Rock core water injection mode determination method and device, equipment and storage medium

Abstract

The invention relates to the technical field of petroleum development, and discloses a rock core water injection mode determination method, device and equipment and a storage medium, and the method comprises the following steps: respectively carrying out steady-state water injection and unsteady-state water injection on an experimental rock core under preset experimental parameters; respectively performing CT scanning on the steady-state water injection process and the non-steady-state water injection process to obtain a steady-state distribution result of an internal fluid of the experimental rock core in a steady-state water injection mode and a non-steady-state distribution result of the internal fluid in a non-steady-state water injection mode; comparing a steady-state distribution result with an unsteady-state distribution result; determining a water injection mode suitable for the actual core in the mine field according to a comparison result. According to the method, the water injection mode suitable for the actual rock core in the mine field is determined by comparing the steady-state distribution result and the non-steady-state distribution result of the experimental rock core, the application conditions of the actual rock core in the mine field can be determined, the situation that an inapplicable water injection mode is adopted in the mine field is avoided, and the oil recovery rate is effectively increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil development, and particularly relates to a core water injection mode determination method, device, equipment and storage medium. BACKGROUND

[0002] At present, in the process of oil development, water drive mode is often used, in order to improve the oil recovery rate, the commonly used water drive mode is a non-steady state water injection mode. The non-steady state water injection refers to a water injection mode in which the injection rate and the production rate are not equal. This mode can effectively improve the water drive development effect and improve the recovery rate of the oil reservoir. However, the non-steady state water injection technology is not suitable for all cores in the mine field. Once the core in a mine field is not suitable for this mode, if the unsuitable water injection mode is used, the oil recovery rate will be reduced.

[0003] The above content is only used to assist in understanding the technical solutions of the present application, and does not represent the acknowledgement of the above content as prior art. SUMMARY

[0004] The main purpose of the present application is to provide a core water injection mode determination method, device, equipment and storage medium, which aims to solve the technical problem that the oil recovery rate is reduced once the unsuitable water injection mode is used in the prior art mine field.

[0005] To achieve the above purpose, the present application provides a core water injection mode determination method, which comprises the following steps:

[0006] Under the preset experimental parameters, the experimental core is subjected to steady state water injection and non-steady state water injection respectively;

[0007] CT scanning is performed on the steady state water injection process and the non-steady state water injection process respectively, to obtain the steady state distribution result of the internal fluid of the experimental core under the steady state water injection mode and the non-steady state distribution result of the internal fluid of the experimental core under the non-steady state water injection mode;

[0008] The steady state distribution result is compared with the non-steady state distribution result;

[0009] According to the comparison result, the water injection mode suitable for the actual core in the mine field is determined.

[0010] Optionally, the step of subjecting the experimental core to steady state water injection and non-steady state water injection under the preset experimental parameters comprises:

[0011] Under the preset experimental parameters, the experimental core is subjected to steady state water injection, first non-steady state water injection, second non-steady state water injection and third non-steady state water injection;

[0012] The steady state water injection is a process in which the water injection end of the experimental core continuously injects water, the production end of the experimental core keeps producing, and the process stops when water appears on the surface of the experimental core.

[0013] The first non-steady-state water injection is a process in which the water injection end injects water and stops injecting water with a preset period, and the production end keeps producing until the oil production rate of the production end starts to decrease;

[0014] The second non-steady-state water injection is a process in which the water injection end keeps injecting water, and the production end produces and stops producing with the preset period until the oil production rate of the production end starts to decrease;

[0015] The third non-steady-state water injection is a process in which the water injection end injects water and stops injecting water with the preset period, and the production end produces and stops producing with the preset period until the oil production rate of the production end starts to decrease.

[0016] Optionally, the step of respectively performing CT scanning on the steady-state water injection process and the non-steady-state water injection process to obtain the steady-state distribution result of the internal fluid of the experimental core under the steady-state water injection mode and the non-steady-state distribution result of the internal fluid of the experimental core under the non-steady-state water injection mode comprises:

[0017] Performing CT scanning on the steady-state water injection process to obtain the steady-state swept volume of the internal fluid of the experimental core under the steady-state water injection mode, and determining the steady-state oil displacement efficiency under the steady-state water injection mode according to the steady-state swept volume;

[0018] Performing CT scanning on each non-steady-state water injection process to obtain the non-steady-state swept volume of the internal fluid of the experimental core under each non-steady-state water injection mode, and determining the non-steady-state oil displacement efficiency under each non-steady-state water injection mode according to each non-steady-state swept volume;

[0019] The non-steady-state oil displacement efficiency includes the first non-steady-state oil displacement efficiency under the first non-steady-state water injection mode, the second non-steady-state oil displacement efficiency under the second non-steady-state water injection mode, and the third non-steady-state oil displacement efficiency under the third non-steady-state water injection mode;

[0020] The steady-state oil displacement efficiency is taken as the steady-state distribution result of the internal fluid under the steady-state water injection mode, and each non-steady-state oil displacement efficiency is taken as the non-steady-state distribution result of the internal fluid under the non-steady-state water injection mode.

[0021] Optionally, the step of determining the water injection mode suitable for the actual core in the oil field according to the comparison result comprises:

[0022] When the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency are all less than the steady-state oil displacement efficiency, the steady-state water injection mode is taken as the water injection mode suitable for the actual core in the oil field;

[0023] determining a maximum value among the first non-steady-state displacement efficiency, the second non-steady-state displacement efficiency and the third non-steady-state displacement efficiency when the first non-steady-state displacement efficiency, the second non-steady-state displacement efficiency or the third non-steady-state displacement efficiency is greater than the steady-state displacement efficiency;

[0024] using the non-steady-state water injection mode corresponding to the maximum value as the water injection mode applicable to the actual core in the oilfield.

