Multi-branch radial well wave injection displacement method and device

Abstract

This specification relates to the field of oil reservoir development technology, and specifically discloses a multi-branch radial well wave injection displacement method and device, wherein the method includes: obtaining reservoir physical property data, injection-production well network data, and production dynamic characteristic data of the target oil reservoir; determining multi-branch radial well network structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well network based on the reservoir physical property data, injection-production well network data, and production dynamic characteristic data of the target oil reservoir; using the production dynamic characteristic data to determine the wave injection parameters for injecting into the transformed multi-branch radial well network; and generating an injection displacement scheme for the target oil reservoir based on the multi-branch radial well network structure data and the wave injection parameters. The above scheme can expand the range of the injected fluid. The multi-branch radial well provides multiple injection points, which can enhance the intensity and range of elastic waves during wave injection, improve the utilization of the remaining oil in the reservoir, and improve the recovery rate.

Description

Technical Field

[0001] The present invention relates to the field of oil reservoir development technology, and in particular to a multi-branch radial well wave injection displacement method and device. Background Art

[0002] As oil reservoirs continue to develop, they face numerous challenges, such as high water cuts, fragmented residual oil distribution, and rising costs. Conventional flooding technologies currently suffer from significant fingering, small swept volumes, and a sudden drop in oil production after water and gas breakthrough, resulting in poor development results.

[0003] To address the above issues, no effective solutions have been proposed so far. Summary of the Invention

[0004] The embodiments of this specification provide a multi-branch radial well wave injection displacement method and device to solve the problems of severe fingering, small swept volume, and sudden drop in oil production after water and gas are encountered in conventional displacement technology in the prior art during oil reservoir development.

[0005] The embodiments of this specification provide a multi-branch radial well wave injection displacement method, comprising:

[0006] Obtain reservoir physical property data, injection-production well pattern data, and production performance characteristic data of the target oil reservoir;

[0007] Determining multi-branch radial well pattern structure data for performing multi-branch radial well transformation on injection wells in the injection-production well pattern based on reservoir physical property data, injection-production well pattern data, and production performance characteristic data of the target oil reservoir;

[0008] Determining the fluctuating injection parameters for injecting into the modified multi-branch radial well pattern using the production dynamic characteristic data;

[0009] An injection displacement plan for the target oil reservoir is generated based on the multi-branch radial well pattern structure data and the fluctuating injection parameters.

[0010] In one embodiment, based on the reservoir physical property data, injection-production well pattern data, and production performance characteristic data of the target oil reservoir, determining the multi-branch radial well pattern structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well pattern includes:

[0011] Determining the location and direction of radial well branches based on reservoir physical property data of the target oil reservoir;

[0012] Determining radial well transformation areas and lengths of radial well branches based on injection and production well pattern data of the target oil reservoir;

[0013] Determining the number of radial well branches using the injection-production well pattern data and the production dynamic characteristic data;

[0014] Multi-branch radial well pattern structure data is generated based on the radial well transformation area, the positions and directions of the radial well branches, the lengths of the radial well branches, and the number of the radial well branches.

[0015] In one embodiment, the reservoir physical property data of the target oil reservoir includes: oil saturation distribution data, fracture distribution data, and porosity and permeability distribution data;

[0016] Accordingly, the position and direction of the radial well branch are determined based on the reservoir physical property data of the target oil reservoir, including:

[0017] Determine the sweet spot position and the secondary sweet spot position of the target reservoir according to the oil saturation distribution data; determine the first position range of the radial well branch based on the sweet spot position and the secondary sweet spot position;

[0018] When the fracture distribution data indicates that natural fractures or hydraulic fractures exist in the reservoir of the target oil reservoir, the direction of the radial well is set to be parallel to the fracture direction of the natural fracture or the hydraulic fracture, and the second position range of the radial well branch is determined according to the position of the natural fracture or the hydraulic fracture;

[0019] The radial well branches are arranged to pass through high-porosity and high-permeability areas according to the porosity and permeability distribution data.

[0020] In one embodiment, the injection-production well pattern data includes: injection-production well pattern layout, injection-production well pattern spacing, and injection-production well type;

[0021] Accordingly, based on the injection and production well pattern data of the target oil reservoir, determining the radial well stimulation area and the length of the radial well branch includes:

[0022] In the case where the injection-production well is a vertical well, determining to perform multi-branch radial well transformation on the injection well;

[0023] Determine, according to the injection-production well pattern layout, an area where the injection-production well pattern is symmetrically distributed, and use the area where the injection-production well pattern is symmetrically distributed as a radial well transformation area;

[0024] The branch length range of the radial well branches is determined based on the injection and production well pattern spacing.

[0025] In one embodiment, the injection-production well pattern data includes the production-injection well ratio; the production dynamic characteristic data includes the water content of the production well;

[0026] Accordingly, the number of radial well branches is determined by using the injection-production well pattern data and the production dynamic characteristic data, including:

[0027] Determine twice the production-injection well ratio as the maximum value of the radial well branch;

[0028] When the water cut of the production well is greater than a preset water cut, the number of branch wells in the multi-branch radial well pattern structure is increased.

[0029] In one embodiment, the production dynamic characteristic data includes: initial injection mode, initial production mode;

[0030] Accordingly, the production dynamic characteristic data is used to determine the fluctuating injection parameters for injecting into the modified multi-branch radial well pattern, including:

[0031] In the case where the initial injection mode is a constant flow injection mode, the injection mode for the modified multi-branch radial well pattern is determined to be a fluctuating flow injection mode;

[0032] In the case where the initial injection mode is a constant pressure injection mode, the injection mode for the modified multi-branch radial well pattern is determined to be a fluctuating pressure injection mode;

[0033] The initial production mode is determined to be the production mode of the modified multi-branch radial well network.

[0034] In one embodiment, the production dynamic characteristic data includes: pumping displacement change data or pumping pressure change data;

[0035] Accordingly, the production dynamic characteristic data is used to determine the fluctuating injection parameters for injecting into the modified multi-branch radial well pattern, including:

[0036] When the injection method for the modified multi-branch radial well network is fluctuating flow injection, the maximum pumping frequency is determined according to the pumping pressure change data; when the injection method for the modified multi-branch radial well network is fluctuating pressure injection, the maximum pumping frequency is determined according to the pumping displacement change data;

[0037] Determining a target pumping frequency for injection into the modified multi-branch radial well pattern by conducting a core wave injection experiment on a reservoir of the target oil reservoir, wherein the target pumping frequency is less than or equal to the maximum pumping frequency;

[0038] The target pumping frequency is used to construct a reservoir numerical model to determine the fluctuation injection amplitude and the fluctuation injection time.

