Experimental apparatus and method for evaluating co2 huff and puff oil recovery and sequestration potential

Abstract

The application discloses an experimental device and method for evaluating the effect of huff and puff oil production and the potential of geological sealing, and belongs to the technical field of oil and gas field development and geological sealing, and provides a basis for accurately evaluating the effect of huff and puff oil production and the potential of geological sealing. The application comprises the following units: a fluid injection unit for selectively injecting water phase, gas phase and oil phase experimental fluid into a core; a core reaction unit for performing huff and puff experiment on the core and obtaining fluid distribution information inside the core; a fluid recovery and metering unit for separating and metering the output multiphase fluid; and an automatic control and analysis unit configured to perform a complete huff and puff experimental process including injection, soak and production according to experimental parameters; and automatically calculate macroscopic crude oil recovery, burial rate and oil exchange rate, spectral crude oil recovery of each round, and crude oil recovery in different pore size intervals. Through the device and method, the experimental efficiency and the reliability and consistency of data are significantly improved.

Description

Technical Field

[0001] This application relates to the field of gas injection development technology for tight oil reservoirs, and particularly to the evaluation of... Experimental apparatus and methods for evaluating the effects of injection and release of oil and its storage potential. Background Technology

[0002] With the world's urgent pursuit of the goal of "carbon neutrality", Capture, utilization, and storage (CCUS) technology has become a key approach to addressing climate change and reducing greenhouse gas emissions. Among these, [CCUS technology]... Injecting oil and gas into reservoirs can effectively improve oil recovery rates. ), and can achieve Geological preservation offers both economic and environmental benefits. Swallowing (also known as " ) as an important The technology, the process of which typically involves injecting into the production well... , close the well and simmer (make) (It interacts fully with the formation crude oil) and then the well is opened for production. This technology shows broad application prospects due to its relatively low investment cost and flexible operation.

[0003] However, The effectiveness of in-situ huff and puff technology is significantly influenced by a complex interplay of factors, including reservoir temperature and pressure conditions, rock pore structure, fluid properties, engineering parameters (such as injection pressure, injection volume, well shut-in time, and huff and puff cycles), and production regimes. This results in substantial uncertainty. For a long time, [the text abruptly ends here, likely due to an incomplete sentence or missing information]. The evaluation of throughput technology's effectiveness and parameter optimization heavily rely on numerical simulations and limited field pilot tests. Numerical simulation methods simulate the effects of throughput technology by establishing geological and fluid phase models. The migration and crude oil extraction processes within the reservoir are relatively low-cost and offer flexible parameter adjustments. Field trials are conducted by implementing actual [measures] in the target block. Injection and production operations allow for direct observation of the increased production effect and gas retention, yielding actual production data. However, both of these evaluation methods have significant limitations. The reliability of numerical simulations heavily relies on the accuracy of the constitutive model and the precision of its description of complex phase behavior and microscopic seepage mechanisms, often exhibiting biases when characterizing the dynamic distribution of multiphase fluids and interphase interactions in porous media. While field tests can reflect actual reservoir responses, they involve substantial investment, high risk, and long cycles, and are difficult to monitor in real time the dynamic changes within the reservoir, thus failing to obtain sufficient data. Key data such as micro-level mobilization patterns and residual oil distribution characteristics.

[0004] In recent years, The indoor experimental research on huff and puff technology continues to develop and has become an important means of evaluating its oil recovery performance and storage potential. Indoor experimental setups can simulate... The intake and output process provides fundamental data for mechanism research and parameter optimization. For example, Chinese patent CN221838311U discloses "A simulation device for evaluating the carbon dioxide intake and output effect of multi-branch horizontal wells". This device simulates the reservoir using a sand-filled box, reproduces complex well network structures using multi-branch horizontal well simulation pipes and vertical well simulation pipes, and is equipped with a constant temperature chamber, pressure pump, and oil-gas-water separation metering device, enabling it to perform tests under multiple sets of parameters. Through throughput simulation experiments, the macroscopic production effects of different schemes were compared.

[0005] Although existing indoor experimental devices, represented by Chinese patent CN221838311U, have achieved the ability to test specific well network structures... The macroscopic physical simulation of the throughput process exists, but it still has three prominent limitations:

[0006] (1) The evaluation dimensions are singular, and the microscopic monitoring mechanism is lacking. This type of device can only collect macroscopic production parameters such as injection pressure and liquid production, and is completely unable to realize the distribution of multiphase fluid saturation inside the core. The lack of in-situ, non-destructive, and dynamic monitoring of microscopic mobilization patterns and the state of residual oil storage means that experimental evaluation remains a "black box" comparison of effects, making it difficult to reveal... The utilization efficiency in pores of different scales also makes it impossible to establish a quantitative correlation between engineering parameters and microscopic displacement mechanisms, which restricts the deepening of mechanism understanding and the precise optimization of parameters.

[0007] (2) Insufficient automation and intelligence in process control. The temperature and pressure control of existing devices mostly adopts open-loop or simple feedback mode, which lacks the ability to accurately control the phased transition of "injection-well shut-in-production" and dynamic temperature and pressure conditions in a closed loop. Furthermore, operations such as fluid switching and data recording still rely on manual or preset sequence control, lacking the ability to adaptively adjust based on real-time operating conditions, resulting in poor consistency of experimental conditions, significant operational errors, and low overall efficiency.

[0008] (3) The disconnect between macro and micro data limits the guiding value of the results. Due to the lack of in-situ monitoring methods, there is no direct and quantitative intrinsic link between macro production data and reservoir micro mechanism evolution. As a result, the experimental conclusions can only answer "which scheme is more effective", but cannot explain "where its advantages lie" and "how to further optimize at the micro level". The data obtained is also difficult to use for calibration and verification of high-precision numerical simulation models, which greatly limits its theoretical guidance and decision support role in mine practice.

[0009] Therefore, existing technologies are effective in addressing... When conducting experimental evaluations of the effects of injection and release of oil and its storage potential, there are generally problems such as limited ability to simulate real environments, low degree of automation in process control, lack of micro-dynamic monitoring, and insufficient combination of macro- and micro-evaluations. These problems restrict in-depth research on the mechanism of action of this technology and parameter optimization for field applications. Summary of the Invention

[0010] Based on this, an evaluation is provided to address the aforementioned technical issues. An experimental setup for evaluating the effects of injection and release of oil and its storage potential, designed to address the limitations of existing technologies. When conducting experimental evaluations of the effects of injection and release of oil and the potential for storage, there are generally problems such as limited ability to simulate real environments, low degree of automation in process control, lack of micro-dynamic monitoring, and insufficient combination of macro- and micro-evaluations.

[0011] Firstly, evaluation An experimental apparatus for evaluating the effects of injection and release of oil and its storage potential, the apparatus comprising:

[0012] The fluid injection unit is used to selectively or alternately inject water-phase, gas-phase, and oil-phase experimental fluids into the core.

[0013] The core reaction unit is used to process the core under simulated formation temperature and pressure conditions. The core was subjected to a throughput experiment to obtain information on the fluid distribution inside the core.

[0014] The fluid recovery and metering unit is used to separate and meter the multiphase fluid produced by the core reaction unit.

[0015] The automatic control and analysis unit is connected to the fluid injection unit, the core reaction unit, and the fluid recovery and metering unit via signals, respectively.

[0016] The automatic control and analysis unit is configured to: based on preset experimental parameters, perform closed-loop control of the fluid injection action of the fluid injection unit, the temperature and pressure conditions and well shut-in status of the core reaction unit, and the opening and closing of the production valve of the fluid recovery and metering unit, thereby automatically executing actions including... A complete injection, well shut-in, and production throughput experimental process; and integrating fluid distribution information from the core reaction unit and fluid metering data from the fluid recovery and metering unit to automatically calculate macroscopic oil recovery rate. Buried rate and oil change rate, per round The oil recovery rate was measured using spectrophotometry and the oil recovery rate within different aperture ranges, in order to conduct... A multi-dimensional quantitative evaluation of the effects of injection and release of oil and its storage potential.