[0025] Optionally, before the step of performing steady-state water injection and non-steady-state water injection on the experimental core under the preset experimental parameters, the method further comprises:

[0026] sucking the heterogeneous core by using a vacuum pump to form a vacuum inside the heterogeneous core;

[0027] saturating the heterogeneous core with water by using vacuum pressure to obtain a water-saturated core, and measuring a water saturation parameter of the water-saturated core;

[0028] saturating the water-saturated core with oil to obtain an experimental core, and measuring an oil saturation of the experimental core;

[0029] determining the preset experimental parameters according to the water saturation parameter and the oil saturation.

[0030] Optionally, the water saturation parameter comprises a water-saturated pore volume, a water-saturated porosity and a water phase permeability, and the step of determining the preset experimental parameters according to the water saturation parameter and the oil saturation comprises:

[0031] determining pressure field distributions of different stages of non-steady-state water injection according to the pore volume, the porosity, the water phase permeability and the oil saturation;

[0032] determining core permeabilities corresponding to different pressure field distributions;

[0033] determining the preset experimental parameters based on the core permeabilities and the pressure field distributions.

[0034] Optionally, the pressure field distribution comprises a pressure increasing stage pressure field distribution and a pressure decreasing stage pressure field distribution, and the step of determining the preset experimental parameters based on the core permeabilities and the pressure field distributions comprises:

[0035] determining an envelope line formed by the pressure increasing stage pressure field distribution and the pressure decreasing stage pressure field distribution under different core permeabilities;

[0036] selecting a target envelope line with the largest range from the envelope lines, and determining a target core permeability corresponding to the target envelope line;

[0037] The target core permeability and the target envelope are used as preset experimental parameters.

[0038] In addition, to achieve the above object, the present invention further proposes a device comprising:

[0039] The core flooding module is used to perform steady-state water injection and unsteady-state water injection on the experimental core under preset experimental parameters;

[0040] a CT scanning module, configured to perform CT scanning on the steady-state water injection process and the unsteady-state water injection process, respectively, to obtain steady-state distribution results of the internal fluid of the experimental core under the steady-state water injection mode, and unsteady-state distribution results of the internal fluid under the unsteady-state water injection mode;

[0041] A result comparison module, configured to compare the steady-state distribution result with the non-steady-state distribution result;

[0042] The water injection determination module is used to determine the water injection method applicable to the experimental core according to the comparison results.

[0043] In addition, to achieve the above-mentioned purpose, the present invention also proposes a core water injection method determination device, which includes: a memory, a processor, and a core water injection method determination program stored in the memory and executable on the processor, wherein the core water injection method determination program is configured to implement the steps of the core water injection method determination method described above.

[0044] In addition, to achieve the above objectives, the present invention also proposes a storage medium, on which a core water injection method determination program is stored. When the core water injection method determination program is executed by a processor, the steps of the core water injection method determination method described above are implemented.

[0045] The present invention provides a method, device, equipment and storage medium for determining a core water injection method. The method performs steady-state water injection and unsteady-state water injection on an experimental core under preset experimental parameters; performs CT scanning on the steady-state water injection process and the unsteady-state water injection process respectively to obtain the steady-state distribution results of the internal fluid of the experimental core under the steady-state water injection method, and the unsteady-state distribution results of the internal fluid under the unsteady-state water injection method; compares the steady-state distribution results with the unsteady-state distribution results; and determines the water injection method applicable to the actual core in the mine based on the comparison results. The present invention performs steady-state water injection and unsteady-state water injection on the same experimental core distribution in advance through an experiment, and then determines the water injection method applicable to the actual core in the mine by comparing the steady-state distribution results of the experimental core with the unsteady-state distribution results. This can clarify the applicable conditions of the actual core in the mine, avoid the mine adopting an inappropriate water injection method, and effectively improve the oil recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the device structure for determining the core water injection method in the hardware operating environment of the embodiment of the present invention;

[0047] Figure 2 This is a flow chart of a first embodiment of the method for determining a core water injection method according to the present invention;

[0048] Figure 3 This is a flow chart of a second embodiment of the method for determining a core water injection method according to the present invention;

[0049] Figure 4 This is a flow chart of a third embodiment of the method for determining a core water injection method according to the present invention;

[0050] Figure 5 Schematic diagram of a heterogeneous core in the third embodiment of the method for determining a core water injection mode of the present invention;

[0051] Figure 6 This is a schematic diagram of the pressure field distribution in the third embodiment of the method for determining the core water injection mode of the present invention;

[0052] Figure 7 This is a structural block diagram of the first embodiment of the core water injection mode determination device of the present invention.

[0053] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0054] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0055] Reference Figure 1 , Figure 1 The present invention provides a schematic diagram of a core water injection device structure for a hardware operating environment according to an embodiment of the present invention.

[0056] like Figure 1As shown in the figure, the core water injection mode determination device can include a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to realize the connection and communication between the components. The user interface 1003 can include a display, an input unit such as a keyboard, and can also include a standard wired interface, a wireless interface. The network interface 1004 can optionally include a standard wired interface, a wireless interface (such as a wireless fidelity (Wi-Fi) interface). The memory 1005 can be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk memory. The memory 1005 can also be a storage device independent of the aforementioned processor 1001.

[0057] Those skilled in the art can understand that Figure 1 The structure shown in the figure does not constitute a limitation on the core water injection mode determination device, and can include more or fewer components than the figure, or combine certain components, or different component arrangements.

[0058] As Figure 1 As shown, the memory 1005 as a storage medium can include an operating system, a network communication module, a user interface module, and a core water injection mode determination program.

[0059] In Figure 1 In the core water injection mode determination device shown in the figure, the network interface 1004 is mainly used for data communication with a network server; the user interface 1003 is mainly used for data interaction with a user; the processor 1001 and the memory 1005 in the core water injection mode determination device can be arranged in the core water injection mode determination device, and the core water injection mode determination device calls the core water injection mode determination program stored in the memory 1005 through the processor 1001, and executes the core water injection mode determination method provided by the embodiment of the application.

[0060] The embodiment of the application provides a core water injection mode determination method, which refers to Figure 2 , Figure 2 The flowchart of the first embodiment of the core water injection mode determination method of the application is shown in the figure.

