A method, system, device and medium for evaluating characteristics of multi-layer reservoir development

Abstract

The present invention relates to a method, system, equipment and medium for evaluating the development characteristics of a multi-layer oil reservoir, including: taking a well group consisting of a central oil production well and n injection wells around it as a research object, and obtaining various physical property production data of the research object; determining the seepage resistance formula between the injection and production wells based on the obtained various physical property production data, and drawing a saturation-seepage resistance chart; calculating the corresponding seepage resistance and drawing a single-layer pressure-flow relationship chart based on the water saturation under the extreme water-containing condition and the initial oil-containing condition; obtaining the development characteristics evaluation results of each layer of the oil reservoir in the multi-layer oil reservoir based on the obtained real-time wellhead pressure of each layer of the oil reservoir and the production profile data at a specific time, as well as the single-layer pressure-flow relationship chart and the saturation-seepage resistance chart. Therefore, the present invention can be widely used in the technical field of oil development reservoir engineering.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil reservoir development engineering, and specifically, the present invention relates to a method, system, equipment and medium for evaluating oil reservoir development characteristics, and in particular, to a method, system, equipment and medium for evaluating multi-layer oil reservoir development characteristics. Background Art

[0002] Accurate determination and quantitative description of the dynamic development status of multi-layer reservoirs are important foundations for adjusting production measures in oilfields. However, due to the limitations of production dynamic monitoring methods, it is impossible to directly and accurately obtain the production rules and characteristics of each layer of multi-layer reservoirs under commingled production conditions, and qualitative descriptive methods are often used to evaluate the dynamic development of stratified layers, lacking quantitative methods and indicators.

[0003] Although the well testing method can obtain reservoir physical parameters through conventional test data such as pressure and production, it is difficult to obtain the dynamic recovery status of multi-layer oil reservoirs and the production dynamic characteristics of each layer; although the numerical simulation method can quantitatively simulate and predict the development dynamics of oil reservoirs, its reliability and accuracy are too dependent on the results of refined reservoir description. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a method, system, equipment and medium for evaluating the development characteristics of multi-layer oil reservoirs. The evaluation method has strong operability, high credibility and good practicality, and can evaluate the development status of each layer of the multi-layer oil reservoir.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for evaluating the development characteristics of a multi-layer reservoir, comprising the following steps:

[0007] The well group consisting of the central oil production well and the n injection wells around it is taken as the research object, and the production data of various physical properties of the research object are obtained;

[0008] Based on the obtained physical property production data, determine the seepage resistance formula between injection and production wells, and draw a saturation-seepage resistance chart;

[0009] Based on the water saturation under the extreme water-bearing condition and the initial oil-bearing condition, the corresponding seepage resistance is calculated and the single-layer pressure-flow relationship chart is drawn;

[0010] Based on the real-time wellhead pressure of each layer of the reservoir and the liquid production profile data at a specific time, as well as the single-layer pressure-flow relationship chart and saturation-permeability resistance chart, the development characteristics evaluation results of each layer of the multi-layer reservoir are obtained.

[0011] Furthermore, the obtained physical property production data include layer thickness, single layer permeability, distance between wells and water content, and each data is taken from the average value of the central oil production well and the surrounding injection wells.

[0012] Furthermore, the method of determining the seepage resistance formula between injection and production wells based on the obtained production data of various physical properties and drawing a saturation-seepage resistance chart includes:

[0013] The relative permeability corresponding to the average water saturation from the injection well to the central production well is taken as the average relative permeability of the entire process. The seepage resistance formula between the injection and production wells is determined by using the Berkeley-Levelt theory and the equivalent seepage resistance method in the water flooding process.

[0014] Based on the seepage resistance formula between injection and production wells, a saturation-seepage resistance chart is drawn.

[0015] Furthermore, the seepage resistance formula between the injection and production wells includes:

[0016] Before water appears in the oil well, the formula for calculating seepage resistance is:

[0017]

[0018] When water appears in the oil well, the calculation formula of seepage resistance is:

[0019]

[0020] In the formula, is the well resistance; is the connectivity coefficient; is the interwell permeability, mD; is the interwell seepage cross-sectional area, m 2 ; is the relative permeability of the oil phase; is the relative permeability of water phase; is the oil phase viscosity, cP; is the viscosity of the water phase, cP; is the injection water advancement distance, m; is the injection-production well spacing, m; is the average water saturation among wells.

