Carbon dioxide miscible displacement simulation system and target injection pressure determination method

Abstract

The invention discloses a carbon dioxide miscible-phase displacement simulation system and a target injection pressure determination method, and relates to the field of energy, the system comprises a high-pressure experiment device used for simulating the high-pressure environment of an oil and gas reservoir, and the high-pressure experiment device is internally provided with an oil and gas sample; the carbon dioxide injection subsystem is connected with the high-pressure experimental device and used for injecting carbon dioxide into the high-pressure experimental device so as to simulate the miscible-phase displacement process of the carbon dioxide and the oil gas sample in the oil and gas reservoir; the data acquisition subsystem is connected with the high-pressure experimental device and is used for acquiring experimental data corresponding to the miscible phase displacement process in the high-pressure experimental device; and the data processing subsystem is connected with the data acquisition subsystem, and is used for determining the minimum miscible pressure when the carbon dioxide and the oil gas sample reach the miscible state according to the experimental data, and determining the target injection pressure of the carbon dioxide according to the minimum miscible pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy, in particular to a carbon dioxide miscible displacement simulation system and a method for determining a target injection pressure. BACKGROUND

[0002] With the increasing global energy demand and the increasingly serious environmental problems, improving the recovery rate of oil and gas fields and reducing greenhouse gas emissions have become important issues in the energy field. Carbon dioxide (CO2) displacement technology, as an effective method for improving oil and gas recovery, has the potential to reduce greenhouse gas emissions, and therefore has received extensive attention.

[0003] However, the traditional simulation test system has limitations in replicating the complex environment of actual oil and gas reservoirs, including the heterogeneity of rock layers and the multiphase flow characteristics of fluids, which leads to significant differences between the CO2 minimum miscibility pressure and displacement efficiency data obtained in the laboratory and the field application. The inaccuracy of experimental simulation limits the optimization and promotion of CO2 displacement technology.

[0004] In view of the problem in the related art that the existing simulation test system often cannot accurately simulate the CO2 displacement process in the actual oil and gas reservoir, resulting in deviation between the experimental results and actual application, no effective solution has been proposed so far.

[0005] Therefore, it is necessary to improve the related art to overcome the defects in the related art. SUMMARY

[0006] The embodiments of the present application provide a carbon dioxide miscible displacement simulation system and a method for determining a target injection pressure, to at least solve the problem in the related art that the existing simulation test system often cannot accurately simulate the CO2 displacement process in the actual oil and gas reservoir, resulting in deviation between the experimental results and actual application.

[0007] According to an aspect of an embodiment of the present application, a carbon dioxide miscible displacement simulation system is provided, comprising: a high-pressure experimental device for simulating a high-pressure environment of an oil and gas reservoir, wherein an oil and gas sample is arranged in the high-pressure experimental device; a carbon dioxide injection subsystem connected with the high-pressure experimental device, for injecting carbon dioxide into the high-pressure experimental device to simulate a miscible displacement process of the carbon dioxide with the oil and gas sample in the oil and gas reservoir; a data acquisition subsystem connected with the high-pressure experimental device, for acquiring experimental data corresponding to the miscible displacement process in the high-pressure experimental device; and a data processing subsystem connected with the data acquisition subsystem, for determining a minimum miscibility pressure at which the carbon dioxide and the oil and gas sample reach a miscible state according to the experimental data, and determining a target injection pressure of the carbon dioxide according to the minimum miscibility pressure.

[0008] In one exemplary embodiment, the data acquisition subsystem further includes: a pressure sensor for monitoring the pressure inside the high-pressure vessel; a temperature sensor for monitoring the temperature inside the high-pressure vessel; and a flow meter for monitoring the injection flow rate of the carbon dioxide.

[0009] In one exemplary embodiment, the carbon dioxide injection subsystem is further configured to control the injection rate of the carbon dioxide based on the injection flow rate monitored by the flow meter.

[0010] In an exemplary embodiment, the carbon dioxide injection subsystem includes: a carbon dioxide cylinder for storing the carbon dioxide; a high-pressure pump connected to the carbon dioxide cylinder for extracting the carbon dioxide from the carbon dioxide cylinder and pressurizing the carbon dioxide; and a flow controller connected to the high-pressure pump for controlling the injection speed according to the injection flow rate.

[0011] In an exemplary embodiment, the carbon dioxide miscible displacement simulation system further includes a heating device for heating the high-pressure experimental device according to the formation temperature corresponding to the oil and gas reservoir before injecting the carbon dioxide into the high-pressure experimental device, so as to simulate the formation conditions of the oil and gas reservoir.

[0012] In an exemplary embodiment, the data processing subsystem is further configured to: determine the pressure change within the high-pressure experimental device during the injection of carbon dioxide based on the experimental data; determine the minimum miscibility pressure within the high-pressure experimental device when the carbon dioxide and the oil / gas sample reach the miscible state based on the pressure change, and determine the first injection pressure of carbon dioxide corresponding to the minimum miscibility pressure; adjust the injection pressure of carbon dioxide within a preset pressure range corresponding to the first injection pressure, simulate the miscibility displacement process based on the obtained multiple second injection pressures, and obtain multiple sets of experimental data; determine the target injection pressure based on the multiple sets of experimental data, wherein the miscibility displacement effect of the target experimental data corresponding to the target injection pressure is the best among the multiple sets of experimental data.

