Carbonate reservoir water injection period complex oil-water layer identification method and related equipment

Abstract

The invention discloses a carbonate reservoir water injection period complex oil-water layer identification method and related equipment, relates to the field of reservoir exploitation, and mainly aims to solve the problem that a traditional differential method cannot well represent a corresponding relation between water saturation and oiliness when porosity is analyzed. The method comprises the steps that a fluid identification index of a target area is determined, and the target area is carbonate rock; constructing a theoretical oil line evaluation standard and a theoretical waterline evaluation standard; and determining an oil-water layer of the target area based on the theoretical oil line evaluation standard, the theoretical waterline evaluation standard and the fluid identification index. The method is used for the complex oil-water layer identification process in the carbonate reservoir water injection period.

Description

Technical Field

[0001] The present invention relates to the field of oil reservoir exploitation, and in particular to a method for identifying complex oil and water layers in a carbonate oil reservoir during water injection period and related equipment. Background Art

[0002] During the long-term development process of an oil field, under the long-term displacement of injected water, parameters such as reservoir physical properties, electrical characteristics and formation water salinity continue to change, making the recovery of remaining oil more difficult. In some areas, the original interpretation models and logging reservoir parameters can no longer meet the requirements of detailed description of oil field development. Therefore, it is necessary to conduct secondary interpretation of certain blocks and oil fields, and to re-identify and study the oil and water layers of the reservoir during the water injection period.

[0003] The traditional total differential method determines oil content based on porosity and water saturation respectively. However, when analyzing porosity, it cannot well show the corresponding relationship between water saturation and oil content. Therefore, the above method still has a certain one-sidedness. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method and related equipment for identifying complex oil and water layers in carbonate oil reservoirs during the water injection period. The main purpose is to solve the problem that the traditional differential method cannot well represent the corresponding relationship between water saturation and oil content when analyzing porosity.

[0005] To solve at least one of the above technical problems, in a first aspect, the present invention provides a method for identifying complex oil and water layers in a carbonate reservoir during water injection, the method comprising:

[0006] determining a fluid identification index of a target area, wherein the target area is carbonate rock;

[0007] Establish theoretical oil line evaluation standards and theoretical water line evaluation standards;

[0008] The oil and water layers in the target area are determined based on the theoretical oil line evaluation standard, the theoretical water line evaluation standard and the fluid identification index.

[0009] Optionally, the above-mentioned determination of the fluid identification index of the target area includes:

[0010] Based on Archie's formula, the porosity and formation water saturation of the target area are fully differentiated to obtain the fluid identification index:

[0011]

[0012] Among them, the above a is the lithology coefficient, b is close to 1, the above m is the cementation index of the rock, the above n is the saturation index, the above Rw is the formation water resistivity, the above Rt is the formation resistivity, the above Φ is the porosity, and the above Sw is the formation water saturation.

[0013] Optionally, the above method further includes:

[0014] The above-mentioned formation water resistivity is determined based on the injection water volume, the salinity of the injected water sample, the formation water salinity and the formation water saturation.

[0015] Optionally, the aforementioned construction of the theoretical oil line evaluation standard and the theoretical water line evaluation standard includes:

[0016] When the formation water saturation is equal to the core irreducible water saturation, the above theoretical oil line evaluation standard is determined based on the following formula:

[0017]

[0018] Wherein, the above Rt is the formation resistivity, and the above Sw is the formation water saturation.

[0019] Optionally, the above method further includes:

[0020] The irreducible water saturation of the core was determined based on the core MICP mercury injection capillary pressure curve data.

[0021] Optionally, the aforementioned construction of the theoretical oil line evaluation standard and the theoretical water line evaluation standard includes:

[0022] When the formation water saturation is equal to 1, the above theoretical waterline evaluation standard is determined based on the following formula:

[0023]

[0024] Wherein, the above Rt is the formation resistivity, and the above Sw is the formation water saturation.

[0025] Optionally, the determining of the oil and water layers in the target area based on the theoretical oil line evaluation standard, the theoretical water line evaluation standard, and the fluid identification index includes:

[0026] When the fluid identification index is greater than or equal to the theoretical oil line evaluation standard, determining the target area as an oil layer;

[0027] When the fluid identification index is less than or equal to the theoretical waterline evaluation standard, determining the target area as a water layer;

[0028] When the fluid identification index is greater than the theoretical waterline evaluation standard and less than the theoretical oilline evaluation standard, the target area is determined to be the same oil and water layer.