[0039] In one embodiment, the method further comprises:

[0040] During the wave injection and displacement process, obtain the injection and production well pressure data and fluid flow change data;

[0041] The fluctuating injection parameters are adjusted according to the injection-production well pressure data and the fluid flow rate change data.

[0042] The present specification also provides a multi-branch radial well wave injection displacement device, comprising:

[0043] Acquisition module, used to obtain reservoir physical property data, injection and production well pattern data and production dynamic characteristic data of the target oil reservoir;

[0044] The first determination module is used to determine the multi-branch radial well pattern structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well pattern according to the reservoir physical property data, injection-production well pattern data and production dynamic characteristic data of the target oil reservoir;

[0045] A second determination module is configured to determine a fluctuating injection parameter for injecting into the modified multi-branch radial well pattern using the production dynamic characteristic data;

[0046] A generation module is used to generate an injection displacement plan for the target oil reservoir based on the multi-branch radial well pattern structure data and the fluctuation injection parameters.

[0047] An embodiment of this specification also provides a computer device, including a processor and a memory for storing processor-executable instructions, wherein when the processor executes the instructions, the steps of the multi-branch radial well wave injection displacement method described in any of the above embodiments are implemented.

[0048] The embodiments of this specification also provide a computer-readable storage medium having computer instructions stored thereon, which, when executed, implement the steps of the multi-branch radial well wave injection displacement method described in any of the above embodiments.

[0049] In an embodiment of the present specification, a wave injection displacement method based on multi-branch radial wells is provided. The multi-branch radial well network structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well network and the wave injection parameters for injecting into the transformed multi-branch radial well network are determined based on the reservoir physical property data, injection-production well network data and production dynamic characteristic data of the target oil reservoir, thereby generating an injection displacement scheme for the target oil reservoir to provide reference and guidance for performing multi-branch radial well wave injection drive on the target oil reservoir. By performing multi-branch radial well transformation on the injection wells and performing wave injection on the fluid, the sweep range of the injected fluid can be expanded, the branch wells provide multiple injection points, the elastic wave intensity and range during wave injection are enhanced, and the degree of utilization of the remaining oil in the reservoir is improved, so as to solve the problems of low recovery rate, insufficient swept volume, rapid water breakthrough, and early gas breakthrough in the existing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings described herein are used to provide a further understanding of this specification, constitute a part of this specification, and do not constitute a limitation of this specification. In the accompanying drawings:

[0051] Figure 1 A flow chart of a multi-branch radial well wave injection displacement method according to an embodiment of the present specification is shown;

[0052] Figure 2 A schematic diagram of a multi-branch radial wellbore in an embodiment of the present specification is shown;

[0053] Figure 3 shows a schematic diagram of wave field superposition at different interval distances;

[0054] Figure 4 shows a schematic diagram of oil production curves under different injection displacement methods;

[0055] Figure 5 It shows a schematic structural diagram of a multi-branch radial well wave injection displacement device according to an embodiment of the present specification;

[0056] Figure 6 A schematic diagram of a computer device in an embodiment of the present specification is shown. DETAILED DESCRIPTION

[0057] The principles and spirit of this specification will be described below with reference to several exemplary embodiments. It should be understood that these embodiments are provided solely to enable those skilled in the art to better understand and implement this specification, and are not intended to limit the scope of this specification in any way. Rather, these embodiments are provided to make this specification more thorough and complete, and to fully convey the scope of this disclosure to those skilled in the art.

[0058] Those skilled in the art will appreciate that the embodiments of this specification may be implemented as a system, device, method, or computer program product. Therefore, the disclosure herein may be implemented in the following forms: entirely in hardware, entirely in software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0059] The embodiments of this specification provide a multi-branch radial well wave injection displacement method. Figure 1A flow chart of a multi-branch radial well pulsating injection displacement method in one embodiment of this specification is shown. Although this specification provides method operation steps or device structures as shown in the following embodiments or drawings, more or fewer operation steps or module units may be included in the method or device based on routine or no creative work. In the steps or structures where there is no necessary causal relationship logically, the execution order of these steps or the module structure of the device is not limited to the execution order or module structure described in the embodiments of this specification and shown in the drawings. When the method or module structure is applied to an actual device or terminal product, it can be connected according to the method or module structure shown in the embodiments or drawings for sequential execution or parallel execution (for example, in a parallel processor or multi-threaded processing environment, or even a distributed processing environment).

[0060] Specifically, if Figure 1 As shown, a multi-branch radial well wave injection displacement method provided by an embodiment of the present specification may include the following steps.

[0061] Step S101: Acquire reservoir physical property data, injection-production well pattern data, and production performance characteristic data of a target oil reservoir.

[0062] The method of this embodiment can be applied to computer equipment. Before performing the wave injection flooding, parameters related to the injection flooding can be determined first to provide guidance and reference for the wave injection flooding.

[0063] Reservoir physical property data, injection and production well pattern data, and production performance data can be obtained for target reservoirs. Target reservoirs can be reservoirs awaiting research and development. These reservoirs can include heavy oil and tight oil reservoirs, particularly those involving massive reservoirs, the potential development of scattered residual oil, and profile control of high-water-cut oilfields.

[0064] Reservoir physical property data can include the target reservoir's oil saturation distribution, fracture distribution, porosity and permeability distribution, and other data. Injection-production well pattern data can include injection-production well pattern layout, spacing between injection-production well patterns, and injection-production well types. Production performance characteristic data can include parameters such as the target reservoir's initial injection method, initial production method, and water content in production wells.

[0065] Step S102: determining multi-branch radial well pattern structure data for performing multi-branch radial well transformation on injection wells in the injection-production well pattern based on reservoir physical property data, injection-production well pattern data, and production performance characteristic data of the target oil reservoir.

