Method and device for calculating water saturation of mixed formation of water-drive reservoir
By acquiring the physical parameters of the target rock sample, a dynamic characterization model of mixed formation water salinity was constructed, the curve relationship between water saturation and rock resistivity was determined, and water saturation was calculated using Archie's formula and equivalent ion exchange rate. This solved the problem of low accuracy in calculating water saturation in mixed formations of water-drive oil reservoirs and achieved more accurate determination of oil saturation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANGTZE UNIVERSITY
- Filing Date
- 2026-03-24
- Publication Date
- 2026-05-12
AI Technical Summary
In existing technologies, the accuracy of water saturation calculation in mixed formations of water-driven oil reservoirs is low, especially in reservoirs with alternating injection of clean and wastewater and in thin water-flooded layers. Spontaneous potential logging data are affected by multiple factors, leading to inaccurate calculation results.
By obtaining the first and second physical parameters of the target rock sample, a dynamic characterization model of mixed formation water salinity is constructed, the curve relationship between water saturation and rock resistivity is determined, and water saturation is calculated using Archie's formula and equivalent ion exchange rate.
This improved the accuracy of water saturation calculation in water-drive reservoirs with mixed formations, ensuring the accuracy of oil saturation and thus determining the oil content.
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Figure CN122014220A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of petroleum logging technology, and in particular to a method and apparatus for calculating the water saturation of mixed formations in water-drive oil reservoirs. Background Technology
[0002] Water-driven oil reservoirs replenish formation energy by injecting water and utilize the density difference between water and oil (water density > oil density) to form gravity differentiation. Water displaces crude oil from the bottom or edge, forming an oil-water mixed flow zone.
[0003] The conventional method for interpreting water saturation logging in open-hole wells first estimates the mixed formation water resistivity using spontaneous potential (SPLP) logging data, and then uses this estimated resistivity to calculate water saturation using a saturation calculation model (such as Archie's formula). However, multiple factors influencing SPLP logging data (the ratio of salt concentration in formation water and mud filtrate, lithology, temperature, the properties of salt in formation water and mud filtrate, formation resistivity, formation thickness, wellbore enlargement, and mud influence) significantly affect the results. This is especially true for water-driven reservoirs with alternating injection of clean and dirty water (where the mixed formation water variation is more complex) or thin water-flooded layers (where SPLP isoelectric characteristics are not obvious or distorted). The differences in mixed formation water properties between different layers are not negligible, but the degree to which SPLP logging data is affected increases significantly, making it impossible to use SPLP logging data to calculate mixed formation water resistivity.
[0004] To address this challenge, selecting formation water resistivity based on factors such as the relative reduction in resistivity logging data in water-drive reservoirs, baseline offset of spontaneous potential (SP) curves, and logging curve morphology can be considered as a solution. Additionally, some researchers use initial water cut data from development wells, combined with static studies, to invert the mixed formation water resistivity of the production layer, calibrate the resistivity of the drilling mud filtrate in the wellbore, and finally apply the basic principles of SP logging to calculate the mixed formation water resistivity of each sub-layer in the vertical direction. When SP logging data is influenced by numerous factors, these methods, to some extent, compensate for the shortcomings of solely using SP logging data to obtain mixed formation water resistivity; however, they still have deficiencies in terms of calculation speed and accuracy.
[0005] Furthermore, there is a broad consensus that the saturation index, a crucial parameter in saturation calculation models, changes with increasing water saturation. However, currently, when determining water saturation, since the water saturation is unknown, a relatively fixed saturation index must be used, which is a factor limiting the accuracy of water saturation calculations.
[0006] In summary, there is a lack of existing technologies for improving the accuracy of water saturation calculation in mixed formations of water-drive oil reservoirs. Summary of the Invention
[0007] In view of this, it is necessary to provide a method, apparatus, electronic equipment and medium for calculating the water saturation of mixed formations in water-drive oil reservoirs, so as to solve the problem of low accuracy in calculating the water saturation of mixed formations in water-drive oil reservoirs in the prior art.
