] Attached Figure 2 Schematic diagram of the wellbore and the core sample after drilling in the present invention.

[0019] Attached Figure 3 This is the T2 spectrum of the core sample in Example 11 of the present invention.

[0020] Attached Figure 4 This is the crude oil two-dimensional imaging and 1D frequency encoding of the core sample in Example 11 of the present invention.

[0021] Attached Figure 5 This is the CT imaging of the fracture distribution of the core sample of Example 11 of the present invention. DETAILED DESCRIPTION

[0022] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0023] In the present invention, unless otherwise specified, the equipment and devices used are all the equipment and devices known and used in the art.

[0024] The present invention will be further described below in conjunction with embodiments: Example 1: Figure 1 As shown, the reservoir supercritical carbon dioxide fracturing well production simulation method is carried out according to the following steps: The first step is core preparation. A wellbore is drilled axially in the center of the core sample. The drilled core sample is washed with oil, dried, and vacuumed to saturate with crude oil. The second step is to simulate cementing, placing the wellbore in the borehole and fixing it with a fixing glue, and the cementing is completed after the fixing glue solidifies; The third step is fracturing simulation, placing the cemented core sample in the core holder 1, applying axial pressure and confining pressure to the core sample, simulating the formation triaxial stress at the required temperature, obtaining the initial experimental data of the core sample at this time, and then injecting supercritical carbon dioxide into the core sample through the wellbore to obtain the experimental data of the core fracturing; The fourth step is to simulate the well shut-in, and the core sample enters the well shut-in stage after fracturing; The fifth step is production simulation. Under specific back pressure conditions, the core samples enter the flowback stage and the experimental data of the core samples in the flowback stage are recorded. The sixth step is three-dimensional imaging analysis. After the production simulation is completed, the core samples are taken out and CT scanned to obtain three-dimensional imaging of the cracks formed by fracturing.

[0025] Embodiment 2: As an optimization of the above embodiment, in the first step, the core sample is cylindrical with a diameter of 30 mm to 50 mm and a length of 60 mm to 100 mm, and the core drilling diameter is 5 mm to 10 mm and the depth is 30 mm to 50 mm.

[0026] Embodiment 3: As an optimization of the above embodiment, in the third step, the confining pressure and the axial pressure are 0 to 30 MPa, and the temperature is 34°C to 90°C.

[0027] Example 4: As an optimization of the above example, in the third step, supercritical carbon dioxide is injected into the core sample at a constant flow rate of 5cc / min to 30cc / min. The injection pressure is monitored during the injection of supercritical carbon dioxide. When the injection pressure suddenly drops, it indicates that the core is fractured and the supercritical carbon dioxide injection is stopped.

[0028] Example 5: As an optimization of the above example, in the third and fifth steps, the experimental data include: T2 spectrum, 1D frequency coding and two-dimensional crude oil distribution.

[0029] Embodiment 6: As an optimization of the above embodiment, in the fourth step, the soaking stage is 1 day to 7 days.

[0030] Example 7: Figure 1As shown, the reservoir supercritical carbon dioxide fracturing soaking production simulation device includes a supercritical carbon dioxide component, a confining pressure loading component, a core clamping component and a data acquisition component. The core clamping component includes a core clamp 1 and a recovery tank 2. The confining pressure loading component includes a fluorinated liquid storage tank 3 and a first constant pressure and constant flow pump 4. The data acquisition component includes a nuclear magnetic resonance spectrometer 5 and a computer 6. A fluorinated liquid pumping pipeline 7 is fixedly connected between the first constant pressure and constant flow pump 4 and the fluorinated liquid storage tank 3. A first fluorinated liquid pipeline 8 is fixedly connected between the discharge end of the fluorinated liquid storage tank 3 and the first feed end of the core clamp 1. A second fluorinated liquid pipeline 9 is fixedly connected between the first fluorinated liquid pipeline 8 and the second feed end of the core clamp 1. The right wellbore feed end of the core clamp 1 is connected to the supercritical carbon dioxide component. A supercritical carbon dioxide pipeline 10 is fixedly connected between the discharge ends of the supercritical carbon dioxide components, a recovery pipeline 11 is fixedly connected between the supercritical carbon dioxide pipeline 10 and the recovery tank 2, a first pressure sensor 12 is arranged on the core clamp 1, a second pressure sensor 13 is arranged on the first fluorinated liquid pipeline 8 between the second fluorinated liquid pipeline 9 and the core clamp 1, a third pressure sensor 14 is arranged on the second fluorinated liquid pipeline 9, a fourth pressure sensor 15 is arranged on the supercritical carbon dioxide pipeline 10 between the recovery pipeline 11 and the core clamp 1, and the first pressure sensor 12, the second pressure sensor 13, the third pressure sensor 14, the fourth pressure sensor 15 and the nuclear magnetic resonance spectrometer 5 are all connected to the computer 6 for communication.

