Complex chemical flooding multi-field coupling strength quantitative characterization method and system and readable medium
By determining the characterization parameters and weight calculation of the chemical flooding composite field, the problem of unified quantification of the composite field intensity was solved, enabling precise optimization of oilfield development schemes and improving crude oil recovery and displacement efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA NAT OFFSHORE OIL CORP
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-28
AI Technical Summary
Existing technologies are insufficient to fully reflect the complex coupling effects of multi-physics fields and lack unified quantitative standards, making it difficult to accurately identify the dominant displacement region in composite field intensity, which affects the scientific nature of oilfield development decisions and the effectiveness of scheme optimization.
By determining the characterization parameters of the chemical flooding composite field, establishing the main control factor parameter matrix, and combining the weights to calculate the comprehensive factor, the oilfield composite field region is divided, thereby achieving unified quantification and dynamic response reflection of the coupling intensity of multiple fields.
Accurately identify strong/weak composite field regions in oil reservoirs, optimize chemical flooding parameters, improve crude oil displacement efficiency, expand the range of strong dominant areas, reduce the area of weak dominant areas, and guide targeted adjustments to well density and injection parameters.
Smart Images
Figure CN121936133A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method, system, and readable medium for quantitative characterization of multi-field coupling intensity in complex chemical flooding, belonging to the field of displacement technology in oil extraction. Background Technology
[0002] Complex chemical flooding is an enhanced oil recovery technology that significantly improves oil recovery by introducing a composite system of polymers, surfactants, alkalis, and other chemical agents into the injected water. This system synergistically alters the physicochemical properties of the displacement fluid and its interaction with the crude oil / rock mineral interface (e.g., reducing interfacial tension, improving mobility ratio, emulsifying crude oil). However, accurate characterization of the complex flow field still faces key challenges: existing technologies often rely on single parameters such as permeability and chemical agent concentration, making it difficult to comprehensively reflect the complex coupling effects of multiple physical fields (e.g., temperature affecting chemical agent degradation, water saturation affecting displacement efficiency); simultaneously, the lack of a unified quantitative standard for the intensity of the complex field makes it difficult to accurately identify advantageous displacement areas, hindering the scientific nature of development decisions; furthermore, the lack of a synergistic analysis mechanism between static geological parameters (e.g., porosity) and dynamic process parameters (e.g., temperature changes, water cut evolution) in characterization leads to significant deviations between predicted results and actual dynamic displacement responses, severely impacting the optimization effect and potential release of the scheme. Therefore, there is an urgent need to develop advanced complex field characterization methods that can integrate multi-field coupling, unify quantitative indicators, and reflect dynamic responses. Summary of the Invention
[0003] To address the aforementioned problems, the purpose of this invention is to provide a method, system, and readable medium for characterizing the strength of complex field couplings that integrates multiple field couplings, unifies quantitative indicators, and reflects dynamic responses for complex chemical flooding.
[0004] To achieve the above objectives, the present invention proposes the following technical solution: a method for quantitative characterization of the intensity of multi-field coupling in complex chemical flooding, comprising the above steps: determining the characterization parameters of the chemical flooding composite field intensity based on the distribution of the composite field in hydrothermal chemical flooding; determining the main controlling factor parameter matrix of the characterization parameters; obtaining a comprehensive factor at different locations in the reservoir based on the main controlling factor parameter matrix and the weights of the characterization parameters; quantitatively characterizing the intensity of the composite field based on the comprehensive factor, and dividing the composite field region of the oilfield according to the intensity of the composite field.
[0005] Furthermore, the factors influencing the distribution of the hydrothermal chemical flooding composite field include static factors and development dynamic factors. The static factors include permeability, porosity, sand body thickness, and underground crude oil viscosity; the dynamic factors include well network density, saturation, temperature, chemical agent concentration, and water cut.
[0006] Furthermore, the characterization parameters for the chemical flooding composite field strength include: permeability, chemical agent injection concentration, injection temperature, and water saturation.
[0007] Furthermore, the method for obtaining the comprehensive factors at different locations in the reservoir is as follows: standardizing the characterization parameters in the main control factor parameter matrix; calculating the weight of each characterization parameter; and obtaining the comprehensive factors at different locations in the reservoir through the standardized characterization parameters and their weights.