[0017] Optionally, in the above scheme, the fluid injection unit includes: a booster pump, a first four-way valve, a first pressure gauge, a second pressure gauge, a third pressure gauge, a first shut-off valve, a second shut-off valve, a third shut-off valve, an oil phase storage tank, a gas phase storage tank, an aqueous phase storage tank, a fourth shut-off valve, a fifth shut-off valve, a sixth shut-off valve, a first flow meter, a second flow meter, a third flow meter, a second four-way valve, a seventh shut-off valve, and a fourth flow meter;

[0018] The outlet of the booster pump is connected to the inlet of the first four-way valve; the three outlets of the first four-way valve are respectively connected to the oil phase storage tank via the first pressure gauge and the first shut-off valve, to the gas phase storage tank via the second pressure gauge and the second shut-off valve, and to the aqueous phase storage tank via the third pressure gauge and the third shut-off valve; the outlets of the oil phase storage tank, the gas phase storage tank, and the aqueous phase storage tank are connected to the inlet pipeline of the second four-way valve; a fourth shut-off valve and a first flow meter are sequentially installed on the pipeline between the outlet of the oil phase storage tank and the inlet pipeline of the second four-way valve; a fifth shut-off valve and a second flow meter are sequentially installed on the pipeline between the outlet of the gas phase storage tank and the inlet pipeline of the second four-way valve; and a sixth shut-off valve and a third flow meter are sequentially installed on the pipeline between the outlet of the aqueous phase storage tank and the inlet pipeline of the second four-way valve.

[0019] The seventh shut-off valve and the fourth flow meter are connected sequentially at the outlet of the second four-way valve.

[0020] In the above scheme, optionally, the core reaction unit includes: a fourth pressure gauge, a core, a core holder, a nuclear magnetic resonance analyzer, a constant temperature chamber, a thermometer, a fifth pressure gauge, an eighth shut-off valve, a confining pressure pump, a back pressure valve, a sixth pressure gauge, a ninth shut-off valve, and a back pressure pump.

[0021] The outlet of the second four-way valve is connected to the inlet of the core holder via the seventh shut-off valve, the fourth flow meter, and the fourth pressure gauge.

[0022] The core is sealed and installed in the internal cavity of the core holder; the detection probe of the nuclear magnetic resonance analyzer 28 is arranged around the outside of the core holder; the core holder is located inside the constant temperature chamber; the thermometer is located inside the constant temperature chamber; the outlet end of the confining pressure pump is connected to the confining pressure port pipeline of the core holder, and the eighth shut-off valve and the fifth pressure gauge are sequentially installed on the connecting pipeline between the outlet end of the confining pressure pump and the confining pressure port of the core holder; the back pressure port of the core holder is connected to the back pressure pump pipeline, and the ninth shut-off valve and the back pressure valve are sequentially installed on the connecting pipeline between the back pressure port of the core holder and the back pressure pump; the core outlet end of the core holder is also provided with a back pressure valve and a sixth pressure gauge.

[0023] In the above scheme, optionally, the fluid recovery and metering unit includes a tenth shut-off valve, a fifth flow meter, a three-phase separator, an eleventh shut-off valve, a sixth flow meter, a gas collector, a twelfth shut-off valve, a seventh flow meter, an oil phase collector, a thirteenth shut-off valve, an eighth flow meter, and a water phase collector.

[0024] The core outlet of the core holder is connected to the inlet pipe of the three-phase separator. The tenth shut-off valve and the fifth flow meter are also installed in the connection pipe between the core outlet of the core holder and the inlet of the three-phase separator. The gas phase outlet of the three-phase separator is connected to the gas collector pipe through the eleventh shut-off valve and the sixth flow meter. The oil phase outlet of the three-phase separator is connected to the oil phase collector through the twelfth shut-off valve and the seventh flow meter. The water phase outlet of the three-phase separator is connected to the water phase collector through the thirteenth shut-off valve and the eighth flow meter.

[0025] In the above scheme, optionally, the automatic control and analysis unit includes a processor, which is also connected to the fluid injection unit booster pump, the first four-way valve, the first pressure gauge, the second pressure gauge, the third pressure gauge, the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the sixth shut-off valve, the first flow meter, the second flow meter, the third flow meter, the second four-way valve, the seventh shut-off valve, and the fourth flow meter.

[0026] The processor is also connected to the core reaction unit, which includes a fourth pressure gauge, a nuclear magnetic resonance analyzer, a constant temperature chamber, a thermometer, a fifth pressure gauge, an eighth shut-off valve, a confining pressure pump, a back pressure valve, a sixth pressure gauge, a ninth shut-off valve, and a back pressure pump.

[0027] The processor is also connected to the tenth shut-off valve, fifth flow meter, eleventh shut-off valve, sixth flow meter, twelfth shut-off valve, seventh flow meter, thirteenth shut-off valve and eighth flow meter of the fluid recovery and metering unit.

[0028] Secondly, evaluation The experimental methods for evaluating the effectiveness of injection and release of oil and its storage potential apply the evaluation methods described in the first aspect above. An experimental setup for evaluating the effectiveness of injection and release of oil and its storage potential includes the following steps:

[0029] S1: Standard core samples taken from the target stratum are loaded into the center of the core holder; the processor controls the core reaction unit to establish the target temperature and target confining pressure of the simulated stratum and maintain them for a preset time, and acquire the nuclear magnetic resonance (NMR) data of the dried core sample collected by the NMR analyzer. Spectrum as a benchmark Spectrum;

[0030] S2: The processor controls the fluid injection unit to independently inject formation water into the core at constant pressure until the formation water is saturated; then the injection of formation water is stopped, and simulated crude oil is injected at constant pressure until there are no bubbles at the outlet and the flow rate is stable; the results are obtained from the core saturated with simulated crude oil using a nuclear magnetic resonance analyzer. Spectrum as the initial oil-bearing state Spectrum;

[0031] S3: The processor controls the back pressure pump of the core reaction unit to discharge the residual free oil and water phases in the core holder and connected pipelines;

[0032] S4: Constant pressure injection is controlled via the processor-controlled fluid injection unit. and obtain Injection volume; and control the core reaction unit to enter a sealed state and maintain the preset well-closing time;

[0033] S5: The processor controls the back pressure valve and back pressure pump of the core reaction unit to control the outlet pressure, and controls the fluid recovery and metering unit to simulate well opening production, separating oil, gas, and water in real time until production ends; the processor acquires the core data collected by the nuclear magnetic resonance analyzer after production ends. Spectrum as the end of production The spectrum, as well as the volumes of oil, gas, and water phases recorded by the fluid recovery and metering unit;

[0034] S6: Repeat steps S4-S5;

[0035] S7: Based on the recorded volumes of oil, gas, and water phases during each throughput cycle, the processor 51 calculates the macro-oil recovery rate for each cycle and the cumulative recovery rate. Burial rate and oil change rate; and based on the initial oil content. Spectrum and production technology after each round of production The spectrum is automatically calculated for each round by the processor 51. The study analyzed the oil recovery rate at different pore sizes, as well as the oil recovery rate within different pore size ranges, to conduct a comprehensive evaluation at both macro and micro levels. Swallowing and spitting effect.

[0036] Optionally, in the above scheme, the macro-oil recovery rate is calculated using the following formula:

[0037]

[0038] in, For macro-level crude oil recovery rate, For the volume of oil produced,

[0039] This represents the volume of saturated oil in the core.

