Method and equipment for determining minimum miscible pressure of oil gas based on CT scanning and medium

Abstract

The embodiment of the invention discloses a method and equipment for determining the minimum miscible pressure of oil and gas based on CT scanning and a medium. The method comprises the following steps: under a preset temperature condition, respectively determining first CT values of to-be-detected displacement gas under a plurality of preset pressures; wherein each preset pressure corresponds to one first CT value; determining a second CT value of the oil sample to be detected under the preset temperature condition; if an absolute value of a difference value between the first CT value and the second CT value under each preset pressure is greater than a preset threshold value, respectively determining CT value distribution of the oil sample to be detected under the action of the displacement gas to be detected under a plurality of target pressures; and determining the minimum miscible pressure between the displacement gas to be measured and the oil sample to be measured based on the CT value distribution. According to the technical scheme, the oil-gas two-phase contact process can be imaged based on CT scanning, so that the oil-gas minimum miscible pressure is rapidly determined, and the oil-gas miscible process is visually displayed through CT value distribution.

Description

Technical Field

[0001] This invention relates to the field of miscible oil displacement technology, and in particular to a method, equipment and medium for determining the minimum miscibility pressure of oil and gas based on CT scanning. Background Technology

[0002] Miscible flooding is a key technology in oilfield development. Taking carbon dioxide miscible flooding as an example, it is a crucial step in the deep decarbonization phase of CCUS-EOR technology, attracting significant attention because it can not only significantly improve oil recovery but also utilize capillary forces to seal some carbon dioxide into the pores. Although carbon dioxide miscible flooding offers numerous advantages, measuring the minimum miscibility pressure is quite complex.

[0003] Currently, several methods have been developed for measuring minimum miscibility pressure, among which the capillary method is the most commonly used and accurate. However, the capillary method involves a very long experimental process and cycle, requiring a month or even longer to accurately determine a minimum miscibility pressure. Furthermore, the capillary method does not allow for direct observation of the diffusion and miscibility processes of the displacing gas during the experiment. Summary of the Invention

[0004] This invention provides a method, device, and medium for determining the minimum miscibility pressure of oil and gas based on CT scanning. It can image the contact process between the two phases of oil and gas based on CT scanning, thereby quickly determining the minimum miscibility pressure of oil and gas, and intuitively displaying the oil and gas miscibility process through the CT value distribution.

[0005] According to one aspect of the present invention, a method for determining the minimum miscibility pressure of oil and gas based on CT scanning is provided, the method comprising:

[0006] Under preset temperature conditions, the first CT value of the displacement gas to be tested is determined at multiple preset pressures; wherein, each preset pressure corresponds to one first CT value;

[0007] Determine the second CT value of the oil sample under the preset temperature conditions;

[0008] If the absolute value of the difference between the first CT value and the second CT value under each preset pressure is greater than a preset threshold, the CT value distribution of the oil sample to be tested under the action of the displacement gas under multiple target pressures is determined respectively.

[0009] The minimum miscibility pressure between the displacement gas to be tested and the oil sample to be tested is determined based on the CT value distribution.

[0010] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0011] At least one processor; and,

[0012] A memory communicatively connected to the at least one processor; wherein,

[0013] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the method for determining the minimum miscibility pressure of oil and gas based on CT scanning as described in any embodiment of the present invention.

[0014] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the method for determining the minimum miscibility pressure of oil and gas based on CT scanning as described in any embodiment of the present invention.

