Inter-well Seepage Channel Characterization Method, Device and Storage Medium Based on Chemical Flooding

Abstract

An embodiment of this specification provides a method, device, and storage medium for characterizing inter-well seepage channels based on chemical flooding, which are applied to the technical field of reservoir development. The method includes: obtaining geological parameters of a target reservoir; determining an equivalent resistance coefficient corresponding to a chemical agent; calculating equivalent fracture seepage parameters and matrix seepage parameters in the target reservoir based on the geological parameters and the equivalent resistance coefficient; the equivalent fracture is formed by connecting horizontal fractures and the matrix in the target reservoir in series; the equivalent fractures in the target reservoir constitute the inter-well seepage channel; obtaining a water cut change curve during the chemical flooding process according to the equivalent fracture seepage parameters and the matrix seepage parameters; and inverting the inter-well seepage channel through the water cut change curve during the chemical flooding process. The above method realizes the calculation of the corresponding parameters of the inter-well seepage channel, effectively realizes the quantitative characterization of the inter-well seepage channel, and further can guide the actual reservoir development, which is beneficial to the effective progress of production and development.

Description

Technical Field

[0001] The embodiments of this specification relate to the technical field of reservoir development, and particularly to a method, device, and storage medium for characterizing inter-well seepage channels based on chemical flooding. Background Art

[0002] Inter-well displacement is an effective way to develop reservoirs. By injecting displacement fluid between injection and production wells, the reservoir between the injection and production wells can be discharged through the inter-well seepage channel under the displacement effect of the displacement fluid, thus effectively completing reservoir recovery.

[0003] Currently, when developing reservoirs, especially fractured-vuggy carbonate reservoirs, due to the development of dominant channels within the reservoir, serious water channeling occurs, inefficient or ineffective circulation of injected water, low utilization rate of injected water. When using the method of combining profile control and water shutoff for construction, the expected effect is often not achieved. The fundamental reason lies in the insufficient understanding of inter-well seepage channels. And during the process of injecting chemical agents to achieve chemical flooding, it is more difficult to determine the characteristics of inter-well seepage channels. Given that studying inter-well seepage channels plays a great role in enhancing oil recovery in reservoir chemical flooding, the inability to effectively characterize inter-well seepage channels in reservoirs will inevitably affect the normal progress of production and development. Therefore, there is an urgent need for a method to effectively quantify and characterize the seepage channels during inter-well chemical flooding. Summary of the Invention

[0004] The purpose of the embodiments of this specification is to provide a method, device, and storage medium for characterizing inter-well seepage channels based on chemical flooding, so as to solve the problem of how to effectively quantify and characterize the seepage channels during inter-well chemical flooding.

[0005] To solve the above technical problems, the embodiments of this specification propose a method for characterizing inter-well seepage channels based on chemical flooding, including: obtaining geological parameters of the target reservoir; determining the equivalent resistance coefficient corresponding to the chemical agent; calculating the equivalent fracture seepage parameters and matrix seepage parameters in the target reservoir based on the geological parameters and the equivalent resistance coefficient; the equivalent fracture is formed by connecting horizontal fractures and the matrix in the target reservoir in series; the equivalent fractures in the target reservoir constitute the inter-well seepage channel; obtaining the water cut change curve during the chemical flooding process according to the equivalent fracture seepage parameters and matrix seepage parameters; and inversely analyzing the inter-well seepage channel through the water cut change curve during the chemical flooding process.

[0006] An embodiment of this specification also provides an inter-well seepage channel characterization device based on chemical flooding, including: a geological parameter acquisition module for acquiring geological parameters of a target oil reservoir; an equivalent resistance coefficient determination module for determining an equivalent resistance coefficient corresponding to a chemical agent; a parameter calculation module for calculating equivalent fracture seepage parameters and matrix seepage parameters in the target oil reservoir based on the geological parameters and the equivalent resistance coefficient; the equivalent fracture is formed by connecting horizontal fractures and the matrix in series in the target oil reservoir; the equivalent fractures in the target oil reservoir constitute the inter-well seepage channel; a water cut change curve acquisition module for obtaining a water cut change curve during the chemical flooding process according to the equivalent fracture seepage parameters and the matrix seepage parameters; an inter-well seepage channel inversion module for inverting the inter-well seepage channel through the water cut change curve during the chemical flooding process.