[0029] In a second aspect, an embodiment of the present invention further provides a device for identifying complex oil and water layers in a carbonate reservoir during water injection, comprising:

[0030] A first determining unit is configured to determine a fluid identification index of a target area, wherein the target area is carbonate rock;

[0031] A construction unit, used to construct a theoretical oil line evaluation standard and a theoretical water line evaluation standard;

[0032] The second determining unit is configured to determine the oil and water layers in the target area based on the theoretical oil line evaluation standard, the theoretical water line evaluation standard, and the fluid identification index.

[0033] In order to achieve the above-mentioned purpose, according to the third aspect of the present invention, a computer-readable storage medium is provided, wherein the above-mentioned computer-readable storage medium includes a stored program, wherein when the above-mentioned program is executed by a processor, the steps of the above-mentioned method for identifying complex oil and water layers in the water injection period of carbonate oil reservoirs are implemented.

[0034] In order to achieve the above-mentioned purpose, according to the fourth aspect of the present invention, an electronic device is provided, comprising at least one processor and at least one memory connected to the above-mentioned processor; wherein the above-mentioned processor is used to call the program instructions in the above-mentioned memory to execute the steps of the above-mentioned method for identifying complex oil and water layers in the water injection period of carbonate oil reservoirs.

[0035] Through the above technical solution, the present invention provides a method and related equipment for identifying complex oil and water layers in carbonate reservoirs during the water injection phase. This method addresses the problem that traditional differential methods cannot effectively represent the corresponding relationship between water saturation and oil content when analyzing porosity. The present invention determines a fluid identification index for a target area, wherein the target area is carbonate rock; constructs theoretical oil line evaluation criteria and theoretical water line evaluation criteria; and identifies the oil and water layers in the target area based on the theoretical oil line evaluation criteria, the theoretical water line evaluation criteria, and the fluid identification index. In this solution, Archie's formula is used to simultaneously take the total differential of porosity and water saturation to better determine the corresponding relationship between porosity, water saturation, and oil layers, thereby improving the sensitivity of identifying oil and gas layers and the rationality of the fluid identification index. Based on this solution, the interpretation consistency of oil and water layers is improved, providing more accurate reservoir, fluid, and other physical parameters and logging parameters for geological reservoir research, guiding the efficient development of oil fields.

[0036] Correspondingly, the device, equipment and computer-readable storage medium for identifying complex oil and water layers in carbonate oil reservoirs during water injection period provided by the embodiments of the present invention also have the above-mentioned technical effects.

[0037] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0039] Figure 1 A schematic flow chart of a method for identifying complex oil and water layers in a carbonate reservoir during water injection period provided by an embodiment of the present invention is shown;

[0040] Figure 2 A comparison diagram of the application effects of a single porosity differential DRTP, a single saturation differential DRSW, and a full differential RTSZ provided in an embodiment of the present invention is shown;

[0041] Figure 3 A schematic block diagram showing the composition of a device for identifying complex oil and water layers in a carbonate oil reservoir during water injection period provided by an embodiment of the present invention is shown;

[0042] Figure 4 The present invention provides a schematic block diagram of the components of an electronic device for identifying complex oil and water layers in a carbonate oil reservoir during water injection. DETAILED DESCRIPTION

[0043] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0044] In order to solve the problem that the traditional differential method cannot well express the corresponding relationship between water saturation and oil content when analyzing porosity, the embodiment of the present invention provides a method for identifying complex oil and water layers in carbonate reservoirs during water injection period, such as Figure 1 shown.

[0045] Furthermore, an embodiment of the present invention provides a method for identifying complex oil and water layers in a carbonate reservoir during water injection, as follows:

[0046] S101, determining a fluid identification index of a target area, wherein the target area is carbonate rock;

[0047] The above step S101 further includes S1011 and S1012:

[0048] S1011. Perform full differential processing on the porosity and formation water saturation of the target area based on Archie's formula to obtain the fluid identification index:

[0049]

[0050] Among them, the above a is the lithology coefficient, b is close to 1, the above m is the cementation index of the rock, the above n is the saturation index, the above Rw is the formation water resistivity, the above Rt is the formation resistivity, the above Φ is the porosity, and the above Sw is the formation water saturation.

