Five-point method well group polymer flooding control degree determination method and device

Abstract

The invention discloses a five-point method well group polymer flooding control degree determining method and device. The method comprises the steps that a production well and an injection well in a five-point method well group serve as a research unit, two rays are drawn with the production well and the injection well as vertexes respectively, and the included angle between each ray and the connecting line of the production well and the injection well is half of a preset angle; determining a rhombus by taking two intersection points of the four rays, the production well and the injection well as vertexes, and taking the rhombus as a fluid flow range controlled by the production well in the research unit; according to the percolation condition lower limit and the fluid flowing range of the production well controlled in the well group, the polymer displacement range of the production well controlled in the well group is determined, and the polymer displacement pore volume controlled by the well group is obtained in combination with the effective reservoir thickness and porosity; and determining the polymer flooding control degree of the well group according to the total pore volume in the boundary of the well group. According to the method, the five-point method well group polymer flooding control degree can be quickly and conveniently determined by using extremely few data.

Description

Technical Field

[0001] This invention relates to the field of reservoir engineering technology, and in particular to a method and apparatus for determining the degree of polymer flooding control in well groups using a five-point method. Background Technology

[0002] The degree of control over polymer flooding plays a crucial role in the design of polymer flooding layer combination, well spacing, and injection parameters. Its accuracy directly affects the development plan and thus the development effect of polymer flooding.

[0003] Polymer flooding control degree refers to the percentage of the oil layer pore volume that polymer solution can enter to the total pore volume of the oil layer. Currently, there are several methods for directly calculating polymer flooding control degree: (1) Using the traditional water flooding control degree calculation method, that is, taking the oil well as the center, the percentage of the cumulative effective thickness of the connection between the oil well and the injection well to the total effective thickness of the well group is calculated. This method only considers the connectivity of the oil layer and does not consider the number of injection-production connection directions and porosity changes on the plane, or the conditions of the pore space that polymer solution can enter. (2) Considering the number of connection directions on the oil layer plane, the permeability of the oil layer and the pore space that polymer solution can enter, the pore volume of the oil layer that polymer solution can reach is determined by using the area that the polymer flooding well network can reach, the thickness of the injection-production well group connection that the polymer solution can reach, and the porosity of the well group, and then the polymer flooding control degree of a well group is calculated. (3) Considering the changes in sand bodies between wells, the three-dimensional geological modeling method is used to directly sum up the grid volumes that the polymer solution can reach to obtain the polymer reachable volume, and then the polymer flooding control degree of a well group is calculated. The latter two methods are theoretically feasible, but neither explains how the swept area (grid) of polymer flooding is determined. This swept area must be calculated using either the average value method or the area sweep efficiency method. If the area sweep efficiency method is used to calculate the swept area, it will be extremely complex; if the average value method is used, it will differ significantly from the actual well group. (4) In engineering, for the convenience and speed of application, based on considering the connection direction, permeability, and the pore space that the polymer solution can enter, the following simplified formula is used to calculate a polymer flooding well group:

[0004]

[0005] Where H is the effective thickness of the injection well, and h1, h2, h3, and h4 are the effective thicknesses of the production wells, respectively.

[0006] This method is simple and easy to implement, but it treats the five-point polymer flooding well group as a regular square with the same porosity in each well, which is obviously inconsistent with the actual well group situation.

[0007] Based on the concept of polymer flooding control degree, the volume of oil layer pores that polymer solution can enter can also be indirectly calculated by calculating the control area of ​​a single well in polymer flooding, and then the control degree of polymer flooding can be calculated. Currently, the methods for determining the control area of ​​a single well are: (1) Based on well test data, the oil drainage area of ​​the well is determined by using the pressure recovery curve, and the oil drainage area is taken as the control area of ​​a single well; (2) Based on the saturated pressure distribution in the numerical simulation calculation results, the pressure gradient between the grid block and the surrounding four wells is calculated, and then the grid controlled by the single well is determined based on the pressure gradient. The area of ​​the grid block controlled by each well is accumulated sequentially, which is the control area of ​​the well; (3) Based on the distribution of sand body types, the control area of ​​a single well is calculated by using the triangular mesh method. Summary of the Invention

