Method, system and equipment for calculating permeability of carbonate reservoir and storage medium

Abstract

The invention belongs to the technical field of oil and gas field development, and provides a carbonate reservoir permeability calculation method, system and device and a storage medium, and the method comprises the steps: dividing T2 spectrum distribution of different pore structure components based on a nuclear magnetic logging T2 spectrum distribution curve; establishing a corresponding relation between T2 spectrum distribution of different pore structure components and core analysis permeability data based on a graph clustering analysis method; and calculating the permeability of the whole well section of the target layer well logging based on the corresponding relation. According to the method, the permeability of the fractured-vuggy reservoir is accurately estimated and solved by establishing the contribution relation of the fractured-vuggy reservoir with different pore structures to the permeability.

Description

Technical Field

[0001] This invention belongs to the field of geological exploration technology, and in particular relates to a method, system, equipment and storage medium for calculating the permeability of carbonate reservoirs. Background Technology

[0002] Fractured-vuggy carbonate reservoirs are a common type of carbonate reservoir. However, due to the severe heterogeneity of fractured-vuggy reservoirs, accurately determining the permeability of different wells and reservoir sections is quite difficult. Permeability results obtained using empirical formulas based on conventional logging and traditional nuclear magnetic resonance logging differ significantly from actual permeability calculations for fractured-vuggy reservoirs. The main reason for this discrepancy lies in the difficulty of finely characterizing and understanding the distribution of the complex pore structure in fractured-vuggy reservoirs. The relationship between the contribution of different pore structures to permeability has not been established, making it impossible to accurately estimate and determine the permeability of fractured-vuggy reservoirs. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a method, system, device, and storage medium for calculating the permeability of carbonate reservoirs.

[0004] The present invention provides a method for calculating the permeability of carbonate reservoirs, the method comprising:

[0005] Based on the T2 spectrum distribution curves of nuclear magnetic resonance logging, the T2 spectrum distributions of different pore structure components are divided;

[0006] Based on the graphical clustering analysis method, the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data of core analysis was established.

[0007] Based on the aforementioned correspondence, the permeability of the entire well section of the target layer is calculated during logging.

[0008] Furthermore, the calculation method also includes:

[0009] The reliability of the permeability was verified by comparing and analyzing the permeability data from the core analysis.

[0010] Furthermore, the step of classifying the T2 spectrum distribution of different pore structure components based on the nuclear magnetic resonance logging T2 spectrum distribution curve includes:

[0011] Based on the T2 spectrum distribution curve of nuclear magnetic resonance logging, the cutoff values ​​for bound water in carbonate mudstone and capillary bound water were determined.

[0012] Furthermore, determining the cutoff values ​​for bound water in carbonate mudstone and capillary bound water includes:

[0013] Based on the cutoff values ​​of bound water in carbonate mudstone and capillary bound water, the distribution curves of T2 spectrum based on nuclear magnetic resonance logging are classified.

[0014] Furthermore, the classification based on the T2 spectrum distribution curves from nuclear magnetic resonance logging includes:

[0015] The T2 spectrum distribution curve of nuclear magnetic resonance logging is divided into mudstone bound water, capillary bound water and free fluid components.

[0016] Furthermore, establishing the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data from core analysis includes:

[0017] By comparing the porosity results in the permeability data from core analysis with the porosity results from the well logging curves, we ensured that the calibration and well logging depth were consistent, thus verifying the consistency between the permeability results from core analysis and the well logging depth analysis results.

[0018] Establish the correspondence between the T2 spectrum distribution of capillary bound water, mudstone bound water and free fluid and the permeability of core analysis.

[0019] Furthermore, verifying the reliability of the penetration rate includes:

[0020] The permeability was compared with the permeability data from core analysis by cross-plotting, and the correlation coefficient between the permeability and the permeability data from core analysis was obtained, thereby verifying the reliability of the permeability.