[0021] Furthermore, based on the real-time wellhead pressure of each layer of the oil reservoir and the liquid production profile data at a specific time, as well as the single-layer pressure-flow relationship chart and the saturation-permeability resistance chart, the development characteristics evaluation results of each layer of the multi-layer oil reservoir are obtained, including:

[0022] 4.1) Obtain the real-time wellhead pressure and the production profile data at a specific time, and find the corresponding point on the single-layer pressure-flow relationship chart for the obtained single-layer injection-production well pressure difference and the corresponding liquid production;

[0023] 4.2) Determine the range defined by the obtained point and the two limit condition straight lines. If the obtained point is within the range defined by the two limit condition straight lines, proceed to step 4.4), otherwise proceed to step 4.3);

[0024] 4.3) After adjusting the corresponding parameters in the single-layer seepage resistance formula between injection and production wells according to the judgment results, return to step 4.1) until the obtained point is within the range defined by the two limit condition straight lines;

[0025] 4.4) Based on the obtained points, a straight line passing through the origin is drawn, and the degree of oil recovery of the reservoir is calculated based on the slope of the straight line.

[0026] Further, the corresponding parameters in the single-layer seepage resistance formula between injection and production wells are adjusted according to the judgment result, including:

[0027] If the plotted point of the measured pressure and the corresponding flow rate falls below the range defined by the two limit condition straight lines, the connectivity coefficient in the seepage resistance formula is adjusted according to the preset rule. Increase; when the connectivity coefficient When the value increases to 1 and still cannot meet the requirements, the value of the interwell permeability K is increased according to the preset amplitude;

[0028] If the plotted point based on the measured pressure and the corresponding flow rate falls above the range defined by the two limit condition straight lines, the connectivity coefficient in the seepage resistance formula is reduced according to the preset rule. ; When the connectivity coefficient When the value is reduced to the preset value and still cannot meet the requirements, the value of the interwell permeability K is reduced according to the preset amplitude;

[0029] After adjusting all parameters, return to step 4.1) until the corresponding point falls within the range defined by the two limit condition straight lines.

[0030] Further, the calculation formula for the recovery degree of the layer is:

[0031]

[0032] In the formula, is the reservoir recovery degree; is the irreducible water saturation of the reservoir.

[0033] In a second aspect, the present invention provides a multi-layer reservoir development characteristic evaluation system, comprising:

[0034] The data acquisition module is used to take the well group consisting of the central oil production well and the n injection wells around it as the research object and obtain the production data of various physical properties of the research object;

[0035] The first chart drawing module is used to determine the seepage resistance formula between the injection and production wells based on the obtained physical property production data, and draw the saturation-seepage resistance chart;

[0036] The second chart drawing module is used to calculate the corresponding seepage resistance and draw a single-layer pressure-flow relationship chart based on the water saturation under the extreme water-containing condition and the initial oil-containing condition;

[0037] The development characteristic evaluation module is used to obtain the multi-layer reservoir development characteristic evaluation results based on the acquired real-time wellhead pressure and the production profile data at a specific time, as well as the obtained single-layer pressure-flow relationship chart and saturation-permeability resistance chart.

[0038] In a third aspect, the present invention provides a processing device, which includes at least a processor and a memory, wherein the memory stores a computer program, and when the processor runs the computer program, it executes the steps of the multi-layer reservoir development characteristic evaluation method.

[0039] In a fourth aspect, the present invention provides a computer storage medium having computer-readable instructions stored thereon, wherein the computer-readable instructions can be executed by a processor to implement the steps of the multi-layer reservoir development characteristic evaluation method.

[0040] The present invention adopts the above technical solution, which has the following advantages:

[0041] 1. The present invention calculates the inter-well single-layer seepage resistance formula and draws the saturation-seepage resistance chart based on it. At the same time, the water saturation under the extreme water content condition and the initial oil content condition is used to calculate the corresponding seepage resistance and draw a single-layer pressure-flow relationship chart, and then calculates the recovery degree of the single-layer oil reservoir, which can give an accurate judgment and quantitative description of the dynamic development status of the multi-layer oil reservoir.