[0040] The The burial rate is calculated using the following formula:

[0041]

[0042] in, for Burial rate, For burial volume, For injection volume, For output volume;

[0043] The oil change rate is calculated using the following formula:

[0044]

[0045] in, For oil change rate, For injection volume, This represents the volume of oil produced.

[0046] Optionally, in the above scheme, the The oil recovery rate is calculated using the following formula:

[0047]

[0048] in, for Spectrum of oil recovery rate In the dry state Spectral amplitude value, In its original oil-bearing state Spectral amplitude value, The remaining oil state after spitting out Spectral amplitude value, summation sign Indicates the whole The amplitude values ​​corresponding to all relaxation time points in the spectrum are summed.

[0049] Optionally, in the above scheme, the oil recovery rate within the different aperture ranges is calculated using the following formula:

[0050]

[0051] in, Let be the oil recovery rate for the j-th aperture range. For the j-th aperture interval Relaxation time range For samples in a dry state that belong to this pore size range The sum of spectral amplitude values, For those in the original oil-bearing state, belonging to this pore size range The sum of spectral amplitude values, The remaining oil after the intake and exhaust process belongs to this orifice size range. The sum of spectral amplitude values.

[0052] This application has at least the following beneficial effects:

[0053] (1) Through the collaboration of the core reaction unit and the automatic control and analysis unit, it is possible to achieve The automated operation and precise control of the entire process of "injection-well shut-in-production" significantly improves experimental efficiency and the reliability and consistency of data.

[0054] (2) By combining the temperature and pressure co-control system with nuclear magnetic resonance technology, it is possible to realistically simulate formation conditions and realize in-situ, non-destructive, and dynamic monitoring of fluid saturation inside the core, revealing The micro-mechanism of utilization and the distribution pattern of residual oil.

[0055] (3) Its automatic control and analysis unit can simultaneously collect and intelligently integrate macroscopic production data from the fluid recovery and metering unit and microscopic data from the core reaction unit. Spectral data. Based on this, the system can automatically calculate not only the macroscopic oil recovery rate, but also... Traditional engineering indicators such as burial rate can be automatically calculated to reflect the micro-level utilization effect. Oil recovery rate by spectral density and oil recovery rate by pore size. Combining macroscopic production data with microscopic nuclear magnetic resonance (NMR) data. By combining spectral information, a multi-dimensional quantitative evaluation of recovery rate, from macroscopic recovery rate to aperture-specific recovery rate, was achieved, providing a basis for a deeper understanding of... The throughput mechanism and optimized engineering parameters provide comprehensive data support.

[0056] (4) The highly integrated modular design and unified central control integrate previously scattered operations such as fluid injection, thermo-pressure reaction, fluid recovery, data acquisition and analysis into a fully automated organic whole. This minimizes human intervention and operational errors, ensuring high repeatability of batch experiments. Simultaneously, closed-loop control and real-time monitoring significantly improve high-pressure... Safety of the experimental process. This is to address... The study provides an efficient and reliable technical platform for the large number of repetitive and precise experiments required for throughput parameter optimization research. Attached Figure Description

[0057] Figure 1 Provided for one embodiment of this application Structural diagram of the experimental setup for testing the effects of injection and release of oil and its storage potential;

[0058] Figure 2 Evaluation provided for one embodiment of this application Flowchart of experimental methods for evaluating the effectiveness of huff and puff oil recovery and its storage potential;

[0059] Figure 3 This application provides multiple groups of sandstone core samples from a certain block in one embodiment. Schematic diagram of the nuclear magnetic resonance T2 spectrum of the swallow-spit experiment;

[0060] Figure 4 Multiple rounds of shale core samples from another block provided in one embodiment of this application Schematic diagram of the nuclear magnetic resonance T2 spectrum of the swallow-spit experiment;

[0061] Among them, 1—fluid injection unit; 2—core reaction unit; 3—fluid recovery and metering unit; 4—automatic control and analysis unit; 5—booster pump; 6—first four-way valve; 7—first pressure gauge; 8—second pressure gauge; 9—third pressure gauge; 10—first shut-off valve; 11—second shut-off valve; 12—third shut-off valve; 13—oil phase storage tank; 14—gas phase storage tank; 15—aqueous phase storage tank; 16—fourth shut-off valve; 17—fifth shut-off valve; 18—sixth shut-off valve; 19—first flow meter; 20—second flow meter; 21—third flow meter; 22—second four-way valve; 23—seventh shut-off valve; 24—fourth flow meter; 25—fourth pressure gauge; 2 6—Core; 27—Core holder; 28—Nuclear magnetic resonance analyzer; 29—Insulated chamber; 30—Thermometer; 31—Fifth pressure gauge; 32—Eighth shut-off valve; 33—Containing pressure pump; 34—Back pressure valve; 35—Sixth pressure gauge; 36—Ninth shut-off valve; 37—Back pressure pump; 38—Tenth shut-off valve; 39—Fifth flow meter; 40—Three-phase separator; 41—Eleventh shut-off valve; 42—Sixth flow meter; 43—Gas collector; 44—Twelfth shut-off valve; 45—Seventh flow meter; 46—Oil phase collector; 47—Thirteenth shut-off valve; 48—Eighth flow meter; 49—Water phase collector; 50—Input terminal; 51—Processor; 52—Display. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0063] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0064] In one embodiment, such as Figure 1 As shown, the evaluation An experimental apparatus for evaluating the effects of injection and release of oil and its storage potential, the apparatus comprising:

[0065] Fluid injection unit 1 is used to selectively inject water-phase, gas-phase, and oil-phase experimental fluids into the core independently or alternately.

[0066] Core reaction unit 2 is used to process the core under simulated formation temperature and pressure conditions. The core was subjected to a throughput experiment to obtain information on the fluid distribution inside the core.

[0067] The fluid recovery and metering unit 3 is used to separate and meter the multiphase fluid produced by the core reaction unit 2;

[0068] Automatic control and analysis unit 4 is connected to fluid injection unit 1, core reaction unit 2 and fluid recovery and metering unit 3 respectively;

[0069] The automatic control and analysis unit 4 is configured to: based on preset experimental parameters, perform closed-loop control of the fluid injection action of the fluid injection unit 1, the temperature and pressure conditions and well shut-in status of the core reaction unit 2, and the opening and closing of the production valve of the fluid recovery and metering unit, thereby automatically executing actions including... A complete injection, well shut-in, and production throughput experimental process; and by integrating core fluid distribution information from the core reaction unit and production fluid metering data from the fluid recovery and metering unit, the macroscopic oil recovery rate is automatically calculated. Buried rate and oil change rate, per round The oil recovery rate was measured using spectrophotometry and the oil recovery rate within different aperture ranges, in order to conduct... A multi-dimensional quantitative evaluation of the effects of injection and release of oil and its storage potential.

[0070] In one embodiment, the fluid injection unit 1 includes: a booster pump 5, a first four-way valve 6, a first pressure gauge 7, a second pressure gauge 8, a third pressure gauge 9, a first shut-off valve 10, a second shut-off valve 11, a third shut-off valve 12, an oil phase storage tank 13, a gas phase storage tank 14, an aqueous phase storage tank 15, a fourth shut-off valve 16, a fifth shut-off valve 17, a sixth shut-off valve 18, a first flow meter 19, a second flow meter 20, a third flow meter 21, a second four-way valve 22, a seventh shut-off valve 23, and a fourth flow meter 24;

[0071] The outlet of the booster pump 5 is connected to the inlet of the first four-way valve 6. The three outlets of the first four-way valve 6 are respectively connected to the oil phase storage tank 13 via the first pressure gauge 7 and the first shut-off valve 10, to the gas phase storage tank 14 via the second pressure gauge 8 and the second shut-off valve 11, and to the aqueous phase storage tank 15 via the third pressure gauge 9 and the third shut-off valve 12. The outlets of the oil phase storage tank 13, the gas phase storage tank 14, and the aqueous phase storage tank 15 are connected to the inlet pipeline of the second four-way valve 20. A fourth shut-off valve 16 and a first flow meter 19 are sequentially installed on the outlet of the oil phase storage tank 13 and the inlet pipeline of the second four-way valve 20. A fifth shut-off valve 17 and a second flow meter 20 are sequentially installed on the outlet of the gas phase storage tank 14 and the inlet pipeline of the second four-way valve 20. A sixth shut-off valve 18 and a third flow meter 21 are sequentially installed on the outlet of the aqueous phase storage tank 13 and the inlet pipeline of the second four-way valve 20.