[0007] An embodiment of this specification also provides a computer storage medium, on which a computer program / instructions are stored, and when the computer program / instructions are executed, the above-mentioned method for characterizing an inter-well seepage channel based on chemical flooding is implemented.

[0008] As can be seen from the technical solutions provided by the embodiments of this specification above, in view of the characteristics of the target oil reservoir, the embodiments of this specification divide it into equivalent fractures formed by connecting horizontal fractures and the matrix in series and the matrix other than the equivalent fractures, and then combine the characteristics of chemical flooding to calculate the equivalent resistance coefficient corresponding to the chemical agent, and on this basis, combine the geological parameters of the target oil reservoir to calculate the equivalent fracture seepage parameters and the matrix seepage parameters of the target oil reservoir respectively, so as to characterize the seepage characteristics of different regions in the target oil reservoir. Then, according to the calculated equivalent fracture seepage parameters and matrix seepage parameters, and combined with the characteristics of the chemical flooding process, determine the water cut change curve corresponding to the chemical flooding process, and further invert the inter-well seepage channel based on the water cut change curve during the chemical flooding process. Through the above implementation methods, the calculation of the corresponding parameters of the inter-well seepage channel is realized, the quantitative characterization of the inter-well seepage channel is effectively realized, and then the actual oil reservoir development can be guided, which is beneficial to the effective progress of production and development. Description of the Drawings

[0009] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0010] Figure 1 It is a flowchart of a method for characterizing an inter-well seepage channel based on chemical flooding according to an embodiment of this specification;

[0011] Figure 2ASchematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0012] Figure 2B Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0013] Figure 2C Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0014] Figure 2D Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0015] Figure 2E Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0016] Figure 2F Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0017] Figure 2G Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0018] Figure 2H Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0019] Figure 2I Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0020] Figure 2J Schematic diagram of a moisture content transformation curve according to an embodiment of this specification;

[0021] Figure 3 Module diagram of an inter-well seepage channel characterization device based on chemical flooding according to an embodiment of this specification. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of this specification will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this specification without creative efforts shall fall within the protection scope of this specification.

[0023] To solve the above technical problems, an inter-well seepage channel characterization method based on chemical flooding is proposed in an embodiment of this specification. The execution subject of the inter-well seepage channel characterization method based on chemical flooding may be an inter-well seepage channel characterization device based on chemical flooding, and the inter-well seepage channel characterization device based on chemical flooding includes but is not limited to a server, an industrial control computer, a PC, etc. As Figure 1As shown, the method for characterizing the inter-well seepage channel based on chemical flooding may include the following specific implementation steps.

[0024] S110: Obtain the geological parameters of the target reservoir.

[0025] The target reservoir is the reservoir targeted for the characterization of the inter-well seepage channel this time, that is, it can correspond to the work area developed this time. There are inter-well seepage channels in the formation of the target reservoir, which serve as the channels for the displacement fluid and the oil fluid to flow during the displacement process. The inter-well seepage channel can be a network or multi-layer structure formed by different fractures.

[0026] In some embodiments, the target reservoir is a fractured-vuggy carbonate reservoir. Since the dominant channels in the fractured-vuggy carbonate reservoir are well-developed, water channeling is severe, the injected water has inefficient or ineffective circulation, and the utilization rate of the injected water is relatively low, which is more in line with the application environment of this application.

[0027] The geological parameters can be the relevant parameters collected or detected for the formation of the target reservoir, and then the subsequent calculations for specific parameter values can be realized. Specifically, in the embodiments of this specification, the geological parameters may include matrix permeability, horizontal fracture length ratio, equivalent fracture aperture, effective reservoir thickness, fracture dip angle, number of horizontal fracture layers, fracture-cavity volume coefficient, total area of seepage interface, width ratio of fractures in the seepage cross-section, etc. In practical applications, other parameters can be set as geological parameters according to requirements, which are not limited to the above examples, and are not restricted in this regard.

[0028] In some embodiments, the target reservoir satisfies the following conditions: there is an equivalent fracture formed by the series connection of horizontal fractures and the matrix between wells, and the widths of the horizontal fractures and the matrix connected in series in the equivalent fracture are equal, and the area outside the equivalent fracture is pure matrix, and / or, the water flooding process is equivalent to piston displacement, and / or, the apertures of different equivalent fractures are different, and the apertures of all equivalent fractures follow a lognormal distribution.