[0042] 2. The various parameters used in drawing the plates in the present invention are easy to obtain, the calculation process is simple, and the relevant indicators can be judged and predicted without establishing a complex numerical simulation model.

[0043] Therefore, the method of the present invention has strong operability, high credibility, good practicality, and can be widely used in the technical field of oil development and reservoir engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0045] Figure 1 is a flow chart of a method for evaluating the development characteristics of a multi-layer reservoir provided by an embodiment of the present invention;

[0046] Figure 2 is a typical medium-high permeability reservoir relative permeability curve provided by an embodiment of the present invention;

[0047] Figure 3 is the relationship between seepage resistance and average water saturation over the entire process provided by the embodiment of the present invention;

[0048] Figure 4 is the injection-production pressure difference-flow relationship provided by an embodiment of the present invention;

[0049] Figure 5 This is a diagram of the evaluation results of the development characteristics of a small layer in the Bohai SZ oilfield provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0051] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0052] In some embodiments of the present invention, a method for evaluating the development characteristics of a multi-layer oil reservoir is provided, including: first, based on the given reservoir phase permeability data and fluid property data, the total seepage resistance is obtained by a graphical method with respect to the change of the average water saturation; second, the single layer pressure-flow relationship is determined by a resistance formula; finally, the permeability resistance is obtained on the single layer pressure-flow relationship chart by measuring the single layer injection pressure and the production profile and the graphical method, and a relationship curve between the average water saturation and the recovery degree is given according to the law of conservation of matter. Thus, the recovery degree of the target single layer can be basically determined.

[0053] Correspondingly, in other embodiments of the present invention, a multi-layer reservoir development characteristic evaluation system, equipment and medium are provided.

[0054] Example 1

[0055] like Figure 1 As shown, this embodiment provides a method for evaluating the development characteristics of a multi-layer reservoir, comprising the following steps:

[0056] 1) The well group consisting of the central oil production well and the n injection wells around it is taken as the research object, and the production data of various physical properties of the research object are obtained;

[0057] 2) Based on the obtained physical property production data, determine the seepage resistance formula between injection and production wells, and draw a saturation-seepage resistance chart;

[0058] 3) Based on the water saturation under the extreme water content condition and the initial oil content condition, the corresponding seepage resistance is calculated and a single layer pressure-flow relationship chart is drawn;

[0059] 4) Based on the acquired real-time wellhead pressure and the production profile data at a specific time, as well as the saturation-permeability resistance diagram obtained in step 2) and the single-layer pressure-flow relationship diagram obtained in step 3), the development characteristic evaluation results of each layer in the multi-layer reservoir are obtained.

[0060] Preferably, in the above step 1), the various physical property production data obtained include layer thickness, single layer permeability, distance between wells and water content, etc., and each data is taken from the average value of the central oil production well and the surrounding injection wells. The specific calculation method is: add the thickness, single layer permeability, distance between wells, etc. of the surrounding injection wells and then remove the number of wells to obtain the arithmetic mean of the physical properties.

[0061] Preferably, in the above step 2), the method for determining the seepage resistance formula between the injection and production wells includes:

[0062] 2.1) The relative permeability corresponding to the average water saturation from the injection well to the central production well is taken as the average relative permeability of the entire process. The seepage resistance formula between the injection and production wells is determined by using the Berkeley-Levelt theory and the equivalent seepage resistance method in the water flooding process.

[0063] Before water appears in the oil well, the formula for calculating seepage resistance is:

[0064]

[0065] In the formula, is the well resistance; is the connectivity coefficient; is the interwell permeability, mD; is the interwell seepage cross-sectional area, m 2 ; is the relative permeability of the oil phase; is the relative permeability of water phase; is the oil phase viscosity, cP; is the viscosity of the water phase, cP; is the injection water advancement distance, m; is the injection-production well spacing, m; is the average water saturation among wells.