[0008] To address the aforementioned problems, in a first aspect, the present invention provides a method for calculating the water saturation of a mixed formation in a water-drive oil reservoir, comprising: The parameters of the Archie formula are obtained based on the first physical parameters of the target rock sample, which include porosity, resistivity, and water saturation. The second physical parameters of the target rock sample are obtained, including the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury saturation. Construct a dynamic characterization model of mixed formation water salinity corresponding to the target rock sample; Determine the curve relationship between water saturation and rock resistivity of target rock samples under different mineralization and brine displacement conditions; The equivalent ion exchange rate is obtained based on the first physical parameter, the second physical parameter, and Archie's formula; The water saturation of the mixed formation was obtained based on the dynamic characterization model of equivalent ion exchange rate and mixed formation water salinity.
[0009] In one possible implementation, the first physical parameter is determined by rock electrical experiments.
[0010] In one possible implementation, the second physical parameter is determined by a mercury porosimetry experiment.
[0011] In one possible implementation, the expression for the dynamic characterization model of mixed formation water salinity is as follows:
[0012] In the formula, Indicates the salinity of mixed formation water. Indicates the original formation water salinity. Indicates the initial water saturation. Indicates the equivalent ion exchange rate. This indicates the degree of mineralization of a solution in which the injected water has undergone sufficient ion exchange with the original formation water.
[0013] In one possible implementation, the dynamic characterization model of mixed formation water salinity is obtained based on the first and second formulas: The expression for the first formula is:
[0014] The expression for the second formula is:
[0015] In the formula, This represents the ratio of total injected water to formation produced oil and gas. Indicates the effective porosity of the reservoir. This indicates the water saturation of the reservoir at a certain moment. Indicates the initial water saturation. Indicates the equivalent ion exchange rate. Indicates the mineralization degree of the solution. This indicates the salinity of the injected water.
[0016] In one possible implementation, the equivalent ion exchange rate ranges from 0 to 1.
[0017] In one possible implementation, when the equivalent ion exchange rate is 0, the original formation consists entirely of unexchanged formation water; when the equivalent ion exchange rate is 1, the original formation consists entirely of fully ion-exchanged injected water.
[0018] Secondly, the present invention also provides a device for calculating the water saturation of a mixed formation in a water-drive oil reservoir, comprising: The parameter acquisition module of the Archie formula is used to obtain the parameters of the Archie formula based on the first physical parameters of the target rock sample. The first physical parameters include porosity, resistivity and water saturation. The second physical parameter acquisition module is used to acquire the second physical parameters of the target rock sample. The second physical parameters include the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury saturation. The module for acquiring dynamic water salinity characterization models is used to construct dynamic water salinity characterization models for mixed formations corresponding to target rock samples. The curve relationship acquisition module is used to determine the curve relationship between water saturation and rock resistivity of target rock samples under different mineralization and salt water displacement conditions. The equivalent ion exchange rate acquisition module is used to obtain the equivalent ion exchange rate based on the first physical parameter, the second physical parameter, and Archie's formula. The water saturation acquisition module is used to obtain the water saturation of mixed formations based on the dynamic characterization model of equivalent ion exchange rate and mixed formation water salinity.
[0019] Thirdly, the present invention also provides an electronic device, including a memory and a processor, wherein, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the method for calculating the water saturation of a water-drive reservoir mixed formation as described in any of the above implementations.
[0020] Fourthly, the present invention also provides a computer-readable storage medium for storing a computer-readable program or instruction, which, when executed by a processor, can implement the steps in the method for calculating the water saturation of a water-drive reservoir mixed formation as described in any of the above implementations.