[0029] In addition, for the convenience of calculation, the following assumed conditions can also be supplemented: in the seepage cross-section, the width ratio of the equivalent fracture is P, and the width ratio of the matrix is 1 - P, and / or, along the seepage direction, the length ratio of the horizontal fracture is R.

[0030] S120: Determine the equivalent resistance coefficient corresponding to the chemical agent.

[0031] Since the chemical flooding process involves the flow of chemical agents in the inter-well channeling channel, therefore, in the chemical flooding process of the target work area, the influence of the chemical agent system on the inter-well channeling channel can be characterized by the equivalent resistance coefficient and the equivalent residual resistance coefficient.

[0032] Specifically, a formula can be constructed as In the formula, R fis the equivalent resistance coefficient; T1 is the resistance multiple, obtained by fitting; t1 is the time when the chemical agent is injected; T2 is the average response time; σ R is the standard deviation of the resistance, which affects the shape of the resistance increase and decrease.

[0033] Based on the equivalent resistance coefficient, the influence of the chemical agent in the displacement process can be effectively combined to perform subsequent water cut calculations.

[0034] S130: Calculate the equivalent fracture seepage parameters and matrix seepage parameters in the target reservoir based on the geological parameters and the equivalent resistance coefficient; the equivalent fracture is formed by connecting horizontal fractures and the matrix in series in the target reservoir; the equivalent fractures in the target reservoir constitute the inter-well seepage channel.

[0035] The equivalent fracture can be a fracture formed by connecting horizontal fractures and the matrix in series. In practical applications, not all fractures may be directly connected to the injection and production wells. During the displacement process, the displacement fluid can flow based on the horizontal fractures and the corresponding matrix, which can also ensure the effective progress of the displacement process. The equivalent fracture is the fracture formed by connecting horizontal fractures and the matrix in series. The inter-well seepage channel is constituted by the equivalent fractures, and the flow of the displacement fluid between wells is realized through the network or layered structure formed by different equivalent fractures.

[0036] The equivalent fracture seepage parameters and matrix seepage parameters are respectively used to characterize the flow characteristics of the liquid in the equivalent fracture and the matrix, so as to better characterize the flow characteristics of the oil and the displacement fluid during the displacement process. In some embodiments, the equivalent fracture seepage parameters include the equivalent fracture water production and the equivalent fracture oil production; the matrix seepage parameters include the matrix water production and the matrix oil production.

[0037] The equivalent fracture water production is used to represent the content of the water produced based on the equivalent fracture, and the equivalent fracture liquid production includes the total amount of the produced water and oil. Correspondingly, the matrix water production is used to represent the content of the water produced based on the matrix, and the equivalent fracture liquid production includes the total amount of the produced water and oil.

[0038] In some embodiments, the process of calculating the equivalent fracture seepage parameters and matrix seepage parameters can be to first calculate the equivalent fracture permeability based on the geological parameters, then calculate the equivalent fracture seepage velocity using the equivalent fracture permeability, and calculate the matrix seepage velocity using the matrix permeability. Then, in combination with the equivalent resistance coefficient, determine the equivalent fracture water production and the equivalent fracture liquid production according to the equivalent fracture seepage velocity, and determine the matrix water production and the matrix liquid production according to the matrix seepage velocity.

[0039] In general, for a single horizontal fracture without a matrix, the permeability of the fracture considering roughness and tortuosity can be expressed as where K f1 is the permeability of a single horizontal fracture, μm2 ; b is the aperture of a single horizontal crack, in μm 2 ; c1 is the influence coefficient of roughness and tortuosity on crack permeability, taking 0.75.

[0040] Combining the above formulas, for the equivalent crack formed by the series connection of horizontal cracks and matrix, according to the principle of equal pressure drop, the relationship corresponding to the permeability of the equivalent crack can be derived as Converted into the formula In the formula, K f is the permeability of a single equivalent crack, in μm 2 ; b is the aperture of a single equivalent crack, in μm 2 ; R is the proportion of the length of the horizontal crack along the seepage direction, taking 0.9 according to the crack model in the work area; K m is the matrix permeability, in μm 2 ; h is the effective thickness of the reservoir, in cm. After trial calculation, the difference between K f and K f1 is mainly affected by R, and the multiple within 100 μm is approximately R.

[0041] Therefore, combining the above formula for the permeability of a single horizontal crack, the permeability of the equivalent crack can be expressed as In the formula, c is the influence coefficient of roughness and tortuosity on crack permeability, c = c1R, taking 0.75×0.9 = 0.675 in this work area.