[0061] In this embodiment, the core water injection mode determination method includes the following steps:

[0062] Step S10: The experimental core is respectively subjected to steady-state water injection and unsteady-state water injection under preset experimental parameters.

[0063] It should be noted that the execution subject of the method of the embodiment can be a computing service device with data processing, network communication and program running functions, such as a mobile phone, a tablet computer, a personal computer and the like, and can also be other electronic devices that realize the same or similar functions. The following describes the embodiment and each of the following embodiments by taking a device (referred to as a water injection device) for determining the core water injection mode as an example.

[0064] It can be understood that the experimental core can be a non-homogeneous block-shaped simulation core saturated with water and oil, consistent with the rock in a mining field, that is, the experimental core is obtained by simulating the actual core in the mining field, and the properties of the experimental core are consistent with those of the actual core in the mining field. The non-homogeneity refers to the inconsistency of the microstructure and physical properties inside the core, which is a basic condition for implementing unsteady-state water injection.

[0065] It should be noted that the preset experimental parameters can be parameters determined in advance according to related parameters of the experimental core when saturation is achieved, which can make the water drive effect optimal.

[0066] It can be understood that the steady-state water injection can be a water injection mode in which the water injection speed is equal to the production speed. In this mode, the fluid pressure and saturation distribution in the formation are relatively uniform, the oil-water interface is relatively stable, and the injected water mainly displaces the original crude oil in the oil layer to drive it to the production well.

[0067] It should be noted that the unsteady-state water injection can be a water injection mode in which the water injection speed and the production speed are not equal. In this mode, the fluid pressure and saturation distribution in the formation are not uniform, forming a pressure and saturation gradient, thereby driving the oil-water interface to move forward continuously to displace the crude oil from the oil layer.

[0068] In a specific implementation, the water injection device can be arranged in a CT scanner, so that a user can implement observation of the displacement process of the experimental core and improve the controllability of the displacement process. The water injection device can respectively perform steady-state water injection and unsteady-state water injection on the experimental core under preset experimental parameters, to realize the displacement process of the steady-state water injection and the displacement process of the unsteady-state water injection. The displacement process can be a process of displacing the crude oil in the experimental core by water injection.

[0069] In addition, the experimental temperature is constant at the formation temperature, the core confining pressure is the formation pressure; the oil used in the experiment is a crude oil configured to be consistent with the physical properties of the field, and the water used in the experiment is a simulated formation water consistent with the salinity of the field formation water.

[0070] Step S20: CT scanning is performed on the steady-state water injection process and the non-steady-state water injection process respectively to obtain the steady-state distribution result of the internal fluid of the experimental core under the steady-state water injection mode and the non-steady-state distribution result of the internal fluid of the experimental core under the non-steady-state water injection mode.

[0071] It should be noted that the steady-state distribution result can be the distribution of water saturation under the steady-state water injection mode. Correspondingly, the non-steady-state distribution result can be the distribution of water saturation under the non-steady-state water injection mode.

[0072] In a specific implementation, the water injection device can scan the steady-state water injection process and the non-steady-state water injection process respectively by the CT scanner to obtain the distribution of water saturation of the internal fluid of the experimental core under the steady-state water injection mode and the distribution of water saturation of the internal fluid of the experimental core under the non-steady-state water injection mode, and then take the water saturation under the steady-state water injection mode as the steady-state distribution result and take the water saturation under the non-steady-state water injection mode as the non-steady-state distribution result.

[0073] It should be understood that, by the CT scanning imaging technology, the displacement process of the core at each moment can be recorded in real time without changing the external form and internal structure of the core, the seepage and distribution characteristics of the porous medium under different pressures can be dynamically observed, the oil and water distribution characteristics in the core can be obtained, the real displacement process can be restored, and the experimental precision can be ensured.

[0074] Step S30: Comparing the steady-state distribution result with the non-steady-state distribution result.

[0075] In a specific implementation, the water injection device can compare the steady-state distribution result with the non-steady-state distribution result, that is, compare the distribution of water saturation under the steady-state water injection mode with the distribution of water saturation under the non-steady-state water injection mode.

[0076] Step S40: Determining the water injection mode applicable to the actual core in the oil field according to the comparison result.

[0077] In a specific implementation, in the process of oil reservoir development, the water saturation and the oil displacement efficiency have a corresponding relationship. With the advance of injected water and the continuous production of oil and water, the water saturation gradually increases, and the oil displacement efficiency gradually decreases. That is, when the water saturation under the steady-state water injection mode is detected to be lower than the water saturation under the non-steady-state water injection mode, it is determined that the oil displacement efficiency of the non-steady-state water injection mode is higher, and it can be determined that the water injection mode applicable to the actual core in the oil field is the non-steady-state water injection mode. Conversely, when the water saturation under the steady-state water injection mode is detected to be higher than the water saturation under the non-steady-state water injection mode, it is determined that the oil displacement efficiency of the steady-state water injection mode is higher, and it can be determined that the water injection mode applicable to the actual core in the oil field is the steady-state water injection mode.

[0078] The above oil displacement efficiency refers to the percentage of the oil volume displaced from the experimental core to the original oil volume in the experimental core.

[0079] It should be understood that since the experimental core is obtained by simulating the actual core in the mine, the applicable conditions of the experimental core are consistent with the applicable conditions of the actual core in the mine. By determining the applicable conditions of the experimental core, the applicable conditions of the actual core can be known, so as to facilitate the subsequent mining of the actual core in the mine, clarify the oil displacement mechanism and main controlling factors of non-steady-state water injection, and provide technical support for the implementation of non-steady-state water injection in the mine.