[0013] According to another aspect of the embodiments of this application, a method for determining a target injection pressure is also provided, applied to a carbon dioxide miscible displacement simulation system, comprising: injecting carbon dioxide into a high-pressure experimental device to simulate the miscible displacement process of the carbon dioxide with an oil and gas sample in an oil and gas reservoir, wherein the high-pressure experimental device is used to simulate the high-pressure environment of the oil and gas reservoir, and the oil and gas sample is provided in the high-pressure experimental device; collecting experimental data corresponding to the miscible displacement process in the high-pressure experimental device; determining the minimum miscible pressure at which the carbon dioxide and the oil and gas sample reach a miscible state based on the experimental data, and determining the target injection pressure of the carbon dioxide based on the minimum miscible pressure.

[0014] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein a computer program is stored in the computer program, and the computer program is configured to execute the above-described method for determining the target injection pressure when it is run.

[0015] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the method for determining the target injection pressure through the computer program.

[0016] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the steps of the methods described in various embodiments of this application.

[0017] This application provides a carbon dioxide miscible displacement simulation system, comprising: a high-pressure experimental device for simulating the high-pressure environment of an oil and gas reservoir, wherein an oil and gas sample is placed in the high-pressure experimental device; a carbon dioxide injection subsystem connected to the high-pressure experimental device for injecting carbon dioxide into the high-pressure experimental device to simulate the miscible displacement process of carbon dioxide with the oil and gas sample in the oil and gas reservoir; a data acquisition subsystem connected to the high-pressure experimental device for acquiring experimental data during the miscible displacement process; and a data processing subsystem connected to the data acquisition subsystem for analyzing and determining the minimum miscible pressure for carbon dioxide and the oil and gas sample to reach a miscible state based on the experimental data, and determining the target injection pressure of carbon dioxide based on the minimum miscible pressure. Using the above system, by providing a precise experimental platform, the minimum miscible displacement behavior of CO2 can be studied, and CO2 displacement parameters can be optimized to improve oil and gas recovery and reduce environmental impact. This solves the problem in related technologies where existing simulation experimental systems often cannot accurately simulate the CO2 displacement process in actual oil and gas reservoirs, leading to deviations between experimental results and practical applications. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a hardware structure block diagram of a computer terminal for a method of determining target injection pressure according to an embodiment of this application.

[0021] Figure 2 This is a structural block diagram (I) of a carbon dioxide miscible displacement simulation system according to an embodiment of this application;

[0022] Figure 3 This is a structural block diagram of a data acquisition subsystem according to an embodiment of this application;

[0023] Figure 4 This is a structural block diagram of a carbon dioxide injection subsystem according to an embodiment of this application;

[0024] Figure 5 This is a structural block diagram (II) of a carbon dioxide miscibility displacement simulation system according to an embodiment of this application;

[0025] Figure 6 This is a flowchart of a method for determining target injection pressure according to an embodiment of this application. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] The methods and embodiments provided in this application can be executed on a computer terminal or similar computing device. Taking running on a computer terminal as an example, Figure 1 This is a hardware structure block diagram of a computer terminal for a method of determining target injection pressure according to an embodiment of this application. For example... Figure 1 As shown, a computer terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor (MCU) or a field-programmable gate array (FPGA)) and a memory 104 for storing data are also shown. The computer terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the computer terminal described above. For example, the computer terminal may also include components that are more complex than those described above. Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0029] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the porous media dispensing method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thus implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to a computer terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0030] The computer terminal uses a wireless network provided by a communications provider. In one example, transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, transmission device 106 may be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0031] This embodiment provides a carbon dioxide miscibility displacement simulation system. Figure 2 This is a structural block diagram of a carbon dioxide miscibility displacement simulation system according to an embodiment of this application, as shown below. Figure 2 As shown, the system includes:

[0032] High-pressure experimental device 22 is used to simulate the high-pressure environment of oil and gas reservoirs, wherein oil and gas samples are set in the high-pressure experimental device;

[0033] The carbon dioxide injection subsystem 24 is connected to the high-pressure experimental device and is used to inject carbon dioxide into the high-pressure experimental device to simulate the miscible displacement process of the carbon dioxide with the oil and gas sample in the oil and gas reservoir.

[0034] The data acquisition subsystem 26 is connected to the high-voltage experimental device and is used to acquire experimental data corresponding to the miscible displacement process in the high-voltage experimental device.

[0035] The data processing subsystem 28 is connected to the data acquisition subsystem and is used to determine the minimum miscibility pressure at which the carbon dioxide and the oil and gas sample reach a miscible state based on the experimental data, and to determine the target injection pressure of the carbon dioxide based on the minimum miscibility pressure.

[0036] The above system provides a carbon dioxide miscible displacement simulation system, comprising: a high-pressure experimental device for simulating the high-pressure environment of an oil and gas reservoir, wherein an oil and gas sample is placed in the high-pressure experimental device; a carbon dioxide injection subsystem connected to the high-pressure experimental device for injecting carbon dioxide into the high-pressure experimental device to simulate the miscible displacement process of carbon dioxide with the oil and gas sample in the oil and gas reservoir; a data acquisition subsystem connected to the high-pressure experimental device for acquiring experimental data during the miscible displacement process; and a data processing subsystem connected to the data acquisition subsystem for analyzing and determining the minimum miscible pressure for carbon dioxide and the oil and gas sample to reach a miscible state based on the experimental data, and determining the target injection pressure of carbon dioxide based on the minimum miscible pressure. Using the above system, by providing a precise experimental platform, the minimum miscible displacement behavior of CO2 can be studied, and CO2 displacement parameters can be optimized to improve oil and gas recovery and reduce environmental impact. This solves the problem in related technologies where existing simulation experimental systems often cannot accurately simulate the CO2 displacement process in actual oil and gas reservoirs, leading to deviations between experimental results and practical applications.