[0042] Subsequently, combining Darcy's law and the cubic law, the seepage motion equation in the crack is derived, and we can obtain In the formula, v f is the inter-well injection water channeling velocity, in cm / s; K f is the permeability of a single equivalent crack, in μm 2 ; μ is the viscosity of the injection water, in mPa.s; △p is the injection-production pressure difference, in bar; L is the injection-production well spacing, in cm; ρ is the density of the mixed fluid, in kg / m 3 ; g is the acceleration due to gravity, in N / kg; α is the crack dip angle.

[0043] Correspondingly, the seepage motion equation in the matrix can be In the formula, v m is the inter-well injection water seepage velocity, in cm / s.

[0044] In addition, there is a relational expression for the injection-production pressure difference The injection-production pressure difference can be substituted for specific solution.

[0045] After obtaining the seepage parameters in the equivalent crack and matrix respectively, the water production, liquid production of the crack and the water production, liquid production of the matrix can be calculated.

[0046] Using the formula the equivalent fracture water production can be calculated. In the formula, Q fw is the equivalent fracture water production, cm 3 / s; n is the number of horizontal fracture layers, which can be determined according to the fracture line density and thickness h; m is the fracture-vug volume coefficient, representing the volume increase multiple brought by the distributed holes in the inter-well fractures; W is the total width of the seepage cross-section, P is the proportion of the width occupied by fractures in the seepage cross-section, b max is the maximum aperture of the fracture occupied by the injected water, b(t) is the aperture of the fracture occupied by the injected water at time t, and f(b) is the probability density function of the average total aperture b of the fracture, which follows a log-normal distribution with a cumulative probability of 1 within (0, b max .

[0047] Using the formula the equivalent fracture liquid production can be calculated. In the formula, Q f is the equivalent fracture liquid production, cm 3 / s.

[0048] Using the formula calculate the matrix water production. In the formula, Q mw is the matrix water production, cm 3 / s, h is the reservoir thickness, cm; φ is the reservoir porosity, f w0 is the initial water saturation of the reservoir.

[0049] Using the formula calculate the matrix liquid production. In the formula, Q m is the matrix liquid production, cm 3 / s.

[0050] In the above formulas, and can be obtained respectively according to Darcy's law and the cubic law. In the formula, t is the water injection time, t = 0 is the start time of water injection; t1 is the time when the water cut of the production well starts to rise.

[0051] The apertures of horizontal fractures all follow a log-normal distribution. In an actual reservoir, the fracture aperture has a minimum value of 0 and a maximum value of b max , that is, the cumulative probability within (0, b max is 1. Therefore, the probability density function of the binary tree fracture aperture is obtained by improving the log-normal distribution density function, which can be specifically expressed as is the logarithmic mean of the fracture, σ is the logarithmic standard deviation of the fracture aperture, σ ∈ (0, +∞).

[0052] S140: Obtain the water cut change curve during the chemical flooding process according to the equivalent fracture seepage parameters and matrix seepage parameters.

[0053] Based on the chemical flooding process, the corresponding water cut change curve of the chemical flooding process can be determined. In some embodiments, the water cut calculation model can be first transformed into a chemical flooding water cut calculation model based on the chemical flooding process to adapt to the actual production and development scenario.

[0054] After calculating the equivalent fracture seepage parameters and matrix seepage parameters, the water cut calculation model can be determined. The water cut calculation model is used to determine the water cut in the target reservoir by comprehensively considering the water production and liquid production in the equivalent fracture and matrix.

[0055] The water cut calculation model can be characterized as That is, the ratio of the sum of water production to the sum of liquid production.

[0056] Specifically, let The above formula can be characterized as

[0057] Combining the chemical flooding process to further simplify the above formula. First, let Then

[0058] Since Then Equation 1 can be written in the form of an expression containing the complementary error function

[0059] In the further transformation process, let y = lnb, then correspondingly, we can get e y = b, so

[0060] Let Then Equation 3 can be changed to

[0061] Also, since y = lnb, then

[0062] Let Then the above Equations 5, 6, and 7 can be further transformed into

[0063] Based on the definition formula of the complementary error function, we can further obtain

[0064] Combining the above Equations 2, 4, 11, 12, and 13 and substituting them into the aforementioned water cut expression, the analytical solution of the theoretical water cut in the chemical flooding process can be formed as In the formula,

[0065]

[0066]

[0067]

[0068] After obtaining the above chemical flooding water cut calculation model, the production parameters corresponding to the target reservoir can be substituted into the chemical flooding water cut calculation model to obtain the water cut values at different times in the target reservoir, and then based on the water cut values, a water cut transformation curve during the chemical flooding process is fitted. That is, the water cut change situation in the target reservoir is characterized by the water cut transformation curve.