[0015] The technical solution of this invention involves determining the first CT value of the displacing gas under multiple preset pressures at a preset temperature, with each preset pressure corresponding to a first CT value; determining the second CT value of the oil sample under the preset temperature conditions; if the absolute value of the difference between the first CT value and the second CT value at each preset pressure is greater than a preset threshold, determining the CT value distribution of the oil sample under the action of the displacing gas at multiple target pressures; and determining the minimum miscibility pressure between the displacing gas and the oil sample based on the CT value distribution. This technical solution can image the oil-gas two-phase contact process based on CT scanning, thereby quickly determining the minimum miscibility pressure of oil and gas, and visually displaying the oil-gas miscibility process through the CT value distribution, which is of great significance for the diffusion, miscibility, and interface changes of the displacing gas during oil displacement.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a method for determining the minimum miscibility pressure of oil and gas based on CT scanning, provided in Embodiment 1 of the present invention;

[0019] Figure 2 This is a schematic diagram of a device for determining the minimum miscibility pressure of oil and gas based on CT scanning, according to Embodiment 1 of the present invention.

[0020] Figure 3 This is a schematic diagram of carbon dioxide CT values ​​at different pressures at 52 degrees Celsius, provided according to Embodiment 1 of the present invention.

[0021] Figure 4 This is a flowchart of a method for determining the minimum miscibility pressure of oil and gas based on CT scanning, according to Embodiment 2 of the present invention;

[0022] Figure 5 This is a schematic diagram of CT values ​​of kerosene containing different mass fractions of bromodecane at 100kV, provided in Embodiment 2 of the present invention.

[0023] Figure 6 This is a schematic diagram of a phase miscibility process of carbon dioxide and kerosene in 30wt% decane according to Embodiment 2 of the present invention;

[0024] Figure 7 This is a schematic diagram of another miscibility process of carbon dioxide and kerosene under 30wt% decane according to Embodiment 2 of the present invention.

[0025] Figure 8 This is a schematic diagram of the structure of an electronic device that implements a method for determining the minimum miscibility pressure of oil and gas based on CT scanning, according to an embodiment of the present invention.

[0026] Figure label:

[0027] 1. Oil pump; 2. Water pump; 3. Intermediate container; 4. Differential pressure sensor; 5. CT scanner; 6. Core holder; 7. Confining pressure pump; 8. Computer; 9. Collection device; 10. Back pressure pump; 11. Temperature control system; 12. First control valve; 13. Second control valve; 14. Third control valve; 15. Fourth control valve; 16. Fifth control valve; 17. Sixth control valve; 18. Seventh control valve; 3-8. PEEK pipe. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first," "second," "target," etc., used in the specification, claims, and accompanying drawings of this invention 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 embodiments of the invention 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.

[0030] Example 1

[0031] Figure 1 This is a flowchart of a method for determining the minimum miscibility pressure of oil and gas based on CT scanning, provided in Embodiment 1 of the present invention. This embodiment is applicable to situations where the minimum miscibility pressure of oil and gas needs to be rapidly determined by CT scanning. This method can be executed by a CT scanning-based minimum miscibility pressure determination device, which can be implemented in hardware and / or software. This CT scanning-based minimum miscibility pressure determination device can be configured in an electronic device with data processing capabilities. Figure 1 As shown, the method includes:

[0032] S110, under preset temperature conditions, determine the first CT value of the displacement gas under multiple preset pressures.

[0033] The preset temperature condition refers to the temperature condition pre-set according to the actual measurement requirements. For example, the preset temperature condition can be set to 52 degrees Celsius. The displacing gas to be measured can be the displacing gas to be measured, such as carbon dioxide or hydrocarbon gases (such as methane, propane), etc. The preset pressure refers to the pressure level pre-set according to the actual measurement requirements. For example, the preset pressure can be set to 5MPa, 6MPa...14MPa, 15MPa. The first CT value can be the CT value obtained by CT scanning of the displacing gas under the preset temperature and preset pressure conditions. It should be noted that each preset pressure corresponds to one first CT value.

[0034] In this embodiment, firstly, under preset temperature conditions, the first CT values ​​of the displacement gas to be tested at multiple preset pressures are determined. Optionally, determining the first CT values ​​of the displacement gas to be tested at multiple preset pressures under preset temperature conditions includes: placing a core holder on a CT scanning bed and fixing its position; placing a PEEK tube inside the core holder and applying a confining pressure of a first preset pressure; evacuating the inside of the PEEK tube; injecting the displacement gas to be tested into the PEEK tube based on each preset pressure under preset temperature conditions; allowing it to stand for a preset time; and performing a CT scan on the target area of ​​the PEEK tube using preset CT scanning parameters to obtain the first CT value of the displacement gas to be tested at each preset pressure.