[0066] After obtaining reservoir property data, injection-production well pattern data, and production performance data for the target reservoir, the multi-branch radial well pattern structure data for implementing multi-branch radial well transformations on injection wells in the injection-production well pattern can be determined. This multi-branch radial well pattern structure data may include various parameters such as the location, orientation, number, and length of the branch wells in the multi-branch radial well pattern.

[0067] In some embodiments of the present specification, determining the multi-branch radial well network structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well network based on the reservoir physical property data, injection-production well network data and production dynamic characteristic data of the target oil reservoir may include: determining the position and direction of the radial well branches based on the reservoir physical property data of the target oil reservoir; determining the radial well transformation area and the length of the radial well branches based on the injection-production well network data of the target oil reservoir; determining the number of the radial well branches using the injection-production well network data and the production dynamic characteristic data; and generating the multi-branch radial well network structure data based on the radial well transformation area, the position and direction of the radial well branches, the length of the radial well branches and the number of the radial well branches.

[0068] In this embodiment, the position and direction of the radial well branches can be determined based on the reservoir physical property data of the target oil reservoir. The position and direction of the radial well branches can include the position and direction of the radial well branches in the injection and production well pattern of the target oil reservoir. The radial well transformation area and the length of the radial branches can also be determined based on the injection and production well pattern data of the target oil reservoir. Thereafter, the number of radial well branches can be determined using the production dynamic characteristic data. Thereafter, multi-branch radial well pattern structure data can be generated based on the radial well transformation area, the position and direction of the radial well branches, the length of the radial well branches, and the number of radial well branches. In this way, multi-branch radial well pattern structure data for the injection displacement scheme can be generated.

[0069] Step S103: using the production dynamic characteristic data, determining the fluctuating injection parameters for injecting into the modified multi-branch radial well pattern.

[0070] Step S104: generating an injection displacement plan for the target reservoir based on the multi-branch radial well pattern structure data and the fluctuation injection parameters.

[0071] Fluctuation injection parameters can be determined based on production performance data. These parameters may include the injection method, amplitude, and duration. Once the multi-branch radial well pattern structure data and the fluctuation injection parameters are obtained, an injection flooding plan for the target reservoir can be generated, providing theoretical reference and guidance for subsequent fluctuation injection flooding.

[0072] In the above embodiment, a wave injection displacement method based on multi-branch radial wells is provided. Based on the reservoir physical property data, injection-production well network data, and production dynamic characteristic data of the target oil reservoir, the multi-branch radial well network structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well network and the wave injection parameters for injecting into the transformed multi-branch radial well network are determined, and then an injection displacement scheme for the target oil reservoir is generated to provide reference and guidance for performing multi-branch radial well wave injection drive on the target oil reservoir. By performing multi-branch radial well transformation on the injection wells and performing wave injection on the fluid, the sweep range of the injected fluid can be expanded. The branch wells provide multiple injection points, which enhances the intensity and range of elastic waves during wave injection, and improves the degree of utilization of the remaining oil in the reservoir, thereby solving the problems of low recovery rate, insufficient swept volume, rapid water breakthrough, and early gas breakthrough in the existing technology.

[0073] In some embodiments of the present specification, the reservoir physical property data of the target oil reservoir may include: oil saturation distribution data, fracture distribution data and porosity and permeability distribution data; accordingly, determining the position and direction of the radial well branch based on the reservoir physical property data of the target oil reservoir may include: determining the sweet spot position and the secondary sweet spot position of the target oil reservoir based on the oil saturation distribution data; determining the first position range of the radial well branch based on the sweet spot position and the secondary sweet spot position; when the fracture distribution data indicates that there are natural fractures or hydraulic fractures in the reservoir of the target oil reservoir, setting the direction of the radial well to be parallel to the fracture direction of the natural fracture or the hydraulic fracture, and determining the second position range of the radial well branch according to the position of the natural fracture or the hydraulic fracture; setting the radial well branch to pass through a high-porosity and high-permeability area based on the porosity and permeability distribution data.

[0074] Specifically, sweet and secondary sweet spots can be optimized based on the current reservoir oil saturation distribution. Sweet spots are typically located within 30 meters on either side of a radial well branch, or along the axis of the two branches. Radial well placement prioritizes the primary sweet spot, while maximizing proximity to the secondary sweet spot to maximize recovery. During wave injection, wave energy decays outward in the form of elastic waves. Simulation results show that at 30 meters, approximately 40% of the elastic wave energy remains, indicating a displacement effect similar to constant displacement. Laboratory experiments have shown a 1-5% increase in recovery. Multi-branch radial injection creates a superposition of multiple wave sources, with the optimal range being within 30 meters. Beyond 30 meters, the wave displacement effect significantly decreases. Sweet spots are typically located within 30 meters on either side of a radial well branch, which can improve wave displacement. When natural and hydraulic fractures are present in the reservoir, the radial well orientation should be parallel to the fracture direction, with a minimum distance of 5 meters. When radial wells intersect fractures, injected fluids flow along the fractures, reducing their sweep range. When radial wells are parallel to fractures, injected fluids can only seep through the matrix, extending their sweep range. This can improve oil recovery between the fractures and radial wells, and enhance the degree of displacement. Porosity and permeability are positively correlated, so radial wells preferentially traverse areas of high porosity and permeability. By arranging radial wells to traverse high porosity and high permeability regions, the resistance to flow is reduced, resulting in more effective wave displacement. When permeability is too low, the resistance to flow is high, and the wave energy overcomes the resistance rapidly, resulting in a less pronounced gain. By prioritizing radial wells to traverse high porosity and high permeability regions, the wave displacement effect can be further improved, potentially increasing oil recovery.

[0075] In some embodiments of the present specification, the injection and production well network data may include: injection and production well network layout, injection and production well network spacing, and injection and production well type; accordingly, based on the injection and production well network data of the target oil reservoir, determining the radial well transformation area and the length of the radial well branch may include: when the injection and production well type is a vertical well, determining to perform multi-branch radial well transformation on the injection well; determining the area where the injection and production well network is symmetrically distributed according to the injection and production well network layout, and using the area where the injection and production well network is symmetrically distributed as the radial well transformation area; determining the branch length range of the radial well branch based on the injection and production well network spacing.