[0072] The seventh shut-off valve 23 and the fourth flow meter 24 are connected sequentially to the outlet of the second four-way valve 22.

[0073] In this embodiment, the fluid injection unit 1 adopts a multi-channel independent design, enabling closed-loop precise control through the automatic control and analysis unit 4. The fluid injection unit 1 can dynamically adjust the operating mode of the booster pump 5 based on feedback signals from the first pressure gauge 7, the second pressure gauge 8, and the third pressure gauge 9 to achieve constant pressure injection. The fluid injection unit 1 can control the opening and closing states of the first shut-off valve 10 to the seventh shut-off valve 23 to achieve oil phase... Alternatively, the aqueous phase may be injected separately, alternately, or in combination.

[0074] In one embodiment, the core reaction unit 2 includes: a fourth pressure gauge 25, a core 26, a core holder 27, a nuclear magnetic resonance analyzer 28, a constant temperature chamber 29, a thermometer 30, a fifth pressure gauge 31, an eighth shut-off valve 32, a confining pressure pump 33, a back pressure valve 34, a sixth pressure gauge 35, a ninth shut-off valve 36, and a back pressure pump 37.

[0075] The outlet of the second four-way valve 22 is connected to the inlet of the core holder 27 via the seventh shut-off valve 23, the fourth flow meter 24, and the fourth pressure gauge 27.

[0076] The core 26 is sealed and installed in the internal cavity of the core holder 27; the detection probe of the nuclear magnetic resonance analyzer 28 is arranged around the outside of the core holder 27; the core holder 27 is located inside the constant temperature chamber 29; the thermometer 30 is located inside the constant temperature chamber 29; the outlet end of the confining pressure pump 33 is connected to the confining pressure port pipeline of the core holder 27, and the eighth shut-off valve 32 and the fifth pressure gauge 31 are sequentially arranged on the connecting pipeline between the outlet end of the confining pressure pump 33 and the confining pressure port of the core holder 27; the back pressure port of the core holder 27 is connected to the back pressure pump 37 pipeline, and the ninth shut-off valve 36 and the back pressure valve 34 are sequentially arranged on the connecting pipeline between the back pressure port of the core holder 27 and the back pressure pump 37; the core outlet end of the core holder 27 is also provided with a back pressure valve 34 and a sixth pressure gauge 35.

[0077] In this embodiment, the core reaction unit 2 adopts a temperature and pressure coordinated control and online analysis design, which can achieve closed-loop precise regulation through the automatic control and analysis unit 4; the core reaction unit 2 can dynamically adjust the working modes of the constant temperature chamber 29, the confining pressure pump 33, and the back pressure pump 37 according to the thermometer 30, the fifth pressure gauge 31, and the sixth pressure gauge 35 to achieve constant temperature, constant confining pressure, or constant back pressure control; the core reaction unit 2 can automatically collect core samples 26 at key experimental nodes through the nuclear magnetic resonance analyzer 28. The key nodes include after the installation of core 26, after the initial saturation of fluid, and after the end of each production cycle.

[0078] In one embodiment, the fluid recovery and metering unit 3 includes a tenth shut-off valve 38, a fifth flow meter 39, a three-phase separator 40, an eleventh shut-off valve 41, a sixth flow meter 42, a gas collector 43, a twelfth shut-off valve 44, a seventh flow meter 45, an oil phase collector 46, a thirteenth shut-off valve 47, an eighth flow meter 48, and a water phase collector 49.

[0079] The core outlet of the core holder 27 is connected to the inlet pipe of the three-phase separator 40. The tenth shut-off valve 38 and the fifth flow meter 39 are also provided in the connection pipe between the core outlet of the core holder 27 and the inlet of the three-phase separator 40. The gas phase outlet of the three-phase separator 40 is connected to the gas collector 43 through the eleventh shut-off valve 41 and the sixth flow meter 42. The oil phase outlet of the three-phase separator 40 is connected to the oil phase collector 46 through the twelfth shut-off valve 44 and the seventh flow meter 45. The water phase outlet of the three-phase separator 40 is connected to the water phase collector 49 through the thirteenth shut-off valve 47 and the eighth flow meter 48.

[0080] In this embodiment, the fluid recovery and metering unit 3 adopts a multi-stage separation and phase-separated metering design, which can achieve closed-loop precise control through the automatic control and analysis unit 4. The fluid recovery and metering unit 3 can control the on / off states of the tenth shut-off valve 38, the eleventh shut-off valve 41, the twelfth shut-off valve 44 and the thirteenth shut-off valve 47 and the working mode of the three-phase separator 40, so as to achieve effective separation and collection of the produced multiphase fluid. The fluid recovery and metering unit 3 can measure the total liquid production and the instantaneous and cumulative production of gas phase, oil phase and water phase fluid in real time according to the feedback signals of the fifth flow meter 39, the sixth flow meter 42, the seventh flow meter 45 and the eighth flow meter 48.

[0081] In one embodiment, the automatic control and analysis unit 4 includes a processor 51, which is also connected to the booster pump 5, the first four-way valve 6, the first pressure gauge 7, the second pressure gauge 8, the third pressure gauge 9, the first shut-off valve 10, the second shut-off valve 11, the third shut-off valve 12, the fourth shut-off valve 16, the fifth shut-off valve 17, the sixth shut-off valve 18, the first flow meter 19, the second flow meter 20, the third flow meter 21, the second four-way valve 22, the seventh shut-off valve 23, and the fourth flow meter 24 of the fluid injection unit 1.

[0082] The processor 51 is also connected to the core reaction unit 2, which includes the fourth pressure gauge 25, nuclear magnetic resonance analyzer 28, constant temperature chamber 29, thermometer 30, fifth pressure gauge 31, eighth shut-off valve 32, confining pressure pump 33, back pressure valve 34, sixth pressure gauge 35, ninth shut-off valve 36, and back pressure pump 37.

[0083] The processor 51 is also connected to the tenth shut-off valve 38, the fifth flow meter 39, the eleventh shut-off valve 41, the sixth flow meter 42, the twelfth shut-off valve 44, the seventh flow meter 45, the thirteenth shut-off valve 47, and the eighth flow meter 48 of the fluid recovery and metering unit 3.

[0084] The automatic control and analysis unit 4 adopts a centralized monitoring and distributed control design. It can preset experimental temperature, pressure, flow parameters, and injection / production procedures via the input terminal 50 (i.e., the keyboard display). The automatic control and analysis unit 4 can receive and process feedback signals from all pressure gauges, flow meters, thermometers 30, and nuclear magnetic resonance analyzers 28 in each system via the processor 51, and accordingly issue control commands to the booster pump 5, each shut-off valve, confining pressure pump 33, and backpressure pump 37. This coordinates and manages the operation of the fluid injection unit 1, the core reaction unit 2, and the fluid recovery and metering unit 3, achieving automatic operation and precise control of the entire device. The automatic control and analysis unit 4 can dynamically display system status, real-time parameter curves, and nuclear magnetic resonance data via the display 52. Spectrum and analysis results.