[0069] As Figures 2A through 2J shown, it is a schematic diagram of water cut fitting in different water flooding stages. Among them, Figure 2A is the water cut fitting result in the direction from Well A to Well B; Figure 2B is the water cut fitting result in the direction from Well A to Well C; Figure 2C is the water cut fitting result in the direction from Well D to Well E; Figure 2D is the water cut fitting result in the direction from Well D to Well C; Figure 2E is the water cut fitting result in the direction from Well A to Well F; Figure 2F is the water cut fitting result in the direction from Well G to Well H; Figure 2G is the water cut fitting result in the direction from Well G to Well E; Figure 2H is the water cut fitting result in the direction from Well I to Well E; Figure 2I is the water cut fitting result in the direction from Well I to Well C; Figure 2J is the water cut fitting result in the direction from Well J to Well E. From the display effect of the above drawings, it can be seen that the above method can effectively obtain the water cut at different times and effectively fit the water cut to obtain the final water cut change curve.

[0070] S150: Invert the inter-well seepage channel through the water cut change curve during the chemical flooding process.

[0071] After obtaining the water cut change curve, the water cut change situation can be analyzed, and then combined with the characteristics of the water cut change curve, the characteristics of the inter-well seepage channel can be determined to realize the inversion of the inter-well seepage channel.

[0072] In some embodiments, equivalent fracture characteristic parameters can be determined based on the water cut change curve during the chemical flooding process. Among them, the equivalent fracture characteristic parameters include at least one of the permeability ratio of a single equivalent fracture, the thickness of the inter-well equivalent channel, and the variance of the equivalent fracture aperture.

[0073] As shown in Table 1 below, the equivalent fracture characteristic parameters corresponding to different wells and determined based on different water inflow directions are presented. Through these equivalent fracture characteristic parameters, the characteristics of the inter-well seepage channels can be effectively analyzed and determined.

[0074] Table 1

[0075]

[0076]

[0077] By classifying the equivalent fracture characteristic parameters, they can be divided into three categories: small equivalent thickness and large gradient, medium gradient and small variance, and large equivalent thickness and medium-large gradient. Among them, in the category of small equivalent thickness and large gradient, the fracture aperture variance ≥ 0.5 and the equivalent thickness ≤ 10 mm, the connectivity of the inter-well fractures is good, large-scale fractures may exist, the volume of the inter-well channel is small, and the gradient is large. In the category of medium gradient and small variance, the fracture aperture variance < 0.5, the connectivity of the inter-well fractures is poor, and the overall performance shows a small gradient. In the category of large equivalent thickness and medium-large gradient, the fracture aperture variance ≥ 0.5 and the equivalent thickness > 10 mm, the connectivity of the inter-well fractures is good, the volume of the inter-well channel is large, and the gradient is medium-large.

[0078] Through the introduction of the above embodiments and examples, it can be seen that the method divides the target reservoir according to its characteristics into equivalent fractures formed by the series connection of horizontal fractures and matrix, and the matrix other than the equivalent fractures. Then, combined with the characteristics of chemical flooding, the equivalent resistance coefficient corresponding to the chemical agent is calculated. On this basis, the equivalent fracture seepage parameters and matrix seepage parameters of the target reservoir are calculated respectively by combining the geological parameters of the target reservoir, which are used to characterize the seepage characteristics of different regions in the target reservoir. Then, according to the calculated equivalent fracture seepage parameters and matrix seepage parameters, and combined with the characteristics of the chemical flooding process, the water cut change curve corresponding to the chemical flooding process is determined, and then the inter-well seepage channel is inverted based on the water cut change curve of the chemical flooding process. Through the above implementation method, the calculation of the corresponding parameters of the inter-well seepage channel is realized, the quantitative characterization of the inter-well seepage channel is effectively realized, and then the actual reservoir development can be guided, which is beneficial to the effective progress of production development.