[0035] The PEEK tube is a type of tubing made from polyetheretherketone (PEEK). The first preset pressure refers to the confining pressure preset according to actual measurement needs when determining the first CT value. For example, the first preset pressure can be set to 1.5 times the injection pressure. It should be noted that the purpose of adding confining pressure is to create a closed measurement environment, making the measurement more accurate. The magnitude of the confining pressure does not affect the measurement process, but to avoid damage to the PEEK tube due to excessive confining pressure, a reasonable confining pressure needs to be selected. The preset duration refers to the settling time preset according to actual measurement needs, such as half an hour, to allow the displacing gas to be measured to be stably distributed within the PEEK tube. For example, preset CT scan parameters may include scan voltage, scan current, and scan mode (such as helical scan or axial scan). The target area refers to the detection area preset according to actual measurement needs, which can be set as the central area of ​​the PEEK tube. For example, assuming the PEEK tube is 5 cm long, the target area can be set to 2 cm or 3 cm of the central area of ​​the PEEK tube.

[0036] Figure 2 This is a schematic diagram of a device for determining the minimum miscibility pressure of oil and gas based on CT scanning, provided in Embodiment 1 of the present invention. The core holder is made of PEEK material. Figure 2 The apparatus shown determines the first CT value. For example, taking carbon dioxide as the displacement gas to be measured, the measurement process is as follows: 1. Place the core holder on the scanning bed and fix its position, and place the PEEK tube... Figure 21. After applying a confining pressure of 18 MPa at the position shown in Figure 3-8; 2. After evacuating the PEEK tube, maintain the experimental temperature at 52 degrees Celsius, inject carbon dioxide at a pressure of 5 MPa, let it stand for a period of time (e.g., half an hour), then set the scanning voltage to 100 kV and the scanning current to 100 mA, and perform a CT scan of the target area using a spiral scanning method; 3. Gradually increase the experimental pressure to 15 MPa, allowing it to stand for a period of time after each pressure increase, and then perform a CT scan of the target area using the same method. Finally, the curve of carbon dioxide CT value changing with pressure can be obtained, as shown below. Figure 3 As shown, it displays the carbon dioxide CT values ​​at different pressures at 52 degrees Celsius. Among them, Figure 3 The horizontal axis represents pressure (in MPa), the vertical axis represents CT value (in HU), and 52 in the legend represents the preset temperature. According to... Figure 3 It can be seen that as the preset pressure increases, the first CT value corresponding to carbon dioxide gradually increases.

[0037] S120, determine the second CT value of the oil sample under the preset temperature conditions.

[0038] The oil sample to be tested can refer to an oil sample awaiting measurement, such as kerosene. The second CT value can refer to the CT value obtained by CT scanning of the oil sample under preset temperature conditions.

[0039] In this embodiment, after determining the first CT value, it is also necessary to determine the second CT value of the oil sample under preset temperature conditions. Optionally, determining the second CT value of the oil sample under preset temperature conditions includes: placing the core holder on the CT scanning bed and fixing its position; placing the PEEK tube inside the core holder and applying a confining pressure of a second preset pressure; evacuating the inside of the PEEK tube; injecting the oil sample into the PEEK tube under preset temperature conditions; and performing a CT scan on the target area of ​​the PEEK tube using preset CT scanning parameters to obtain the second CT value of the oil sample under preset temperature conditions.