[0080] This embodiment performs steady-state water injection and unsteady-state water injection on the experimental core under preset experimental parameters; performs CT scanning on the steady-state water injection process and the unsteady-state water injection process respectively, obtains the steady-state distribution results of the internal fluid of the experimental core under the steady-state water injection mode, and the unsteady-state distribution results of the internal fluid under the unsteady-state water injection mode; compares the steady-state distribution results with the unsteady-state distribution results; and determines the water injection method applicable to the actual core in the mine based on the comparison results. The present invention performs steady-state water injection and unsteady-state water injection on the same experimental core distribution in advance through an experiment, and then determines the water injection method applicable to the actual core in the mine by comparing the steady-state distribution results of the experimental core with the unsteady-state distribution results. This can clarify the applicable conditions of the actual core in the mine, avoid the mine adopting an inappropriate water injection method, and effectively improve the oil recovery rate.

[0081] refer to Figure 3 , Figure 3 This is a flow chart of the second embodiment of the method for determining the core water injection mode of the present invention.

[0082] Based on the above first embodiment, in this embodiment, step S10 includes:

[0083] Step S101: performing steady-state water injection, first unsteady-state water injection, second unsteady-state water injection and third unsteady-state water injection on the experimental core under preset experimental parameters.

[0084] The steady-state water injection is a process that a water injection end of the experimental core is continuously injected with water, a production end of the experimental core is kept producing, and the process is stopped when water appears on a surface of the experimental core; the first non-steady-state water injection is a process that the water injection end is injected with water and stopped injecting with water in a preset period, the production end is kept producing, and the process is stopped when an oil production rate of the production end starts to decrease; the second non-steady-state water injection is a process that the water injection end is kept injecting with water, the production end is produced and stopped producing in the preset period, and the process is stopped when the oil production rate of the production end starts to decrease; and the third non-steady-state water injection is a process that the water injection end is injected with water and stopped injecting with water in the preset period, the production end is produced and stopped producing in the preset period, and the process is stopped when the oil production rate of the production end starts to decrease.

[0085] It should be noted that, in order to improve the accuracy of the water injection mode determination, a plurality of non-steady-state water injection modes can be used, i.e., the first non-steady-state water injection mode, the second non-steady-state water injection mode, and the third non-steady-state water injection mode.

[0086] It can be understood that the water injection end can be a position of a water injection well, i.e., a position of injecting water into a formation. Correspondingly, the production end can be a position of an oil production well, i.e., a position of extracting crude oil.

[0087] It should be noted that the preset period can be a period that is preset according to production requirements.

[0088] In a specific implementation, the water injection device can perform the steady-state water injection, the first non-steady-state water injection, the second non-steady-state water injection, and the third non-steady-state water injection on the experimental core under the same preset experimental parameters.

[0089] In the steady-state water injection stage, i.e., a water drive oil production stage, the water injection end of the experimental core is continuously injected with water, the production end of the experimental core is kept producing stably, and the experiment is stopped when water appears on the surface of the experimental core.

[0090] In the first non-steady-state water injection stage, a non-steady-state water injection mode is used, the water injection end is injected with water and stopped injecting with water in a preset period, i.e., the water injection end is periodically injected with water and stopped injecting with water, the production end is kept producing, and the experiment is stopped when the oil production rate of the production end starts to decrease. The displacement flow rate of the displacement process is determined according to that the seepage velocity of fluid in the core and the seepage velocity of fluid in the oil layer should be approximately equal. For example, after a sandstone oil field enters a medium-high water cut period, the water injection speed is generally 0.15 times the pore volume per year. The average seepage velocity of fluid in the oil layer is taken.

[0091] In the second non-steady-state water injection stage, a non-steady-state water injection mode is used, the water injection end is kept normally injected with water, the production end is produced and stopped producing in a preset period, and the experiment is stopped when the oil production rate of the production end starts to decrease.

[0092] The third non-steady-state water injection stage: the non-steady-state water injection mode is adopted, the water injection end injects water and stops water injection with a preset period, and the production end produces and stops production with a preset period, and the experiment is stopped when the oil production rate of the production end begins to decrease.

[0093] Correspondingly, in the embodiment, the step S20 includes:

[0094] Step S201: CT scanning is performed on the steady-state water injection process to obtain the steady-state swept volume of the internal fluid of the experimental core under the steady-state water injection mode, and the steady-state oil displacement efficiency under the steady-state water injection mode is determined according to the steady-state swept volume.

[0095] In a specific implementation, the water injection equipment can perform CT scanning on the steady-state water injection process through a CT scanner to obtain the front-end swept volume and the end swept volume of the internal fluid of the experimental core in the water flooding process as the steady-state swept volume, and then determine the steady-state oil displacement efficiency under the steady-state water injection mode according to the steady-state swept volume.

[0096] When the front-end swept volume is small and the end swept volume is large, it indicates that most of the crude oil has been displaced by the injected water, and it is determined that the oil displacement efficiency is high. When the front-end swept volume is large and the end swept volume is small, it indicates that the injected water has not fully displaced the crude oil, and it is determined that the water flooding efficiency is low. When the front-end swept volume and the end swept volume are not much different, it indicates that the injected water has displaced the crude oil relatively uniformly, and it is determined that the water flooding efficiency is relatively high.

[0097] Step S202: CT scanning is performed on each non-steady-state water injection process to obtain the non-steady-state swept volume of the internal fluid of the experimental core under each non-steady-state water injection mode, and the non-steady-state oil displacement efficiency under each non-steady-state water injection mode is determined according to each non-steady-state swept volume.

[0098] In a specific implementation, the water injection equipment can perform CT scanning on the first non-steady-state water injection process, the second non-steady-state process and the third non-steady-state process through a CT scanner to obtain the front-end swept volume and the end swept volume of the internal fluid of the experimental core under each non-steady-state water injection mode as the non-steady-state swept volume, and then determine the non-steady-state oil displacement efficiency under each non-steady-state water injection mode according to the non-steady-state swept volume.

[0099] The non-steady-state oil displacement efficiency under each non-steady-state water injection mode includes the first non-steady-state oil displacement efficiency under the first non-steady-state water injection mode, the second non-steady-state oil displacement efficiency under the second non-steady-state water injection mode, and the third non-steady-state oil displacement efficiency under the third non-steady-state water injection mode.