[0051] For example, since porosity and water saturation are the main factors in the Archie formula, the Archie formula can be used to take the total differential of porosity and water saturation at the same time to better determine the corresponding relationship between porosity, water saturation and oil layer. Therefore, the Archie formula can be used to take the total differential of porosity and water saturation Sw to obtain RTSZ as the fluid identification index:

[0052]

[0053] For example, for the complex pore structure of carbonate reservoirs, the rock electrical parameters a, b, m, and n are obtained through core experimental analysis, and different rock electrical parameters are used for different strata. By fully considering the complex pore structure of carbonate reservoirs and using core analysis of rock electrical parameters, the rationality of the fluid identification index RTSZ is improved.

[0054] Specifically, in the above-mentioned method for identifying complex oil and water layers in carbonate rocks during water injection, since porosity and water saturation play the main roles in the Archie formula, the Archie formula can be used to simultaneously take the total differential of porosity and water saturation to better determine the corresponding relationship between porosity, water saturation and oil layers. Based on the above scheme, its sensitivity in identifying oil and gas layers can be improved.

[0055] S1012. Determine the formation water resistivity based on the injection volume, the injected water sample salinity, the formation water salinity, and the formation water saturation.

[0056] For example, the embodiment of the present application uses simulation calculation and calculation of formation water saturation S based on the injection volume, the salinity of the injected water sample and the salinity of the formation water w :

[0057] First, the Archie formula is as follows:

[0058]

[0059] Furthermore, without considering a, b, m, n and Follow S w Under the ideal condition of change, calculate S on both sides of the above formula w Partial derivatives of :

[0060]

[0061] Let S w =S wc have to:

[0062]

[0063] Obtain:

[0064]

[0065] Where S wc It is the critical water saturation point where the resistivity changes from decreasing to increasing.

[0066] When S w =S wi , R w =R wi ,have:

[0067]

[0068]

[0069] Where S wi is the irreducible water saturation of the core, decimal; R wi is the bound water resistivity, Ω·m.

[0070] When S w =1-S or When R w =R wj , then the formation water saturation S w for:

[0071]

[0072] Where S or is the residual oil saturation, decimal; R wj is the resistivity of injected water, Ω·m.

[0073] It should be noted that the water saturation at the rising point of the "U" curve is related to the n value, the multiple of the injected water relative to the primary water salinity, the core bound water saturation and the final residual oil saturation. For a given reservoir, if the injection multiple is constant, then S wc The resistivity of the mixed fluid (R z )for:

[0074]

[0075] Furthermore, the resistivity of the mixed fluid is related to the resistivity of the primary water, the resistivity of the injected water, the irreducible water saturation of the core, the residual oil saturation, and the current water saturation, but has nothing to do with m and n.

[0076] In summary, since porosity and water saturation are the primary factors in the Archie equation, the present embodiment optimizes the aforementioned method. By fully differentiating porosity and water saturation using the Archie equation (taking into account the characteristics of porous carbonate rocks), the corresponding relationship between porosity, water saturation, and oil reservoirs is better determined.

[0077] S102. Establish theoretical oil line evaluation standards and theoretical water line evaluation standards;

[0078] The above step S102 further includes S1021, S1022, and S1023:

[0079] S1021. When the formation water saturation is equal to the core irreducible water saturation, the above-mentioned theoretical oil line evaluation standard is determined based on the following formula:

[0080]

[0081] Wherein, the above Rt is the formation resistivity, and the above Sw is the formation water saturation.

[0082] For example, when the water saturation Sw is equal to the core irreducible water saturation Swir, the theoretical oil line evaluation standard can be obtained based on the total differential method:

[0083]

[0084] S1022. Determine the irreducible water saturation of the core based on the core MICP mercury injection capillary pressure curve data.

[0085] For example, the irreducible water saturation S of the core is determined by the core MICP mercury injection capillary pressure curve data. wir In this embodiment, the core is returned to the core, the core is combined with the conventional logging curve, and the conventional logging curve is calculated using the machine learning method. wir .

[0086] Furthermore, the above scheme uses core calibration logging based on core MICP analysis of irreducible water saturation to predict irreducible water saturation in coreless wells through machine learning methods based on conventional logging data, thereby improving the reliability of the RTSZ oil line.