[0008] Furthermore, the standardized formula for the concentration of the injected chemical agent is as follows:
[0009] The standardized formula for the penetration rate is:
[0010] The standardized formula for the injection temperature is:
[0011] The standardized formula for the water saturation is:
[0012] in, C p ’ To standardize the concentration of chemical reagents injected, C p To inject the chemical agent into a certain concentration, C pmax This represents the maximum injection concentration of the chemical agent. K ’ To standardize penetration rate, K max For maximum penetration, T ’ To standardize the injection temperature, T For the injection temperature, T max For maximum injection temperature, S w ’、S w These are the standardized water saturation and the water saturation, respectively.
[0013] Furthermore, the weight of each representation parameter is calculated using the analytic hierarchy process (AHP).
[0014] Furthermore, the formula for calculating the comprehensive factor at different locations in the reservoir is as follows:
[0015] in, F s For composite field intensity factor, a , b , c ,d All are regression coefficients.
[0016] Furthermore, the method for dividing the composite field region of the oilfield according to the intensity of the composite field is as follows: the composite field region is divided into a strong dominant region, a dominant region, and a weak region; the intensity range of the strong dominant region is 0.75-0.9; the intensity range of the dominant region is 0.65-0.75; and the intensity range of the weak region is 0.5-0.65.
[0017] This invention also discloses a quantitative characterization system for the intensity of multi-field coupling in complex chemical flooding, comprising: a characterization parameter determination module for determining characterization parameters of the intensity of the chemical flooding composite field based on the distribution of the composite field in hydrothermal chemical flooding; a main control factor parameter matrix determination module for determining the main control factor parameter matrix of the characterization parameters; a comprehensive factor calculation module for obtaining comprehensive factors at different locations in the reservoir based on the main control factor parameter matrix and the weights of the characterization parameters; and a composite field region division module for quantitatively characterizing the intensity of the composite field based on the comprehensive factors and dividing the composite field region of the oilfield based on the intensity of the composite field.
[0018] The present invention also discloses a computer-readable storage medium storing a computer program, which is executed by a processor to implement the method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in any of the preceding claims.
[0019] The technical solution of this invention has at least the following technical effects or advantages: The solution can integrate multi-field coupling, unified quantitative indicators, and reflect the composite field coupling strength of dynamic response, for optimizing reservoir design. The solution in this invention can accurately identify strong / weak composite field regions in the reservoir, guiding the optimization of complex chemical flooding parameters; when the chemical agent concentration increases from 1000 mg / L to 2000 mg / L at 80℃, the strong dominant zone expands from 50m to 100m, and the dominant zone expands from 100m to 150m; by optimizing the injected chemical agent concentration and injection temperature, the area of the weak zone is reduced by more than 20%; the composite field region can be partitioned based on comprehensive factors, allowing for targeted adjustment of well density or injection parameters. Attached Figure Description
[0020] Figure 1 This is a flowchart of a method for quantitative characterization of multi-field coupling intensity in complex chemical flooding according to an embodiment of the present invention; Figure 2 This is a comparison diagram of the composite field intensity distribution when the chemical agent concentration is 0.001 in one embodiment of the present invention; Figure 3 This is a comparison diagram of the composite field intensity distribution when the chemical agent concentration is 0.002 in one embodiment of the present invention. Detailed Implementation
[0021] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention is described in detail through specific embodiments. However, it should be understood that the specific embodiments are provided only for a better understanding of the present invention and should not be construed as limiting the present invention. In the description of the present invention, it should be understood that the terminology used is for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0022] To address the shortcomings of existing technologies, such as the inability to fully reflect the complex coupling effects of multiple physical fields, the lack of a collaborative analysis mechanism between static geological parameters and dynamic process parameters in characterization, leading to significant deviations between predicted results and actual dynamic responses of chemical flooding, and severely impacting the optimization of schemes and the release of potential, this invention proposes a quantitative characterization method, system, and readable medium for the multi-field coupling intensity of complex chemical flooding. The method includes the following steps: determining the characterization parameters of the chemical flooding composite field intensity based on the distribution of the hydrothermal chemical flooding composite field; determining the main controlling factor parameter matrix of the characterization parameters; obtaining comprehensive factors at different locations in the reservoir based on the main controlling factor parameter matrix and the weights of the characterization parameters; quantitatively characterizing the intensity of the composite field based on the comprehensive factors; and dividing the oilfield into composite field regions based on the intensity of the composite field. This method can integrate multi-field coupling, unify quantitative indicators, and reflect the composite field coupling intensity of dynamic responses.