[0040] The second preset pressure can refer to the confining pressure used to measure the second CT value, preset according to actual measurement needs. It should be noted that the second preset pressure can be the same as or different from the first preset pressure; this embodiment does not impose any limitation on this. Figure 2 The device shown determines the second CT value, and the measurement process is as follows: 1. Place the core holder on the scanning bed and fix its position. Place the PEEK tube in the core holder and apply a certain pressure (such as 1.5 times the carbon dioxide displacement pressure) to the confining pressure; 2. After evacuating the inside of the PEEK tube, inject the prepared oil sample into the PEEK tube; 3. Set the same scanning mode to perform a CT scan on the target area to obtain the second CT value.

[0041] S130, if the absolute value of the difference between the first CT value and the second CT value under each preset pressure is greater than the preset threshold, determine the CT value distribution of the oil sample under the action of the displacement gas under multiple target pressures.

[0042] The preset threshold can be a reference value for the absolute value of the difference between the first CT value and the second CT value, which is preset according to actual measurement needs. It can be used as a basis for judging whether the first CT value and the second CT value can be clearly distinguished. Optionally, the preset threshold is 500HU.

[0043] In this embodiment, after determining the first CT value and the second CT value, it is necessary to calculate the absolute value of the difference between each first CT value and the second CT value, and determine whether all absolute values ​​of the difference are greater than a preset threshold. Further, according to... Figure 3 As can be seen, since the first CT value corresponding to carbon dioxide increases with the increase of the preset pressure, in order to improve the calculation speed, the first CT value that is closest to the second CT value can be selected from multiple first CT values ​​as the target first CT value, and it is only necessary to determine whether the absolute value of the difference between the target first CT value and the second CT value is greater than the preset threshold.

[0044] If the absolute value of the difference between the first CT value and the second CT value at each preset pressure is greater than a preset threshold, it indicates that the first CT value and the second CT value can be clearly distinguished. In this case, the CT value distribution of the oil sample under the action of the displacement gas at multiple target pressures can be determined separately. Optionally, determining the CT value distribution of the oil sample under the action of the displacement gas at multiple target pressures includes: placing the core holder on the CT scanning bed and fixing its position; placing the PEEK tube inside the core holder and applying a confining pressure of a third preset pressure; evacuating the inside of the PEEK tube; injecting the oil sample under the preset temperature into the preset position of the PEEK tube; injecting the displacement gas into the PEEK tube based on the target pressure; performing a CT scan on the target area of ​​the PEEK tube using preset CT scanning parameters; and obtaining the CT value distribution of the oil sample under the action of the displacement gas at each target pressure when both the displacement gas CT value and the oil sample CT value corresponding to the target area reach a stable state.

[0045] The third preset pressure can refer to the confining pressure used when measuring the CT value of mixed-phase CT, preset according to actual measurement needs. For example, the third preset pressure can be set to the first preset pressure. The preset position can refer to a preset position within the PEEK tube. For example, the preset position can be set to 1 / 2 or 2 / 3 of the way inside the PEEK tube. The target pressure can refer to the pressure used when measuring the CT value of mixed-phase CT. For example, the target pressure can be set according to a pressure gradient of 1 MPa.

[0046] For example, taking carbon dioxide as the displacement gas to be tested, the CT value distribution of the oil-gas miscibility process is determined as follows: 1. Place the core holder on the CT scanning bed and fix its position. Place the PEEK tube inside the core holder and apply a certain amount of confining pressure. 2. Evacuate the inside of the PEEK tube, set the experimental temperature to 52 degrees Celsius, and inject the oil sample to be tested into 1 / 2 of the PEEK tube. According to a pressure gradient of 1 MPa, inject carbon dioxide into the PEEK tube at pressures of 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, and 11 MPa respectively. 3. Set the same scanning mode and perform a CT scan on the target area at regular intervals. When the carbon dioxide CT value and the oil sample CT value corresponding to the target area reach a stable state (tend to be stable), the CT value distribution of the oil sample under the action of carbon dioxide at each target pressure is obtained.

[0047] S140, the minimum miscibility pressure between the displacement gas and the oil sample to be tested is determined based on the CT value distribution.