[0100] In addition, the oil displacement efficiency can be determined by the percentage of the sum of the front-end swept volume and the end-end swept volume in the original oil volume in the core. The steady-state oil displacement efficiency and each non-steady-state oil displacement efficiency can be determined based on this.

[0101] Step S203: taking the steady-state oil displacement efficiency as the steady-state distribution result of the internal fluid under the steady-state water injection mode, and taking each non-steady-state oil displacement efficiency as the non-steady-state distribution result of the internal fluid under the non-steady-state water injection mode.

[0102] In a specific implementation, the water injection device can take the steady-state oil displacement efficiency as the steady-state distribution result of the internal fluid under the steady-state water injection mode, and can take the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency as the non-steady-state distribution result of the internal fluid under the non-steady-state water injection mode.

[0103] Further, in the embodiment, the step S40 comprises:

[0104] Step S401: when the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency are all less than the steady-state oil displacement efficiency, taking the steady-state water injection mode as the water injection mode suitable for the actual core in the mine field.

[0105] In a specific implementation, when the steady-state distribution result and the non-steady-state distribution result are compared, the water injection device can compare the steady-state oil displacement efficiency, the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency with each other. When it is detected that the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency are all less than the steady-state oil displacement efficiency, it is determined that the oil displacement efficiency of the experimental core under the steady-state water injection mode is optimal, and based on this, the steady-state water injection mode can be taken as the water injection mode suitable for the actual core in the mine field.

[0106] Step S402: when the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, or the third non-steady-state oil displacement efficiency is greater than the steady-state oil displacement efficiency, determining the maximum value among the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency.

[0107] In a specific implementation, when it is detected that any one of the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency is greater than the steady-state oil displacement efficiency, it is determined that the oil displacement efficiency of the experimental core under the non-steady-state water injection mode is optimal, and at this time, the maximum value among the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency can be determined.

[0108] Step S403: taking the non-steady-state water injection mode corresponding to the maximum value as the water injection mode suitable for the actual core in the mine field.

[0109] In a specific implementation, the water injection equipment can determine that the oil displacement efficiency of the experimental core reaches the best under the non-steady-state water injection mode corresponding to the maximum value, and can take the non-steady-state water injection mode corresponding to the maximum value as the water injection mode applicable to the actual core in the field.

[0110] In the embodiment, when the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency are all less than the steady-state oil displacement efficiency, the steady-state water injection mode is taken as the water injection mode applicable to the actual core in the field; when the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, or the third non-steady-state oil displacement efficiency is greater than the steady-state oil displacement efficiency, the maximum value of the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency is determined; and the non-steady-state water injection mode corresponding to the maximum value is taken as the water injection mode applicable to the actual core in the field, so that the water injection mode applicable to the actual core in the field can be accurately determined, and the recovery rate of oil in the core is effectively improved.

[0111] Reference Figure 4 , Figure 4 FIG. 1 is a flowchart of a core water injection mode determination method according to a third embodiment of the present application.

[0112] Based on the first embodiment, before the step S10, the method further includes:

[0113] Step S01: A vacuum pump is used to suck the heterogeneous core, so that a vacuum is formed in the heterogeneous core.

[0114] It should be noted that the heterogeneous core can be a multi-layer core, and a partition is arranged between layers. For details, refer to Figure 5 , Figure 5 FIG. 2 is a schematic diagram of a heterogeneous core in the core water injection mode determination method according to the third embodiment of the present application. Figure 5In the embodiment, the three-dimensional sand filling plate is used to explain the heterogeneous core, but the three-dimensional sand filling plate is not limited to the heterogeneous core. The three-dimensional sand filling plate is composed of a first sand filling plate 101, a second sand filling plate 201, and a third sand filling plate 301 from top to bottom. The permeability of the first sand filling plate 101 is 10 mD, the permeability of the second sand filling plate 201 is 100-500 mD, and the permeability of the third sand filling plate 301 is 10 mD. Because the permeability of the middle layer of the core is high, the fluid exchange characteristics between the low-permeability layer and the high-permeability layer can be reflected during the unsteady-state water injection experiment. In addition, because the permeability of the three layers of the block core is different, the core cannot be fully saturated by using the conventional method. Therefore, a saturation valve is arranged at one end of each layer of the sand filling plate. The first sand filling plate 101 is provided with a first saturation valve 102, the second sand filling plate 201 is provided with a second saturation valve 202, and the third sand filling plate 301 is provided with a third saturation valve 302. During saturation, the saturation valves are opened in sequence to saturate the layers of the sand filling plate one by one, thereby reducing the influence of heterogeneity on saturation.

[0115] In the embodiment, the water injection device can use a vacuum pump to suck the heterogeneous core, so that a vacuum is formed in the heterogeneous core, and the pressure is stabilized at the bottom pressure for a certain period of time, for example, 24 hours.

[0116] Step S02: saturating the heterogeneous core with water by vacuum pressure to obtain a water-saturated core, and measuring water saturation parameters of the water-saturated core.

[0117] In the embodiment, the water injection device can use the vacuum pressure in the heterogeneous core to self-saturate the heterogeneous core with water, and then use a displacement pump to perform pressure boosting saturation, so that the pores or capillary holes in the heterogeneous core are filled with water to reach a saturated state, thereby obtaining a water-saturated core. The water saturation parameters of the water-saturated core can be calculated by using the water output, the injection volume, the dry weight, and the wet weight to calculate the pore volume and the porosity, respectively, and then measuring the water phase permeability.

[0118] The water phase permeability refers to the ability of water to flow in the core under a certain pressure difference. The water phase permeability can be calculated by measuring the flow rate of water in the core, the pressure difference, and other parameters.

[0119] Step S03: saturating the water-saturated core with oil to obtain an experimental core, and measuring the oil saturation of the experimental core.

[0120] In the embodiment, the water-saturated core is saturated with oil, that is, the pores or capillary holes in the water-saturated core are filled with oil to reach a saturated state, thereby obtaining an experimental core. Then, the ratio of the volume of the oil contained in the experimental core to the pore volume of the experimental core is measured as the oil saturation.