[0021] This invention also provides a permeability calculation system for carbonate reservoirs, used to implement the aforementioned permeability calculation method for carbonate reservoirs, comprising:

[0022] The classification module is used to classify the T2 spectrum distribution of components with different pore structures;

[0023] The analysis module is used to establish the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data from core analysis.

[0024] The calculation module is used to calculate the permeability of the entire well section of the target layer based on the correspondence.

[0025] The verification module is used to verify the correlation between the permeability and the permeability data from core analysis.

[0026] The present invention also provides an apparatus including a processor coupled to a memory; the processor is configured to read and execute the computer program stored in the memory to implement the aforementioned method for calculating the permeability of carbonate reservoirs.

[0027] The present invention also provides a computer-readable storage medium storing a program or instructions that, when run on a computer, cause the computer to execute the aforementioned method for calculating the permeability of carbonate reservoirs.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] This invention provides a method, system, equipment, and storage medium for calculating the permeability of carbonate reservoirs. By establishing the relationship between the contribution of fractured-vuggy reservoirs with different pore structures to permeability, the permeability of fractured-vuggy reservoirs can be accurately estimated and determined. This invention can calculate the permeability not only for complex fractured-vuggy carbonate reservoir types but also for other carbonate reservoir types with simple pore structures, such as pore or vuggy carbonate reservoirs or fracture-pore carbonate reservoirs, and has good applicability. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the permeability calculation method for carbonate reservoirs according to the present invention;

[0032] Figure 2 This is a schematic diagram of the permeability calculation system for carbonate reservoirs according to the present invention;

[0033] Figure 3 This is a schematic diagram of the device structure of the present invention;

[0034] Figure 4 This is a schematic diagram of the T2 spectrum distribution of different pore structure components in an embodiment of the present invention;

[0035] Figure 5 A cross-plot of permeability calculated by the SDR model of nuclear magnetic resonance logging and permeability data from core analysis;

[0036] Figure 6 A cross-plot of permeability calculated using the COATS model for nuclear magnetic resonance logging and permeability data from core analysis;

[0037] Figure 7 This is a cross-plot of permeability calculated and permeability data from core analysis, as shown in an embodiment of the present invention.

[0038] Figure 8 This is a schematic diagram of the permeability calculation results according to an embodiment of the present invention;

[0039] In the diagram, 201 is the classification module, 202 is the analysis module, 203 is the calculation module, 204 is the verification module, 301 is the processor, and 302 is the memory. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In one embodiment of the present invention, a method for calculating the permeability of carbonate reservoirs is provided, such as... Figure 1 As shown, the method includes:

[0042] Based on the T2 spectrum distribution curves from nuclear magnetic resonance logging, the T2 spectrum distributions of different pore structure components were classified, including:

[0043] Based on the distribution curve of the T2 spectrum from nuclear magnetic resonance logging, the cutoff values ​​for bound water in carbonate mudstone and capillary bound water were determined.

[0044] Based on the cutoff values ​​of bound water in carbonate mudstone and capillary bound water, the distribution curves of T2 spectrum based on nuclear magnetic resonance logging are classified.

[0045] The T2 spectrum distribution curve of nuclear magnetic resonance logging is divided into mudstone bound water, capillary bound water and free fluid components.

[0046] Based on a graphical clustering analysis method, the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data from core analysis was established, including:

[0047] By comparing the porosity results in the permeability data from core analysis with the porosity results from the well logging curves, and ensuring that the calibration and well logging depth are consistent, the consistency between the permeability results from core analysis and the well logging depth analysis results is verified.

[0048] Establish the correspondence between the T2 spectrum distribution of capillary bound water, mudstone bound water and free fluid and the permeability of core analysis.

[0049] Based on the aforementioned correspondence, the permeability of the entire well section of the target layer is calculated during logging.

[0050] The permeability was compared with the permeability data from core analysis using a cross-plot, and the correlation coefficient was obtained to verify the reliability of the permeability.