[0031] Example 8: Figure 1 As shown, as an optimization of the above embodiment, the supercritical carbon dioxide assembly includes a supercritical carbon dioxide storage tank 16, a second constant pressure and constant flow pump 17 and a carbon dioxide gas cylinder 18, a carbon dioxide pipeline 19 is fixedly connected between the gas outlet end of the carbon dioxide gas cylinder 18 and the gas inlet end of the supercritical carbon dioxide storage tank 16, a supercritical carbon dioxide pipeline 10 is fixedly connected between the discharge end of the supercritical carbon dioxide storage tank 16 and the feed end of the wellbore on the right side of the core clamp 1, a supercritical carbon dioxide pumping pipeline 20 is fixedly connected between the supercritical carbon dioxide storage tank 16 and the second constant pressure and constant flow pump 17, and a gas booster pump 21 is fixedly installed on the carbon dioxide pipeline 19.

[0032] Example 9: Figure 1As shown, as an optimization of the above embodiment, a first valve 22 is fixedly installed on the carbon dioxide pipeline 19 between the supercritical carbon dioxide storage tank 16 and the gas booster pump 21, a second valve 23 is fixedly installed on the supercritical carbon dioxide pipeline 10 between the supercritical carbon dioxide storage tank 16 and the recovery pipeline 11, a third valve 24 and a back pressure valve 28 are fixedly installed on the recovery pipeline 11 along the material flow direction, a fourth valve 25 is fixedly installed on the first fluorinated liquid pipeline 8 between the second pressure sensor 13 and the core clamp 1, a fifth valve 26 is fixedly installed on the second fluorinated liquid pipeline 9 between the third pressure sensor 14 and the core clamp 1, and a sixth valve 27 is fixedly installed on the first fluorinated liquid pipeline 8 between the second fluorinated liquid pipeline 9 and the fluorinated liquid storage tank 3.

[0033] Example 10: Figure 1 , 2 As shown, as an optimization of the above embodiment, the wellbore is made of Peek material, and the wellbore includes a lower end that penetrates into the borehole and an upper end connected to the core holder 1. A fixing glue filling groove is opened from bottom to top on the outer side of the lower end of the wellbore, and an O-ring groove (such as Figure 2 As shown). To meet the experimental requirements, the wellbore is made of Peek material to meet the test requirements of the nuclear magnetic resonance spectrometer 5 and the CT device. Similarly, the materials involved in the experiment cannot be magnetic, so the core holder also needs to be made of Peek material. The fixing glue filling groove opened on the outside of the wellbore facilitates the injection of the fixing glue, so that the wellbore and the core sample are better fixed, and the O-ring groove ensures the fixation and sealing between the wellbore and the core holder 1.

[0034] As required, valves, temperature control and detection devices are fixedly installed on each pipeline of the reservoir supercritical carbon dioxide fracturing well soaking production simulation device to enable its normal operation.