[0023] Example 1 This embodiment discloses a method for quantitatively characterizing the multi-field coupling intensity of complex chemical flooding, such as... Figure 1 As shown, the steps above are included: S1 determines the characterization parameters of the chemical flooding composite field intensity based on the distribution of the hot water chemical flooding composite field.
[0024] Factors influencing the distribution of the composite field in hydrothermal chemical flooding include static and dynamic factors. Static factors include permeability, porosity, sand body thickness, and underground crude oil viscosity; dynamic factors include well density, saturation, temperature, chemical agent concentration, and water cut. However, permeability, saturation, and oil displacement efficiency can only characterize the differences in composite field intensity from one perspective and cannot comprehensively describe the composite field. Since the distribution characteristics of the composite field are related not only to reservoir static parameters but also to development dynamic parameters, it is necessary to optimize the relevant parameters reflecting the distribution characteristics of the composite field and to comprehensively characterize it.
[0025] The characterization parameters for the combined field strength of chemical flooding include four parameters: permeability, chemical agent injection concentration, injection temperature, and water saturation.
[0026] Permeability is an important parameter characterizing reservoir properties. It refers to the ability of porous media to allow fluid to pass through, reflecting the physical properties of porous media. Its magnitude can indirectly reflect the seepage characteristics of the reservoir. Therefore, permeability is used as one of the main parameters for characterizing the composite flow field.
[0027] The concentration of injected chemical agents directly affects the concentration distribution of chemical agents in the formation, and can directly determine the intensity distribution characteristics of the composite field. Therefore, the injection concentration of chemical agents is selected as one of the important parameters for characterizing the composite field.
[0028] The injection temperature directly and decisively affects the temperature field distribution; the higher the injection temperature, the better the overall heat injection effect. Meanwhile, because the concentration of chemical agents is sensitive to temperature, at higher temperatures, the chemical agents are affected by thermal degradation, resulting in poor transport within the reservoir and producing a negative effect. Temperature can directly and significantly influence the distribution of the composite field; therefore, injection temperature is chosen as one of the important parameters for characterizing the composite field.
[0029] Water saturation can reflect the differences in oil displacement efficiency and potential, as well as the degree of displacement within the reservoir area. It can also indirectly determine the distribution characteristics of the composite field intensity. Therefore, water saturation is selected as one of the main parameters for characterizing the composite field.
[0030] S2 determines the main control factor parameter matrix for characterizing the parameters.
[0031] The main control factor parameter matrix is as follows:
[0032] in, It's penetration rate. It refers to the concentration of the injected chemical agent. It is the injection temperature. It is the water saturation level. i It is the grid number. It is a parameter matrix.
[0033] S3 obtains comprehensive factors for different locations in the reservoir based on the main control factor parameter matrix and the weights of the characterization parameters.
[0034] The method for obtaining comprehensive factors at different locations in an oil reservoir is as follows: S3.1 Standardizes the representative parameters in the main control factor parameter matrix.
[0035] To facilitate the calculation of characterization parameters with different dimensions, membership functions are used to characterize fuzzy sets, and each characterization parameter is standardized separately. Since the concentration of the injected chemical agent varies widely, a logarithmic membership function is chosen for standardization.
[0036] The standardized formula for the concentration of chemical agents injected is as follows:
[0037] The standardized formula for penetration rate is:
[0038] The temperature distribution varies between the injection temperature and the initial reservoir temperature. The standardized formula for the injection temperature is:
[0039] The water saturation ranges from 17% to 80%, and the standardized formula for water saturation is as follows:
[0040] in, C p ’ To standardize the concentration of chemical reagents injected, C p To inject the chemical agent into a certain concentration, C pmax This represents the maximum injection concentration of the chemical agent. K ’ To standardize penetration rate, K max For maximum penetration, T ’ To standardize the injection temperature, T For the injection temperature, T max For maximum injection temperature, S w ’、S w These are the standardized water saturation and the water saturation, respectively.