[0076] Specifically, injection and production wells can include horizontal wells and vertical wells. For vertical injection and production wells, radial transformations are performed. For radial transformations of injection wells in the well pattern, the branch length should take into account the spacing between the injection and production main wellbore. The end of the branch well should be no less than 150 meters from the production well. The recommended branch length is 30-100 meters, and the branch length should be less than one-third of the injection and production well spacing. This method can be used to determine the requirements for multi-branch radial well transformations and the range of branch lengths.

[0077] In some embodiments of the present specification, the injection-production well network data includes the injection-production well ratio; the production dynamic characteristic data may include the water cut of the production well; accordingly, using the injection-production well network data and the production dynamic characteristic data to determine the number of radial well branches may include: determining twice the injection-production well ratio as the maximum value of the radial well branches; when the water cut of the production well is greater than the preset water cut, increasing the number of branch wells in the multi-branch radial well network structure. The number of branches should be spatially symmetrical when designing, and the maximum number of branches is twice the injection-production well ratio. When the water cut of the production well is too high (for example, above 70%), the number of branches can be increased by 1-2 branches. The number of branches can be determined in the above manner.

[0078] In some embodiments of the present specification, the production dynamic characteristic data may include: an initial injection mode and an initial production mode; accordingly, using the production dynamic characteristic data to determine the fluctuating injection parameters for injecting into the modified multi-branch radial well network may include: when the initial injection mode is a constant flow injection mode, determining the injection mode for the modified multi-branch radial well network as a fluctuating flow injection; when the initial injection mode is a constant pressure injection mode, determining the injection mode for the modified multi-branch radial well network as a fluctuating pressure injection; and determining the initial production mode as the production mode of the modified multi-branch radial well network.

[0079] Specifically, the initial injection method and the initial production method are the initial injection method and production method of the target oil reservoir. When the initial injection method is a constant flow injection method, the injection method for the modified multi-branch radial well network will be determined as a fluctuating flow injection. When the initial injection method is a constant pressure injection method, the injection method for the modified multi-branch radial well network will be determined as a fluctuating pressure injection. There are two main production methods for production wells, a constant pressure production method and a fixed displacement production method. When changing to fluctuating injection, the production method of the production well remains unchanged and is the same as the original production method. Through the above method, production costs can be reduced.

[0080] In some embodiments of the present specification, the production dynamic characteristic data may include: pumping volume change data or pumping pressure change data; accordingly, using the production dynamic characteristic data to determine the fluctuation injection parameters for injection into the modified multi-branch radial well network may include: when the injection method for the modified multi-branch radial well network is fluctuation flow injection, determining the maximum pumping frequency according to the pumping pressure change data; when the injection method for the modified multi-branch radial well network is fluctuation pressure injection, determining the maximum pumping frequency according to the pumping volume change data; determining the target pumping frequency for injection into the modified multi-branch radial well network by conducting a core fluctuation injection experiment on the reservoir of the target oil reservoir, the target pumping frequency being less than or equal to the maximum pumping frequency; and using the target pumping frequency to perform a reservoir numerical model to determine the fluctuation injection amplitude and the fluctuation injection time.

[0081] Specifically, the pumping frequency range is determined by the following steps. The fluctuation period gradually decreases from 1 hour. When the injection method is the displacement fluctuation injection method, it is necessary to pay attention to the change of the pumping pressure. The maximum pumping frequency is when it exceeds 90% of the rated pressure of the pipe string. When the injection method is the pressure fluctuation injection method, it is necessary to pay attention to the change of the pumping displacement. The maximum pumping frequency is when the displacement drops sharply. After determining the pumping frequency range, the optimal pumping frequency can be determined through the core fluctuation injection experiment. Within this range (zero to maximum pumping frequency), the fluctuation flooding experiment is preferentially carried out. The optimal frequency is when the recovery rate is the largest. When the recovery rates are the same, a smaller frequency is selected.

[0082] The optimal pumping frequency can be determined through core wave injection experiments. Take the target block core, with a recommended experimental core size of φ2.5×5cm, saturate the target block with crude oil, and perform wave flooding under reservoir temperature and pressure conditions. The frequency range of wave flooding refers to the field test range. The optimal frequency is when the recovery rate is the highest within this range. If the recovery rate is the same, a smaller frequency is selected.

[0083] After determining the optimal frequency, numerical reservoir simulations are conducted by designing different fluctuation injection amplitudes and injection times. Optimizing these parameters with maximum oil recovery as the goal is to determine the corresponding fluctuation injection amplitude and injection time. For pressure fluctuation injection, the fluctuation injection amplitude refers to the difference between the maximum or minimum pressure fluctuations and the average pressure. For displacement fluctuation injection, the fluctuation injection amplitude refers to the difference between the maximum or minimum displacement fluctuations and the average displacement. Numerical reservoir simulation involves obtaining reservoir physical properties (length, width, height, porosity, permeability, and oil saturation) and inputting them into the model to determine injection and recovery parameters. This method can be used to determine fluctuation injection parameters and improve oil recovery.

[0084] In some embodiments of the present specification, the method may further include: obtaining injection and production well pressure data and fluid flow change data during the fluctuation injection displacement process; and adjusting the fluctuation injection parameters according to the injection and production well pressure data and fluid flow change data.

[0085] Fluctuating fluid injection is performed in each radial well, creating periodic pressure pulsations. Pumping is controlled in the main wellbore according to the designed optimal frequency. Each nozzle in the branch wellbore uses the same wave injection structure, and the elastic waves generated by the wave pulses are of the same frequency and phase. This allows for wave field superposition in the direction perpendicular to the wellbore, enhancing the wave displacement effect. By varying the injection pressure, wave injection significantly improves the fluid mobilization capacity within the reservoir, thereby effectively increasing the recovery factor. During the wave injection process, elastic waves from multiple sources within the radial wells are superimposed in the reservoir, enhancing pressure pulsations within the reservoir, improving pore pressure distribution, and increasing the mobilization capacity of oil and water.