[0085] The experimental setup described above for evaluating CO2 huff and puff oil recovery and storage potential includes the following beneficial effects:

[0086] (1) Through the collaboration of the core reaction unit and the automatic control and analysis unit, it is possible to achieve The automated operation and precise control of the entire process of "injection-well shut-in-production" significantly improves experimental efficiency and the reliability and consistency of data.

[0087] (2) By combining the temperature and pressure co-control system with nuclear magnetic resonance technology, it is possible to realistically simulate formation conditions and realize in-situ, non-destructive, and dynamic monitoring of fluid saturation inside the core, revealing The micro-mechanism of utilization and the distribution pattern of residual oil.

[0088] (3) Its automatic control and analysis unit can simultaneously collect and intelligently integrate macroscopic production data from the fluid recovery and metering unit and microscopic data from the core reaction unit. Spectral data. Based on this, the system can automatically calculate not only the macroscopic oil recovery rate, but also... Traditional engineering indicators such as burial rate can be automatically calculated to reflect the micro-level utilization effect. Oil recovery rate by spectral density and oil recovery rate by pore size. Combining macroscopic production data with microscopic nuclear magnetic resonance (NMR) data. By combining spectral information, a multi-dimensional quantitative evaluation of recovery rate, from macroscopic recovery rate to aperture-specific recovery rate, was achieved, providing a basis for a deeper understanding of... The throughput mechanism and optimized engineering parameters provide comprehensive data support.

[0089] (4) The highly integrated modular design and unified central control integrate previously scattered operations such as fluid injection, thermo-pressure reaction, fluid recovery, data acquisition and analysis into a fully automated organic whole. This minimizes human intervention and operational errors, ensuring high repeatability of batch experiments. Simultaneously, closed-loop control and real-time monitoring significantly improve high-pressure... Safety of the experimental process. This is to address... The study provides an efficient and reliable technical platform for the large number of repetitive and precise experiments required for throughput parameter optimization research.

[0090] In one embodiment, evaluation The experimental methods for evaluating the effectiveness of huff and puff oil recovery and storage potential were applied using the evaluation methods described above. An experimental setup for evaluating the effectiveness of injection and release of oil and its storage potential includes the following steps:

[0091] S1: The standard core 26 taken from the target stratum is placed in the center of the core holder 27; the processor 51 controls the core reaction unit 2 to establish the target temperature and target confining pressure of the simulated stratum and maintain them for a preset time, and the nuclear magnetic resonance (NMR) of the dried core 26 sample is acquired by the nuclear magnetic resonance analyzer 28. Spectrum as a benchmark Spectrum.

[0092] In step S1: Specifically, it includes:

[0093] S11: Core Preparation and Installation: The standard core 26 taken from the target formation is cleaned and dried, and its basic physical properties, including length, diameter, porosity, and permeability, are measured. It is then inserted into the central cavity of the core holder 27 and sealed. Formation water, crude oil, and... Inject the aqueous phase storage tank 15, oil phase storage tank 13, and gas phase storage tank 14 respectively; close the first shut-off valve 10, the second shut-off valve 11, the third shut-off valve 12, the fourth shut-off valve 16, the fifth shut-off valve 17, and the sixth shut-off valve 18; connect the vacuum pump to the end of the vacuum / venting pipeline to evacuate the core reaction unit and the connected pipeline, then close the venting valve and remove the vacuum pump.

[0094] S12: Core parameter input: Input the basic physical property parameters of the core through the input terminal 50 of the automatic control and analysis unit 4.

[0095] S13: Experimental Parameter Setting: The experimental temperature, confining pressure, initial saturated fluid type and sequence, throughput cycles, and parameters for each cycle are set via input terminal 50, including... Injection pressure, injection volume, and well shut-in time.

[0096] S14: System temperature and pressure establishment: confining pressure pump 33 The pressure is increased to the target confining pressure at a rate of 29°C in the constant temperature chamber. The temperature is increased to the target temperature at a certain rate and maintained stably for at least 2 hours.

[0097] S15: Collect dry samples Spectrum: Nuclear magnetic resonance (NMR) of core sample 26 collected by NMR analyzer 28 Spectrum as a basis signal;

[0098] S2: The processor 51 controls the fluid injection unit 1 to independently inject formation water into the core at constant pressure until the formation water is saturated; then the injection of formation water is turned off, and simulated crude oil is injected at constant pressure until there are no bubbles at the outlet and the flow rate is stable; the nuclear magnetic resonance analyzer 28 collects data from the core 26 after it is saturated with simulated crude oil. Spectrum as the initial oil-bearing state Spectrum.

[0099] Step S2 specifically includes:

[0100] S21: Saturated formation water: Using the automatic control and analysis unit 4, the fluid injection unit 1 opens the third shut-off valve 12 and the sixth shut-off valve 18 of the water phase fluid channel, closes the shut-off valves of the oil phase and gas phase channels, and injects formation water into the core in a constant pressure manner until there are no air bubbles at the outlet and the flow rate is stable; an appropriate amount of MnCl2 needs to be added to the injected formation water to shield the nuclear magnetic resonance signal in the water.

[0101] S22: Saturated simulated oil: After the formation water is saturated, switch to the oil phase fluid channel, open the first shut-off valve 10 and the fourth shut-off valve 16, close the shut-off valves of the water phase and gas phase channels, and inject simulated crude oil in a constant pressure manner until there are no bubbles at the outlet and the flow rate is stable.

[0102] S23: After collecting saturated oil Spectrum: Automatic control and analysis unit 4 controls nuclear magnetic resonance analyzer 28 to collect core samples 26 after saturation with simulated crude oil. The spectrum serves as a baseline for the initial oil-bearing state.

[0103] S3: The processor 51 controls the back pressure pump 37 of the core reaction unit 2 to discharge the residual free oil and water phases in the core holder 27 and the connected pipeline.

[0104] In step S3, Before injection, open the tenth shut-off valve 38 and adjust the outlet pressure through the back pressure control device to discharge the residual free oil and water phases in the core holder 27 and connected pipelines.

[0105] S4: The processor 51 controls the constant pressure injection via the fluid injection unit 1. and obtain Injection volume; and control the core reaction unit 2 to enter a sealed state and maintain the preset well-closing time.

[0106] Step S4 specifically includes:

[0107] S41: Injection: The automatic control and analysis unit 4 controls the fluid injection unit 1 to open the second shut-off valve 11 and the fifth shut-off valve 17 of the gas phase fluid channel, and close the shut-off valves of the oil phase and water phase channels. Constant pressure injection is achieved through the booster pump 5, the first pressure gauge 7, and the second pressure gauge 8. The injection volume is monitored and recorded by the second flow meter 20, and stops when the preset target injection volume is reached.

[0108] S42: Well-sealing simulation: Using the automatic control and analysis unit 4 to close the seventh stop valve 23 and the tenth stop valve 38, the core is kept in a sealed state for the preset target well-sealing time.

[0109] S43: Well Opening Production: The tenth shut-off valve 38 is opened using the automatic control and analysis unit 4, and the outlet pressure is controlled by the back pressure valve 34 and the back pressure pump 37 to simulate the production process.

[0110] S5: The processor 51 controls the back pressure valve 34 and back pressure pump 37 of the core reaction unit 2 to control the outlet pressure, and controls the fluid recovery and metering unit 3 to simulate well opening production, separating oil, gas, and water in real time until production ends; the processor 51 acquires the core sample 26 collected by the nuclear magnetic resonance analyzer 28 after production ends. Spectrum as the end of production The spectrum, and the volume of each phase of oil, gas and water obtained and recorded by the fluid recovery and metering unit 3.