[0048] The minimum miscibility pressure refers to the lowest pressure at which crude oil of a specific composition and the displacing gas can achieve miscibility at a specific temperature; that is, the pressure point at which they are just miscible. In this embodiment, after determining the CT value distribution of the oil sample under multiple target pressures of the displacing gas, the distribution of CT values ​​can be used to visually determine whether each target pressure is miscible or immiscible. A finer pressure gradient can be set between the miscible and immiscible pressures until the pressure point at which they are just miscible is observed, thus obtaining the minimum miscibility pressure.

[0049] The technical solution of this invention involves determining the first CT value of the displacing gas under multiple preset pressures at a preset temperature, with each preset pressure corresponding to a first CT value; determining the second CT value of the oil sample under the preset temperature conditions; if the absolute value of the difference between the first CT value and the second CT value at each preset pressure is greater than a preset threshold, determining the CT value distribution of the oil sample under the action of the displacing gas at multiple target pressures; and determining the minimum miscibility pressure between the displacing gas and the oil sample based on the CT value distribution. This technical solution can image the oil-gas two-phase contact process based on CT scanning, thereby quickly determining the minimum miscibility pressure of oil and gas, and visually displaying the oil-gas miscibility process through the CT value distribution, which is of great significance for the diffusion, miscibility, and interface changes of the displacing gas during oil displacement.

[0050] In this embodiment, optionally, a CT scan is performed on the target area of ​​the PEEK tube using preset CT scan parameters to obtain the first CT value of the displacing gas under each preset pressure. This includes: performing multiple CT scans on the target area of ​​the PEEK tube using preset CT scan parameters to obtain multiple candidate CT values; and determining the first CT value of the displacing gas under each preset pressure based on the average value of the multiple candidate CT values.

[0051] Here, candidate CT values ​​can refer to the individual CT values ​​of the displacing gas to be tested, obtained by performing multiple CT scans on the target area. For example, the same preset CT scan parameters can be used to perform three CT scans on the target area of ​​the PEEK tube to obtain three candidate CT values. Then, the average of these three candidate CT values ​​is taken as the first CT value of the displacing gas to be tested at a certain preset pressure.

[0052] This solution, through this setup and by averaging multiple CT scans, can effectively reduce the error of a single measurement, thereby improving measurement accuracy.

[0053] Example 2

[0054] Figure 4 This is a flowchart of a method for determining the minimum miscibility pressure of oil and gas based on CT scanning, provided in Embodiment 2 of the present invention. This embodiment is an optimization based on the above embodiment. Specifically, the optimization is as follows: after determining the second CT value of the oil sample under a preset temperature condition, the method further includes: if the absolute value of the difference between the first CT value and the second CT value under a preset pressure is less than or equal to a preset threshold, adding a target contrast agent with a preset mass fraction to the oil sample to be tested, so that the absolute value of the difference between the first CT value under each preset pressure and the second CT value of the oil sample after adding the target contrast agent is greater than the preset threshold.

[0055] like Figure 4 As shown, the method in this embodiment specifically includes the following steps:

[0056] S210, under preset temperature conditions, determine the first CT value of the displacement gas to be tested under multiple preset pressures.

[0057] Each preset pressure corresponds to a first CT value.

[0058] S220, determine the second CT value of the oil sample under preset temperature conditions.

[0059] S230, determine whether the absolute value of the difference between the first CT value and the second CT value under each preset pressure is greater than a preset threshold.

[0060] If yes, then execute S240; otherwise, execute S250-S260.

[0061] S240, determine the CT value distribution of the oil sample under test under the action of the displacement gas at multiple target pressures.

[0062] The specific implementation of S210-S240 can be found in the relevant description in Embodiment 1 above, and will not be repeated here.

[0063] S250, add a target contrast agent with a preset mass fraction to the oil sample to be tested, so that the absolute value of the difference between the first CT value at each preset pressure and the second CT value of the oil sample after adding the target contrast agent is greater than a preset threshold.