[0021] The beneficial effects of this invention are as follows: This invention provides a method for calculating the water saturation of a mixed formation in a water-driven oil reservoir. The method includes obtaining the parameters of the Archie formula based on the first physical parameters of the target rock sample. The first physical parameters include porosity, resistivity, and water saturation. The method also includes obtaining the second physical parameters of the target rock sample, including the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury ingress saturation. A dynamic characterization model of the water salinity of the mixed formation corresponding to the target rock sample is then constructed. The method further determines the curve relationship between water saturation and rock resistivity of the target rock sample under different salinity levels of brine displacement, and experimentally determines the relationship between water saturation and rock resistivity. Based on the first physical parameters, the second physical parameters, the Archie formula, and the curve relationship, the equivalent ion exchange rate is obtained. Further, based on the curve relationship, the equivalent ion exchange rate is obtained. Finally, the water saturation is obtained based on the equivalent ion exchange rate and the dynamic characterization model of the water salinity of the mixed formation. This invention obtains the relationship between water saturation and rock resistivity, further derives the equivalent ion exchange rate, and then uses the equivalent ion exchange rate to obtain the water saturation, thereby improving the calculation accuracy of water saturation in water-drive reservoir mixed formations. Attached Figure Description
[0022] Figure 1 A flowchart illustrating an embodiment of the method for calculating water saturation in a water-drive reservoir mixed formation provided by the present invention; Figure 2 A flowchart illustrating an embodiment of the method for calculating water saturation in a water-drive reservoir mixed formation provided by the present invention; Figure 3 The graph shows the relationship between water saturation and rock resistivity of a target rock sample under different salinity levels and brine displacement, which is part of the method for calculating water saturation in a water-driven oil reservoir mixed formation provided by the present invention. Figure 4 A schematic flowchart of an embodiment of the device for calculating the water saturation of a water-drive reservoir mixed formation provided by the present invention; Figure 5 A schematic diagram of an embodiment of the electronic device provided by the present invention. Detailed Implementation
[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0024] In the description of the embodiments of the present invention, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.
[0025] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.
[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0027] This invention provides a method, apparatus, electronic device, and medium for calculating the water saturation of mixed formations in water-drive oil reservoirs, which will be described below.
[0028] Figure 1 This is a schematic flowchart of an embodiment of the method for calculating water saturation in mixed formations of water-drive oil reservoirs provided by the present invention, as shown below. Figure 1 As shown, the method for calculating the water saturation of mixed formations in water-drive reservoirs includes: S101. Based on the first physical parameters of the target rock sample, the parameters of the Archie formula are obtained. The first physical parameters include porosity, resistivity, and water saturation. It should be noted that the target rock sample is the rock in the mixed formation of the corresponding water-drive oil reservoir. The parameters of the Archie formula are obtained through the first physical parameter, providing model parameters for calculating oil saturation using the Archie formula from resistivity logging data.
[0029] S102. Obtain the second physical parameters of the target rock sample. The second physical parameters include the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury saturation. It should be noted that the second physical parameter is obtained through mercury intrusion porosimetry (MIP). The capillary pressure curve of the target rock sample obtained by MIP reflects the pore structure characteristics inside the rock sample.
[0030] S103. Construct a dynamic characterization model of mixed formation water salinity corresponding to the target rock sample; By incorporating the equivalent ion exchange rate into the dynamic characterization model of mixed formation water salinity through ion exchange between the original formation and the injected water.
[0031] S104. Determine the curve relationship between water saturation and rock resistivity of the target rock sample under different mineralization and salt water displacement conditions. The experiment determined the relationship between water saturation and rock resistivity of the target rock sample under different salinity levels and salt displacement.
[0032] S105. Equivalent ion exchange rate obtained based on the first physical parameter, the second physical parameter, Archie's formula, and the curve relationship; The relationship between the equivalent ion exchange rate and the first physical parameter, the second physical parameter, the Archie formula, and the curve relationship was further obtained.
[0033] S106. The water saturation of the mixed formation is obtained based on the dynamic characterization model of equivalent ion exchange rate and mixed formation water salinity.
[0034] Compared with existing technologies, this embodiment provides a method for calculating the water saturation of a mixed formation in a water-driven oil reservoir, comprising: obtaining the parameters of the Archie formula based on the first physical parameters of the target rock sample, the first physical parameters including porosity, resistivity, and water saturation; obtaining the second physical parameters of the target rock sample, the second physical parameters including the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury ingress saturation; constructing a dynamic characterization model of the water salinity of the mixed formation corresponding to the target rock sample; determining the curve relationship between the water saturation and rock resistivity of the target rock sample under different salinity brine displacement conditions; determining the relationship between water saturation and rock resistivity through experiments; obtaining the equivalent ion exchange rate based on the first physical parameters, the second physical parameters, the Archie formula, and the curve relationship; further obtaining the equivalent ion exchange rate based on the curve relationship; and obtaining the water saturation based on the equivalent ion exchange rate and the dynamic characterization model of the water salinity of the mixed formation. This invention obtains the relationship between water saturation and rock resistivity, further derives the equivalent ion exchange rate, and then uses the equivalent ion exchange rate to obtain the water saturation, thereby improving the calculation accuracy of water saturation in water-drive reservoir mixed formations.