[0087] Specifically, the irreducible water saturation of the core was obtained by reading the mercury injection curve. The response of conventional well logging curves was then combined with the irreducible water saturation of the core. A machine learning method was used to construct a prediction model for irreducible water saturation of the core. The conventional well logging response was used as the feature vector, and the irreducible water saturation of the core was used as the training target. A grid search method was used to determine the hyperparameters in the random forest. The number of decision trees was 150, and the minimum number of split features was 2. A validation set was constructed using core data to verify the prediction results, and the relative error was 14%.

[0088] S1023. When the formation water saturation is equal to 1, determine the above-mentioned theoretical water line evaluation criteria based on the following formula:

[0089]

[0090] Where, the above-mentioned Rt is the formation resistivity, and the above-mentioned Sw is the formation water saturation.

[0091] S103. Determine the oil and water layers in the above-mentioned target area based on the above-mentioned theoretical oil line evaluation criteria, the above-mentioned theoretical water line evaluation criteria, and the above-mentioned fluid identification index.

[0092] The steps of the above-mentioned S103 further include S1031:

[0093] S1031. When the above-mentioned fluid identification index is greater than or equal to the above-mentioned theoretical oil line evaluation criteria, determine that the above-mentioned target area is an oil layer; when the above-mentioned fluid identification index is less than or equal to the above-mentioned theoretical water line evaluation criteria, determine that the above-mentioned target area is a water layer; when the above-mentioned fluid identification index is greater than the above-mentioned theoretical water line evaluation criteria and less than the above-mentioned theoretical oil line evaluation criteria, determine that the above-mentioned target area is an oil-water layer.

[0094] Exemplarily, the method for distinguishing oil and water layers: when the fluid identification index is greater than the theoretical oil line (RTSZ > RTSO), it can be classified as an oil layer; when the fluid identification index is less than the theoretical water line (RTSZ < RTSW), it can be classified as a water layer; when the fluid identification index is between the theoretical oil line and the theoretical water line (RTSW < RTSZ < RTSW), it is an oil-water layer.

[0095] It should be noted that in the Archie formula, the rock skeleton is non-conductive and the formation water in the rock pores is conductive. When the porosity and water saturation are not zero, the resistivity formula is as follows:

[0096] Through the above technical solution, the present invention provides a method for identifying complex oil and water layers in carbonate reservoirs during the water injection phase. This method addresses the problem that traditional differential methods cannot effectively represent the corresponding relationship between water saturation and oil content when analyzing porosity. The present invention determines a fluid identification index for a target area, wherein the target area is carbonate rock; constructs theoretical oil line evaluation criteria and theoretical water line evaluation criteria; and identifies the oil and water layers in the target area based on the theoretical oil line evaluation criteria, the theoretical water line evaluation criteria, and the fluid identification index. In the above scheme, Archie's formula is used to simultaneously take the total differential of porosity and water saturation to better determine the corresponding relationship between porosity, water saturation, and oil layers, thereby improving its sensitivity in identifying oil and gas layers and the rationality of the fluid identification index. Based on the above scheme, the interpretation consistency of oil and water layers is improved, providing more accurate reservoir, fluid, and other physical parameters and logging parameters for geological reservoir research, guiding the efficient development of oil fields.

[0097] Furthermore, the following shows a traditional differential identification method (1)-(5) for complex oil-water layers in carbonate reservoirs during water injection:

[0098] (1) The rock skeleton is not conductive, but the formation water in the rock pores is conductive. When the porosity is zero, the conductivity is zero according to the following formula:

[0099]

[0100] Where: R t is the formation resistivity, in Ω·m; R w is the formation water resistivity, in Ω·m; φ is the porosity; S w Water saturation, a is the lithology coefficient, b is close to 1, m is the cementation index of the rock, and n is the saturation index.

[0101] Assuming that the parameters of lithologic coefficients a, b, m, n and formation water resistivity Rw vary with depth, while their values ​​remain unchanged within the same depth, the main factors in the formula are porosity and water saturation.