[0079] Based on the above method for characterizing the inter-well seepage channel based on chemical flooding, an embodiment of this specification also proposes a device for characterizing the inter-well seepage channel based on chemical flooding. The device for characterizing the inter-well seepage channel based on chemical flooding can be set in the device for characterizing the inter-well seepage channel based on chemical flooding. As Figure 3 shown, the device for characterizing the inter-well seepage channel based on chemical flooding may include the following modules.

[0080] The geological parameter acquisition module 310 is used to acquire the geological parameters of the target reservoir.

[0081] The equivalent resistance coefficient determination module 320 is configured to determine the equivalent resistance coefficient corresponding to the chemical agent.

[0082] The parameter calculation module 330 is configured to calculate the equivalent fracture seepage parameter and the matrix seepage parameter in the target reservoir based on the geological parameters and the equivalent resistance coefficient; the equivalent fracture is formed by connecting the horizontal fractures in the target reservoir in series with the matrix; the equivalent fractures in the target reservoir constitute the inter-well seepage channel.

[0083] The water cut change curve acquisition module 340 is configured to obtain the water cut change curve during the chemical flooding process according to the equivalent fracture seepage parameter and the matrix seepage parameter.

[0084] The inter-well seepage channel inversion module 350 is configured to invert the inter-well seepage channel through the water cut change curve during the chemical flooding process.

[0085] Based on Figure 1 The corresponding method for characterizing the inter-well seepage channel based on chemical flooding, an embodiment of the present specification provides a computer-readable storage medium, on which computer programs / instructions are stored. The computer-readable storage medium can be read by a processor based on the internal bus of the device, and then the program instructions in the computer-readable storage medium are implemented through the processor.

[0086] In this embodiment, the computer-readable storage medium can be implemented in any suitable manner. The computer-readable storage medium includes, but is not limited to, random access memory (RAM), read-only memory (ROM), cache, hard disk drive (HDD), memory card, etc. The computer storage medium stores computer program instructions. When the computer program instructions are executed, the program instructions or modules of the corresponding embodiment of the present specification are implemented. Figure 1 The program instructions or modules of the corresponding embodiment.

[0087] In this embodiment, the processor can be implemented in any suitable manner. For example, the processor can take the form of, for example, a microprocessor or a processor and a computer-readable medium storing computer-readable program code (such as software or firmware) executable by the (micro)processor, logic gates, switches, application specific integrated circuit (ASIC), programmable logic controller, and embedded microcontroller, etc. Specifically, when the processor is arranged on the device for characterizing the inter-well seepage channel based on chemical flooding, it can execute Figure 1 The method steps in the corresponding embodiment.

[0088] The method, device, and storage medium for characterizing inter-well seepage channels based on chemical flooding in the embodiments of this specification can be applied to the field of reservoir development technology, and can also be applied to other technical fields outside the reservoir development technology field, without limitation in this regard.

[0089] Although the process flow described above includes multiple operations that occur in a specific order, it should be clearly understood that these processes can include more or fewer operations, and these operations can be executed sequentially or in parallel (for example, using a parallel processor or a multi-threaded environment).

[0090] This application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of this specification. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0091] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0093] Those skilled in the art should understand that the embodiments of this specification can be provided as a method, a system, or a computer program product. Therefore, the embodiments of this specification can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of this specification can take the form of a computer program product implemented 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.

[0094] The embodiments of this specification can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The embodiments of this specification can also be practiced in a distributed computing environment, where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0095] The various embodiments in this specification are described in a progressive manner. For the same or similar parts among the various embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of this specification. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0096] The above are only the embodiments of this application and are not used to limit this application. For those skilled in the art, various changes and modifications can be made to this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.