[0037] In one exemplary embodiment, Figure 3 A schematic diagram of an optional structure for the data acquisition subsystem is shown, such as... Figure 3 As shown, the data acquisition subsystem 26 further includes: a pressure sensor 262 for monitoring the pressure inside the high-pressure container; a temperature sensor 264 for monitoring the temperature inside the high-pressure container; and a flow meter 266 for monitoring the injection flow rate of the carbon dioxide.

[0038] The data acquisition subsystem is a key component of the carbon dioxide miscibility displacement simulation experimental system. Its design aims to accurately monitor and acquire critical parameters during the experiment to ensure the accuracy of experimental data and the controllability of experimental conditions. Specifically, it includes the following three important components:

[0039] 1. Pressure Sensor: Used for real-time monitoring of pressure changes inside the high-pressure vessel. Because the carbon dioxide miscibility displacement process is extremely sensitive to pressure, especially when reaching or exceeding the minimum miscibility pressure (MMP), even small pressure fluctuations can affect the phase changes of carbon dioxide and crude oil and the displacement effect. The high-precision measurement capability of the pressure sensor can capture these changes, providing researchers with real-time pressure data to help them precisely control experimental conditions and ensure that carbon dioxide reaches and is maintained in the required miscibility state during the experiment.

[0040] 2. Temperature Sensor: Used to measure the temperature inside the high-pressure vessel. Temperature is another important factor affecting the interaction between carbon dioxide and crude oil. At different temperatures, the physicochemical properties of carbon dioxide change, thus affecting its miscibility with crude oil. Monitoring with a temperature sensor ensures that the experimental environment reaches the actual formation temperature of the oil reservoir, making the experimental conditions closer to real-world applications and improving the reliability and validity of the experimental results.

[0041] 3. Flow meter: Used to monitor the injected carbon dioxide flow rate. Flow control is crucial for the repeatability of experiments and the accuracy of results. The flow meter provides precise data on the carbon dioxide injection rate, ensuring that the amount of carbon dioxide injected during the experiment meets design requirements. This not only helps maintain experimental stability but also assists researchers in analyzing the efficiency and impact of carbon dioxide displacing crude oil at different flow rates, thus providing a basis for optimizing displacement parameters.

[0042] Overall, the data acquisition subsystem, through the coordinated operation of pressure sensors, temperature sensors, and flow meters, ensured precise control of experimental conditions and accurate data acquisition, providing strong technical support for studying the mechanism of carbon dioxide miscible displacement, optimizing displacement parameters, and improving oil and gas recovery. This subsystem allows researchers to better understand the interaction between carbon dioxide and crude oil under high pressure and high temperature conditions, providing more scientific and precise guidance for the application of carbon dioxide displacement technology in actual oil reservoirs.

[0043] Optionally, the carbon dioxide injection subsystem 24 is further configured to control the injection rate of the carbon dioxide based on the injection flow rate monitored by the flow meter.

[0044] The carbon dioxide injection subsystem plays a crucial role in the carbon dioxide miscibility displacement simulation experiment, especially in the precise control of the carbon dioxide injection process. This subsystem not only handles the injection of carbon dioxide but also has the ability to dynamically adjust the carbon dioxide injection rate based on real-time injection flow information fed back from the flow meter. Details are as follows:

[0045] 1. Flow Monitoring and Feedback: The flow meter monitors the injected carbon dioxide flow rate in real time, ensuring the accuracy and stability of the carbon dioxide injection volume under experimental conditions. The flow meter provides high-precision flow readings, which are fundamental to controlling the carbon dioxide injection rate.

[0046] 2. Automatic Adjustment of Injection Rate: The carbon dioxide injection subsystem, integrated with a flow meter, can automatically adjust the injection rate based on the monitored flow information. This means that if the actual injection flow detected by the flow meter deviates from the flow rate required by the experimental design, the carbon dioxide injection subsystem will immediately respond and adjust the injection rate to achieve the predetermined flow target.

[0047] 3. Optimization of experimental conditions: This real-time monitoring and control mechanism helps optimize experimental conditions, ensuring the reliability and repeatability of experimental results. By precisely controlling the carbon dioxide injection rate, researchers can more accurately simulate the displacement process in actual oil reservoirs, which is crucial for studying the miscibility of carbon dioxide and crude oil and determining the optimal displacement parameters.

[0048] 4. Improved experimental efficiency: Automated flow control reduces the need for manual adjustments, improving experimental efficiency and safety. Researchers no longer need to frequently adjust the carbon dioxide injection rate manually; the system automatically maintains the required flow rate, saving time and manpower, and reducing errors caused by human intervention.

[0049] 5. Addressing Heterogeneity: In simulating actual reservoirs, the heterogeneity and variability of core samples can lead to flow rate fluctuations during carbon dioxide injection. The dynamic adjustment capability of the carbon dioxide injection subsystem effectively addresses these challenges, ensuring stable injection conditions throughout the experiment.