[0102] Therefore, performing total differential processing on Archie's formula yields:

[0103]

[0104]

[0105] (2) When the water saturation is equal to the irreducible water saturation of the core (i.e. Sw = Swir), the two lines obtained are called the theoretical oil lines OLIP:

[0106]

[0107] Two lines that can be obtained when the water saturation is equal to 1 (i.e., Sw = 100%) are called the theoretical water line WLIP:

[0108]

[0109] (3) Identification of oil and water layers based on porosity:

[0110] When the measured value of porosity is greater than the theoretical oil line (DRTP > OLIP), it can be classified as an oil layer;

[0111] When the measured value of porosity is less than the theoretical water line (DRTP < WLIP), it can be classified as a water layer;

[0112] When the measured value of porosity is between the theoretical oil line and the theoretical water line (WLIP < DRTP < OLIP), it is an oil - water layer.

[0113] (4) Identification of oil and water layers based on water saturation:

[0114] When the measured value of water saturation is greater than the theoretical oil line (DRSW > OLIS), it can be classified as an oil layer;

[0115] When the measured value of water saturation is less than the theoretical water line (DRSW < WLIS), it can be classified as a water layer;

[0116] When the measured value of water saturation is between the theoretical oil line and the theoretical water line (WLIS < DRSW < OLIS), it is an oil - water layer.

[0117] Furthermore, as Figure 2 shown, the traditional differential method (the fifth and sixth tracks) can use two sets of discrimination models to separately determine the water - flooded layers, but it is difficult to determine when the conclusions are inconsistent; the improved total differential method (the seventh track) of this application example can consider the change trends of both porosity and water saturation simultaneously, which is more practical and more comprehensive. Select Well A:

[0118] The first track is the depth track, the second track is the lithology track, including spontaneous potential, natural gamma ray, and well diameter. The third track is the resistivity track, including deep, medium, and shallow resistivity curves. The fourth track is the porosity track, including density, neutron, and acoustic porosity tracks. The fifth and sixth tracks are the calculated lines for differentiating porosity and water saturation respectively, and their corresponding oil - layer reference lines and water - layer reference lines. The seventh track is the improved total differential method used in this article. As Figure 2 shown, the total differential shows that below 3085m, there are oil - water layers and water layers caused by water flooding, which is in good agreement with the interpretation conclusion, improving the interpretation coincidence rate of oil - water layers, providing more accurate physical parameters such as reservoirs and fluids and logging parameters for geological reservoir research, and guiding the efficient development of oilfields.

[0119] Furthermore, as an improvement to the above Figure 1 In order to realize the method shown in the figure, the embodiment of the present invention also provides a device for identifying complex oil and water layers in carbonate reservoirs during water injection period, which is used to identify the complex oil and water layers in the carbonate reservoirs during water injection period. Figure 1 This device embodiment corresponds to the aforementioned method embodiment. For ease of reading, this device embodiment will not describe the details of the aforementioned method embodiment one by one, but it should be clear that the device in this embodiment can implement all the contents of the aforementioned method embodiment. Figure 3 As shown, the device includes: a first determining unit 21, a constructing unit 22 and a second determining unit 23, wherein

[0120] A first determining unit 21 is configured to determine a fluid identification index of a target area, wherein the target area is carbonate rock;

[0121] A construction unit 22 is used to construct a theoretical oil line evaluation standard and a theoretical water line evaluation standard;

[0122] The second determining unit 23 is configured to determine the oil and water layers in the target area based on the theoretical oil line evaluation standard, the theoretical water line evaluation standard, and the fluid identification index.

[0123] The processor includes a kernel, which retrieves corresponding program units from memory. One or more kernels can be configured, and kernel parameters are adjusted to implement a method for identifying complex oil and water layers in carbonate reservoirs during water injection. This method addresses the problem of traditional differential methods failing to adequately represent the relationship between water saturation and oil content when analyzing porosity.

[0124] An embodiment of the present invention provides a computer-readable storage medium, which includes a stored program. When the program is executed by a processor, the method for identifying complex oil and water layers in a carbonate reservoir during water injection is implemented.

[0125] An embodiment of the present invention provides a processor, which is used to run a program, wherein the program, when running, executes the method for identifying complex oil and water layers in a carbonate oil reservoir during water injection.

[0126] An embodiment of the present invention provides an electronic device, comprising at least one processor and at least one memory connected to the processor; wherein the processor is configured to call program instructions in the memory to execute the above-mentioned method for identifying complex oil and water layers in a carbonate reservoir during water injection.