[0066] Since the connectivity between the production well and the surrounding injection wells varies with the reservoir heterogeneity, the connectivity is determined first, that is, the connectivity coefficient. Due to the influence of heterogeneity, the oil and water wells located in the river sand section have good connectivity in the seepage channel and the fluid is easy to flow; on the contrary, when there is a deteriorating reservoir blocking between the oil and water wells, the seepage is difficult or even has no flow. Through the results of the injection volume and production of different types of oil layers at different water-containing stages, it can be seen that when the oil and water wells are located in the river sand section or there is no deteriorating reservoir blocking between the oil and water wells, there is no obvious waterline breakthrough and bypass flow. At this time, the formation thickness and permeability heterogeneity in the oil and water well group unit have little effect, and it can be considered that each well point is Z=1; when there is blocking and bypass flow is required, the connectivity coefficient is 0.5; when the oil layer is blocked by a large range of mudstone layers, the connectivity coefficient Z is 0.

[0067] Before water appears in the oil well, the average water saturation between wells The BL equation can be expressed as follows:

[0068]

[0069] In the formula, is the water saturation at the water flooding front, is the water saturation at the water flooding front corresponding to the water content, It is the derivative of water saturation at the water flooding front corresponding to water cut.

[0070] During the water injection development process, as the two-phase zone continues to expand, the average water saturation from the injection well to the oil production well will continue to increase, causing corresponding changes in the seepage resistance between the injection well and the oil production well.

[0071] When water appears in the oil well, the calculation formula of its seepage resistance is as follows:

[0072]

[0073] After water appears in the oil well, the average water saturation in the two-phase zone is the average water saturation in the whole process:

[0074]

[0075] As the isosaturation planes reach the production wells one by one, the average water saturation increases continuously. The relative permeability values ​​of the oil phase and the water phase required in the calculation process can be measured by experimental methods. Given the reservoir relative permeability data and fluid property data, the change of the total seepage resistance with the average water saturation can be obtained by graphical method.

[0076] 2.2) Based on the relationship formula between the average water saturation of a single layer between injection and production wells and the seepage resistance, draw a saturation-seepage resistance chart.

[0077] like Figure 2 , Figure 3 As shown, the penetration resistance formula can be used to give the penetration resistance Average water saturation According to the law of conservation of matter, we can give The degree of extraction Therefore, by measuring the injection pressure and liquid production profile of a single layer, the recovery degree of the target single layer can be basically determined.

[0078] Preferably, in the above step 3), if Figure 4 As shown in the figure, according to the seepage resistance formula, the relationship curve between the injection-production pressure difference and the flow rate at different water-cut stages can be obtained. When a single layer is in the initial oil-bearing state, the seepage resistance is the largest, and it is the straight line with the smallest slope on the pressure-flow relationship chart. Assuming that the layer is under the condition of 100% complete flooding, and the average oil saturation between the injection and production wells is close to the residual oil saturation, then the seepage resistance between the injection and production wells is the smallest at this time, which is reflected in the straight line with the largest slope on the pressure-flow relationship chart. Under ideal conditions, the single-layer pressure and flow relationship curves at any other water-cut moment should be distributed in the area between the above two straight lines.

[0079]

[0080] In the above formula, is the single-layer flow difference, is the corresponding pressure difference.

[0081] Preferably, in the above step 4), the method for obtaining the multi-layer reservoir development characteristic evaluation result comprises:

[0082] 4.1) Obtain the real-time wellhead pressure and the production profile data at a specific time, and find the corresponding point on the single-layer pressure-flow relationship chart for the obtained single-layer injection-production well pressure difference and the corresponding liquid production;

[0083] 4.2) Determine the range defined by the obtained point and the two limit condition straight lines. If the obtained point is within the range defined by the two limit condition straight lines, proceed to step 4.4), otherwise proceed to step 4.3);

[0084] 4.3) After adjusting the corresponding parameters in the relationship formula between the average water saturation of the single layer between the injection and production wells and the seepage resistance according to the judgment result, return to step 4.1) until the obtained point is within the range defined by the two limit condition straight lines.