[0050] In summary, the carbon dioxide injection subsystem, through its tight integration with the flow meter, achieved precise control of the carbon dioxide injection rate, providing a solid technical guarantee for the successful implementation of the carbon dioxide miscibility displacement simulation experiment. The design of this subsystem optimized the experimental procedure, improved data quality, and contributed to a deeper understanding of the mechanism of carbon dioxide displacement technology, providing a strong experimental foundation and data support for the dual objectives of improving oil and gas recovery and reducing greenhouse gas emissions.

[0051] Optionally, embodiments of this application illustrate the structure of an optional carbon dioxide injection subsystem 24, such as... Figure 4 As shown, the carbon dioxide injection subsystem 24 includes: a carbon dioxide cylinder 242 for storing the carbon dioxide; a high-pressure pump 244 connected to the carbon dioxide cylinder for extracting the carbon dioxide from the carbon dioxide cylinder and pressurizing the carbon dioxide; and a flow controller 246 connected to the high-pressure pump for controlling the injection speed according to the injection flow rate.

[0052] The carbon dioxide injection subsystem is an indispensable part of the carbon dioxide miscibility displacement simulation experiment. Its design aims to precisely control the carbon dioxide injection process, ensuring that the experimental conditions accurately reflect the real behavior of carbon dioxide displacement in oil and gas reservoirs. This subsystem mainly consists of the following three key components:

[0053] 1. Carbon Dioxide Cylinder: This is a storage device for carbon dioxide, used to store the carbon dioxide gas required for experiments. The cylinder must be designed to withstand high pressure to ensure a stable supply of carbon dioxide during the experiment. Before the experiment begins, the cylinder is filled with sufficient carbon dioxide to meet the needs throughout the entire experimental period.

[0054] 2. High-Pressure Pump: The high-pressure pump is directly connected to the carbon dioxide cylinder. Its function is to extract carbon dioxide from the cylinder and pressurize it. This pressurization process is necessary because the experiment needs to simulate the high-pressure environment of an oil reservoir. Under high pressure, carbon dioxide mixes better with crude oil, improving displacement efficiency. The stability and pressurization capacity of the high-pressure pump directly affect the success rate and safety of the experiment. Therefore, selecting a high-performance, highly reliable high-pressure pump is crucial for the entire experimental system.

[0055] 3. Flow Controller: The flow controller connects to the high-pressure pump and is used to precisely control the injection flow rate and speed of carbon dioxide according to the experimental design and requirements. The flow controller can receive flow information from the data acquisition subsystem, compare it with the experimental setpoint, and adjust the carbon dioxide injection rate in real time according to the deviation to ensure the accuracy of experimental conditions. This closed-loop control mechanism can effectively cope with unexpected flow changes in the experiment, such as changes in the permeability of the core sample, maintain the constant injection conditions required for the experiment, thereby improving the reliability and repeatability of experimental results.

[0056] This carbon dioxide injection subsystem, through the coordinated operation of the aforementioned components, not only provides a stable supply of carbon dioxide but also enables precise control of the injection rate and flow rate. This is of great significance for researching carbon dioxide miscible displacement technology, especially for determining the minimum miscibility pressure and optimizing displacement parameters. By precisely controlling the carbon dioxide injection conditions, researchers can more accurately simulate the interaction between carbon dioxide and crude oil in actual oil and gas fields, providing a scientific basis and optimization strategies for improving oil and gas recovery and reducing greenhouse gas emissions.

[0057] Optionally, the carbon dioxide miscible displacement simulation system further includes: a heating device 30, such as... Figure 5 As shown, the heating device 30 is used to heat the high-pressure experimental device according to the formation temperature corresponding to the oil and gas reservoir before injecting the carbon dioxide into the high-pressure experimental device, so as to simulate the formation conditions of the oil and gas reservoir.

[0058] In a carbon dioxide miscible displacement simulation system, the heating device is one of the key components ensuring that the experimental conditions accurately reflect the underground oil and gas reservoir environment. Its design and function are mainly reflected in the following aspects:

[0059] 1. Simulated Formation Temperature: The heating device is used to heat the high-pressure experimental apparatus to the formation temperature corresponding to a specific oil and gas reservoir before the experiment begins. Reservoir formation temperature is often a crucial factor affecting the miscibility and displacement effect of carbon dioxide and crude oil. Different formation temperatures lead to changes in the viscosity, density, and phase state of crude oil in the reservoir, and these changes directly affect the carbon dioxide displacement efficiency. Through the heating device, researchers can replicate the actual formation temperature of the reservoir in a laboratory environment, thereby more accurately simulating underground conditions and improving the reliability and applicability of experimental results.

[0060] 2. Heating Uniformity and Stability: The heating device must possess excellent heating uniformity and thermal stability to ensure a uniform temperature distribution within the high-pressure experimental apparatus and maintain stability throughout the experiment. Non-uniform temperature distribution or temperature fluctuations may lead to deviations in experimental conditions, affecting the accuracy of experimental results. Therefore, the design of the heating device must consider the precision and response speed of temperature control to achieve accurate temperature regulation and monitoring.

[0061] 3. Heating Efficiency and Safety: Considering both experimental efficiency and operator safety, the heating device should possess rapid heating and automatic safety protection functions. Rapid heating capability can shorten experimental preparation time and improve experimental efficiency; while the automatic safety protection mechanism can prevent potential risks such as overheating and leakage during the heating process, ensuring the safety of experimental operations.