[0121] Step S04: determining preset experiment parameters according to the water saturation parameter and the oil saturation.

[0122] In a specific implementation, the water injection device can determine the interwell pressure field distribution at different shut-in times according to the water saturation parameter and the oil saturation, and then determine the maximum envelope line range and the permeability under the maximum envelope line range as the preset experiment parameters according to the size of the envelope line between the pressure fields at the time of pressure rising and pressure dropping.

[0123] Further, in the embodiment, the water saturation parameter includes the pore volume of saturated water, the porosity of saturated water, and the water phase permeability, and the step S04 includes:

[0124] Step S041: determining the pressure field distribution at different stages of unsteady water injection according to the pore volume, the porosity, the water phase permeability, and the oil saturation.

[0125] In a specific implementation, the water injection device can calculate the continuous water injection formation pressure field distribution and the pressure field distribution at different stages of unsteady water injection according to the pore volume, the porosity, the water phase permeability, and the oil saturation, where the pressure field distribution at different stages of unsteady water injection includes the pressure field distribution at the stage of pressure rising and the pressure field distribution at the stage of pressure dropping.

[0126] Correspondingly, the continuous water injection formation pressure distribution field can be calculated by the following formula:

[0127]

[0128] The pressure field distribution at the stage of pressure rising can be calculated by the following formula:

[0129]

[0130] The pressure field distribution at the stage of pressure dropping can be calculated by the following formula:

[0131]

[0132] In the formula, P is the original formation pressure, Q1 is the production rate at t=0 to t=t0, Q2 is the production rate after t=t0, μ is the fluid viscosity, K is the reservoir matrix permeability, h is the reservoir effective thickness, Ei is the form of Bessel function solution, r is the borehole radius, η is the pressure coefficient, and t is the time. i

[0133] Step S042: determining the core permeability corresponding to different pressure field distributions.

[0134] ​In a specific implementation, the water injection equipment can determine the core permeability corresponding to each pressure field distribution according to the calculation formula of each pressure field distribution.

[0135] Step S043: determining the preset experiment parameters based on the core permeability and the pressure field distribution.

[0136] In a specific implementation, the water injection equipment can determine the size of the envelope line between the pressure field distribution in the pressure increasing stage and the pressure field distribution in the pressure decreasing stage under different core permeabilities, determine the maximum envelope line range, and determine the permeability under the maximum envelope line range as the preset experiment parameters.

[0137] Further, in the embodiment, the pressure field distribution includes the pressure field distribution in the pressure increasing stage and the pressure field distribution in the pressure decreasing stage, and the step S043 includes:

[0138] Step S0431: determining the envelope line formed by the pressure field distribution in the pressure increasing stage and the pressure field distribution in the pressure decreasing stage under different core permeabilities.

[0139] In a specific implementation, the water injection equipment can determine the pressure field distribution in the pressure increasing stage, the pressure field distribution in the pressure decreasing stage, and the continuous water injection formation pressure field distribution under different core permeabilities and different injection and shut-in times, refer to Figure 6 , Figure 6 The pressure field distribution schematic diagram in the third embodiment of the core water injection method is shown in the figure, taking the injection and shut-in time as 15 minutes and the core permeability as 1 mD as an example. In the figure, the horizontal axis is the core length with the unit of mm, and the vertical axis is the formation pressure with the unit of Mpa. The function image of the periodic pressure increasing corresponds to the pressure field distribution in the pressure increasing stage, the function image of the periodic pressure decreasing corresponds to the pressure field distribution in the pressure decreasing stage, and the function image of the continuous water injection corresponds to the continuous water injection formation pressure field distribution. The pressure field distribution functions in different stages under different injection and shut-in times and different core permeabilities are different. The area surrounded by the function image of the periodic pressure increasing and the function image of the periodic pressure decreasing is the envelope line formed by the pressure field distribution in the pressure increasing stage and the pressure field distribution in the pressure decreasing stage.

[0140] Step S0432: selecting the target envelope line with the largest range from the envelope lines, and determining the target core permeability corresponding to the target envelope line.

[0141] In a specific implementation, the water injection equipment can traverse the envelope lines under different core permeabilities and different injection and shut-in times, then select the target envelope line with the largest envelope line range, and determine the target core permeability and the target injection and shut-in time corresponding to the target envelope line.

[0142] Step S0433: taking the target core permeability and the target envelope line as the preset experiment parameters.

[0143] In a specific implementation, the water injection device can take the target core permeability and the target envelope line as the preset experimental parameters, and the water injection duration can be the target injection and shut-in time. For example, if the core permeability is 0.5 mD, the envelope line envelope range is the largest when the injection and shut-in time is 15 minutes, and then the core permeability of 0.5 mD, the injection and shut-in time of 15 minutes, and the envelope line can be taken as the preset experimental parameters.

[0144] The embodiment forms a vacuum in the interior of the heterogeneous core by pumping the heterogeneous core by using a vacuum pump; saturates the heterogeneous core with water by vacuum pressure to obtain a water-saturated core, and measures water saturation parameters of the water-saturated core; saturates the water-saturated core with oil to obtain an experimental core, and measures oil saturation of the experimental core; and determines preset experimental parameters according to the water saturation parameters and the oil saturation. The embodiment determines the envelope line formed by the pressure field distribution in the pressure-increasing stage and the pressure field distribution in the pressure-decreasing stage under different core permeabilities, and determines the preset experimental parameters according to the envelope line with the largest range, thereby effectively improving the determination accuracy of the preset experimental parameters.

[0145] In addition, the embodiment of the present application further provides a storage medium, wherein the storage medium stores a core water injection mode determination program, and the core water injection mode determination program is executed by a processor to implement the steps of the core water injection mode determination method.

[0146] Reference Figure 7 , Figure 7 is a structural block diagram of the first embodiment of the core water injection mode determination device of the present application.

[0147] As Figure 7 shown, the core water injection mode determination device provided by the embodiment of the present application comprises:

[0148] The core displacement module 501 is configured to perform steady-state water injection and unsteady-state water injection on the experimental core under the preset experimental parameters.