[0008] The inventors discovered numerous problems with existing direct methods for calculating polymer flooding control levels. Similarly, the aforementioned indirect methods also have issues. The determination of the single-well control area, while called the single-well control area, actually refers to the area controlled by the single well in terms of sand body type, not the true "area within the flow range controlled by the single well." While the above methods can be used to calculate the single-well control area of ​​a five-point well network for polymer injection, in the high-water-cut and ultra-high-water-cut development stages of multi-layer sandstone oilfields, the calculation of the single-well control area during polymer injection using a five-point well network for densification and adjustment to further improve recovery is hampered by the complexity of the exploited formations, the presence of multiple well network combinations, and the lack of pressure test data in most cases. Even when such data exists, it is often incomplete (not available for every five-point well group or sedimentary unit), making it impossible to use pressure test data for single-well control area calculation. While numerical simulation can calculate the control area of ​​a single well, it requires a large amount of input data and takes a long time, making it difficult to perform rapid calculations of the single-well control area in a timely manner, thus failing to meet the needs of polymer flooding control level calculation in the design of polymer flooding schemes.

[0009] To enrich process routes and increase the options, this invention provides a method and apparatus for determining the degree of polymer flooding control in a five-point well group. It is particularly suitable for the development stage of multi-layer sandstone oilfields with high and ultra-high water cut, and for the development stage where polymer injection using a five-point well network is adopted to further improve the recovery rate. It can quickly and conveniently determine the degree of polymer flooding control in a five-point well group using very little data.

[0010] In a first aspect, embodiments of the present invention provide a method for determining the degree of polymer flooding control in a five-point well group, comprising:

[0011] Taking one production well and one injection well in the five-point well group as a research unit, two rays are drawn with the production well and the injection well as vertices respectively. The angle between each ray and the line connecting the production well and the injection well is half of a preset angle. A rhomboid range is determined with the two intersection points of the four rays and the production well and the injection well as vertices. This range is taken as the fluid flow range controlled by the production well in the research unit, and the fluid flow range controlled by the production well in the well group is obtained.

[0012] Based on the seepage condition limit and the fluid flow range controlled by the production well within the well group, the polymer displacement range controlled by the production well within the well group is determined. Combined with the corresponding effective reservoir thickness and effective porosity, the polymer displacement pore volume controlled by the production well within the well group is determined, thus obtaining the polymer displacement pore volume controlled by the well group.

[0013] The total pore volume of the oil layer corresponding to the well group is determined based on the well group boundary, the effective reservoir thickness, and the effective porosity. The well group boundary is determined based on the relationship between the injection wells and the production wells in the well group.

[0014] The ratio of the polymer-displaced pore volume controlled by the well group to the total pore volume is determined as the degree of polymer flooding control of the well group.

[0015] Secondly, embodiments of the present invention provide a device for determining the degree of polymer flooding control in a five-point well group, comprising:

[0016] The fluid flow range determination module is used to take one production well and one injection well in a five-point well group as a research unit. Two rays are drawn with the production well and the injection well as vertices respectively. The angle between each ray and the line connecting the production well and the injection well is half of a preset angle. A rhomboid range is determined with the two intersection points of the four rays and the production well and the injection well as vertices. This range is used as the fluid flow range controlled by the production well in the research unit, thus obtaining the fluid flow range controlled by the production well in the well group.

[0017] The polymer displacement pore volume determination module is used to determine the polymer displacement range controlled by the production well within the well group based on the seepage condition limit and the fluid flow range controlled by the production well within the well group. Combined with the corresponding effective reservoir thickness and effective porosity, the module determines the polymer displacement pore volume controlled by the production well within the well group, thus obtaining the polymer displacement pore volume controlled by the well group.