[0041] After standardization, the characterization parameters are formed as dimensionless data within [0, 1]. Four membership degrees are calculated: permeability, chemical injection concentration, injection temperature, and water saturation. The membership degree matrix is as follows:
[0042] S3.2 Calculate the weight of each characterization parameter.
[0043] The weight of each representation parameter is calculated using the Analytic Hierarchy Process (AHP). The AHP method is a decision-making approach that decomposes elements relevant to decision-making into levels such as objectives, criteria, and solutions, and then conducts qualitative and quantitative analysis based on this. The basic principle of this method is to decompose the problem into different components based on its nature and the overall objective, and then group these components at different levels according to their interrelationships and membership relationships, forming a multi-level analytical structure model. Ultimately, this reduces the problem to determining the relative importance or ranking of the bottom-level components (solutions, measures, etc. for decision-making) relative to the top-level component (the overall objective).
[0044] The weights of permeability, chemical injection concentration, injection temperature, and water saturation obtained through the analytic hierarchy process are shown in Table 1. Based on this, the weight vectors of the above four factors can be calculated. B for: B = (0.0867, 0.473, 0.2978, 0.1425) T .
[0045] Table 1 Weighting of Composite Field Characterization Parameters
[0046] S3.3 Obtains comprehensive factors for different locations in the reservoir by using standardized characterization parameters and their weights.
[0047] The formula for calculating the comprehensive factor at different locations in the reservoir is as follows:
[0048] in, F s For composite field intensity factor, a , b , c , d All are regression coefficients.
[0049] Substituting the weights of permeability, chemical concentration, injection temperature, and water saturation into the above formula, we can obtain: .
[0050] S4 quantitatively characterizes the intensity of the composite field based on comprehensive factors, and divides the composite field region of the oilfield according to the intensity of the composite field.
[0051] Based on the one-injection-four-production mechanism model, the composite field intensity was studied using a composite field intensity characterization method. Based on the aforementioned comprehensive composite field intensity identification index, the composite field intensity at different reservoir locations was calculated, such as... Figure 2 , Figure 3As shown, the standard values of the influencing parameters were first determined: the concentration of the injected chemical agent was set to 0.001 and 0.002, and the injection temperature was set to 80℃. The distribution of the composite field was then analyzed after 1000 days of production.
[0052] Depend on Figure 2 As can be seen, when the injection temperature is 80℃ and the concentration of the injected chemical agent is 0.001, the dominant area of the composite field strength is distributed around the injection well. As the injection range expands, the strength gradually decreases, and the area with a composite field strength greater than 0.65 is mainly concentrated within 100m of the well. Figure 2 The intensity distribution of the composite field can divide the composite field region into a strong dominant region, a dominant region, and a weak region. The intensity range of the strong dominant region is 0.75-0.9, the intensity range of the dominant region is 0.65-0.75, and the intensity range of the weak region is 0.5-0.65.
[0053] Depend on Figure 3 It can be observed that when the injected chemical concentration is increased to 0.002, the overall intensity distribution of the composite field is significantly improved compared to when the injected concentration is 0.001. The area of the strong dominant region expands significantly, increasing from a range of 50m near the wellbore to a range of 100m. The range of the dominant region increases from a range of 100m near the wellbore to a range of 150m. Comparison shows that at an injection temperature of 80℃, increasing the concentration of the injected chemical agent can effectively increase the overall distribution range of the thermochemical composite field intensity, reduce the area of the weak region, and thus improve the crude oil displacement efficiency during hydrothermal chemical flooding. Based on the above research, in actual development, different targeted measures can be adopted to optimize and adjust the composite field for different types of composite fields.
[0054] Example 2 Based on the same inventive concept, this embodiment discloses a quantitative characterization system for the intensity of multi-field coupling in complex chemical flooding, comprising: The characterization parameter determination module is used to determine the characterization parameters of the chemical flooding composite field intensity based on the distribution of the hot water chemical flooding composite field.
[0055] The main control factor parameter matrix determination module is used to determine the main control factor parameter matrix that characterizes the parameters.