Claims

1. A method for characterizing inter-well seepage channels based on chemical flooding, characterized in that Including: Obtaining geological parameters of a target reservoir; Determining an equivalent resistance coefficient corresponding to a chemical agent; Calculating equivalent fracture seepage parameters and matrix seepage parameters in the target reservoir based on the geological parameters and the equivalent resistance coefficient; The equivalent fracture is formed by connecting horizontal fractures in the target reservoir in series with the matrix; the equivalent fractures in the target reservoir constitute an inter-well seepage channel; Obtaining a water cut change curve during the chemical flooding process according to the equivalent fracture seepage parameters and matrix seepage parameters; Inverting the inter-well seepage channel through the water cut change curve during the chemical flooding process; Wherein, the equivalent fracture seepage parameters include equivalent fracture water production and equivalent fracture liquid production; the matrix seepage parameters include matrix water production and matrix liquid production; the calculating the equivalent fracture seepage parameters and matrix seepage parameters in the target reservoir based on the geological parameters and the equivalent resistance coefficient includes: Calculating the equivalent fracture permeability based on geological parameters; Calculating the equivalent fracture seepage velocity using the equivalent fracture permeability; Calculating the matrix seepage velocity using the matrix permeability; Combining the equivalent resistance coefficient, and determining the equivalent fracture water production and equivalent fracture liquid production according to the equivalent fracture seepage velocity; Determining the matrix water production and matrix liquid production according to the matrix seepage velocity; Wherein, the calculating the equivalent fracture permeability based on geological parameters includes: Using the formula to calculate the equivalent fracture permeability, where K f is the permeability of a single equivalent fracture, R is the proportion of the horizontal fracture length along the seepage direction, b is the aperture of a single equivalent fracture, c1 is the influence coefficient of roughness and tortuosity on the fracture permeability, h is the effective thickness of the reservoir, and K m is the matrix permeability; The calculating the equivalent fracture seepage velocity using the equivalent fracture permeability includes: Using the formula to calculate the equivalent fracture seepage velocity, where v f is the inter-well injected water channeling velocity, μ is the viscosity of the injected water, △p is the injection-production pressure difference, L is the injection-production well spacing, ρ is the density of the mixed fluid, g is the acceleration due to gravity, α is the fracture dip angle, c is the influence coefficient of roughness and tortuosity on the fracture permeability, c = c1R, and R is the proportion of the horizontal fracture length along the seepage direction; The calculating the matrix seepage velocity using the matrix permeability includes: Using the formula calculate the matrix seepage velocity, where v m is the seepage velocity of the injected water between wells; The combining the equivalent resistance coefficient, and determining the equivalent fracture water production and equivalent fracture liquid production according to the equivalent fracture seepage velocity includes: Using the formula to calculate the equivalent fracture water production. In the formula, Q fw is the equivalent fracture water production, n is the number of horizontal fracture layers, m is the fracture-vug volume coefficient, W is the total width of the seepage cross-section, P is the proportion of the width occupied by fractures in the seepage cross-section, b max is the maximum opening of the fracture occupied by the injected water, b(t) is the opening of the fracture occupied by the injected water at time t, and f(b) is the probability density function of the average total opening b of the fracture, where Among them, is the logarithmic mean of the cracks, σ is the logarithmic standard deviation of the crack aperture; Using the formula to calculate the equivalent fracture liquid production. In the formula, Q f is the equivalent fracture liquid production; The determining the matrix water production and matrix liquid production according to the matrix seepage velocity includes: Using the formula to calculate the matrix water production, where Q mw is the matrix water production, h is the reservoir thickness, φ is the reservoir porosity, and f w0 is the initial water saturation of the reservoir; Use the formula to calculate the matrix liquid production rate. In the formula, Q m is the matrix liquid production rate.

2. The method according to claim 1, characterized in that, The target reservoir includes a fractured-vuggy carbonate reservoir.

3. The method according to claim 1, wherein The determining the equivalent resistance coefficient corresponding to a chemical agent includes: Using the formula calculate the equivalent resistance coefficient corresponding to the chemical agent. In the formula, R f is the equivalent resistance coefficient, T1 is the resistance multiple, t1 is the time when the chemical agent is injected, T2 is the average value of the chemical agent effective time, and σ R is the resistance standard deviation.

4. The method according to claim 1, wherein The obtaining a water cut change curve during the chemical flooding process according to the equivalent fracture seepage parameters and matrix seepage parameters includes: Based on the chemical flooding process, the water cut calculation model is transformed into a chemical flooding water cut calculation model; the chemical flooding water cut calculation model is In the formula,[[]]END]] Substituting production parameters corresponding to the target reservoir into the chemical flooding water cut calculation model to obtain the water cut values of the target reservoir at different times; Fitting a water cut transformation curve during the chemical flooding process based on the water cut values.

5. The method according to claim 1, characterized in that The inverting the inter-well seepage channel through the water cut change curve during the chemical flooding process includes: Determining equivalent fracture characteristic parameters based on the water cut change curve during the chemical flooding process; the equivalent fracture characteristic parameters include at least one of the permeability ratio of a single equivalent fracture, the thickness of the inter-well equivalent channel, and the variance of the equivalent fracture aperture.