[0086] During the displacement process, sensors installed at the wellhead and in the wellbore monitor changes in injection and production well pressure and fluid flow in real time. Data analysis assesses changes in various parameters during the displacement process, and injection strategies are adjusted as needed to ensure continuous optimization of the displacement effect. When the water production rate of an oil well increases rapidly during oscillatory injection, the oscillatory pressure or displacement amplitude is gradually increased, while the injection frequency is also increased. Each adjustment of pressure or displacement increases by 10%, with an adjustment period of 3-4 weeks, and the frequency is adjusted to 1.1-1.5 times the original value. After water breakthrough continues to decrease, the displacement and pressure changes remain unchanged, and the frequency is adjusted back to the original value. This method allows real-time adjustment of oscillatory injection parameters during the displacement process, improving the displacement effect, expanding the swept volume, and increasing the recovery factor.

[0087] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. For details, please refer to the description of the aforementioned related processing embodiments, and no further description is given here.

[0088] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0089] The above method is described below with reference to a specific embodiment. However, it should be noted that this specific embodiment is only for better illustrating this specification and does not constitute an improper limitation to this specification.

[0090] In this specific embodiment, a multi-branch radial well wave injection displacement method is provided. In this specific embodiment, it is taken into account that the current conventional displacement technology has problems such as severe fingering, small swept volume, and a sudden drop in oil production after seeing water and gas in oil reservoir exploitation, resulting in poor development effect. Multi-branch radial well technology is flexible in well shape design, has low well construction cost, is convenient for communicating with residual oil reservoirs, improves existing flow channels by artificial means, alleviates the problem of water seeing in oil-producing wells, etc. At the same time, radial wells can increase the contact area between the injected fluid and the oil reservoir, enhance the effect and range of wave injection, and are suitable for oil reservoir development. Wave injection technology can use periodic pressure fluctuations to increase the fluid mobilization capacity and recovery rate in the oil reservoir, improve the flow capacity of residual oil, and increase the swept volume. Therefore, combining multi-branch radial wells and wave injection methods is expected to significantly improve the recovery rate in oil reservoirs.

[0091] The method in this embodiment can expand the swept range of the injected fluid by performing wave injection of fluid (such as CO2, water, surfactant solution, nanofluid, etc.), provide multiple injection points in branch wells, enhance the intensity and range of elastic waves during wave injection, and improve the utilization rate of remaining oil in the reservoir, so as to solve the problems of low recovery rate, insufficient swept volume, rapid water breakthrough, and early gas breakthrough in the existing technology.

[0092] Please refer to Figure 2 , shows a schematic diagram of a multi-branch radial wellbore. A multi-branch radial wellbore may include a main wellbore 11 and multiple branch wellbores 21. A main wellbore wave eccentric injection tool 13 can be used to inject fluid into the main wellbore 11 along a main wellbore injection line 12. Branch radial well injection nozzles 23 can be used to inject fluid into the branch wellbores 21 along a branch radial well injection line 22.

[0093] The multi-branch radial well wave injection displacement method in this embodiment may include the following steps.

[0094] Reservoir physical property data analysis and well pattern design. Multi-branch radial well pattern design is based on reservoir physical property data (oil saturation distribution, fracture distribution, porosity and permeability distribution), injection-production well pattern data (injection-production well pattern layout, injection-production well pattern spacing, injection-production well type), and production performance characteristics (injection-production mode, constant pressure injection, constant flow injection, constant pressure production, constant flow production). Sweet spots and sub-sweet spots are selected based on the current reservoir oil saturation distribution. Sweet spots are located within 30 meters of either radial well branch or along the axis of the two branches. When natural and hydraulic fractures exist in the reservoir, the radial well orientation should be parallel to the fracture direction and at least 5 meters away. Porosity and permeability are positively correlated, and radial wells should preferentially penetrate areas of high porosity and high permeability. In the stimulation area, symmetrical injection-production well patterns are prioritized. Production performance provides a reference for fluctuating injection and production. The production mode of production wells remains consistent. When injecting at constant pressure, the injection well is subsequently adjusted to pressure fluctuations, and when injecting at constant flow, the injection well is adjusted to displacement fluctuations. On this basis, blocky oil reservoirs with low utilization or scattered oil areas with high oil saturation are used as radial well drilling areas. Radial well drilling avoids directly passing through the oil reservoir, and the radial wellbore is controlled within 30m from the oil reservoir. When the oil reservoir is located between radial wells, the distance from both sides should be kept as consistent as possible. The direction of the radial well should avoid the direction of the oil production well. When the radial well is along the direction of the oil production well, the length of the radial well should be shortened, and the distance between the radial well and the oil production well should be greater than 150m.

[0095] Design of wave injection parameters. Wave injection can be achieved using eccentric injection tools, self-excited wave injection tools, etc. The recommended injection nozzle spacing is 1-2m. The same pumping process is adopted between radial wells in the same main wellbore. Due to the limited borehole size of radial wells, the pressure bearing capacity of the pumping pipe is reduced. The pumping frequency range is determined by the following steps. The fluctuation period gradually decreases from 1h. When the displacement fluctuates, attention should be paid to the change in pumping pressure. The maximum pumping frequency is when it exceeds 90% of the rated pressure of the pipe string. When the pressure fluctuates, attention should be paid to the change in pumping displacement. The maximum pumping frequency is when the displacement suddenly decreases. After determining the pumping frequency range, the optimal pumping frequency can be determined through core wave injection experiments. Within this range, wave flooding experiments should be conducted first. The optimal frequency is when the recovery factor is the highest. A smaller frequency is selected when the recovery factor is the same.

[0096] Fluctuation injection displacement. Fluid fluctuation injection is carried out in each radial well to form periodic pressure pulsation. Pump injection is controlled in the main wellbore according to the designed optimal frequency. Each nozzle in the branch wellbore uses the same fluctuation injection structure. The elastic waves generated by the fluctuation pulse are of the same frequency and phase, thereby achieving wave field superposition in the vertical wellbore direction and enhancing the fluctuation displacement effect. Figure 3Figure 2 shows a schematic diagram of wave field superposition at different intervals. By varying the injection pressure, wave injection significantly enhances the fluid mobilization capacity within the reservoir, effectively increasing the recovery factor. During wave injection, elastic waves from multiple sources within the radial well are superimposed within the reservoir, enhancing pressure pulsation within the reservoir, improving pore pressure distribution, and increasing the mobilization capacity of oil and water.