[0018] The module for determining the total pore volume of the oil layer within a well group is used to determine the total pore volume of the oil layer corresponding to the well group based on the well group boundary, the effective reservoir thickness, and the effective porosity. The well group boundary is determined based on the relationship between the injection wells and the production wells in the well group.

[0019] The polymer flooding control degree determination module is used to determine the ratio of the polymer flooding displacement pore volume controlled by the well group to the total pore volume as the polymer flooding control degree of the well group.

[0020] Thirdly, embodiments of the present invention provide a computer storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-mentioned method for determining polymer drive control program for well groups using the five-point method.

[0021] Fourthly, embodiments of this disclosure provide a server, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described method for determining the polymer drive control program of the five-point well group.

[0022] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0023] The five-point well group polymer flooding control process determination method provided in this invention treats one production well and one injection well within a five-point well group as a research unit, approximating its streamline field range as a rhombus. Based on pre-determined rhombus angles and seepage condition limits, only the location information of each well within the five-point well group and easily obtainable effective thickness and porosity distribution data of each flow unit are needed to quickly and conveniently determine the polymer flooding control process. Furthermore, the rhomboid approximation of the streamline field range fully meets the accuracy requirements for polymer flooding control process analysis in reservoir engineering. This method solves the problem of insufficient or incomplete pressure test data and production dynamics during the opening stage of multi-layer sandstone oilfields with high and ultra-high water cut, necessitating the calculation of control pore volume to determine the polymer flooding control process. It also solves the problem of long simulation times and difficulty in quickly calculating polymer flooding control process in reservoir numerical simulations of single-well control pore volume. Finally, it addresses the issue that the control pore volume of a single well (the pore volume controlling the sand body type in a single well) determined by existing technologies is not necessarily the pore volume within the control fluid flow range of that single well.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0027] Figure 1 This is a schematic diagram of the streamline field distribution of the five-point well group in an embodiment of the present invention;

[0028] Figure 2 This is a flowchart of the method for determining the polymer flooding control process of a five-point well group in Embodiment 1 of the present invention;

[0029] Figure 3 This is a flowchart illustrating the specific implementation of the polymer flooding control process for the five-point well group in Embodiment 2 of the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of the polymer drive control process determination device for the five-point well group in an embodiment of the present invention. Detailed Implementation

[0031] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0032] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0033] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0034] In the high-water-cut and ultra-high-water-cut development stages of multi-layer sandstone oilfields, the well network densification employed to further enhance oil recovery is typically a five-point well network, composed of multiple five-point well groups. A typical five-point well group includes a central injection well and four surrounding production wells. (See [link to documentation]). Figure 1 As shown; or, the five-point well group includes a central production well and four surrounding injection wells. The above two scenarios represent the standard setup for a five-point well group. Optionally, other well placement methods can also be used for the five-point well group; this embodiment does not limit the specific method used.

[0035] Based on the concept of single-well controlled pore volume—the pore volume within the fluid flow range controlled by a single well—numerical simulations of multiple five-point well groups revealed that the streamline field distribution exhibits a "petal-like" characteristic. (See [link to relevant documentation]). Figure 1 As shown, a production well and an injection well within a five-point well group are taken as a research unit, and its streamline field envelope includes two symmetrical arc segments.

[0036] From a mathematical perspective, the region enclosed by two symmetrical arcs is not easy to quantify, the area is not easy to calculate, and it is not easy to average. Therefore, in order to simplify the calculation, this embodiment approximates the region enclosed by two symmetrical arcs, that is, the envelope of the flow field line of each research unit, as a rhomboid region while meeting the requirements of calculation accuracy.