[0035] Example 11: The reservoir supercritical carbon dioxide fracturing well production simulation method is carried out according to the following steps: The first step is core preparation. The core is processed into a core sample with a diameter and length of 38mm*70, and a hole with a diameter and depth of 8mm*40mm is drilled axially in the center of the core sample; the core is washed with oil and dried, and then vacuumed and saturated with crude oil. The oil washing operation is as follows: the core sample is placed in an oil washing device (Soxhlet extractor), dichloromethane is added to it, and the heating and circulation devices are turned on. When the solvent in the solvent chamber reaches colorless and transparent, the heating is stopped, and the core sample is taken out and placed in an oven, dried at 110°C for 24 hours, and the oil washing is completed. The crude oil saturation operation is as follows: the core sample is placed in a vacuum saturation device, vacuumed to -0.1MPa, and this vacuum is maintained for 24 hours. Then, crude oil is pumped into the vacuum saturation device and pressurized to 15MPa to 35MPa, and saturated for 7 days.

[0036] The second step is to simulate cementing. Figure 2 The wellbore shown is placed in the borehole of the core sample after being saturated with crude oil. The wellbore is made of Peek material and fixed with epoxy resin. After standing for 2 days, the epoxy resin is completely solidified to complete the cementing.

[0037] Step 3: Fracturing simulation: ① Place the O-ring in the O-ring groove of the wellbore, press the wellbore into the plug at the wellbore feed end of the core holder 1, place the core in the core holder 1, and then use a thermoplastic tube to wrap the core and the plug together; ② Place the core holder 1 in the nuclear magnetic resonance spectrometer 5, and apply axial pressure and confining pressure to the core sample to simulate the actual triaxial stress of the formation. The specific operation is: open the fourth valve 25, the fifth valve 26 and the sixth valve 27, inject fluorinated liquid into the core holder 1 through the first fluorinated liquid pipeline 8 and the second fluorinated liquid pipeline 9, apply specific confining pressure and axial pressure (0 to 30MPa) to the core sample, and control the experimental temperature to 34℃ to 90℃; ③ Start the online monitoring of NMR fluid to obtain the initial experimental data of the core sample at this time (T2 spectrum, 1D frequency coding and two-dimensional crude oil distribution); ④ Preparation of supercritical carbon dioxide: Open the first valve 22, inject carbon dioxide gas into the supercritical carbon dioxide storage tank 16, pressurize the gas pressure in the supercritical carbon dioxide storage tank 16 to 7.2MPa through the gas booster pump 21, and the temperature of the supercritical carbon dioxide storage tank 16 is above 31°C to prepare supercritical carbon dioxide; ⑤ After the supercritical carbon dioxide is prepared, the second valve 23 is opened, the fourth valve 25 and the sixth valve 27 are closed, and the supercritical carbon dioxide is injected into the core sample through the wellbore at a constant flow rate (5cc / min to 30cc / min). At the same time, the first pressure sensor 12 and the fourth pressure sensor 15 respectively collect the changes in the axial pressure (or confining pressure) and the supercritical carbon dioxide injection pressure; ⑥ When the supercritical carbon dioxide injection pressure of the core sample suddenly drops, indicating that the core sample is fractured, the second constant pressure and constant flow pump 17 is turned off, and the T2 spectrum, 1D frequency coding and two-dimensional crude oil distribution of the core sample are collected.

[0038] The fourth step is to simulate the well-keeping phase, which lasts from 1 to 7 days.

[0039] Step 5, production simulation: After the well is soaked, the production simulation phase begins. The back pressure required for the experiment is set through the back pressure valve 28, with the back pressure range of 0.1MPa to 15MPa. The second valve 23 is closed, and the third valve 24 is opened to enter the flowback (production) phase. In this phase, the T2 spectrum, 1D frequency coding, and two-dimensional crude oil distribution of the core sample during the production simulation process need to be monitored.