[0085] Among them, the method of adjusting the corresponding parameters in the relationship formula between the average water saturation of the single layer between the injection and production wells and the seepage resistance according to the judgment result includes:

[0086] If the plotted point of measured pressure and corresponding flow rate falls below the range defined by the two limit condition straight lines, then the connectivity coefficient in the seepage resistance formula is Adjustment is made. The greater the deviation, the greater the connectivity coefficient. The larger the value, the greater the connectivity coefficient. When the value increases to 1 and still cannot meet the requirements, the value of the interwell permeability K is increased according to the preset amplitude;

[0087] If the plotted point based on the measured pressure and the corresponding flow rate falls above the range defined by the two limit condition straight lines, then the connectivity coefficient in the seepage resistance formula is Adjustment is made. The greater the deviation, the lower the connectivity coefficient. The larger the value, the lower the connectivity coefficient. When the value still cannot meet the requirements, the value of the interwell permeability K is reduced according to the preset range; in this case, the accuracy of the calculated recovery degree is reduced, and the possibility of predicting severe crossflow is greatly increased;

[0088] After adjusting all parameters, return to step 4.1) until the corresponding point falls within the range defined by the two limit condition straight lines.

[0089] 4.4) Based on the obtained points, a straight line passing through the origin is drawn, and the degree of oil recovery of the reservoir is calculated based on the slope of the straight line.

[0090] If the point is within the range defined by the two limit condition lines, the slope of the line passing through the origin can be calculated to obtain the seepage resistance value between the injection and production wells of the single layer at a certain moment. Combined with the saturation-seepage resistance chart, the average water saturation of the single layer can be calculated, and then the production degree of the layer can be obtained;

[0091]

[0092] In the above formula, is the reservoir recovery degree; is the irreducible water saturation of the reservoir.

[0093] Example 2

[0094] like Figure 5As shown in the figure, this embodiment evaluates the development characteristics of a small layer in the Bohai SZ oilfield. The triangle marks in the figure are the relationship points made by the test results in October 2014, and the circle marks are the relationship points of the test results in December 2019. This layer is the main water-absorbing layer, and the water absorption ratio in 2014 and 2019 was 17.7% and 56.1% respectively. It can be seen from the resistance characteristic status diagram that both tests show that there is a certain degree of large pore development in this layer, and the situation in 2019 is more serious than that in 2014.

[0095] Example 3

[0096] The above-mentioned embodiment 1 provides a multi-layer reservoir development characteristic evaluation method, and correspondingly, this embodiment provides a multi-layer reservoir development characteristic evaluation system. The system provided in this embodiment can implement the multi-layer reservoir development characteristic evaluation method of embodiment 1, and the system can be implemented by software, hardware, or a combination of software and hardware. For example, the system may include integrated or separate functional modules or functional units to execute the corresponding steps in each method of embodiment 1. Since the system of this embodiment is basically similar to the method embodiment, the process described in this embodiment is relatively simple, and the relevant parts can refer to the partial description of embodiment 1. The embodiment of the system provided in this embodiment is only illustrative.

[0097] The multi-layer reservoir development characteristic evaluation system provided in this embodiment includes:

[0098] The data acquisition module is used to take the well group consisting of the central oil production well and the n injection wells around it as the research object and obtain the production data of various physical properties of the research object;

[0099] The first chart drawing module is used to determine the seepage resistance formula between the injection and production wells based on the obtained physical property production data, and draw the saturation-seepage resistance chart;

[0100] The second chart drawing module is used to calculate the corresponding seepage resistance and draw a single-layer pressure-flow relationship chart based on the water saturation under the extreme water-containing condition and the initial oil-containing condition;

[0101] The development characteristic evaluation module is used to obtain the development characteristic evaluation results of each layer of the multi-layer oil reservoir based on the real-time wellhead pressure of each layer of the oil reservoir and the liquid production profile data at a specific time, as well as the obtained single-layer pressure-flow relationship chart and saturation-permeability resistance chart.

[0102] Example 4

[0103] This embodiment provides a processing device corresponding to the multi-layer reservoir development characteristic evaluation method provided in this embodiment 1. The processing device can be a processing device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of embodiment 1.