[0149] The CT scanning module 502 is configured to perform CT scanning on the steady-state water injection process and the unsteady-state water injection process respectively, to obtain a steady-state distribution result of the internal fluid of the experimental core under the steady-state water injection mode and an unsteady-state distribution result of the internal fluid of the experimental core under the unsteady-state water injection mode.

[0150] The result comparison module 503 is configured to compare the steady-state distribution result with the unsteady-state distribution result.

[0151] The water injection determination module 504 is configured to determine the water injection mode applicable to the experimental core according to the comparison result.

[0152] The embodiment carries out steady-state water injection and unsteady-state water injection on the experimental core under preset experimental parameters respectively, carries out CT scanning on the steady-state water injection process and the unsteady-state water injection process respectively, obtains the steady-state distribution result of the internal fluid of the experimental core under the steady-state water injection mode and the unsteady-state distribution result of the internal fluid of the experimental core under the unsteady-state water injection mode, compares the steady-state distribution result with the unsteady-state distribution result, and determines the water injection mode suitable for the actual core in the mine field according to the comparison result. The application can determine the applicable condition of the actual core in the mine field, avoids the use of unsuitable water injection mode in the mine field, and effectively improves the oil recovery rate.

[0153] Based on the first embodiment of the core water injection mode determination device, the second embodiment of the core water injection mode determination device is provided.

[0154] In the embodiment, the core displacement module 501 is further used for carrying out steady-state water injection, first unsteady-state water injection, second unsteady-state water injection and third unsteady-state water injection on the experimental core under preset experimental parameters.

[0155] The steady-state water injection is a process that the water injection end of the experimental core continuously injects water, the production end of the experimental core keeps producing, and the process stops when water appears on the surface of the experimental core; the first unsteady-state water injection is a process that the water injection end injects water and stops water injection with a preset period, the production end keeps producing, and the process stops when the oil production rate of the production end begins to decrease; the second unsteady-state water injection is a process that the water injection end keeps injecting water, the production end produces and stops production with the preset period, and the process stops when the oil production rate of the production end begins to decrease; and the third unsteady-state water injection is a process that the water injection end injects water and stops water injection with the preset period, the production end produces and stops production with the preset period, and the process stops when the oil production rate of the production end begins to decrease.

[0156] As an implementation manner, the CT scanning module 502 is further used for carrying out CT scanning on the steady-state water injection process, obtaining the steady-state swept volume of the internal fluid of the experimental core under the steady-state water injection mode, and determining the steady-state oil displacement efficiency under the steady-state water injection mode according to the steady-state swept volume; carrying out CT scanning on each unsteady-state water injection process, obtaining the unsteady-state swept volume of the internal fluid of the experimental core under each unsteady-state water injection mode, and determining the unsteady-state oil displacement efficiency under each unsteady-state water injection mode according to each unsteady-state swept volume.

[0157] The non-steady-state oil displacement efficiency includes a first non-steady-state oil displacement efficiency under a first non-steady-state water injection mode, a second non-steady-state oil displacement efficiency under a second non-steady-state water injection mode, and a third non-steady-state oil displacement efficiency under a third non-steady-state water injection mode; the steady-state oil displacement efficiency is taken as a steady-state distribution result of internal fluid under the steady-state water injection mode, and each non-steady-state oil displacement efficiency is taken as a non-steady-state distribution result of internal fluid under the non-steady-state water injection mode.

[0158] As an implementation form, the water injection determination module 504 is further configured to: when the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency are all less than the steady-state oil displacement efficiency, take the steady-state water injection mode as a water injection mode suitable for the actual core in the oil field; when the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, or the third non-steady-state oil displacement efficiency is greater than the steady-state oil displacement efficiency, determine a maximum value of the first non-steady-state oil displacement efficiency, the second non-steady-state oil displacement efficiency, and the third non-steady-state oil displacement efficiency; and take a non-steady-state water injection mode corresponding to the maximum value as the water injection mode suitable for the actual core in the oil field.

[0159] Based on the first embodiment of the core water injection mode determination device, the third embodiment of the core water injection mode determination device is provided.

[0160] In this embodiment, the core displacement module 501 is further configured to: use a vacuum pump to suck the heterogeneous core, so that a vacuum is formed in the heterogeneous core; saturate the heterogeneous core with water through vacuum pressure to obtain a water-saturated core, and measure a water saturation parameter of the water-saturated core; saturate the water-saturated core with oil to obtain an experimental core, and measure an oil saturation of the experimental core; and determine preset experimental parameters according to the water saturation parameter and the oil saturation.

[0161] As an implementation form, the water saturation parameter includes a saturated water pore volume, a saturated water porosity, and a water phase permeability, and the core displacement module 501 is further configured to: determine pressure field distributions of different stages of non-steady-state water injection according to the pore volume, the porosity, the water phase permeability, and the oil saturation; determine core permeabilities corresponding to the different pressure field distributions; and determine the preset experimental parameters based on the core permeabilities and the pressure field distributions.

[0162] As an embodiment, the pressure field distribution includes the pressure field distribution in the boosting stage and the pressure field distribution in the decompression stage. The core displacement module 501 is also used to determine the envelope formed by the pressure field distribution in the boosting stage and the pressure field distribution in the decompression stage under different core permeabilities; select the target envelope with the largest range from each envelope, and determine the target core permeability corresponding to the target envelope; and use the target core permeability and the target envelope as preset experimental parameters.

[0163] The specific implementation of the core water injection method determination device of the present invention can refer to the above-mentioned method embodiments and will not be repeated here.

[0164] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0165] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0166] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0167] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for determining a core water injection method, characterized in that: The method comprises: Under the preset experimental parameters, steady-state water injection and unsteady-state water injection were carried out on the experimental core respectively; Performing CT scanning on the steady-state water injection process and the unsteady-state water injection process respectively to obtain steady-state distribution results of the internal fluid of the experimental core under the steady-state water injection mode and unsteady-state distribution results of the internal fluid under the unsteady-state water injection mode; Comparing the steady-state distribution result with the non-steady-state distribution result; Based on the comparison results, the water injection method suitable for the actual core in the mine is determined.