[0040] Step 6: 3D imaging analysis. After the production simulation is completed, the fifth valve 26 is closed, the core holder 1 is removed, and placed in a high-precision industrial CT to obtain a CT image of the crack distribution of the core sample (see Figure 5 ), and conduct three-dimensional imaging analysis of the cracks formed by fracturing.

[0041] The experimental data collected in this example, T2 spectrum, 1D frequency encoding and two-dimensional crude oil distribution Figure 3 and Figure 4 .

[0042] The present invention uses a nuclear magnetic resonance spectrometer and a CT imaging device to realize online monitoring of the spatial and microscopic distribution characteristics of crude oil during supercritical carbon dioxide fracturing of unconventional reservoirs, and clarifies the use of crude oil in pores of different scales by this development method. The recovery rate of pores of different scales can be obtained from the T2 spectrum, the spatial distribution of crude oil can be obtained from 1D frequency encoding and two-dimensional imaging, and the distribution state of cracks can be obtained from the CT imaging device, thereby forming a comprehensive characterization of the spatial distribution of cracks and crude oil during the fracturing process.

[0043] In summary, the reservoir supercritical carbon dioxide fracturing and well-insertion production simulation method and device of the present invention provide an unconventional supercritical carbon dioxide fracturing-well-insertion-production integrated physical simulation. The wellbore is fixed in the reservoir core saturated with crude oil by cementing, and the axial pressure and confining pressure devices are used to simulate the tight / shale reservoir conditions. After fracturing, the characteristics of crude oil utilization and the distribution of fractures during the development process are clarified by a nuclear magnetic resonance spectrometer and a high-precision CT device.

[0044] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A reservoir supercritical carbon dioxide fracturing well production simulation method, characterized in that Follow these steps: The first step is core preparation. A wellbore is drilled axially in the center of the core sample. The drilled core sample is washed with oil, dried, and vacuumed to saturate with crude oil. The second step is to simulate cementing, placing the wellbore in the borehole and fixing it with a fixing glue, and the cementing is completed after the fixing glue solidifies; The third step is fracturing simulation. The cemented core sample is placed in a core holder and axial pressure and confining pressure are applied to the core sample to simulate the triaxial stress of the formation at the required temperature to obtain the initial experimental data of the core sample. Then, supercritical carbon dioxide is injected into the core sample through the wellbore to obtain the experimental data of the core fracturing. The fourth step is to simulate the well shut-in, and the core sample enters the well shut-in stage after fracturing; The fifth step is production simulation. Under specific back pressure conditions, the core samples enter the flowback stage and the experimental data of the core samples in the flowback stage are recorded. The sixth step is three-dimensional imaging analysis. After the production simulation is completed, the core samples are taken out and CT scanned to obtain three-dimensional imaging of the cracks formed by fracturing.

2. The reservoir supercritical carbon dioxide fracturing well shut-in production simulation method according to claim 1 is characterized in that In the first step, the core sample is cylindrical with a diameter of 30mm to 50mm and a length of 60mm to 100mm, and the core drilling diameter is 5mm to 10mm and the depth is 30mm to 50mm.

3. The reservoir supercritical carbon dioxide fracturing well shut-in production simulation method according to claim 1 or 2, characterized in that In the third step, the confining pressure and the axial pressure are 0 to 30 MPa, and the temperature is 34°C to 90°C.

4. The reservoir supercritical carbon dioxide fracturing well shut-in production simulation method according to any one of claims 1 to 3, characterized in that In the third step, supercritical carbon dioxide is injected into the core sample at a constant flow rate of 5cc / min to 30cc / min. The injection pressure is monitored during the injection of supercritical carbon dioxide. When the injection pressure suddenly drops, it indicates that the core is fractured and the supercritical carbon dioxide injection is stopped.

5. The reservoir supercritical carbon dioxide fracturing well shut-in production simulation method according to any one of claims 1 to 4, characterized in that In the third and fifth steps, the experimental data include: T2 spectrum, 1D frequency encoding and two-dimensional crude oil distribution.