[0062] 4. Integrated Control and Monitoring: The heating device is tightly integrated with the data acquisition subsystem, enabling real-time monitoring of the internal temperature of the high-pressure experimental apparatus and comparison with the set formation temperature. If the detected temperature deviates from the set value, the heating device will automatically adjust the heating power until the target temperature is reached and maintained. This closed-loop control mechanism helps ensure the consistency of experimental conditions and the accuracy of experimental data.

[0063] By employing a heating device, the carbon dioxide miscible displacement simulation system can simulate the real environment of underground oil reservoirs, including the key parameter of formation temperature, providing an experimental platform for studying the miscible displacement behavior of carbon dioxide under different temperature conditions. This simulation capability is of great value for optimizing carbon dioxide displacement technology, improving oil and gas recovery rates, and evaluating the safety and effectiveness of carbon dioxide sequestration. The high efficiency, precision, and safety of the heating device make it an indispensable part of this simulation system.

[0064] Optionally, the data processing subsystem 28 is further configured to: determine the pressure change within the high-pressure experimental device during the injection of carbon dioxide based on the experimental data; determine the minimum miscibility pressure within the high-pressure experimental device when the carbon dioxide and the oil / gas sample reach the miscible state based on the pressure change, and determine the first injection pressure of carbon dioxide corresponding to the minimum miscibility pressure; adjust the injection pressure of carbon dioxide within a preset pressure range corresponding to the first injection pressure, simulate the miscibility displacement process based on the obtained multiple second injection pressures, and obtain multiple sets of experimental data; determine the target injection pressure based on the multiple sets of experimental data, wherein the miscibility displacement effect of the target experimental data corresponding to the target injection pressure is the best among the multiple sets of experimental data.

[0065] The data processing subsystem plays a crucial analytical and optimization role in the carbon dioxide miscibility displacement simulation experiment. Through in-depth processing of the various data collected during the experiment, it aims to determine the most effective carbon dioxide injection pressure and displacement conditions to optimize the miscibility displacement effect. Specifically, the workflow and functions of the data processing subsystem can be divided into the following steps:

[0066] 1. Monitoring and Recording Pressure Changes: The data processing subsystem first monitors and records pressure changes inside the high-pressure experimental apparatus based on experimental data, especially real-time pressure information provided by pressure sensors. This process provides fundamental data for subsequent analysis and determination of the minimum miscibility pressure (MMP).

[0067] 2. Determining the Minimum Miscibility Pressure: Based on the collected pressure change data, the data processing subsystem uses a dedicated algorithm or model to determine the minimum miscibility pressure (MMP) at which carbon dioxide and oil / gas samples reach a miscible state. MMP is a key parameter in carbon dioxide miscible displacement technology; it indicates that carbon dioxide and crude oil are completely mixed, forming a single phase, thus achieving the optimal displacement effect.

[0068] 3. Determination of the first injection pressure: After determining the MMP, the data processing subsystem further determines the first injection pressure of carbon dioxide corresponding to the MMP. This is the injection pressure when the phase is first reached in the experiment, providing a reference point for subsequent pressure adjustment and optimization.

[0069] 4. Adjusting Injection Pressure and Simulating Miscible Displacement: Based on the initial injection pressure, the data processing subsystem adjusts the carbon dioxide injection pressure within a preset pressure range and conducts multiple experiments to simulate the miscible displacement process under different pressure conditions. In this way, multiple sets of experimental data on the interaction between carbon dioxide and oil / gas samples at different pressures can be obtained, including information on displacement efficiency and fluid phase changes.

[0070] 5. Determining the Target Injection Pressure: Finally, based on multiple sets of collected experimental data, the data processing subsystem determines the target injection pressure corresponding to the optimal miscible displacement effect through comparative analysis. This target injection pressure is the optimal solution obtained after experimental verification and data processing, which can most effectively improve oil and gas recovery rate, while optimizing carbon dioxide utilization efficiency and reducing unnecessary energy consumption and costs.

[0071] Throughout the data processing workflow, the subsystem is not only responsible for data acquisition and storage, but more importantly, for data analysis, modeling, and optimization decision-making. Its functionality relies on advanced data processing technologies and algorithms, as well as tight integration with the hardware system. Through these steps, the data processing subsystem provides scientific and precise support for carbon dioxide miscibility displacement simulation experiments, helping researchers gain a deeper understanding of the displacement mechanism of carbon dioxide in oil and gas reservoirs, and providing data basis and guidance for optimizing carbon dioxide displacement technology in practical applications.

[0072] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0073] This embodiment also provides a method for determining the target injection pressure, applied to the aforementioned carbon dioxide miscible displacement simulation system. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0074] Figure 6 This is a flowchart of a method for determining a target injection pressure according to an embodiment of this application. The method includes the following steps:

[0075] Step S602: Inject carbon dioxide into the high-pressure experimental device to simulate the miscible displacement process of the carbon dioxide with the oil and gas sample in the oil and gas reservoir. The high-pressure experimental device is used to simulate the high-pressure environment of the oil and gas reservoir, and the oil and gas sample is placed in the high-pressure experimental device.

[0076] Step S604: Collect experimental data corresponding to the miscible displacement process in the high-pressure experimental device;

[0077] Step S606: Determine the minimum miscibility pressure for the carbon dioxide and the oil and gas sample to reach a miscible state based on the experimental data, and determine the target injection pressure of the carbon dioxide based on the minimum miscibility pressure.