[0056] The comprehensive factor calculation module is used to obtain the comprehensive factor at different locations in the reservoir based on the main control factor parameter matrix and the weights of the characterization parameters.
[0057] The composite field region division module is used to quantitatively characterize the intensity of the composite field based on comprehensive factors, and to divide the composite field region of the oilfield according to the intensity of the composite field.
[0058] Example 3 Based on the same inventive concept, this embodiment discloses a computer-readable storage medium storing a computer program, which is executed by a processor to implement the complex chemical flooding multi-field coupling intensity quantitative characterization method described above.
[0059] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0060] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0061] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0062] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific embodiments of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention. The above content is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.
Claims
1. A method for quantitatively characterizing the intensity of multi-field coupling in complex chemical flooding, characterized in that, Including the above steps: Based on the distribution of the chemical flooding composite field, the characterization parameters of the chemical flooding composite field intensity are determined; Determine the main controlling factor parameter matrix of the characterization parameters; Based on the main control factor parameter matrix, combined with the weights of the characterization parameters, a comprehensive factor for different locations in the reservoir is obtained; The intensity of the composite field is quantitatively characterized based on comprehensive factors, and the composite field regions of the oilfield are divided according to the intensity of the composite field.
2. The method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in claim 1, characterized in that, Factors influencing the distribution of the hydrothermal chemical flooding composite field include static factors and development dynamic factors. The static factors include permeability, porosity, sand body thickness, and underground crude oil viscosity; the dynamic factors include well density, saturation, temperature, chemical agent concentration, and water cut.
3. The method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in claim 2, characterized in that, The characterization parameters of the chemical flooding composite field strength include: permeability, chemical agent injection concentration, injection temperature, and water saturation.
4. The method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in claim 3, characterized in that, The method for obtaining the comprehensive factors at different locations in the reservoir is as follows: The representative parameters in the main control factor parameter matrix are standardized. Calculate the weight of each representation parameter; The comprehensive factors at different locations in the reservoir are obtained by using standardized characterization parameters and their weights.
5. The method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in claim 4, characterized in that, The standardized formula for the concentration of the injected chemical agent is as follows: The standardized formula for the penetration rate is: The standardized formula for the injection temperature is: The standardized formula for the water saturation is: in, C p ’ To standardize the concentration of chemical reagents injected, C p To inject the chemical agent into a certain concentration, C pmax This represents the maximum injection concentration of the chemical agent. K ’ To standardize penetration rate, K max For maximum penetration, T ’ To standardize the injection temperature, T For the injection temperature, T max For maximum injection temperature, S w ’、S w These are the standardized water saturation and the water saturation, respectively.
6. The method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in claim 4, characterized in that, The weight of each representation parameter is calculated using the analytic hierarchy process (AHP).
7. The method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in any one of claims 1-6, characterized in that, The formula for calculating the comprehensive factor at different locations in the reservoir is as follows: in, F s For composite field intensity factor, a , b , c , d All are regression coefficients.
8. The method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in any one of claims 1-6, characterized in that, The method for dividing the composite field region of an oilfield based on the intensity of the composite field is as follows: The composite field area is divided into a strong dominant area, a dominant area, and a weak area; the intensity range of the strong dominant area is 0.75-0.9; the intensity range of the dominant area is 0.65-0.75; and the intensity range of the weak area is 0.5-0.
65.
9. A quantitative characterization system for the intensity of multi-field coupling in complex chemical flooding, characterized in that, include: The characterization parameter determination module is used to determine the characterization parameters of the chemical flooding composite field intensity based on the distribution of the hot water chemical flooding composite field. The main control factor parameter matrix determination module is used to determine the main control factor parameter matrix of the characterization parameter; The comprehensive factor calculation module is used to obtain the comprehensive factor at different locations in the reservoir based on the main control factor parameter matrix and the weights of the characterization parameters. The composite field region division module is used to quantitatively characterize the intensity of the composite field based on comprehensive factors, and to divide the composite field region of the oilfield according to the intensity of the composite field.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that is executed by a processor to implement the method for quantitative characterization of multi-field coupling intensity in complex chemical flooding as described in any one of claims 1-8.