[0035] It should be noted that the application scenario of this invention is oil exploration. By calculating the water saturation of the mixed formation in the water-drive oil reservoir, the oil saturation of the mixed formation in the water-drive oil reservoir is obtained, and then the oil content is determined by the oil saturation.
[0036] In specific embodiments of the present invention, such as Figure 2 The diagram shown is a flowchart of the method in this embodiment.
[0037] In specific embodiments of the present invention, rock samples are selected for physical property experiments, rock electrical experiments, and mercury intrusion porosimetry experiments. In some embodiments of the present invention, in step S101, the first physical parameter is determined by the rock electrical experiment.
[0038] Specifically, rock electrical experiments obtain the four model parameters a, b, m, and n in Archie's formula by measuring parameters such as porosity, resistivity, and saturation of the rock samples taken. These parameters provide model parameters for subsequent calculation of oil saturation using Archie's formula based on resistivity logging data.
[0039] In some embodiments of the present invention, in step S101, the second physical parameter is determined by a mercury intrusion porosimetry experiment.
[0040] Specifically, the capillary pressure curves obtained from mercury intrusion porosimetry (MIP) experiments reflect the pore structure characteristics within rock samples. The curve morphology allows for a general analysis of pore sorting and skewness within the sample. Alternatively, parameters such as displacement pressure, median radius, median pressure, and maximum mercury saturation can be obtained from the MIP curves. Based on these parameters, and combined with pore throat distribution characteristic maps, in-depth studies can be conducted on porosity, permeability, mobile fluid saturation, maximum pore throat connectivity radius, pore throat radius, and pore type (primary and secondary pores).
[0041] In addition, the fractal dimension of the pore structure can be calculated using mercury porosimetry data. This method is commonly used and has been mentioned in many documents.
[0042] It should be noted that, typically in the early stages of flooding, the mixing (ion exchange) of the injected water and the original formation water has just begun, and as the flooding progresses, the ion exchange tends to be complete. In a specific embodiment of the present invention, the dynamic characterization step of the mixed formation water salinity specifically includes: If the original formation water salinity is The original water saturation was The salinity of the injected water is The salinity of the mixed formation water is The effective porosity of the reservoir is Assuming the reservoir's water saturation at a certain moment is... , the equivalent ion exchange rate x of the two types of water at this moment is proposed, that is, there is a complete and sufficient ion exchange between the original formation water with an equivalent ratio of x (0 < x < 1) and the injected water, and the original formation water with an equivalent ratio of (1 - x) has not undergone ion exchange with the injected water.
[0043] Let be the ratio of the total injected water volume to the formation-produced oil and gas volume, and the volume of the part where the injected water and the original formation water are fully ion-exchanged is , let the salinity of this part of the solution be , there is:
[0044] The above expressions are arranged into the first formula, and the expression of the first formula is:
[0045] After considering the original formation water that has not undergone ion exchange with the injected water, there is a second formula, and the expression of the second formula is:
[0046] In the formula, represents the ratio of the total injected water volume to the formation-produced oil and gas volume, represents the effective porosity of the reservoir, represents the water saturation of the reservoir at a certain moment, represents the original water saturation, represents the equivalent ion exchange rate, represents the salinity of the solution, represents the salinity of the injected water.
[0047] By combining the above two formulas, a dynamic characterization model of the salinity of the mixed formation water is obtained. In some embodiments of the present invention, the dynamic characterization model of the salinity of the mixed formation water is obtained based on the first formula and the second formula, and the expression of the dynamic characterization model of the salinity of the mixed formation water:
[0048] In the formula, represents the salinity of the mixed formation water, represents the salinity of the original formation water, represents the original water saturation, represents the equivalent ion exchange rate, represents the salinity of the solution where the injected water and the original formation water are fully ion-exchanged.