[0037] Based on numerical simulation results of multiple five-point well groups within the target reservoir, the streamline field envelope of each study unit within each five-point well group was obtained. For the streamline field envelope of each study unit, a rhombus was determined with the produced well and the injection well within the study unit as its two opposite vertices. The area difference between the rhombus and the envelope did not exceed a set area difference threshold. The average value of the acute angle of the rhombus was obtained. In subsequent studies of other five-point well groups within the target reservoir, to avoid the diversification of data required for numerical simulation and excessively long model time, this average value was determined as the acute angle of the approximate rhombus of the streamline field of each study unit in the five-point well groups that were not numerically simulated, facilitating subsequent calculations.

[0038] Specifically, how to determine a rhombus with the production well and the injection well as its two opposite vertices, such that the area difference between it and the envelope does not exceed a set area difference threshold, can be determined manually by geologists or after precise mathematical calculations. This embodiment does not limit the specific determination method.

[0039] In addition to determining the acute angle of the approximate rhombus shape of the streamline field envelope of the research unit mentioned above, the preparatory work required for this embodiment also requires comprehensively determining the seepage condition limit based on the perforation situation of the production wells in the target reservoir, geological characteristics, fluid properties, and other static and dynamic conditions.

[0040] Specifically, the lower limit of the seepage condition includes both the lower limit of porosity and the lower limit of permeability. That is, only regions with porosity exceeding the lower limit of porosity and permeability exceeding the lower limit of permeability can potentially be considered pore volume control regions. Optionally, the lower limit of the seepage condition may also include the lower limit of effective thickness, etc.

[0041] To address the challenge of determining polymer flooding control ranges in high and ultra-high water-cut development stages of multi-layer sandstone oilfields due to incomplete data, such as the inability to calculate control pore volume using test data or production dynamics data, and the difficulty in performing polymer flooding control range calculations through numerical simulation, this invention provides a method and apparatus for determining polymer flooding control ranges in five-point well groups. This method enables rapid and convenient determination of the control pore volume of a five-point well group using minimal data, thereby rationally determining the polymer flooding control range. The method and apparatus provided in this embodiment are particularly suitable for real-time and rapid calculation of polymer flooding control ranges in single-well groups of five-point well networks used in high and ultra-high water-cut development stages of multi-layer sandstone oilfields to further enhance oil recovery.

[0042] Example 1

[0043] Embodiment 1 of the present invention provides a method for determining the control process of polymer flooding in well groups using the five-point method, the process of which is as follows: Figure 2 As shown, it includes the following steps:

[0044] Step S21: Taking one production well and one injection well in the five-point well group as a research unit, draw two rays with the production well and the injection well as vertices respectively. The angle between each ray and the line connecting the production well and the injection well is half of the preset angle. Use the two intersection points of the four rays and the production well and the injection well as vertices to determine a rhomboid range, which is the fluid flow range controlled by the production well in the research unit, and obtain the fluid flow range controlled by the production well in the well group.

[0045] Specifically, the aforementioned preset angle is the average acute angle of the approximate rhombus shape of the streamline field envelope of the research unit within the reservoir where the five-point well group is located, determined by the method described above.

[0046] In some embodiments, the well group boundary is determined based on the relationship between the injection wells and the production wells in the well group, and it is determined whether the two intersection points of the four rays are within the well group boundary. If so, a rhombus range can be determined directly using the two intersection points of the four rays, the production well, and the injection well as vertices; if not, if the production well is located at the edge of the well group, a rhombus range is determined using the midpoints between the production well and each of the other two adjacent wells, as well as the production well and the injection well as vertices; if the injection well is located at the edge of the well group, a rhombus range is determined using the midpoints between the injection well and each of the other two adjacent wells, as well as the production well and the injection well as vertices.

[0047] by Figure 1For example, if the research unit consists of production well 1 and injection well, and if the two intersection points of the four rays are not within the boundary of the well group, then the midpoint between production well 1 and production well 2, the midpoint between production well 1 and production well 3, and production well 1 and injection well are taken as the four vertices to determine the rhombus range.