[0127] An embodiment of the present invention provides an electronic device 30, such as Figure 4As shown, the electronic device includes at least one processor 301, and at least one memory 302 and a bus 303 connected to the processor; wherein the processor 301 and the memory 302 communicate with each other through the bus 303; the processor 301 is used to call the program instructions in the memory to execute the above-mentioned complex oil and water layer identification method during the water injection period of carbonate oil reservoirs.

[0128] The intelligent electronic devices in this article can be PCs, PADs, mobile phones, etc.

[0129] The present application also provides a computer program product, which, when executed on a process management electronic device, is suitable for executing a program initialized with the steps of the above-mentioned method for identifying complex oil and water layers in a carbonate oil reservoir during water injection.

[0130] It should be noted that, in the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0131] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0132] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0133] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0134] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0135] The present application also provides a computer program product, which includes computer software instructions. When the computer software instructions are executed on a processing device, the processing device is caused to execute the following Figure 1 This corresponds to the flow of memory control in the embodiment.

[0136] A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state drive (SSD)).

[0137] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0138] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0139] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0140] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0141] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0142] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for identifying complex oil and water layers in a carbonate reservoir during water injection, characterized in that: include: determining a fluid identification index of a target area, wherein the target area is carbonate rock; Establish theoretical oil line evaluation standards and theoretical water line evaluation standards; The oil and water layers in the target area are determined based on the theoretical oil line evaluation standard, the theoretical water line evaluation standard, and the fluid identification index.

2. The method according to claim 1, characterized in that Determining the fluid identification index of the target area includes: Based on Archie's formula, the porosity and formation water saturation of the target area are fully differentiated to obtain the fluid identification index: Wherein, a is the lithology coefficient, b is close to 1, m is the cementation index of the rock, n is the saturation index, Rw is the formation water resistivity, Rt is the formation resistivity, Φ is the porosity, and Sw is the formation water saturation.

3. The method according to any one of claim 2, characterized in that Also includes: The formation water resistivity is determined based on the injection volume, the salinity of the injected water sample, the formation water salinity and the formation water saturation.

4. The method according to claim 1, wherein The construction of the theoretical oil line evaluation standard and the theoretical water line evaluation standard includes: When the formation water saturation is equal to the core irreducible water saturation, the theoretical oil line evaluation standard is determined based on the following formula: Wherein, Rt is the formation resistivity, and Sw is the formation water saturation.

5. The method according to claim 4, characterized in that Also includes: The irreducible water saturation of the core is determined based on the core MICP mercury injection capillary pressure curve data.

6. The method according to claim 1, wherein The construction of the theoretical oil line evaluation standard and the theoretical water line evaluation standard includes: When the formation water saturation is equal to 1, the theoretical waterline evaluation standard is determined based on the following formula: Wherein, Rt is the formation resistivity, and Sw is the formation water saturation.

7. The method according to claim 1, characterized in that The determining of the oil and water layers in the target area based on the theoretical oil line evaluation standard, the theoretical water line evaluation standard and the fluid identification index includes: When the fluid identification index is greater than or equal to the theoretical oil line evaluation standard, determining that the target area is an oil layer; When the fluid identification index is less than or equal to the theoretical waterline evaluation standard, determining that the target area is a water layer; When the fluid identification index is greater than the theoretical waterline evaluation standard and less than the theoretical oilline evaluation standard, the target area is determined to be an oil-water layer.

8. A device for identifying complex oil and water layers in a carbonate reservoir during water injection, characterized in that: include: a first determining unit, configured to determine a fluid identification index of a target area, wherein the target area is carbonate rock; A construction unit, used to construct a theoretical oil line evaluation standard and a theoretical water line evaluation standard; The second determining unit is configured to determine the oil and water layers in the target area based on the theoretical oil line evaluation standard, the theoretical water line evaluation standard, and the fluid identification index.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed by a processor, the method for identifying complex oil and water layers in a carbonate oil reservoir during water injection period according to any one of claims 1 to 8 is implemented.

10. An electronic device, characterized in that: The electronic device includes at least one processor and at least one memory connected to the processor; wherein the processor is used to call program instructions in the memory to execute the method for identifying complex oil and water layers in a carbonate oil reservoir during the water injection period according to any one of claims 1 to 8.

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