[0049] In some embodiments of the present invention, the value range of the equivalent ion exchange rate is from 0 to 1.
[0050] In some embodiments of the present invention, when the equivalent ion exchange rate is 0, the original formation consists entirely of unexchanged formation water; when the equivalent ion exchange rate is 1, the original formation consists entirely of fully ion-exchanged injected water.
[0051] In a specific embodiment of the present invention, step S104, determining the curve relationship between water saturation and rock resistivity of the target rock sample under different salinity levels of brine displacement, specifically includes: Multi-mineralized water-driven rock resistivity experiment The selected rock samples were washed, dried, and their porosity and permeability were tested. The total salinity of the water used in the experiment was 180,000 mg / L, and the pH value was 7.0. The water type was designed according to actual conditions. Water with other salinities was obtained by diluting water with a salinity of 180,000 mg / L sequentially. The oil used in the experiment was simulated oil, and the oil-water viscosity ratio was designed according to actual conditions.
[0052] After the rock samples were saturated with brine of 160,000 mg / L (this value can be designed according to the original formation water conditions), oil flooding was carried out. Each rock sample was flooded with brine of 50,000 ppm, 80,000 ppm, 120,000 ppm and 180,000 ppm respectively to carry out displacement experiments. The resistivity of the rock was measured at different water saturation levels to determine the relationship between water saturation and rock resistivity under different brine displacement conditions.
[0053] like Figure 3 As shown, after the rock sample No. 1 from Well X was saturated with brine of 160,000 mg / L, the remaining water saturation was 35.5% after oil flooding. Displacement experiments were conducted on the rock sample with brine of 50,000 ppm, 80,000 ppm, 120,000 ppm, and 180,000 ppm, respectively. The resistivity of the rock at different water saturations was measured to determine the relationship between water saturation and rock resistivity under different brine displacement conditions.
[0054] In a specific embodiment of the present invention, in step S105, based on the first physical parameter, the second physical parameter, and the equivalent ion exchange rate obtained by Archie's formula, specifically, the influencing factors of the mixing rate between the injected water and the original formation water are first determined. More specifically, using data on different rock resistivity corresponding to different water saturations provided by multi-mineralization water-drive rock resistivity experiments, and the physical property characteristics provided by rock electrical and mercury injection experiments, based on Archie's formula, and using the conversion relationship between formation water resistivity and mineralization, the mixing rate (equivalent ion exchange rate x) of the two types of water corresponding to different saturations during the water-drive process is calculated in reverse.
[0055] Based on the conclusions of mercury intrusion porosimetry and rock electrical experiments, a correlation study was conducted on the equivalent ion exchange rate x with characteristics such as porosity, permeability, mobile fluid saturation, maximum pore throat connectivity radius, pore throat radius, median radius, median pressure, and maximum mercury intrusion saturation. The characteristics closely related to the equivalent ion exchange rate x were selected. Under the condition of two different initial water conditions, a calculation model for the equivalent ion exchange rate x based on the reservoir rock physical properties and pore structure characteristics was established.
[0056] In a specific embodiment of the present invention, the equivalent ion exchange rate x calculation model is substituted into the dynamic characterization model of mixed formation water salinity established in step S103 to obtain the water saturation of the mixed formation in the water-drive oil reservoir, which also yields the oil saturation of the mixed formation in the water-drive oil reservoir.
[0057] In summary, this embodiment combines the saturation index determined in rock electrical experiments and Archie's formula, employing a reverse approach to determine the water saturation of mixed formations. Essentially, the method establishes an evaluation system for the water resistivity and water saturation of mixed formations based on the measured formation resistivity at each sampling point. The evaluation result of this system calculates the required water saturation level under certain injected water salinity conditions to achieve the actual formation resistivity logging response value at that point, thereby improving the accuracy of water-oil saturation calculations in water-drive reservoirs.