[0048] The five-point well group consists of four study units. After the fluid flow range controlled by the production wells in the four study units is determined, for each production well in the well group (there may be only one), the sum of the fluid flow range controlled by the production well in each study unit is determined as the fluid flow range controlled by that production well in the well group.

[0049] Step S22: Based on the seepage condition limit and the fluid flow range controlled by the production well within the well group, determine the polymer displacement range controlled by the production well within the well group. Combined with the corresponding effective reservoir thickness and effective porosity, determine the polymer displacement pore volume controlled by the production well within the well group, and obtain the polymer displacement pore volume controlled by the well group.

[0050] Based on the physical property distribution characteristics of each flow unit, and according to the seepage condition limit and the fluid flow range controlled by the production well in the well group, the control area of ​​the production well in each flow unit is determined. Combined with the effective reservoir thickness and effective porosity of the production well in each flow unit, the polymer displacement pore volume controlled by the production well in each flow unit is determined by the volumetric method, thus obtaining the polymer displacement pore volume controlled by the production well in the well group.

[0051] Step S23: Determine the total pore volume of the oil layer corresponding to the well group based on the well group boundary, effective reservoir thickness, and effective porosity.

[0052] The well group boundary is determined based on the relationship between the injection wells and the production wells in the well group.

[0053] Step S24: The ratio of the polymer-displaced pore volume controlled by the well group to the total pore volume is determined as the degree of polymer flooding control of the well group.

[0054] The five-point well group polymer flooding control process determination method provided in Embodiment 1 of this invention treats one production well and one injection well within a five-point well group as a research unit, approximating its streamline field range as a rhombus. Based on pre-determined rhombus angles and seepage condition limits, only the location information of each well within the five-point well group and easily obtainable effective thickness and porosity distribution data of each flow unit are needed to quickly and conveniently determine the polymer flooding control process of the five-point well group. Furthermore, the rhomboid approximation of the streamline field range fully meets the accuracy requirements for polymer flooding control process analysis in reservoir engineering. This method solves the problem of lacking or incomplete pressure test data and production dynamics during the opening stage of multi-layer sandstone oilfields with high and ultra-high water cut, requiring the calculation of control pore volume to determine the polymer flooding control process; it also solves the problem of long simulation times and difficulty in quickly calculating polymer flooding control process in reservoir numerical simulation calculations of single-well control pore volume; and it addresses the issue that the control pore volume of a single well (the pore volume of a single well controlling the sand body type) determined by existing technologies is not necessarily the pore volume within the control fluid flow range of the single well.

[0055] Example 2

[0056] Embodiment 2 of the present invention provides a specific implementation flow of the five-point method for determining the polymer flooding control process of well groups, referring to... Figure 3 As shown, it includes the following steps:

[0057] Step S31: Establish a polymer drive control program calculation database.

[0058] Based on the study block's fine-grained layer database, sedimentary unit layer database, sedimentary unit reservoir database, oil bottom and water top database, and coordinate library, a database for polymer flooding control process calculations was formed. This database contains relevant information for polymer flooding control process calculations, such as well name, horizontal and vertical coordinates, sand body type, thickness level, effective reservoir thickness, and effective porosity for each sedimentary unit.

[0059] Step S32: Determine the boundary of the five-point well group.

[0060] Based on the relationship between injection wells and production wells, the boundaries of each five-point well group in the study block are determined.

[0061] Step S33: Calculate the total pore volume of each sedimentary unit in the five-point well group.

[0062] Within the boundary of the five-point method well group, for each sedimentary unit, the single-well area method (using the triangular mesh method to determine the single-well area) is adopted, and the pore volume of different types of sand bodies is calculated using the formula of single-well area × single-well thickness × porosity. Then, the total pore volume of each sedimentary unit in the five-point method well group is calculated.

[0063] Step S34: Determine the fluid flow range controlled by the production well in the five-point well group.

[0064] The specific determination process is described in Example 1.

[0065] Step S35: Calculate the single-well control pore volume of each production well in a five-point well group.