[0064] The target contrast agent can be used to enhance the difference in CT values ​​between the two phases during the oil-gas miscibility process, so as to observe the oil-gas miscibility process more clearly and intuitively through CT distribution. For example, the target contrast agent can be decane bromide or iodized oil. Preferably, the target contrast agent is decane bromide.

[0065] Figure 5 This is a schematic diagram of CT values ​​for kerosene containing different mass fractions of bromodecane at 100kV, provided in Embodiment 2 of the present invention. Figure 5 As shown, 1%, 2%, 3%, 5%, 10%, 15%, 20%, 25%, and 30% by mass of bromodecane were added to kerosene, and CT scans were performed under the same conditions. From Figure 5 As can be seen, the CT value of kerosene gradually increases with the increase of the mass fraction of bromodecane.

[0066] S260, determine the CT value distribution of the oil sample to be tested after the addition of the target contrast agent under the action of the displacement gas at multiple target pressures.

[0067] S270, based on CT value distribution, determines the minimum miscibility pressure between the displacement gas and the oil sample to be tested.

[0068] Figure 6 This is a schematic diagram illustrating the miscibility process of carbon dioxide and kerosene in 30 wt% decane bromide according to Embodiment 2 of the present invention. The target pressures are set sequentially to 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, and 11 MPa. Kerosene is used as the oil sample to be tested, and carbon dioxide is used as the displacement gas. Figure 6 It can be seen that the minimum miscibility pressure between kerosene and carbon dioxide is between 8 MPa and 9 MPa. Furthermore, a finer pressure gradient was set within the 8 MPa-9 MPa range, i.e., the target pressures were increased to 8.2 MPa, 8.5 MPa, and 8.7 MPa, and the test was repeated in the above manner, yielding the following results: Figure 7 As shown. From Figure 7A distinct mixed-phase transition zone can be clearly observed at 8 MPa, which does not completely disappear until 8.5 MPa.

[0069] The technical solution of this invention involves adding a target contrast agent of a predetermined mass fraction to the oil sample if the absolute value of the difference between the first CT value and the second CT value at a predetermined pressure is less than or equal to a predetermined threshold. This ensures that the absolute value of the difference between the first CT value at each predetermined pressure and the corresponding second CT value of the oil sample after adding the target contrast agent is greater than the predetermined threshold. This allows for oil-gas miscibility testing based on the oil sample after adding the target contrast agent and the displacement gas. This technical solution effectively distinguishes the CT values ​​of the oil and gas phases using the target contrast agent, enabling more obvious and intuitive observation of the oil-gas miscibility process through CT distribution.

[0070] Example 3

[0071] Figure 8 A schematic diagram of an electronic device 20 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0072] like Figure 8 As shown, the electronic device 20 includes at least one processor 21 and a memory, such as a read-only memory (ROM) 22 or a random access memory (RAM) 23, communicatively connected to the at least one processor 21. The memory stores computer programs executable by the at least one processor. The processor 21 can perform various appropriate actions and processes based on the computer program stored in the ROM 22 or loaded from storage unit 28 into the RAM 23. The RAM 23 can also store various programs and data required for the operation of the electronic device 20. The processor 21, ROM 22, and RAM 23 are interconnected via a bus 24. An input / output (I / O) interface 25 is also connected to the bus 24.

[0073] Multiple components in electronic device 20 are connected to I / O interface 25, including: input unit 26, such as keyboard, mouse, etc.; output unit 27, such as various types of monitors, speakers, etc.; storage unit 28, such as disk, optical disk, etc.; and communication unit 29, such as network card, modem, wireless transceiver, etc. Communication unit 29 allows electronic device 20 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0074] Processor 21 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 21 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 21 performs the various methods and processes described above, such as the method for determining the minimum miscibility pressure of oil and gas based on CT scans.

[0075] In some embodiments, the method for determining the minimum miscibility pressure of oil and gas based on CT scans can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 28. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 20 via ROM 22 and / or communication unit 29. When the computer program is loaded into RAM 23 and executed by processor 21, one or more steps of the method for determining the minimum miscibility pressure of oil and gas based on CT scans described above can be performed. Alternatively, in other embodiments, processor 21 can be configured to perform the method for determining the minimum miscibility pressure of oil and gas based on CT scans by any other suitable means (e.g., by means of firmware).