[0111] Step S5 specifically includes:

[0112] S51: Fluid Separation and Metering: After production is completed, the output fluid is obtained by the automatic control and analysis unit 4. After the total output is measured by the fifth flow meter 39, it enters the three-phase separator 40 for separation. The gas phase is measured by the sixth flow meter 42 and enters the gas collector 43. The oil phase is measured by the seventh flow meter 45 and enters the oil phase collector 46. The water phase is measured by the eighth flow meter 48 and enters the water phase collector 49. Production continues until the flow rate is lower than the specified value. .

[0113] S52: Collection after production Spectrum: The nuclear magnetic resonance analyzer 28, controlled by the automatic control and analysis unit 4, collects core samples 26 after production is completed. Spectrum.

[0114] S6: Repeat steps S4-S5. This achieves multiple rounds. In throughput simulation, the processor 51 automatically records the injection parameters, output data, and throughput of each round. Spectral data;

[0115] S7: Based on the recorded volumes of oil, gas, and water phases during each throughput cycle, the processor 51 calculates the macro-oil recovery rate for each cycle and the cumulative recovery rate. Burial rate and oil change rate; and based on the initial oil content. Spectrum and production technology after each round of production The spectrum is automatically calculated for each round by the processor 51. The study analyzed the oil recovery rate at different pore sizes, as well as the oil recovery rate within different pore size ranges, to conduct a comprehensive evaluation at both macro and micro levels. Swallowing and spitting effect.

[0116] Step S7 specifically includes:

[0117] S71: Macroscopic Evaluation Parameter Calculation: Based on the cumulative collection volume of gas phase collector 43, oil phase collector 46, and water phase collector 49 during each round of throughput, the automatic control and analysis unit 4 automatically calculates the macroscopic oil recovery rate for each round and cumulatively. Buried rate and oil change rate;

[0118] S72: Oil recovery calculation based on the initial oil-bearing state of the sampled oil. After each round of production of the spectrum and acquisition The automatic control and analysis unit 4 automatically calculates the spectrum for each round. The crude oil recovery rate was measured and compared with the macro crude oil recovery rate of the corresponding round for verification.

[0119] S73: Oil Recovery Calculation by Orifice Diameter: Based on The relationship between relaxation time and aperture, defined. For small holes, For the central hole, For macropores; based on the initial oil-bearing state Spectrum and after each round of production The automatic control and analysis unit 4 automatically calculates the oil recovery rate in different aperture ranges for each round;

[0120] S74: Influencing Factor Analysis: Processor 51 analyzes the impact of four key engineering parameters—injection pressure, injection volume, well shut-in time, and throughput—on macro-oil recovery rate. Burial rate, oil change rate, The influence of spectral oil recovery rate and oil recovery rate by aperture size;

[0121] S75: Comprehensive Performance Evaluation: Combining macro-level crude oil recovery rate, Burial rate, oil change rate, Comprehensive evaluation of oil recovery rate by spectral density and by aperture Huff and puff oil recovery effectiveness and storage potential; including macro-level oil recovery rate and The oil recovery rate reflects the overall oil recovery effect. Burial rate and oil exchange rate characterize storage capacity, while crude oil recovery rate by pore size reflects... The effects of motion in pores of different sizes.

[0122] In one embodiment, the macro-oil recovery rate is calculated using the following formula:

[0123]

[0124] in, For macro-level crude oil recovery rate, For the volume of oil produced,

[0125] This represents the volume of saturated oil in the core.

[0126] The The burial rate is calculated using the following formula:

[0127]

[0128] in, for Burial rate, For burial volume, For injection volume, For output volume;

[0129] The oil change rate is calculated using the following formula:

[0130]

[0131] in, For oil change rate, For injection volume, This represents the volume of oil produced.

[0132] In one embodiment, the The oil recovery rate is calculated using the following formula:

[0133]

[0134] in, for Spectrum of oil recovery rate In the dry state Spectral amplitude value, In its original oil-bearing state Spectral amplitude value, The remaining oil state after spitting out Spectral amplitude value, summation sign Indicates the whole The amplitude values ​​corresponding to all relaxation time points in the spectrum are summed.

[0135] In one embodiment, the oil recovery rate within the different aperture ranges is calculated using the following formula:

[0136]

[0137] in, Let be the oil recovery rate for the j-th aperture range. For the j-th aperture interval Relaxation time range For samples in a dry state that belong to this pore size range The sum of spectral amplitude values, For those in the original oil-bearing state, belonging to this pore size range The sum of spectral amplitude values, The remaining oil after the intake and exhaust process belongs to this orifice size range. The sum of spectral amplitude values.

[0138] This application has been divided into the following groups. Swallowing experiment:

[0139] Example 1:

[0140] Multiple groups of full-diameter sandstone cores from a certain block were selected for testing. Intake and discharge test. Four standard core samples were drilled (numbered SA-1, SA-2, SA-3, and SA-4), with a core diameter of 2.5 cm, a length of 5.0 cm, and a porosity of [missing information]. The permeability was 25 mD. After cleaning and drying, the core was placed in a core holder and sealed. Basic core physical properties were entered through the input terminal of the automatic control and analysis unit, and the temperature of the constant temperature chamber was set to [temperature value missing]. The confining pressure was 30 MPa, the initial saturation order was water first, then oil, and the injection / pump cycle was 1. The experimental results for each group... Injection pressure, injection volume, and well shut-in time are shown in Table 1 below:

[0141] Table 1

[0142]

[0143] After the experiment began, the incubator was set to... The rate of heating up to Confining pressure pump The pressure was increased to 30 MPa and maintained stably for 2 hours. The nuclear magnetic resonance analyzer collected dry core samples. The spectrum was used as the base signal. Subsequently, simulated formation water and simulated crude oil were sequentially saturated until there were no bubbles at the outlet and the flow rate stabilized. and collect saturated fluid Spectrum.

[0144] The system operates according to the parameters in Table 1 above. Injection, well shut-in simulation, and well opening production: the produced fluid is separated by a three-phase separator, and the output of each phase is metered. Production continues until the flow rate is below [a certain value]. After each production cycle, core samples are collected. Spectrum.

[0145] Based on measurement data and Spectral data, such as Figure 3 As shown, the macro-level crude oil recovery rate is automatically calculated. Burial rate, oil change rate, The oil recovery rates by aperture and spectral density are shown in Table 2 below:

[0146] Table 2

[0147]

[0148] As shown in Table 2 above, after one round After the injection and rejection, the macroscopic oil recovery rate of the sandstone core was basically consistent with the oil recovery rate calculated using the T2 spectrum, verifying the reliability of the experimental setup and method. It should be noted that the macroscopic oil recovery rate was slightly lower than... The difference in oil recovery rate may be due to a small amount of residual oil remaining in the pipelines, which is not completely collected. This difference further highlights the importance of integrating a nuclear magnetic resonance analyzer to achieve... The in-situ, non-destructive, and dynamic monitoring of the activation mechanism and remaining oil distribution is of significant value. The results of the four sets of experiments show that the activation effect of large-diameter wells is significantly better than that of medium-diameter and small-diameter wells, while the activation effect of small-diameter wells is generally the least ideal. Comparing the second, third, and fourth sets of experiments with the first set, it can be found that increasing the injection pressure, increasing the injection volume, and extending the well-keeping time all help improve the oil recovery rate. However, it is worth noting that when… When the injection volume is increased from 0.4 PV to 0.6 PV, Both the burial rate and the oil change rate showed a significant decrease, indicating that at this time... The utilization efficiency has decreased.