[0066] Within the fluid flow range, the seepage conditions of fluid flow in each sedimentary unit are first determined—the lower limits of effective thickness and permeability. Then, the pore volume of different flow units controlled by each production well is calculated using the single-well area method (a method that uses the triangular network method to determine the single-well area and then uses the volume method to calculate the pore volume). The pore volumes of the production wells in the five-point well group are then accumulated to obtain the single-well controlled pore volume of the production wells.

[0067] Step S36: Accumulate the total single-well control pore volume for each production well.

[0068] After calculating the single-well controlled pore volume of each production well in each five-point well group using the above method, the total single-well controlled pore volume of each production well is obtained by summing them up. Optionally, the well-controlled pore volume of each flow unit and the well-controlled pore volume of the entire study block can also be obtained by summing them up.

[0069] Step S37: Determine the degree of polymer flooding control in the five-point well group.

[0070] The ratio of the polymer-displaced pore volume controlled by the well group to the total pore volume is determined as the degree of polymer flooding control of the well group. Optionally, the degree of polymer flooding control of the well group in each flow unit can also be determined, and so on.

[0071] Using the method of this invention, the polymer flooding control degree of single wells in 10 well groups and 5 sedimentary units in a development block of an oilfield in eastern my country was calculated. An effective thickness of 0.2 meters and a permeability of 0.05 μm were used. 2 Using a maximum streamline angle of 65 degrees for both injection and production wells as a control condition, the degree of polymer flooding control was calculated, and the results (partial) are shown in Table 1. These results are more reliable than those calculated using the "engineering simplified algorithm (thickness flattening method)," providing a geological basis for the design of a polymer flooding enhancement scheme in this block.

[0072] Table 1. Calculation Results of Polymer Flooding Control Level for Two Well Groups in a Development Block of an Oilfield in Eastern China

[0073]

[0074] Based on the inventive concept of this invention, embodiments of this invention also provide a device for determining the degree of polymer flooding control in a five-point well group, the structure of which is as follows: Figure 4As shown, it includes:

[0075] The fluid flow range determination module 41 is used to take one production well and one injection well in the five-point well group as a research unit, draw two rays with the production well and the injection well as vertices respectively, and the angle between each ray and the line connecting the production well and the injection well is half of a preset angle. The two intersection points of the four rays and the production well and the injection well are used as vertices to determine a rhomboid range, which is the fluid flow range controlled by the production well in the research unit, and the fluid flow range controlled by the production well in the well group is obtained.

[0076] The polymer displacement pore volume determination module 42 is used to determine the polymer displacement range controlled by the production well in the well group based on the seepage condition limit and the fluid flow range controlled by the production well in the well group, and to determine the polymer displacement pore volume controlled by the production well in the well group in combination with the corresponding effective reservoir thickness and effective porosity, so as to obtain the polymer displacement pore volume controlled by the well group.

[0077] The module 43 for determining the total pore volume of the oil layer within the well group is used to determine the total pore volume of the oil layer corresponding to the well group based on the well group boundary, the effective reservoir thickness, and the effective porosity. The well group boundary is determined based on the relationship between the injection wells and the production wells in the well group.

[0078] The polymer flooding control degree determination module 44 is used to determine the ratio of the polymer flooding displacement pore volume controlled by the well group to the total pore volume as the polymer flooding control degree of the well group.

[0079] In some embodiments, the fluid flow range determination module 41, which defines a rhomboid range using the two intersections of the four rays and the production well and injection well as vertices, is also used for:

[0080] Determine whether the two intersection points of the four rays are within the well group boundary, which is determined based on the relationship between the injection wells and production wells in the well group. If yes, a rhombus-shaped range is determined using the two intersection points of the four rays, the production well, and the injection well as vertices. If no, if the production well is located at the edge of the well group, a rhombus-shaped range is determined using the midpoints between the production well and each of the other two adjacent wells, as well as the production well and the injection well as vertices. If the injection well is located at the edge of the well group, a rhombus-shaped range is determined using the midpoints between the injection well and each of the other two adjacent wells, as well as the production well and the injection well as vertices.