[0078] The above method involves injecting carbon dioxide into a high-pressure experimental device to simulate the miscible displacement process of carbon dioxide with oil and gas samples in an oil and gas reservoir. This high-pressure experimental device simulates the high-pressure environment of the reservoir and contains oil and gas samples. Experimental data corresponding to the miscible displacement process in the high-pressure experimental device are collected and analyzed to determine the minimum miscible pressure at which carbon dioxide and oil and gas samples reach a miscible state. Based on this minimum miscible pressure, the target injection pressure of carbon dioxide is determined. This approach provides a precise experimental platform to study the minimum miscible displacement behavior of CO2, optimize CO2 displacement parameters, and improve oil and gas recovery while reducing environmental impact. This solves the problem that existing simulation systems often fail to accurately simulate the CO2 displacement process in actual oil and gas reservoirs, leading to discrepancies between experimental results and practical applications.

[0079] In one exemplary embodiment, the method further includes controlling the injection rate of carbon dioxide based on the injection flow rate monitored by the flow meter.

[0080] The carbon dioxide injection subsystem plays a crucial role in the carbon dioxide miscibility displacement simulation experiment, especially in the precise control of the carbon dioxide injection process. This subsystem not only handles the injection of carbon dioxide but also has the ability to dynamically adjust the carbon dioxide injection rate based on real-time injection flow information fed back from the flow meter. Details are as follows:

[0081] 1. Flow Monitoring and Feedback: The flow meter monitors the injected carbon dioxide flow rate in real time, ensuring the accuracy and stability of the carbon dioxide injection volume under experimental conditions. The flow meter provides high-precision flow readings, which are fundamental to controlling the carbon dioxide injection rate.

[0082] 2. Automatic Adjustment of Injection Rate: The carbon dioxide injection subsystem, integrated with a flow meter, can automatically adjust the injection rate based on the monitored flow information. This means that if the actual injection flow detected by the flow meter deviates from the flow rate required by the experimental design, the carbon dioxide injection subsystem will immediately respond and adjust the injection rate to achieve the predetermined flow target.

[0083] 3. Optimization of experimental conditions: This real-time monitoring and control mechanism helps optimize experimental conditions, ensuring the reliability and repeatability of experimental results. By precisely controlling the carbon dioxide injection rate, researchers can more accurately simulate the displacement process in actual oil reservoirs, which is crucial for studying the miscibility of carbon dioxide and crude oil and determining the optimal displacement parameters.

[0084] 4. Improved experimental efficiency: Automated flow control reduces the need for manual adjustments, improving experimental efficiency and safety. Researchers no longer need to frequently adjust the carbon dioxide injection rate manually; the system automatically maintains the required flow rate, saving time and manpower, and reducing errors caused by human intervention.

[0085] 5. Addressing Heterogeneity: In simulating actual reservoirs, the heterogeneity and variability of core samples can lead to flow rate fluctuations during carbon dioxide injection. The dynamic adjustment capability of the carbon dioxide injection subsystem effectively addresses these challenges, ensuring stable injection conditions throughout the experiment.

[0086] In summary, the carbon dioxide injection subsystem, through its tight integration with the flow meter, achieved precise control of the carbon dioxide injection rate, providing a solid technical guarantee for the successful implementation of the carbon dioxide miscibility displacement simulation experiment. The design of this subsystem optimized the experimental procedure, improved data quality, and contributed to a deeper understanding of the mechanism of carbon dioxide displacement technology, providing a strong experimental foundation and data support for the dual objectives of improving oil and gas recovery and reducing greenhouse gas emissions.

[0087] In one exemplary embodiment, before injecting carbon dioxide into the high-pressure experimental apparatus, the method further includes heating the high-pressure experimental apparatus according to the formation temperature corresponding to the oil and gas reservoir to simulate the formation conditions of the oil and gas reservoir.

[0088] In a carbon dioxide miscible displacement simulation system, the heating device is one of the key components ensuring that the experimental conditions accurately reflect the underground oil and gas reservoir environment. Its design and function are mainly reflected in the following aspects:

[0089] 1. Simulated Formation Temperature: The heating device is used to heat the high-pressure experimental apparatus to the formation temperature corresponding to a specific oil and gas reservoir before the experiment begins. Reservoir formation temperature is often a crucial factor affecting the miscibility and displacement effect of carbon dioxide and crude oil. Different formation temperatures lead to changes in the viscosity, density, and phase state of crude oil in the reservoir, and these changes directly affect the carbon dioxide displacement efficiency. Through the heating device, researchers can replicate the actual formation temperature of the reservoir in a laboratory environment, thereby more accurately simulating underground conditions and improving the reliability and applicability of experimental results.

[0090] 2. Heating Uniformity and Stability: The heating device must possess excellent heating uniformity and thermal stability to ensure a uniform temperature distribution within the high-pressure experimental apparatus and maintain stability throughout the experiment. Non-uniform temperature distribution or temperature fluctuations may lead to deviations in experimental conditions, affecting the accuracy of experimental results. Therefore, the design of the heating device must consider the precision and response speed of temperature control to achieve accurate temperature regulation and monitoring.

[0091] 3. Heating Efficiency and Safety: Considering both experimental efficiency and operator safety, the heating device should possess rapid heating and automatic safety protection functions. Rapid heating capability can shorten experimental preparation time and improve experimental efficiency; while the automatic safety protection mechanism can prevent potential risks such as overheating and leakage during the heating process, ensuring the safety of experimental operations.