2. The method for determining a core water injection method according to claim 1, wherein: The steps of performing steady-state water injection and unsteady-state water injection on the experimental core under preset experimental parameters include: Under the preset experimental parameters, the experimental core is subjected to steady-state water injection, the first unsteady-state water injection, the second unsteady-state water injection and the third unsteady-state water injection respectively; The steady-state water injection is a process in which the water injection end of the experimental core continuously injects water, and the production end of the experimental core maintains production until water appears on the surface of the experimental core; The first unsteady-state water injection is a process in which the water injection end injects water and stops injecting water at a preset cycle, and the production end maintains production until the oil production rate of the production end begins to decrease and then stops; The second unsteady-state water injection is a process in which the water injection end maintains water injection, and the production end produces and stops production at the preset cycle until the oil production rate of the production end begins to decrease and stops; The third unsteady-state water injection is a process in which the water injection end injects and stops water injection at the preset cycle, and the production end produces and stops production at the preset cycle until the oil production rate of the production end begins to decrease and stops.

3. The method for determining a core water injection method according to claim 2, wherein: The step of performing CT scanning on the steady-state water injection process and the unsteady-state water injection process respectively to obtain the steady-state distribution result of the internal fluid of the experimental core under the steady-state water injection mode and the unsteady-state distribution result of the internal fluid under the unsteady-state water injection mode includes: Performing CT scanning on the steady-state water injection process to obtain the steady-state swept volume of the internal fluid of the experimental core under the steady-state water injection mode, and determining the steady-state oil displacement efficiency under the steady-state water injection mode based on the steady-state swept volume; Performing CT scanning on each unsteady water injection process to obtain the unsteady swept volume of the internal fluid of the experimental core under each unsteady water injection mode, and determining the unsteady oil displacement efficiency under each unsteady water injection mode according to each unsteady swept volume; The unsteady-state oil displacement efficiency includes a first unsteady-state oil displacement efficiency under a first unsteady-state water injection mode, a second unsteady-state oil displacement efficiency under a second unsteady-state water injection mode, and a third unsteady-state oil displacement efficiency under a third unsteady-state water injection mode. The steady-state oil displacement efficiency is taken as the steady-state distribution result of the internal fluid under the steady-state water injection mode, and each unsteady-state oil displacement efficiency is taken as the unsteady-state distribution result of the internal fluid under the unsteady water injection mode.

4. The method for determining a core water injection method according to claim 3, wherein: The step of determining the water injection method applicable to the actual core in the mine based on the comparison results includes: When the first unsteady-state oil displacement efficiency, the second unsteady-state oil displacement efficiency, and the third unsteady-state oil displacement efficiency are all lower than the steady-state oil displacement efficiency, the steady-state water injection method is used as the water injection method applicable to actual cores in the mine; When the first unsteady-state oil displacement efficiency, the second unsteady-state oil displacement efficiency, or the third unsteady-state oil displacement efficiency is greater than the steady-state oil displacement efficiency, determining a maximum value among the first unsteady-state oil displacement efficiency, the second unsteady-state oil displacement efficiency, and the third unsteady-state oil displacement efficiency; The non-steady-state water injection method corresponding to the maximum value is used as the water injection method applicable to the actual core in the mine.

5. The method for determining a core water injection method according to claim 1, wherein: Before the steps of respectively performing steady-state water injection and unsteady-state water injection on the experimental core under the preset experimental parameters, the method further includes: Using a vacuum pump to suck the heterogeneous core to form a vacuum inside the heterogeneous core; saturating the heterogeneous core with water by vacuum pressure to obtain a water-saturated core, and measuring water saturation parameters of the water-saturated core; saturating the water-saturated core with oil to obtain an experimental core, and measuring the oil saturation of the experimental core; The preset experimental parameters are determined according to the water saturation parameter and the oil saturation.

6. The method for determining a core water injection method according to claim 5, wherein: The water saturation parameters include: saturated water pore volume, saturated water porosity, and water phase permeability. The step of determining the preset experimental parameters based on the water saturation parameters and the oil saturation includes: determining the pressure field distribution at different stages of unsteady water injection according to the pore volume, the porosity, the water phase permeability, and the oil saturation; Determine the core permeability corresponding to different pressure field distributions; The preset experimental parameters are determined based on the permeability of each core and the distribution of each pressure field.

7. The method for determining a core water injection method according to claim 6, wherein: The pressure field distribution includes the pressure field distribution in the pressure increase stage and the pressure field distribution in the pressure reduction stage. The step of determining the preset experimental parameters based on the permeability of each core and each pressure field distribution includes: Determining envelopes formed by the pressure field distribution in the pressurization stage and the pressure field distribution in the decompression stage under different core permeabilities; Selecting a target envelope line with the largest range from each envelope line, and determining a target core permeability corresponding to the target envelope line; The target core permeability and the target envelope are used as preset experimental parameters.

8. A device for determining a core water injection method, characterized in that: The device comprises: The core flooding module is used to perform steady-state water injection and unsteady-state water injection on the experimental core under preset experimental parameters; a CT scanning module, configured to perform CT scanning on the steady-state water injection process and the unsteady-state water injection process, respectively, to obtain steady-state distribution results of the internal fluid of the experimental core under the steady-state water injection mode, and unsteady-state distribution results of the internal fluid under the unsteady-state water injection mode; A result comparison module, configured to compare the steady-state distribution result with the non-steady-state distribution result; The water injection determination module is used to determine the water injection method applicable to the experimental core according to the comparison results.

9. A device for determining a core water injection method, characterized in that: The device includes: a memory, a processor, and a core water injection method determination program stored in the memory and executable on the processor, wherein the core water injection method determination program is configured to implement the steps of the core water injection method determination method according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores a core water injection method determination program, which, when executed by the processor, implements the steps of the core water injection method determination method according to any one of claims 1 to 7.

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