[0081] In some embodiments, the above-described apparatus further includes a streamline field angle determination module 45, configured to:

[0082] Based on the numerical simulation results of multiple five-point well groups within the reservoir where the five-point well group is located, the streamline field envelope of each research unit within the multiple five-point well groups is obtained. The envelope includes two symmetrical arc segments. For the streamline field envelope of each research unit, a rhombus is determined with the production well and injection well within the research unit as the two opposite vertices. The area difference between the rhombus and the envelope does not exceed a set area difference threshold. The average value of the acute angles of the obtained rhombus is determined as the preset angle.

[0083] In some embodiments, the fluid flow range determination module 41, which obtains the fluid flow range controlled by the produced well within the well group, is used for:

[0084] Identify all research units within the well group that contain the same production well; determine the sum of the fluid flow ranges controlled by the production well within each research unit as the fluid flow range controlled by the production well within the well group.

[0085] In some embodiments, the polymer displacement pore volume determination module 42, by combining the corresponding effective reservoir thickness and effective porosity to determine the polymer displacement pore volume controlled by the produced well within the well group, is used for:

[0086] By combining the effective reservoir thickness and effective porosity of the production well in each flow unit, the volumetric method is used to determine the polymer displacement pore volume controlled by the production well in each flow unit, thus obtaining the polymer displacement pore volume controlled by the production well in the well group.

[0087] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0088] Based on the inventive concept of the present invention, embodiments of the present invention also provide a computer storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-mentioned method for determining the degree of polymer flooding control in well groups using the five-point method.

[0089] Based on the inventive concept of the present invention, embodiments of the present invention also provide a server, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-mentioned method for determining the degree of polymer flooding control in well groups using the five-point method.

[0090] Unless otherwise specifically stated, terms such as processing, calculation, operation, determination, display, etc., may refer to the actions and / or processes of one or more processing or computing systems or similar devices that represent the manipulation and conversion of data representing physical (e.g., electronic) quantities within the registers or memory of the processing system into other data similarly representing physical quantities within the memory, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0091] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0092] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than those stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby clearly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0093] Those skilled in the art will also understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application; however, such implementation decisions should not be construed as departing from the scope of this disclosure.

[0094] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. Alternatively, the processor and storage medium can exist as discrete components in the user terminal.

[0095] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. This software code can be stored in memory units and executed by a processor. The memory units can be implemented within the processor or outside the processor; in the latter case, they are communicatively coupled to the processor via various means, as is well known in the art.

[0096] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A method for determining the degree of polymer flooding control in a well group using a five-point method, characterized in that, include: Taking one production well and one injection well in the five-point well group as a research unit, two rays are drawn with the production well and the injection well as vertices respectively. The angle between each ray and the line connecting the production well and the injection well is half of a preset angle. A rhomboid range is determined with the two intersection points of the four rays and the production well and the injection well as vertices. This range is taken as the fluid flow range controlled by the production well in the research unit, and the fluid flow range controlled by the production well in the well group is obtained. Based on the seepage condition limit and the fluid flow range controlled by the production well within the well group, the polymer displacement range controlled by the production well within the well group is determined. Combined with the corresponding effective reservoir thickness and effective porosity, the polymer displacement pore volume controlled by the production well within the well group is determined, thus obtaining the polymer displacement pore volume controlled by the well group. The total pore volume of the oil layer corresponding to the well group is determined based on the well group boundary, the effective reservoir thickness, and the effective porosity. The well group boundary is determined based on the relationship between the injection wells and the production wells in the well group. The ratio of the polymer-displaced pore volume controlled by the well group to the total pore volume is determined as the degree of polymer flooding control of the well group.