[0097] Optimization of injection parameters and rational design of multi-branch wells. During the entire wave injection process, the branch length, number of branches, and injection parameters of the multi-branch radial wells should be rationally designed. The branch length should take into account the spacing between the main wellbore of the injection and production wells. The end of the branch well should be no less than 150m away from the production well. The number of branches should be spatially symmetrical when designed, and the maximum number of branches should be twice the ratio of production and injection wells to ensure that the injection pressure fluctuations are effectively propagated within the well network, slowing down the attenuation of the wave energy, and reducing the amount of injected gas while increasing the recovery rate. Through experiments and numerical simulations, the optimal injection frequency, pressure amplitude, and duration are determined to obtain the best displacement effect. The injection frequency is obtained by the wave injection parameter design. After determining the optimal frequency, numerical simulation studies are conducted by designing different amplitudes and wave injection times, and the parameters are optimized with the maximum recovery rate as the target.

[0098] Monitoring and data analysis. During the displacement process, sensors installed at the wellhead and in the wellbore monitor changes in injection and production well pressure and fluid flow in real time. Data analysis evaluates changes in various parameters during the displacement process, and injection strategies are adjusted as needed to ensure continuous optimization of the displacement effect. When the water production rate of an oil well increases rapidly during fluctuating injection, gradually increase the fluctuating pressure or displacement amplitude, while also increasing the injection frequency. Each time the pressure or displacement is adjusted, the pressure or displacement is increased by 10%, over a period of 3-4 weeks, and the frequency is adjusted to 1.1-1.5 times the original value. After water seepage continues to decrease, the displacement and pressure changes remain unchanged, and the frequency is adjusted back to the original value.

[0099] Compared to constant displacement technology, the method in this embodiment can effectively improve the utilization of remaining oil, expand the swept volume, and enhance the recovery rate by combining multi-branch radial wells with wave injection. Specific effects are reflected in the following aspects.

[0100] Improved recovery: Experimental results show that the method in this example improves recovery by 0.83% to 1.05% compared to conventional methods. This is because the wave injection effectively improves the fluid seepage environment within the reservoir and enhances the ability to mobilize residual oil.

[0101] Improved oil change efficiency: Taking CO2 flooding as an example, through the wave injection method, the required CO2 injection volume can be reduced by about 1.8 to 4.2×10 5 m 3This not only reduces development costs, but also reduces the impact on the environment, which has good environmental benefits.

[0102] Expanded swept volume: The multi-branch radial well design can achieve the same frequency and phase of the wave pulse elastic wave, and the elastic wave superposition effect is more obvious. Through the propagation of the elastic wave, the swept volume is effectively expanded, further improving the recovery rate of the reservoir.

[0103] The following is an explanation with reference to a specific embodiment. The basic physical property parameters of the target reservoir to which the method in this specific embodiment is applied are shown in Table 1.

[0104] Table 1

[0105]

[0106] Based on this method, production in an oil field was simulated. The method in this example was used for CO2 wave injection displacement. The well pattern consisted of four production wells and one injection well. Each injection well was equipped with one to four radial branches, each with a branch length of 30 meters. The injection process used a wave frequency of 2 Hz and an amplitude of 1 MPa. After 2000 days of displacement operations, the recovery factor increased by approximately 1.05% compared to traditional CO2 displacement, and the total CO2 injection volume was reduced by approximately 2.1×105m 3 By real-time monitoring of injection pressure and fluid flow, it was found that wave injection can significantly improve the pressure distribution near the wellbore and greatly improve the displacement efficiency. Figure 4 . Figure 4 The diagram shows the oil production curves under different injection displacement methods. Figure 4 As shown, compared with the single-branch non-fluctuation displacement method, the multi-branch radial well fluctuating injection method in the embodiment of this specification can significantly improve the recovery rate.

[0107] Based on the same inventive concept, the embodiments of this specification also provide a multi-branch radial well pulsating injection displacement device, as described in the following embodiments. Since the principle of solving the problem of the multi-branch radial well pulsating injection displacement device is similar to that of the multi-branch radial well pulsating injection displacement method, the implementation of the multi-branch radial well pulsating injection displacement device can refer to the implementation of the multi-branch radial well pulsating injection displacement method, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived. Figure 5 This is a structural block diagram of a multi-branch radial well wave injection displacement device according to an embodiment of this specification. Figure 5As shown, it may include: an acquisition module 501, a first determination module 502, a second determination module 503 and a generation module 504. The structure is described below.

[0108] The acquisition module 501 is used to acquire reservoir physical property data, injection and production well pattern data and production dynamic characteristic data of the target oil reservoir.

[0109] The first determination module 502 is used to determine the multi-branch radial well pattern structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well pattern according to the reservoir physical property data, injection-production well pattern data and production performance characteristic data of the target oil reservoir.

[0110] The second determining module 503 is configured to determine the fluctuating injection parameters for injecting into the modified multi-branch radial well pattern using the production dynamic characteristic data.

[0111] The generation module 504 is configured to generate an injection displacement plan for the target reservoir based on the multi-branch radial well pattern structure data and the fluctuation injection parameters.

[0112] In some embodiments of the present specification, the first determination module is specifically used to: determine the position and direction of the radial well branch based on the reservoir physical property data of the target oil reservoir; determine the radial well transformation area and the length of the radial well branch based on the injection and production well network data of the target oil reservoir; determine the number of the radial well branches using the injection and production well network data and the production dynamic characteristic data; generate multi-branch radial well network structure data based on the radial well transformation area, the position and direction of the radial well branch, the length of the radial well branch and the number of the radial well branches.

[0113] In some embodiments of the present specification, the reservoir physical property data of the target oil reservoir may include: oil saturation distribution data, fracture distribution data and porosity and permeability distribution data; accordingly, determining the position and direction of the radial well branch based on the reservoir physical property data of the target oil reservoir may include: determining the sweet spot position and the secondary sweet spot position of the target oil reservoir based on the oil saturation distribution data; determining the first position range of the radial well branch based on the sweet spot position and the secondary sweet spot position; when the fracture distribution data indicates that there are natural fractures or hydraulic fractures in the reservoir of the target oil reservoir, setting the direction of the radial well to be parallel to the fracture direction of the natural fracture or the hydraulic fracture, and determining the second position range of the radial well branch according to the position of the natural fracture or the hydraulic fracture; setting the radial well branch to pass through a high-porosity and high-permeability area based on the porosity and permeability distribution data.