[0076] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0077] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0078] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0079] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0080] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0081] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0082] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0083] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for determining the minimum miscibility pressure of oil and gas based on CT scanning, characterized in that, The method includes: Under preset temperature conditions, the first CT value of the displacement gas to be tested is determined at multiple preset pressures; wherein, each preset pressure corresponds to one first CT value; Determine the second CT value of the oil sample under the preset temperature conditions; If the absolute value of the difference between the first CT value and the second CT value under each preset pressure is greater than a preset threshold, the CT value distribution of the oil sample to be tested under the action of the displacement gas under multiple target pressures is determined respectively. The minimum miscibility pressure between the displacement gas to be tested and the oil sample to be tested is determined based on the CT value distribution.

2. The method according to claim 1, characterized in that, Under preset temperature conditions, the first CT value of the displacing gas to be tested is determined at multiple preset pressures, including: Place the core holder on the CT scanning table and fix its position. Place the PEEK tube inside the core holder and apply a confining pressure of the first preset pressure. The PEEK tube is evacuated, and the displacement gas to be tested is injected into the PEEK tube at the preset temperature and based on each preset pressure, and then left to stand for a preset time. The target area of ​​the PEEK tube is CT scanned using preset CT scanning parameters to obtain the first CT value of the displacement gas under each preset pressure.

3. The method according to claim 2, characterized in that, A CT scan is performed on the target area of ​​the PEEK tube using preset CT scan parameters to obtain the first CT value of the displacement gas under each preset pressure, including: Multiple CT scans were performed on the target area of ​​the PEEK tube using preset CT scan parameters to obtain multiple candidate CT values. The first CT value of the displacement gas under each preset pressure is determined based on the average of the multiple candidate CT values.

4. The method according to claim 1, characterized in that, Determining the second CT value of the oil sample under the preset temperature conditions includes: Place the core holder on the CT scanning table and fix its position. Place the PEEK tube inside the core holder and apply a second preset pressure. The PEEK tube is evacuated, and the oil sample to be tested is injected into the PEEK tube under the preset temperature condition. The target area of ​​the PEEK tube is CT scanned using preset CT scanning parameters to obtain the second CT value of the oil sample under the preset temperature conditions.

5. The method according to claim 1, characterized in that, Determine the CT value distribution of the oil sample under test under the action of the displacement gas at multiple target pressures, including: Place the core holder on the CT scanning table and fix its position. Place the PEEK tube inside the core holder and apply a third preset pressure. The PEEK tube is evacuated, and under the preset temperature conditions, the oil sample to be tested is injected into the preset position of the PEEK tube. The displacement gas to be tested is injected into the PEEK tube based on the target pressure. The target area of ​​the PEEK tube is CT scanned using preset CT scanning parameters. When the CT value of the displacing gas and the CT value of the oil sample corresponding to the target area both reach a stable state, the CT value distribution of the oil sample under the action of the displacing gas at each target pressure is obtained.

6. The method according to claim 1, characterized in that, After determining the second CT value of the oil sample under the preset temperature condition, the method further includes: If the absolute value of the difference between the first CT value and the second CT value under the preset pressure is less than or equal to the preset threshold, a target contrast agent with a preset mass fraction is added to the oil sample to be tested, so that the absolute value of the difference between the first CT value under the preset pressure and the second CT value corresponding to the oil sample after adding the target contrast agent is greater than the preset threshold.

7. The method according to claim 6, characterized in that, The target contrast agent is bromodecane.

8. The method according to claim 1 or 6, characterized in that, The preset threshold is 500HU.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the method for determining the minimum miscibility pressure of oil and gas based on CT scanning as described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the method for determining the minimum miscibility pressure of oil and gas based on CT scanning as described in any one of claims 1-8.

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