[0149] Example 2:

[0150] Multiple rounds of testing were conducted on full-diameter sandstone cores from a certain block. Intake and discharge test. A standard core sample (numbered SH-1) was drilled, with a diameter of 2.5 cm, a length of 5.0 cm, and a porosity of [missing information]. The permeability was 0.17 mD. After cleaning and drying, the core was placed in a core holder and sealed. Basic core physical properties were entered through the input terminal of the automatic control and analysis unit, and the temperature of the constant temperature chamber was set to [value missing]. The confining pressure was 30 MPa. To avoid shale hydration, only saturated simulated crude oil was used as the initial fluid. The throughput was set to 4 cycles, with each cycle... The injection pressure was 15 MPa, the injection volume was 0.4 PV, and the well shut-in time was 24 h.

[0151] After the experiment began, the incubator was set to... The rate of heating up to Confining pressure pump The pressure was increased to 30 MPa and maintained stably for 2 hours. The nuclear magnetic resonance analyzer collected dry core samples. The spectrum was used as the base signal. Subsequently, simulated oil was saturated and samples were collected from the saturated fluid. Spectrum.

[0152] Perform 4 rounds in sequence Injection, well shut-in, and production operations; data collected after each production cycle. The spectrum was analyzed, and the yield of each phase was measured. Based on the measurement data and... Spectral data, such as Figure 4 As shown, the macro-level crude oil recovery rate is automatically calculated. Burial rate, oil change rate, The oil recovery rates by aperture and spectral density are shown in Table 3 below:

[0153] Table 3

[0154]

[0155] As shown in Table 3 above, after four rounds After the injection and extraction, the macro-oil recovery rate of the shale core in each round and the final recovery stage is compared with The results of the macroscopic oil recovery are largely consistent, further verifying the reliability of the experimental apparatus and method. It should be noted that the macroscopic oil recovery rate for each cycle and the final recovery rate are slightly lower than expected. The difference in oil recovery rate may be due to a small amount of residual oil remaining in the pipelines, which is not completely collected. This difference further highlights the importance of integrating a nuclear magnetic resonance analyzer to achieve... The in-situ, non-destructive, and dynamic monitoring of the recovery mechanism and remaining oil distribution is of significant value. Furthermore, by comparing the experimental results of the first round of injection and drainage of this shale core with those of the SA-1 sandstone core in Example 1 under the same injection pressure, injection volume, and well-closing time, it can be found that the macroscopic oil recovery rate, oil exchange rate, and... The oil recovery rate of the spectral core and the oil recovery rate by aperture were significantly lower than those of the sandstone core, but its The burial rate is higher. This indicates that shale reservoirs have a higher burial rate compared to sandstone reservoirs. While the oil recovery efficiency during huff and puff is relatively poor, it exhibits greater storage potential. Notably, increasing the number of huff and puff cycles can effectively improve the oil recovery efficiency of shale cores. As shown in Table 3, after four cycles... After the injection and rejection, the macro-oil recovery rate of the shale core is related to The oil recovery rate of the spectrum increased to The recovery rates for small, medium, and large holes also increased to [percentages missing]. However, as the number of throughput rounds increases, the macro-recovery rate per round, Burial rate, oil change rate, Both the spectral recovery rate and the recovery rate by aperture showed a decreasing trend with each round, indicating that the effect of a single round of huff and puff gradually weakened. Therefore, in practical applications, it is necessary to scientifically formulate a reasonable huff and puff cycle to balance oil recovery effect, burial potential and economy, and avoid ineffective investment and resource waste.

[0156] In summary, this invention, through a highly integrated and automated system design, achieves [the following]: A multi-dimensional and precise evaluation of the oil recovery effect and storage potential of the injection and release system. The experimental setup can accurately simulate formation temperature and pressure conditions and use nuclear magnetic resonance technology to monitor the fluid distribution inside the core in real time, providing a basis for in-depth research. It provides a reliable technical platform for understanding the injection and release mechanism, optimizing engineering parameters, and evaluating oil production performance and storage potential.

[0157] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0158] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. Evaluation An experimental apparatus for evaluating the effects of injection and release of oil and its storage potential, characterized in that, The device includes: The fluid injection unit (1) is used to selectively inject water-phase, gas-phase, and oil-phase experimental fluids into the core independently or alternately. The core reaction unit (2) is used to react the core under simulated formation environment temperature and pressure conditions. The core was subjected to a throughput experiment to obtain information on the fluid distribution inside the core. The fluid recovery and metering unit (3) is used to separate and meter the multiphase fluid produced by the core reaction unit (2); The automatic control and analysis unit (4) is connected to the fluid injection unit (1), the core reaction unit (2) and the fluid recovery and metering unit (3) respectively; The automatic control and analysis unit (4) is configured to: control the fluid injection action of the fluid injection unit (1), the temperature and pressure conditions and well shut-off status of the core reaction unit (2), and the opening and closing of the production valve of the fluid recovery and metering unit (3) in a closed loop according to preset experimental parameters, thereby automatically executing the functions including... A complete injection, well-closing, and production process is implemented; and by integrating the fluid distribution information inside the core from the core reaction unit (2) and the produced fluid metering data from the fluid recovery and metering unit (3), the macro-oil recovery rate is automatically calculated. Buried rate and oil change rate, per round The oil recovery rate was measured using spectrophotometry and the oil recovery rate within different aperture ranges, in order to conduct... A multi-dimensional quantitative evaluation of the effects of injection and release of oil and its storage potential.

2. The evaluation according to claim 1 An experimental apparatus for evaluating the effects of injection and release of oil and its storage potential, characterized in that, The fluid injection unit (1) includes: a booster pump (5), a first four-way valve (6), a first pressure gauge (7), a second pressure gauge (8), a third pressure gauge (9), a first shut-off valve (10), a second shut-off valve (11), a third shut-off valve (12), an oil phase storage tank (13), a gas phase storage tank (14), an aqueous phase storage tank (15), a fourth shut-off valve (16), a fifth shut-off valve (17), a sixth shut-off valve (18), a first flow meter (19), a second flow meter (20), a third flow meter (21), a second four-way valve (22), a seventh shut-off valve (23), and a fourth flow meter (24). The outlet of the booster pump (5) is connected to the inlet of the first four-way valve (6); the three outlets of the first four-way valve (6) are respectively connected to the oil phase storage tank (13) via the first pressure gauge (7) and the first shut-off valve (10), to the gas phase storage tank (14) via the second pressure gauge (8) and the second shut-off valve (11), and to the aqueous phase storage tank (15) via the third pressure gauge (9) and the third shut-off valve (12); the outlets of the oil phase storage tank (13), the gas phase storage tank (14), and the aqueous phase storage tank (15) are connected to the inlet of the first four-way valve (6); The outlet is connected to the inlet pipe of the second four-way valve (20); a fourth shut-off valve (16) and a first flow meter (19) are sequentially installed on the outlet of the oil phase storage tank (13) and the inlet pipe of the second four-way valve (20); a fifth shut-off valve (17) and a second flow meter (20) are sequentially installed on the outlet of the gas phase storage tank (14) and the inlet pipe of the second four-way valve (20); and a sixth shut-off valve (18) and a third flow meter (21) are sequentially installed on the outlet of the water phase storage tank (13) and the inlet pipe of the second four-way valve (20). The seventh shut-off valve (23) and the fourth flow meter (24) are connected in sequence at the outlet of the second four-way valve (22).