[0114] In some embodiments of the present specification, the injection and production well network data may include: injection and production well network layout, injection and production well network spacing, and injection and production well type; accordingly, based on the injection and production well network data of the target oil reservoir, determining the radial well transformation area and the length of the radial well branch may include: when the injection and production well type is a vertical well, determining to perform multi-branch radial well transformation on the injection well; determining the area where the injection and production well network is symmetrically distributed according to the injection and production well network layout, and using the area where the injection and production well network is symmetrically distributed as the radial well transformation area; determining the branch length range of the radial well branch based on the injection and production well network spacing.

[0115] In some embodiments of the present specification, the injection-production well network data includes the injection-production well ratio; the production dynamic characteristic data may include the water cut of the production well; accordingly, using the injection-production well network data and the production dynamic characteristic data to determine the number of radial well branches may include: determining twice the injection-production well ratio as the maximum value of the radial well branches; and when the water cut of the production well is greater than the preset water cut, increasing the number of branch wells in the multi-branch radial well network structure.

[0116] In some embodiments of the present specification, the production dynamic characteristic data may include: an initial injection mode and an initial production mode; accordingly, the second determination module is specifically used to: when the initial injection mode is a constant flow injection mode, determine the injection mode for the modified multi-branch radial well network as a fluctuating flow injection; when the initial injection mode is a constant pressure injection mode, determine the injection mode for the modified multi-branch radial well network as a fluctuating pressure injection; and determine the initial production mode as the production mode of the modified multi-branch radial well network.

[0117] In some embodiments of the present specification, the production dynamic characteristic data may include: pumping displacement change data or pumping pressure change data; accordingly, the second determination module is specifically used to: when the injection method for the transformed multi-branch radial well network is fluctuating flow injection, determine the maximum pumping frequency according to the pumping pressure change data; when the injection method for the transformed multi-branch radial well network is fluctuating pressure injection, determine the maximum pumping frequency according to the pumping displacement change data; determine the target pumping frequency for injection into the transformed multi-branch radial well network by conducting a core fluctuation injection experiment on the reservoir of the target oil reservoir, the target pumping frequency being less than or equal to the maximum pumping frequency; and use the target pumping frequency to perform a reservoir numerical model to determine the fluctuation injection amplitude and fluctuation injection time.

[0118] In some embodiments of the present specification, the device may further include an adjustment module, which is specifically used to: obtain injection and production well pressure data and fluid flow change data during the fluctuation injection displacement process; and adjust the fluctuation injection parameters according to the injection and production well pressure data and fluid flow change data.

[0119] This specification also provides a computer device. Figure 6 The diagram shows the structure of a computer device for the multi-branch radial well wave injection flooding method according to an embodiment of this specification. The computer device may include an input device 61, a processor 62, and a memory 63. The memory 63 is used to store processor-executable instructions. When the processor 62 executes these instructions, the steps of the multi-branch radial well wave injection flooding method described in any of the above embodiments are implemented.

[0120] In this embodiment, the input device can specifically be one of the primary devices for exchanging information between a user and a computer system. The input device can include a keyboard, mouse, camera, scanner, light pen, handwriting input tablet, voice input device, etc.; the input device is used to input raw data and programs for processing these data into the computer. The input device can also receive data transmitted from other modules, units, and devices. The processor can be implemented in any appropriate manner. For example, the processor can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (such as software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers, etc. The memory can specifically be a memory device used to store information in modern information technology. The memory can include multiple levels. In digital systems, anything that can store binary data can be considered a memory device. In integrated circuits, a circuit with storage functionality that does not have a physical form is also called a memory device, such as a RAM or FIFO. In systems, a physical storage device is also called a memory device, such as a memory stick or a TF card.

[0121] In this embodiment, the specific functions and effects achieved by the computer device can be explained in comparison with other embodiments and will not be repeated here.

[0122] The embodiments of this specification also provide a computer storage medium based on the multi-branch radial well fluctuation injection displacement method, wherein the computer storage medium stores computer program instructions, and when the computer program instructions are executed, the steps of the multi-branch radial well fluctuation injection displacement method described in any of the above embodiments are implemented.

[0123] In this embodiment, the storage medium includes, but is not limited to, random access memory (RAM), read-only memory (ROM), cache, hard disk drive (HDD), or memory card. The memory can be used to store computer program instructions. The network communication unit can be an interface configured in accordance with the standards specified by the communication protocol for network connection communication.

[0124] In this embodiment, the functions and effects specifically implemented by the program instructions stored in the computer storage medium can be explained in comparison with other embodiments and will not be repeated here.

[0125] Obviously, those skilled in the art should understand that the various modules or steps of the above-mentioned embodiments of this specification can be implemented using a general-purpose computing device, they can be concentrated on a single computing device, or distributed across a network composed of multiple computing devices. Alternatively, they can be implemented using program code executable by the computing device, so that they can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described can be performed in a different order than herein, or they can be made into separate integrated circuit modules, or multiple modules or steps can be made into a single integrated circuit module for implementation. Thus, the embodiments of this specification are not limited to any specific combination of hardware and software.

[0126] It should be understood that the above description is intended to be illustrative and not limiting. Numerous embodiments and applications beyond the examples provided will be readily apparent to those skilled in the art upon reading the above description. Therefore, the scope of this specification should not be determined with reference to the above description, but rather with reference to the preceding claims, along with the full scope of equivalents to which such claims are entitled.

[0127] The above description is merely a preferred embodiment of this specification and is not intended to limit this specification. Those skilled in the art will readily appreciate that various modifications and variations to the embodiments of this specification are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this specification shall be within the scope of protection of this specification.