6. The reservoir supercritical carbon dioxide fracturing well shut-in production simulation method according to any one of claims 1 to 5, characterized in that In the fourth step, the well-keeping stage lasts from 1 day to 7 days.

7. A reservoir supercritical carbon dioxide fracturing well shut-in production simulation device for implementing the method according to any one of claims 1 to 6, characterized in that The invention comprises a supercritical carbon dioxide component, a confining pressure loading component, a core clamping component and a data acquisition component, wherein the core clamping component comprises a core clamp and a recovery tank, the confining pressure loading component comprises a fluorinated liquid storage tank and a first constant pressure and constant flow pump, the data acquisition component comprises a nuclear magnetic resonance spectrometer and a computer, a fluorinated liquid pumping pipeline is fixedly connected between the first constant pressure and constant flow pump and the fluorinated liquid storage tank, a first fluorinated liquid pipeline is fixedly connected between the discharge end of the fluorinated liquid storage tank and the first feed end of the core clamp, a second fluorinated liquid pipeline is fixedly connected between the first fluorinated liquid pipeline and the second feed end of the core clamp, and a wellbore feed end on the right side of the core clamp is connected to the supercritical carbon dioxide component. A supercritical carbon dioxide pipeline is fixedly connected between the discharge ends of the carbon dioxide components, a recovery pipeline is fixedly connected between the supercritical carbon dioxide pipeline and the recovery tank, a first pressure sensor is arranged on the core holder, a second pressure sensor is arranged on the first fluorinated liquid pipeline between the second fluorinated liquid pipeline and the core holder, a third pressure sensor is arranged on the second fluorinated liquid pipeline, a fourth pressure sensor is arranged on the supercritical carbon dioxide pipeline between the recovery pipeline and the core holder, and the first pressure sensor, the second pressure sensor, the third pressure sensor, the fourth pressure sensor and the nuclear magnetic resonance spectrometer are all connected to the computer for communication.

8. The reservoir supercritical carbon dioxide fracturing well shut-in production simulation device according to claim 7, characterized in that The supercritical carbon dioxide assembly includes a supercritical carbon dioxide storage tank, a second constant pressure and constant flow pump and a carbon dioxide gas cylinder. A carbon dioxide pipeline is fixedly connected between the gas outlet end of the carbon dioxide gas cylinder and the gas inlet end of the supercritical carbon dioxide storage tank. A supercritical carbon dioxide pipeline is fixedly connected between the discharge end of the supercritical carbon dioxide storage tank and the feed end of the wellbore on the right side of the core clamp. A supercritical carbon dioxide pumping pipeline is fixedly connected between the supercritical carbon dioxide storage tank and the second constant pressure and constant flow pump, and a gas booster pump is fixedly installed on the carbon dioxide pipeline.

9. The reservoir supercritical carbon dioxide fracturing well shut-in production simulation device according to claim 8, characterized in that A first valve is fixedly installed on the carbon dioxide pipeline between the supercritical carbon dioxide storage tank and the gas booster pump, a second valve is fixedly installed on the supercritical carbon dioxide pipeline between the supercritical carbon dioxide storage tank and the recovery pipeline, a third valve and a back pressure valve are fixedly installed along the material flow direction of the recovery pipeline, a fourth valve is fixedly installed on the first fluorinated liquid pipeline between the second pressure sensor and the core clamp, a fifth valve is fixedly installed on the second fluorinated liquid pipeline between the third pressure sensor and the core clamp, and a sixth valve is fixedly installed on the first fluorinated liquid pipeline between the second fluorinated liquid pipeline and the fluorinated liquid storage tank.

10. The reservoir supercritical carbon dioxide fracturing well shut-in production simulation method according to claim 7, 8 or 9, characterized in that The wellbore is made of Peek material and includes a lower end that penetrates into the borehole and an upper end connected to the core holder. A fixing glue filling groove is provided on the outer side of the lower end of the wellbore from bottom to top, and an O-ring groove is provided on the outer side of the upper end of the wellbore.

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