[0104] The processing device includes a processor, a memory, a communication interface and a bus, and the processor, the memory and the communication interface are connected through the bus to complete mutual communication. The memory stores a computer program that can be run on the processor, and the processor executes the multi-layer reservoir development feature evaluation method provided in this embodiment 1 when running the computer program.

[0105] In some embodiments, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0106] In other embodiments, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or other general-purpose processors of various types, which are not limited herein.

[0107] Example 5

[0108] The multi-layer reservoir development characteristic evaluation method of this embodiment 1 can be specifically implemented as a computer program product, which may include a computer-readable storage medium carrying computer-readable program instructions for executing the multi-layer reservoir development characteristic evaluation method described in this embodiment 1.

[0109] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned 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 invention.

Claims

1. A method for evaluating the development characteristics of a multi-layer reservoir, characterized in that: The following steps are involved: The well group consisting of the central oil production well and the n injection wells around it is taken as the research object, and the production data of various physical properties of the research object are obtained; Based on the obtained physical property production data, determine the seepage resistance formula between injection and production wells, and draw a saturation-seepage resistance chart; Based on the water saturation under the extreme water-bearing condition and the initial oil-bearing condition, the corresponding seepage resistance is calculated and the single-layer pressure-flow relationship chart is drawn; Based on the real-time wellhead pressure of each layer of the reservoir and the production profile data at a specific time, as well as the single-layer pressure-flow relationship chart and saturation-permeability resistance chart, the development characteristics evaluation results of each layer of the multi-layer reservoir are obtained; Based on the obtained physical property production data, the seepage resistance formula between the injection and production wells is determined, and the saturation-seepage resistance chart is drawn, including: The relative permeability corresponding to the average water saturation from the injection well to the central production well is taken as the average relative permeability of the entire process. The seepage resistance formula between the injection and production wells is determined by using the Berkeley-Levelt theory and the equivalent seepage resistance method in the water flooding process. Based on the seepage resistance formula between injection and production wells, draw a saturation-seepage resistance chart; The seepage resistance formula between the injection and production wells includes: Before water appears in the oil well, the formula for calculating seepage resistance is: When water appears in the oil well, the calculation formula of seepage resistance is: In the formula, is the well resistance; is the connectivity coefficient; is the interwell permeability, mD; is the cross-sectional area of ​​interwell seepage, m 2 ; is the relative permeability of the oil phase; is the relative permeability of water phase; is the viscosity of the oil phase, cP; is the viscosity of the water phase, cP; is the injection water advancement distance, m; is the injection-production well spacing, m; is the average water saturation among wells; The development characteristic evaluation results of each layer of the multi-layer oil reservoir are obtained based on the real-time wellhead pressure of each layer of the oil reservoir and the liquid production profile data at a specific time, as well as the single-layer pressure-flow relationship chart and the saturation-permeability resistance chart, including: ① Obtain the real-time wellhead pressure and the production profile data at a specific time, and find the corresponding point on the single-layer pressure-flow relationship chart for the obtained single-layer injection-production well pressure difference and the corresponding liquid production; ② Judge the range defined by the obtained point and the two limit condition straight lines. If the obtained point is within the range defined by the two limit condition straight lines, proceed to step ④, otherwise proceed to step ③; ③ After adjusting the corresponding parameters in the single-layer seepage resistance formula between the injection and production wells according to the judgment results, return to step ① until the obtained point is within the range defined by the two limit condition straight lines; ④ Based on the obtained points, a straight line passing through the origin is drawn, and the degree of oil recovery of the reservoir is calculated based on the slope of the straight line.

2. A method for evaluating the development characteristics of a multi-layer reservoir as claimed in claim 1, characterized in that: The obtained physical property production data include layer thickness, single layer permeability, distance between wells and water content, and each data is taken from the average value of the central oil production well and the surrounding injection wells.