Claims

1. A multi-branch radial well wave injection displacement method, characterized in that: include: Obtain reservoir physical property data, injection-production well pattern data, and production performance characteristic data of the target oil reservoir; The reservoir physical property data of the target oil reservoir include: oil saturation distribution data, fracture distribution data and porosity and permeability distribution data; the injection-production well pattern data include: injection-production well pattern layout, injection-production well pattern spacing, and injection-production well type; the production dynamic characteristic data include: initial injection mode and initial production mode; Determining multi-branch radial well pattern structure data for performing multi-branch radial well transformation on injection wells in the injection-production well pattern based on reservoir physical property data, injection-production well pattern data, and production performance characteristic data of the target oil reservoir; Determining the fluctuating injection parameters for injecting into the modified multi-branch radial well pattern using the production dynamic characteristic data; generating an injection displacement plan for the target oil reservoir based on the multi-branch radial well pattern structure data and the fluctuating injection parameters; Wherein, according to the reservoir physical property data of the target oil reservoir, the injection-production well pattern data and the production dynamic characteristic data, the multi-branch radial well pattern structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well pattern is determined, including: determining the position and direction of the radial well branches according to the reservoir physical property data of the target oil reservoir; determining the radial well transformation area and the length of the radial well branches based on the injection-production well pattern data of the target oil reservoir; determining the number of the radial well branches using the injection-production well pattern data and the production dynamic characteristic data; generating the multi-branch radial well pattern structure data based on the radial well transformation area, the position and direction of the radial well branches, the length of the radial well branches and the number of the radial well branches; Among them, the production dynamic characteristic data is used to determine the fluctuating injection parameters for injecting into the modified multi-branch radial well network, including: when the initial injection mode is a constant flow injection mode, the injection mode for the modified multi-branch radial well network is determined to be a fluctuating flow injection; when the initial injection mode is a constant pressure injection mode, the injection mode for the modified multi-branch radial well network is determined to be a fluctuating pressure injection; and the initial production mode is determined to be the production mode of the modified multi-branch radial well network.

2. The multi-branch radial well wave injection displacement method according to claim 1, characterized in that: Determining the location and direction of radial well branches based on reservoir physical property data of the target reservoir includes: Determine the sweet spot position and the secondary sweet spot position of the target reservoir according to the oil saturation distribution data; determine the first position range of the radial well branch based on the sweet spot position and the secondary sweet spot position; When the fracture distribution data indicates that natural fractures or hydraulic fractures exist in the reservoir of the target oil reservoir, the direction of the radial well is set to be parallel to the fracture direction of the natural fracture or the hydraulic fracture, and the second position range of the radial well branch is determined according to the position of the natural fracture or the hydraulic fracture; The radial well branches are arranged to pass through high-porosity and high-permeability areas according to the porosity and permeability distribution data.

3. The multi-branch radial well wave injection displacement method according to claim 1, characterized in that: Determining a radial well stimulation area and a length of the radial well branch based on the injection and production well pattern data of the target oil reservoir includes: In the case where the injection-production well is a vertical well, determining to perform multi-branch radial well transformation on the injection well; Determine, according to the injection-production well pattern layout, an area where the injection-production well pattern is symmetrically distributed, and use the area where the injection-production well pattern is symmetrically distributed as a radial well transformation area; The branch length range of the radial well branches is determined based on the injection and production well pattern spacing.

4. The multi-branch radial well wave injection displacement method according to claim 1, characterized in that: The injection-production well pattern data includes the production-injection well ratio; the production dynamic characteristic data includes the water content of the production well; Accordingly, the number of radial well branches is determined by using the injection-production well pattern data and the production dynamic characteristic data, including: Determine twice the production-injection well ratio as the maximum value of the radial well branch; When the water cut of the production well is greater than a preset water cut, the number of branch wells in the multi-branch radial well pattern structure is increased.

5. The multi-branch radial well wave injection displacement method according to claim 1, characterized in that: The production dynamic characteristic data include: pumping displacement change data or pumping pressure change data; Accordingly, the production dynamic characteristic data is used to determine the fluctuating injection parameters for injecting into the modified multi-branch radial well pattern, including: When the injection method for the modified multi-branch radial well network is fluctuating flow injection, the maximum pumping frequency is determined according to the pumping pressure change data; when the injection method for the modified multi-branch radial well network is fluctuating pressure injection, the maximum pumping frequency is determined according to the pumping displacement change data; Determining a target pumping frequency for injection into the modified multi-branch radial well pattern by conducting a core wave injection experiment on a reservoir of the target oil reservoir, wherein the target pumping frequency is less than or equal to the maximum pumping frequency; The target pumping frequency is used to construct a reservoir numerical model to determine the fluctuation injection amplitude and the fluctuation injection time.

6. The multi-branch radial well wave injection displacement method according to claim 1, characterized in that: Also includes: During the wave injection and displacement process, obtain the injection and production well pressure data and fluid flow change data; The fluctuating injection parameters are adjusted according to the injection-production well pressure data and the fluid flow rate change data.

7. A multi-branch radial well wave injection displacement device, characterized in that: include: Acquisition module, used to obtain reservoir physical property data, injection and production well pattern data and production dynamic characteristic data of the target oil reservoir; The reservoir physical property data of the target oil reservoir include: oil saturation distribution data, fracture distribution data and porosity and permeability distribution data; the injection-production well pattern data include: injection-production well pattern layout, injection-production well pattern spacing, and injection-production well type; the production dynamic characteristic data include: initial injection mode and initial production mode; The first determination module is used to determine the multi-branch radial well pattern structure data for performing multi-branch radial well transformation on the injection wells in the injection-production well pattern according to the reservoir physical property data, injection-production well pattern data and production dynamic characteristic data of the target oil reservoir; A second determination module is configured to determine a fluctuating injection parameter for injecting into the modified multi-branch radial well pattern using the production dynamic characteristic data; A generating module, configured to generate an injection displacement plan for the target oil reservoir based on the multi-branch radial well pattern structure data and the fluctuating injection parameters; The first determination module is specifically configured to: determine the position and direction of the radial well branches based on the reservoir physical property data of the target oil reservoir; determine the radial well transformation area and the length of the radial well branches based on the injection and production well pattern data of the target oil reservoir; determine the number of the radial well branches using the injection and production well pattern data and the production performance characteristic data; and generate multi-branch radial well pattern structure data based on the radial well transformation area, the position and direction of the radial well branches, the length of the radial well branches, and the number of the radial well branches; Among them, the second determination module is specifically used to: when the initial injection mode is a constant flow injection mode, determine the injection mode of the modified multi-branch radial well network as a fluctuating flow injection mode; when the initial injection mode is a constant pressure injection mode, determine the injection mode of the modified multi-branch radial well network as a fluctuating pressure injection mode; and determine the initial production mode as the production mode of the modified multi-branch radial well network.

8. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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