2. The method as described in claim 1, characterized in that, The method of defining a rhomboid range using the two intersection points of the four rays, the production well, and the injection well as vertices also includes: Determine whether the two intersection points of the four rays are within the boundary of the well group; If so, a rhombus-shaped area is defined by taking the two intersection points of the four rays and the production well and injection well as the vertices; If not, if the production well is located at the edge of the well group, a rhombus-shaped range is defined with the midpoint between the production well and each of the other two adjacent wells, as well as the production well and the injection well, as the vertices; if the injection well is located at the edge of the well group, a rhombus-shaped range is defined with the midpoint between the injection well and each of the other two adjacent wells, as well as the production well and the injection well, as the vertices.

3. The method as described in claim 1, characterized in that, The preset angle is determined in the following manner: Based on the numerical simulation results of multiple five-point well groups in the reservoir where the five-point well group is located, the streamline field envelope of each research unit in the multiple five-point well groups is obtained, and the envelope includes two symmetrical arc segments. For the streamline field envelope of each research unit, a rhombus is determined with the produced well and the injected well in the research unit as the two opposite vertices. The area difference between the rhombus and the envelope does not exceed the set area difference threshold. The average value of the obtained acute angles of the rhombus is determined as the preset angle.

4. The method as described in claim 1, characterized in that, The fluid flow range controlled by the production well within the well group includes: The study units within the well group are identified as containing the same production well. The sum of the fluid flow ranges controlled by the production wells within each research unit is determined as the fluid flow range controlled by the production wells within the well group.

5. The method as described in claim 1, characterized in that, The determination of the polymer displacement pore volume controlled by the production well within the well group, based on the corresponding effective reservoir thickness and effective porosity, includes: By combining the effective reservoir thickness and effective porosity of the production well in each flow unit, the volumetric method is used to determine the polymer displacement pore volume controlled by the production well in each flow unit, thus obtaining the polymer displacement pore volume controlled by the production well in the well group.

6. The method as described in claim 1, characterized in that, The lower limit of the seepage condition is determined comprehensively based on the perforation status, geological characteristics, and fluid properties of the produced wells in the reservoir where the five-point method well group is located.

7. The method according to any one of claims 1 to 6, characterized in that, The five-point well group comprises four research units; The five-point well group includes a central injection well and four surrounding production wells, or the five-point well group includes a central production well and four surrounding injection wells.

8. A device for determining the degree of polymer flooding control in a well group using a five-point method, characterized in that, include: The fluid flow range determination module is used to take one production well and one injection well in a five-point well group as a research unit. Two rays are drawn with the production well and the injection well as vertices respectively. The angle between each ray and the line connecting the production well and the injection well is half of a preset angle. A rhomboid range is determined with the two intersection points of the four rays and the production well and the injection well as vertices. This range is used as the fluid flow range controlled by the production well in the research unit, thus obtaining the fluid flow range controlled by the production well in the well group. The polymer displacement pore volume determination module is used to determine the polymer displacement range controlled by the production well within the well group based on the seepage condition limit and the fluid flow range controlled by the production well within the well group. Combined with the corresponding effective reservoir thickness and effective porosity, the module determines the polymer displacement pore volume controlled by the production well within the well group, thus obtaining the polymer displacement pore volume controlled by the well group. The module for determining the total pore volume of the oil layer within a well group is used to determine the total pore volume of the oil layer corresponding to the well group based on the well group boundary, the effective reservoir thickness, and the effective porosity. The well group boundary is determined based on the relationship between the injection wells and the production wells in the well group. The polymer flooding control degree determination module is used to determine the ratio of the polymer flooding displacement pore volume controlled by the well group to the total pore volume as the polymer flooding control degree of the well group.

9. A computer storage medium, characterized in that, The computer storage medium stores computer-executable instructions, which, when executed by a processor, implement the five-point well group polymer drive control program determination method as described in any one of claims 1 to 7.

10. A server, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the five-point well group polymer drive control program determination method according to any one of claims 1 to 7.

Images