[0092] 4. Integrated Control and Monitoring: The heating device is tightly integrated with the data acquisition subsystem, enabling real-time monitoring of the internal temperature of the high-pressure experimental apparatus and comparison with the set formation temperature. If the detected temperature deviates from the set value, the heating device will automatically adjust the heating power until the target temperature is reached and maintained. This closed-loop control mechanism helps ensure the consistency of experimental conditions and the accuracy of experimental data.

[0093] By employing a heating device, the carbon dioxide miscible displacement simulation system can simulate the real environment of underground oil reservoirs, including the key parameter of formation temperature, providing an experimental platform for studying the miscible displacement behavior of carbon dioxide under different temperature conditions. This simulation capability is of great value for optimizing carbon dioxide displacement technology, improving oil and gas recovery rates, and evaluating the safety and effectiveness of carbon dioxide sequestration. The high efficiency, precision, and safety of the heating device make it an indispensable part of this simulation system.

[0094] In an exemplary embodiment, determining the minimum miscibility pressure at which the carbon dioxide and the oil / gas sample reach a miscible state based on the experimental data, and determining the target injection pressure of the carbon dioxide based on the minimum miscibility pressure, includes: determining the pressure change within the high-pressure experimental device during the injection of the carbon dioxide based on the experimental data; determining the minimum miscibility pressure within the high-pressure experimental device when the carbon dioxide and the oil / gas sample reach the miscible state based on the pressure change, and determining a first injection pressure of the carbon dioxide corresponding to the minimum miscibility pressure; adjusting the injection pressure of the carbon dioxide within a preset pressure range corresponding to the first injection pressure, simulating the miscibility displacement process based on multiple obtained second injection pressures to obtain multiple sets of experimental data; and determining the target injection pressure based on the multiple sets of experimental data, wherein the miscibility displacement effect of the target experimental data corresponding to the target injection pressure is the best among the multiple sets of experimental data.

[0095] The data processing subsystem plays a crucial analytical and optimization role in the carbon dioxide miscibility displacement simulation experiment. Through in-depth processing of the various data collected during the experiment, it aims to determine the most effective carbon dioxide injection pressure and displacement conditions to optimize the miscibility displacement effect. Specifically, the workflow and functions of the data processing subsystem can be divided into the following steps:

[0096] 1. Monitoring and Recording Pressure Changes: The data processing subsystem first monitors and records pressure changes inside the high-pressure experimental apparatus based on experimental data, especially real-time pressure information provided by pressure sensors. This process provides fundamental data for subsequent analysis and determination of the minimum miscibility pressure (MMP).

[0097] 2. Determining the Minimum Miscibility Pressure: Based on the collected pressure change data, the data processing subsystem uses a dedicated algorithm or model to determine the minimum miscibility pressure (MMP) at which carbon dioxide and oil / gas samples reach a miscible state. MMP is a key parameter in carbon dioxide miscible displacement technology; it indicates that carbon dioxide and crude oil are completely mixed, forming a single phase, thus achieving the optimal displacement effect.

[0098] 3. Determination of the first injection pressure: After determining the MMP, the data processing subsystem further determines the first injection pressure of carbon dioxide corresponding to the MMP. This is the injection pressure when the phase is first reached in the experiment, providing a reference point for subsequent pressure adjustment and optimization.

[0099] 4. Adjusting Injection Pressure and Simulating Miscible Displacement: Based on the initial injection pressure, the data processing subsystem adjusts the carbon dioxide injection pressure within a preset pressure range and conducts multiple experiments to simulate the miscible displacement process under different pressure conditions. In this way, multiple sets of experimental data on the interaction between carbon dioxide and oil / gas samples at different pressures can be obtained, including information on displacement efficiency and fluid phase changes.

[0100] 5. Determining the Target Injection Pressure: Finally, based on multiple sets of collected experimental data, the data processing subsystem determines the target injection pressure corresponding to the optimal miscible displacement effect through comparative analysis. This target injection pressure is the optimal solution obtained after experimental verification and data processing, which can most effectively improve oil and gas recovery rate, while optimizing carbon dioxide utilization efficiency and reducing unnecessary energy consumption and costs.

[0101] Throughout the data processing workflow, the subsystem is not only responsible for data acquisition and storage, but more importantly, for data analysis, modeling, and optimization decision-making. Its functionality relies on advanced data processing technologies and algorithms, as well as tight integration with the hardware system. Through these steps, the data processing subsystem provides scientific and precise support for carbon dioxide miscibility displacement simulation experiments, helping researchers gain a deeper understanding of the displacement mechanism of carbon dioxide in oil and gas reservoirs, and providing data basis and guidance for optimizing carbon dioxide displacement technology in practical applications.

[0102] Embodiments of this application also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above method embodiments when run.

[0103] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0104] S1, inject carbon dioxide into the high-pressure experimental device to simulate the miscible displacement process of the carbon dioxide with the oil and gas sample in the oil and gas reservoir, wherein the high-pressure experimental device is used to simulate the high-pressure environment of the oil and gas reservoir, and the oil and gas sample is set in the high-pressure experimental device.

[0105] S2, Collect experimental data corresponding to the miscible displacement process in the high-pressure experimental device;

[0106] S3, determine the minimum miscibility pressure required for the carbon dioxide and the oil and gas sample to reach a miscible state based on the experimental data, and determine the target injection pressure of the carbon dioxide based on the minimum miscibility pressure.