[0058] To better implement the method for calculating the water saturation of a water-drive reservoir mixed formation according to an embodiment of the present invention, based on the method for calculating the water saturation of a water-drive reservoir mixed formation, correspondingly, as follows: Figure 4 As shown, this embodiment of the invention also provides a device for calculating the water saturation of a mixed formation in a water-drive oil reservoir. The device 400 for calculating the water saturation of a mixed formation in a water-drive oil reservoir includes: The parameter acquisition module 401 of the Archie formula is used to obtain the parameters of the Archie formula based on the first physical parameters of the target rock sample. The first physical parameters include porosity, resistivity and water saturation. The second physical parameter acquisition module 402 is used to acquire the second physical parameters of the target rock sample. The second physical parameters include the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury saturation. The water salinity dynamic characterization model acquisition module 403 is used to construct a dynamic characterization model of water salinity in mixed formations corresponding to the target rock sample. The curve relationship acquisition module 404 is used to determine the curve relationship between water saturation and rock resistivity of the target rock sample under different mineralization and salt water displacement. The equivalent ion exchange rate acquisition module 405 is used to obtain the equivalent ion exchange rate based on the first physical parameter, the second physical parameter and Archie's formula. The water saturation acquisition module 406 is used to obtain the water saturation of the mixed formation based on the dynamic characterization model of equivalent ion exchange rate and mixed formation water salinity.
[0059] The above embodiment provides a calculation device 400 for water saturation of a water-drive oil reservoir mixed formation, which can realize the technical solution described in the above embodiment of the method for calculating water saturation of a water-drive oil reservoir mixed formation. The specific implementation principle of each module or unit can be found in the corresponding content in the above embodiment of the method for calculating water saturation of a water-drive oil reservoir mixed formation, and will not be repeated here.
[0060] like Figure 5 As shown, the present invention also provides an electronic device 500. The electronic device 500 includes a processor 501, a memory 502, and a display 503. Figure 5 Only some components of the electronic device 500 are shown, but it should be understood that it is not required to implement all the components shown, and more or fewer components may be implemented instead.
[0061] In some embodiments, processor 501 may be a central processing unit (CPU), microprocessor, or other data processing chip, used to run program code stored in memory 502 or process data, such as a method for calculating water saturation in a water-drive reservoir mixed formation according to the present invention.
[0062] In some embodiments, processor 501 may be a single server or a group of servers. The server group may be centralized or distributed. In some embodiments, processor 501 may be local or remote. In some embodiments, processor 501 may be implemented on a cloud platform. In some embodiments, the cloud platform may include a private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, internal cloud, multi-cloud, or any combination thereof.
[0063] In some embodiments, memory 502 may be an internal storage unit of electronic device 500, such as a hard disk or memory of electronic device 500. In other embodiments, memory 502 may also be an external storage device of electronic device 500, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on electronic device 500.
[0064] Furthermore, the memory 502 may include both internal storage units of the electronic device 500 and external storage devices. The memory 502 is used to store application software and various types of data installed on the electronic device 500.
[0065] In some embodiments, display 503 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 503 is used to display information from electronic device 500 and to display a visual user interface. Components 501-503 of electronic device 500 communicate with each other via a system bus.
[0066] In one embodiment, when processor 501 executes a program in memory 502 to calculate the water saturation of a mixed formation in a water-drive oil reservoir, the following steps can be implemented: The parameters of the Archie formula are obtained based on the first physical parameters of the target rock sample, which include porosity, resistivity, and water saturation. The second physical parameters of the target rock sample are obtained, including the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury saturation. Construct a dynamic characterization model of mixed formation water salinity corresponding to the target rock sample; Determine the curve relationship between water saturation and rock resistivity of target rock samples under different mineralization and brine displacement conditions; The equivalent ion exchange rate is obtained based on the first physical parameter, the second physical parameter, and Archie's formula; The water saturation of the mixed formation was obtained based on the dynamic characterization model of equivalent ion exchange rate and mixed formation water salinity.
[0067] It should be understood that when the processor 501 executes the calculation program for the water saturation of a water-driven oil reservoir mixed formation stored in the memory 502, in addition to the functions mentioned above, it can also perform other functions, as detailed in the description of the corresponding method embodiments above.