3. A multi-layer reservoir development characteristic evaluation method as claimed in claim 1, characterized in that: The adjusting of the corresponding parameters in the single-layer seepage resistance formula between the injection and production wells according to the judgment result includes: If the plotted point of the measured pressure and the corresponding flow rate falls below the range defined by the two limit condition straight lines, the connectivity coefficient in the seepage resistance formula is adjusted according to the preset rule. Increase; when the connectivity coefficient When the value increases to 1 and still cannot meet the requirements, the value of the interwell permeability K is increased according to the preset amplitude; If the plotted point based on the measured pressure and the corresponding flow rate falls above the range defined by the two limit condition straight lines, the connectivity coefficient in the seepage resistance formula is reduced according to the preset rule. ; When the connectivity coefficient When the value is reduced to the preset value and still cannot meet the requirements, the value of the interwell permeability K is reduced according to the preset amplitude; After adjusting all parameters, return to step ① until the corresponding point falls within the range defined by the two limit condition straight lines.

4. A method for evaluating the development characteristics of a multi-layer reservoir as claimed in claim 1, characterized in that: The calculation formula for the recovery degree of the oil reservoir is: In the formula, is the reservoir recovery degree; is the irreducible water saturation of the reservoir.

5. A multi-layer reservoir development characteristic evaluation system, characterized in that: include: The data acquisition module is used to take the well group consisting of the central oil production well and the n injection wells around it as the research object and obtain the production data of various physical properties of the research object; The first chart drawing module is used to determine the seepage resistance formula between the injection and production wells based on the obtained physical property production data, and draw the saturation-seepage resistance chart; The second chart drawing module is used to calculate the corresponding seepage resistance and draw a single-layer pressure-flow relationship chart based on the water saturation under the extreme water-containing condition and the initial oil-containing condition; The development characteristic evaluation module is used to obtain the development characteristic evaluation results of each layer of the multi-layer reservoir based on the real-time wellhead pressure of each layer of the reservoir and the liquid production profile data at a specific time, as well as the single-layer pressure-flow relationship chart and saturation-permeability resistance chart; Based on the obtained physical property production data, the seepage resistance formula between the injection and production wells is determined, and the saturation-seepage resistance chart is drawn, including: The relative permeability corresponding to the average water saturation from the injection well to the central production well is taken as the average relative permeability of the entire process. The seepage resistance formula between the injection and production wells is determined by using the Berkeley-Levelt theory and the equivalent seepage resistance method in the water flooding process. Based on the seepage resistance formula between injection and production wells, draw a saturation-seepage resistance chart; The seepage resistance formula between the injection and production wells includes: Before water appears in the oil well, the formula for calculating seepage resistance is: When water appears in the oil well, the calculation formula of seepage resistance is: In the formula, is the well resistance; is the connectivity coefficient; is the interwell permeability, mD; is the cross-sectional area of ​​interwell seepage, m 2 ; is the relative permeability of the oil phase; is the relative permeability of water phase; is the viscosity of the oil phase, cP; is the viscosity of the water phase, cP; is the injection water advancement distance, m; is the injection-production well spacing, m; is the average water saturation among wells; The development characteristic evaluation results of each layer of the multi-layer oil reservoir are obtained based on the real-time wellhead pressure of each layer of the oil reservoir and the liquid production profile data at a specific time, as well as the single-layer pressure-flow relationship chart and the saturation-permeability resistance chart, including: ① Obtain the real-time wellhead pressure and the production profile data at a specific time, and find the corresponding point on the single-layer pressure-flow relationship chart for the obtained single-layer injection-production well pressure difference and the corresponding liquid production; ② Judge the range defined by the obtained point and the two limit condition straight lines. If the obtained point is within the range defined by the two limit condition straight lines, proceed to step ④, otherwise proceed to step ③; ③ After adjusting the corresponding parameters in the single-layer seepage resistance formula between the injection and production wells according to the judgment results, return to step ① until the obtained point is within the range defined by the two limit condition straight lines; ④ Based on the obtained points, a straight line passing through the origin is drawn, and the degree of oil recovery of the reservoir is calculated based on the slope of the straight line.

6. A processing device, comprising at least a processor and a memory, wherein a computer program is stored in the memory, wherein: When the processor runs the computer program, the computer program is executed to implement the steps of the multi-layer reservoir development characteristic evaluation method according to any one of claims 1 to 4.

7. A computer storage medium, characterized in that: Computer-readable instructions are stored thereon, and the computer-readable instructions can be executed by a processor to implement the steps of the multi-layer reservoir development characteristic evaluation method according to any one of claims 1 to 4.

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