[0107] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0108] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0109] Embodiments of this application also provide an electronic device including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0110] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0111] S1, inject carbon dioxide into the high-pressure experimental device to simulate the miscible displacement process of the carbon dioxide with the oil and gas sample in the oil and gas reservoir, wherein the high-pressure experimental device is used to simulate the high-pressure environment of the oil and gas reservoir, and the oil and gas sample is set in the high-pressure experimental device.

[0112] S2, Collect experimental data corresponding to the miscible displacement process in the high-pressure experimental device;

[0113] S3, determine the minimum miscibility pressure required for the carbon dioxide and the oil and gas sample to reach a miscible state based on the experimental data, and determine the target injection pressure of the carbon dioxide based on the minimum miscibility pressure.

[0114] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0115] Embodiments of this application also provide a computer program product, including a non-volatile computer-readable storage medium storing the computer program product, wherein the computer program, when executed by a processor, implements the steps of the methods described in various embodiments of this application.

[0116] Optionally, in this embodiment, the computer program described above can be configured to perform the following steps when executed by the processor:

[0117] S1, inject carbon dioxide into the high-pressure experimental device to simulate the miscible displacement process of the carbon dioxide with the oil and gas sample in the oil and gas reservoir, wherein the high-pressure experimental device is used to simulate the high-pressure environment of the oil and gas reservoir, and the oil and gas sample is set in the high-pressure experimental device.

[0118] S2, Collect experimental data corresponding to the miscible displacement process in the high-pressure experimental device;

[0119] S3, determine the minimum miscibility pressure required for the carbon dioxide and the oil and gas sample to reach a miscible state based on the experimental data, and determine the target injection pressure of the carbon dioxide based on the minimum miscibility pressure.

[0120] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0121] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0122] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A carbon dioxide miscible displacement simulation system, characterized in that, include: A high-pressure experimental device is used to simulate the high-pressure environment of an oil and gas reservoir, wherein an oil and gas sample is placed in the high-pressure experimental device; A carbon dioxide injection subsystem, connected to the high-pressure experimental device, is used to inject carbon dioxide into the high-pressure experimental device to simulate the miscible displacement process of the carbon dioxide with the oil and gas sample in the oil and gas reservoir. A data acquisition subsystem is connected to the high-voltage experimental device and is used to acquire experimental data corresponding to the miscible displacement process in the high-voltage experimental device. A data processing subsystem, connected to the data acquisition subsystem, is used to determine the minimum miscibility pressure at which the carbon dioxide and the oil and gas sample reach a miscible state based on the experimental data, and to determine the target injection pressure of the carbon dioxide based on the minimum miscibility pressure.

2. The system according to claim 1, characterized in that, The data acquisition subsystem also includes: A pressure sensor is used to monitor the pressure inside the high-pressure vessel; A temperature sensor is used to monitor the temperature inside the high-pressure vessel; A flow meter is used to monitor the injection flow rate of the carbon dioxide.

3. The system according to claim 2, characterized in that, The carbon dioxide injection subsystem is also used to control the injection rate of carbon dioxide based on the injection flow rate monitored by the flow meter.

4. The system according to claim 3, characterized in that, The carbon dioxide injection subsystem includes: Carbon dioxide cylinders are used to store the carbon dioxide; A high-pressure pump, connected to the carbon dioxide cylinder, is used to extract the carbon dioxide from the carbon dioxide cylinder and pressurize the carbon dioxide. A flow controller, connected to the high-pressure pump, is used to control the injection speed according to the injection flow rate.

5. The system according to claim 1, characterized in that, The carbon dioxide miscible displacement simulation system further includes a heating device for heating the high-pressure experimental device according to the formation temperature corresponding to the oil and gas reservoir before injecting the carbon dioxide into the high-pressure experimental device, so as to simulate the formation conditions of the oil and gas reservoir.

6. The system according to claim 1, characterized in that, The data processing subsystem is also used to: determine the pressure changes inside the high-pressure experimental device during the injection of carbon dioxide based on the experimental data; The minimum miscibility pressure in the high-pressure experimental device when the carbon dioxide and the oil and gas sample reach the miscible state is determined based on the pressure change, and the first injection pressure of the carbon dioxide corresponding to the minimum miscibility pressure is determined. The carbon dioxide injection pressure is adjusted within a preset pressure range corresponding to the first injection pressure, and the miscible displacement process is simulated based on the obtained multiple second injection pressures to obtain multiple sets of experimental data. The target injection pressure is determined based on the multiple sets of experimental data, wherein the displacement effect of the target experimental data corresponding to the target injection pressure is the best among the multiple sets of experimental data.

7. A method for determining a target injection pressure, characterized in that, The system applied to the carbon dioxide miscible displacement simulation system according to any one of claims 1 to 6 comprises: Carbon dioxide is injected into a high-pressure experimental device to simulate the miscible displacement process of carbon dioxide with oil and gas samples in an oil and gas reservoir. The high-pressure experimental device is used to simulate the high-pressure environment of the oil and gas reservoir, and the oil and gas samples are placed in the high-pressure experimental device. Collect experimental data corresponding to the miscible displacement process in the high-pressure experimental apparatus; The minimum miscibility pressure required for the carbon dioxide and the oil and gas sample to reach a miscible state is determined based on the experimental data, and the target injection pressure of the carbon dioxide is determined based on the minimum miscibility pressure.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein the program, when executed, performs the method of claim 7.

9. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to execute the method of claim 7 through the computer program.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 7.

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