6. The method according to claim 1, characterized in that The target reservoir satisfies the following conditions: The widths of the horizontal fractures and the matrix connected in series in the equivalent fracture are equal, and outside the equivalent fracture is pure matrix, and / or, The chemical flooding process is equivalent to piston displacement, and / or, The apertures of different equivalent fractures are different, and the apertures of all equivalent fractures follow a lognormal distribution.

7. An inter-well seepage channel characterization device based on chemical flooding, characterized in that, Including: A geological parameter acquisition module for acquiring geological parameters of a target reservoir; An equivalent resistance coefficient determination module for determining an equivalent resistance coefficient corresponding to a chemical agent; A parameter calculation module for calculating equivalent fracture seepage parameters and matrix seepage parameters in the target reservoir based on the geological parameters and the equivalent resistance coefficient; The equivalent fracture is formed by connecting horizontal fractures and matrix in the target reservoir in series; the equivalent fractures in the target reservoir constitute the inter-well seepage channel; The water cut change curve acquisition module is used to obtain the water cut change curve during the chemical flooding process according to the equivalent fracture seepage parameters and matrix seepage parameters; The inter-well seepage channel inversion module is used to invert the inter-well seepage channel through the water cut change curve during the chemical flooding process; Among them, the equivalent fracture seepage parameters include the water production of the equivalent fracture and the liquid production of the equivalent fracture; the matrix seepage parameters include the water production of the matrix and the liquid production of the matrix; calculating the equivalent fracture seepage parameters and matrix seepage parameters in the target reservoir based on the geological parameters and the equivalent resistance coefficient includes: Calculating the equivalent fracture permeability based on geological parameters; Calculating the equivalent fracture seepage velocity using the equivalent fracture permeability; Calculating the matrix seepage velocity using the matrix permeability; Combined with the equivalent resistance coefficient, determining the water production of the equivalent fracture and the liquid production of the equivalent fracture according to the equivalent fracture seepage velocity; Determining the water production of the matrix and the liquid production of the matrix according to the matrix seepage velocity; Among them, calculating the equivalent fracture permeability based on geological parameters includes: Using the formula to calculate the equivalent fracture permeability, where K f is the permeability of a single equivalent fracture, R is the proportion of the length of the horizontal fracture along the seepage direction, b is the aperture of a single equivalent fracture, c1 is the influence coefficient of roughness and tortuosity on the fracture permeability, h is the effective thickness of the reservoir, and K m is the matrix permeability; Calculating the equivalent fracture seepage velocity using the equivalent fracture permeability includes: Using the formula to calculate the equivalent fracture seepage velocity, where v f is the crossflow velocity of the injected water between wells, μ is the viscosity of the injected water, Δp is the injection-production pressure difference, L is the injection-production well spacing, ρ is the density of the mixed fluid, g is the acceleration due to gravity, α is the fracture dip angle, c is the influence coefficient of roughness and tortuosity on the fracture permeability, c = c1R, and R is the proportion of the horizontal fracture length along the seepage direction; Calculating the matrix seepage velocity using the matrix permeability includes: Using the formula calculate the matrix seepage velocity, where v m is the seepage velocity of the injected water between wells; Combined with the equivalent resistance coefficient, determining the water production of the equivalent fracture and the liquid production of the equivalent fracture according to the equivalent fracture seepage velocity includes: Using the formula to calculate the equivalent fracture water production. In the formula, Q fw is the equivalent fracture water production, n is the number of horizontal fracture layers, m is the fracture-vug volume coefficient, W is the total width of the seepage cross-section, P is the proportion of the width occupied by fractures in the seepage cross-section, b max is the maximum opening of the fracture occupied by the injected water, b(t) is the opening of the fracture occupied by the injected water at time t, and f(b) is the probability density function of the average total opening b of the fracture, where Among them, is the logarithmic mean of the cracks, σ is the logarithmic standard deviation of the crack opening; Use the formula to calculate the equivalent fracture liquid production. In the formula, Q f is the equivalent fracture liquid production; Determining the water production of the matrix and the liquid production of the matrix according to the matrix seepage velocity includes: Using the formula to calculate the matrix water production, where Q mw is the matrix water production, h is the reservoir thickness, φ is the reservoir porosity, and f w0 is the initial water saturation of the reservoir; Calculate the matrix liquid production using the formula where Q m is the matrix liquid production.

8. A computer storage medium having computer programs / instructions stored thereon, characterized in that, The computer program / instructions, when executed, implement the method according to any one of claims 1-6.

Images