3. The evaluation according to claim 2 An experimental apparatus for evaluating the effects of injection and release of oil and its storage potential, characterized in that, The core reaction unit (2) includes: a fourth pressure gauge (25), a core (26), a core holder (27), a nuclear magnetic resonance analyzer (28), a constant temperature chamber (29), a thermometer (30), a fifth pressure gauge (31), an eighth shut-off valve (32), a confining pressure pump (33), a back pressure valve (34), a sixth pressure gauge (35), a ninth shut-off valve (36), and a back pressure pump (37); The outlet of the second four-way valve (22) is connected to the inlet of the core holder (27) via the seventh shut-off valve (23), the fourth flow meter (24), and the fourth pressure gauge (27); The core (26) is sealed and installed in the internal cavity of the core holder (27); the detection probe of the nuclear magnetic resonance analyzer (28) is arranged around the outside of the core holder (27); the core holder (27) is located inside the constant temperature chamber (29); the thermometer (30) is located inside the constant temperature chamber (29); the outlet end of the confining pressure pump (33) is connected to the confining pressure port pipeline of the core holder (27), and the outlet end of the confining pressure pump (33) is connected to the core holder (27). The eighth shut-off valve (32) and the fifth pressure gauge (31) are sequentially installed on the connecting pipe of the confining pressure port of the core holder (27); the back pressure port of the core holder (27) is connected to the back pressure pump (37) pipeline, and the ninth shut-off valve (36) and the back pressure valve (34) are sequentially installed on the connecting pipe between the back pressure port of the core holder (27) and the back pressure pump (37); the core outlet end of the core holder 27 is also provided with a back pressure valve (34) and a sixth pressure gauge (35).

4. The evaluation according to claim 3 An experimental apparatus for evaluating the effects of injection and release of oil and its storage potential, characterized in that, The fluid recovery and metering unit (3) includes a tenth shut-off valve (38), a fifth flow meter (39), a three-phase separator (40), an eleventh shut-off valve (41), a sixth flow meter (42), a gas collector (43), a twelfth shut-off valve (44), a seventh flow meter (45), an oil phase collector (46), a thirteenth shut-off valve (47), an eighth flow meter (48), and a water phase collector (49). The core outlet of the core holder (27) is connected to the inlet pipe of the three-phase separator (40). The tenth shut-off valve (38) and the fifth flow meter (39) are also provided in the connection pipe between the core outlet of the core holder (27) and the inlet of the three-phase separator (40). The gas phase outlet of the three-phase separator (40) is connected to the gas collector (43) through the eleventh shut-off valve (41) and the sixth flow meter (42). The oil phase outlet of the three-phase separator (40) is connected to the oil phase collector (46) through the twelfth shut-off valve (44) and the seventh flow meter (45). The water phase outlet of the three-phase separator (40) is connected to the water phase collector (49) through the thirteenth shut-off valve (47) and the eighth flow meter (48).

5. The evaluation according to claim 4 An experimental apparatus for evaluating the effects of injection and release of oil and its storage potential, characterized in that, The automatic control and analysis unit (4) includes a processor (51), which is also connected to the booster pump (5), the first four-way valve (6), the first pressure gauge (7), the second pressure gauge (8), the third pressure gauge (9), the first shut-off valve (10), the second shut-off valve (11), the third shut-off valve (12), the fourth shut-off valve (16), the fifth shut-off valve (17), the sixth shut-off valve (18), the first flow meter (19), the second flow meter (20), the third flow meter (21), the second four-way valve (22), the seventh shut-off valve (23), and the fourth flow meter (24) of the fluid injection unit (1). The processor (51) is also connected to the core reaction unit (2) including the fourth pressure gauge (25), nuclear magnetic resonance analyzer (28), constant temperature chamber (29), thermometer (30), fifth pressure gauge (31), eighth shut-off valve (32), confining pressure pump (33), back pressure valve (34), sixth pressure gauge (35), ninth shut-off valve (36) and back pressure pump (37); The processor (51) is also connected to the tenth shut-off valve (38), the fifth flow meter (39), the eleventh shut-off valve (41), the sixth flow meter (42), the twelfth shut-off valve (44), the seventh flow meter (45), the thirteenth shut-off valve (47), and the eighth flow meter (48) of the fluid recovery and metering unit (3).

6. Evaluation The experimental method for evaluating the effectiveness of injection and release of oil and its storage potential, using the evaluation method described in any one of claims 1 to 5. An experimental apparatus for evaluating the effects of injection and release of oil and its storage potential, characterized by comprising the following steps: S1: Insert the standard core (26) taken from the target stratum into the center of the core holder (27); control the core reaction unit (2) through the processor (51) to establish the target temperature and target confining pressure of the simulated stratum and maintain it for a preset time, and acquire the nuclear magnetic resonance of the dried core (26) sample by the nuclear magnetic resonance analyzer (28). Spectrum as a benchmark Spectrum; S2: The processor (51) controls the fluid injection unit (1) to independently inject formation water into the core at constant pressure until the formation water is saturated; then the injection of formation water is turned off, and simulated crude oil is injected at constant pressure until there are no bubbles at the outlet and the flow rate is stable; the nuclear magnetic resonance analyzer (28) collects the core (26) after it is saturated with simulated crude oil. Spectrum as the initial oil-bearing state Spectrum; S3: The processor (51) controls the back pressure pump (37) of the core reaction unit (2) to discharge the residual free oil and water phases in the core holder (27) and connected pipelines; S4: The processor (51) controls the fluid injection unit (1) to control the constant pressure injection of CO2 and obtain the CO2 injection amount; and controls the core reaction unit (2) to enter the sealed state and maintain the preset well simmering time; S5: The processor (51) controls the back pressure valve (34) and back pressure pump (37) of the core reaction unit (2) to control the outlet pressure, and controls the fluid recovery and metering unit (3) to simulate well opening production, separating oil, gas and water in real time until the production ends; the processor (51) acquires the core samples (26) collected by the nuclear magnetic resonance analyzer (28) after the production ends. Spectrum as the end of production The spectrum, and the fluid recovery and metering unit (3) obtains and records the volumes of each phase of oil, gas and water; S6: Repeat steps S4-S5; S7: Based on the oil, gas, and water phase volumes recorded during each round of throughput, the macro-oil recovery rate for each round and the cumulative recovery rate are calculated by the processor (51). Burial rate and oil change rate; and based on the initial oil content. The spectrum and the end of production after each round of production. The spectrum is automatically calculated for each round by the processor (51). The study analyzed the oil recovery rate at different pore sizes, as well as the oil recovery rate within different pore size ranges, to conduct a comprehensive evaluation at both macro and micro levels. Swallowing and spitting effect.

7. The evaluation according to claim 6 An experimental method for evaluating the effectiveness of huff and puff oil recovery and its storage potential, characterized in that... The macro-level oil recovery rate is calculated using the following formula: in, For macro-level crude oil recovery rate, For the volume of oil produced, This represents the volume of saturated oil in the core. The The burial rate is calculated using the following formula: in, for Burial rate, For burial volume, For injection volume, For output volume; The oil change rate is calculated using the following formula: in, For oil change rate, For injection volume, This represents the volume of oil produced.

8. The evaluation according to claim 6 An experimental method for evaluating the effectiveness of huff and puff oil recovery and its storage potential, characterized in that... The The oil recovery rate is calculated using the following formula: in, for Spectrum of oil recovery rate In the dry state Spectral amplitude value, In its original oil-bearing state Spectral amplitude value, The remaining oil state after spitting out Spectral amplitude value, summation sign Indicates the whole The amplitude values ​​corresponding to all relaxation time points in the spectrum are summed.

9. The evaluation according to claim 6 An experimental method for evaluating the effectiveness of huff and puff oil recovery and its storage potential, characterized in that... The oil recovery rate within the different aperture ranges is calculated using the following formula: in, Let be the oil recovery rate for the j-th aperture range. For the j-th aperture interval Relaxation time range For samples in a dry state that belong to this pore size range The sum of spectral amplitude values, For those in the original oil-bearing state, belonging to this pore size range The sum of spectral amplitude values, The remaining oil after the intake and exhaust process belongs to this orifice size range. The sum of spectral amplitude values.

Images