[0068] Furthermore, the embodiments of the present invention do not specifically limit the type of electronic device 500 mentioned. Electronic device 500 can be a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, laptop computer, or other portable electronic device. Exemplary embodiments of portable electronic devices include, but are not limited to, portable electronic devices running iOS, Android, Microsoft, or other operating systems. The aforementioned portable electronic device can also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, electronic device 500 may not be a portable electronic device, but rather a desktop computer with a touch-sensitive surface (e.g., a touch panel).
[0069] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.
[0070] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for calculating the water saturation of a mixed formation in a water-drive oil reservoir, characterized in that, include: The parameters of the Archie formula are obtained based on the first physical parameters of the target rock sample, which include porosity, resistivity, and water saturation. The second physical parameters of the target rock sample are obtained, including the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury saturation. Construct a dynamic characterization model of mixed formation water salinity corresponding to the target rock sample; Determine the curve relationship between water saturation and rock resistivity of target rock samples under different mineralization and brine displacement conditions; The equivalent ion exchange rate is obtained based on the first physical parameter, the second physical parameter, and Archie's formula; Water saturation was obtained based on a dynamic characterization model of equivalent ion exchange rate and mixed formation water salinity.
2. The method for calculating water saturation in a water-drive reservoir mixed formation according to claim 1, wherein the first physical parameter is determined by rock electrical experiments.
3. The method for calculating the water saturation of a water-drive reservoir mixed formation according to claim 1, wherein the second physical parameter is determined by mercury intrusion porosimetry.
4. The method for calculating the water saturation of mixed formations in water-drive oil reservoirs according to claim 1, characterized in that, The expression for the dynamic characterization model of mixed formation water salinity is as follows: In the formula, Indicates the salinity of mixed formation water. Indicates the original formation water salinity. Indicates the initial water saturation. Indicates the equivalent ion exchange rate. This indicates the degree of mineralization of a solution in which the injected water has undergone sufficient ion exchange with the original formation water.
5. The method for calculating the water saturation of a mixed formation in a water-drive oil reservoir according to claim 4, characterized in that, The dynamic characterization model of mixed formation water salinity is obtained based on the first and second formulas: The expression for the first formula is: The expression for the second formula is: In the formula, This represents the ratio of total injected water to formation produced oil and gas. Indicates the effective porosity of the reservoir. This indicates the water saturation of the reservoir at a certain moment. Indicates the initial water saturation. Indicates the equivalent ion exchange rate. Indicates the mineralization degree of the solution. This indicates the salinity of the injected water.
6. The method for calculating the water saturation of mixed formations in water-drive oil reservoirs according to claim 1, characterized in that, The equivalent ion exchange rate ranges from 0 to 1.
7. The method for calculating the water saturation of a mixed formation in a water-drive oil reservoir according to claim 6, characterized in that, When the equivalent ion exchange rate is 0, the original formation consists entirely of unexchanged formation water; when the equivalent ion exchange rate is 1, the original formation consists entirely of fully ion-exchanged injected water.
8. A device for calculating the water saturation of a mixed formation in a water-drive oil reservoir, characterized in that, include: The parameter acquisition module of the Archie formula is used to obtain the parameters of the Archie formula based on the first physical parameters of the target rock sample. The first physical parameters include porosity, resistivity and water saturation. The second physical parameter acquisition module is used to acquire the second physical parameters of the target rock sample. The second physical parameters include the maximum pore throat radius, pore throat radius, median radius, median pressure, and maximum mercury saturation. The module for acquiring dynamic water salinity characterization models is used to construct dynamic water salinity characterization models for mixed formations corresponding to target rock samples. The curve relationship acquisition module is used to determine the curve relationship between water saturation and rock resistivity of target rock samples under different mineralization and salt water displacement conditions. The equivalent ion exchange rate acquisition module is used to obtain the equivalent ion exchange rate based on the first physical parameter, the second physical parameter, and Archie's formula. The water saturation acquisition module is used to obtain water saturation based on the dynamic characterization model of equivalent ion exchange rate and mixed formation water salinity.
9. An electronic device, characterized in that, Including memory and processor, among which, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the method for calculating the water saturation of a water-drive reservoir mixed formation as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the method for calculating the water saturation of a water-drive reservoir mixed formation as described in any one of claims 1 to 7.