[0051] Embodiments of the present invention also provide a permeability calculation system for carbonate reservoirs, such as... Figure 2 As shown, it includes:

[0052] Classification module 201 is used to classify the T2 spectrum distribution of components with different pore structures;

[0053] Analysis module 202 is used to establish the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data of core analysis;

[0054] The calculation module 203 is used to calculate the permeability of the entire well section of the target layer based on the correspondence.

[0055] The verification module 204 is used to verify the correlation between the permeability and the permeability data from the core analysis.

[0056] like Figure 3 As shown, an embodiment of the present invention also provides a device, including: a processor 301, the processor 301 being coupled to a memory 302, the processor 301 being used to read and execute a computer program stored in the memory 302 to implement the permeability calculation method for carbonate reservoirs as described in the above method embodiments.

[0057] Embodiments of the present invention also provide a computer-readable storage medium storing a program or instructions that, when executed on a computer, cause the computer to perform the permeability calculation method for carbonate reservoirs as described in the above method embodiments.

[0058] According to embodiments of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, electronic device, or apparatus.

[0059] Example 1

[0060] Using the method described in the above embodiments, the permeability of a complex fractured carbonate reservoir is calculated.

[0061] Based on the T2 spectrum distribution curves from nuclear magnetic resonance logging, the T2 spectrum distributions of different pore structure components were classified, including:

[0062] Based on the T2 spectrum distribution curve of nuclear magnetic resonance logging, the cutoff values ​​for bound water in carbonate mudstone and capillary bound water were determined.

[0063] Based on the cutoff values ​​of bound water in carbonate mudstone and capillary bound water, the distribution curves of T2 spectrum based on nuclear magnetic resonance logging are classified.

[0064] The T2 spectrum distribution curve of nuclear magnetic resonance logging is divided into mudstone bound water, capillary bound water and free fluid components.

[0065] like Figure 4 The T2 spectrum distribution curves shown in the nuclear magnetic resonance (NMR) logging primarily reflect the formation's pore structure. Smaller pore structures are generally distributed on the far left of the T2 spectrum, while larger pore structures are generally distributed on the far right. Therefore, the cutoff value for T2 spectrum corresponding to mudstone-bound water is generally about 0.3 ms from the far left of the T2 spectrum, the cutoff value for capillary-bound water is generally about 3 ms, and the cutoff value for free fluid is generally about 100 ms.

[0066] Based on the graphical clustering analysis method, the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data of core analysis was established.

[0067] Based on the aforementioned correspondence, the permeability of the entire well section of the target layer is calculated during logging.

[0068] The permeability was compared with the permeability data from core analysis by cross-plotting, and the correlation coefficient between the permeability and the permeability data from core analysis was obtained, thereby verifying the reliability of the permeability.

[0069] Figure 5 and Figure 6 Cross-plot of permeability calculated from SDR and COATS models using nuclear magnetic resonance logging, and permeability data from core analysis, such as... Figure 3 and Figure 4 As shown, the correlation coefficients between the permeability calculated by the SDR and COATS models of traditional nuclear magnetic resonance logging and the permeability data from core analysis are between 0.1 and 0.2, indicating poor correlation, which basically cannot meet the needs of practical applications.

[0070] Figure 7 This is a cross-plot of permeability calculated and core analysis permeability data from an embodiment of the present invention, as shown below. Figure 7 As shown, the correlation coefficient between the permeability calculated by the nuclear magnetic resonance logging T2 spectrum method based on graphical clustering analysis and the permeability data from core analysis can be 0.94, which meets the needs of practical applications.

[0071] like Figure 8As shown, the actual calculation results of the embodiments of the present invention are in good agreement with the permeability data of the core analysis of carbonate reservoirs.

[0072] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the permeability of carbonate reservoirs, characterized in that, The calculation method includes: Based on the T2 spectrum distribution curves of nuclear magnetic resonance logging, the T2 spectrum distributions of different pore structure components are divided; Based on the graphical clustering analysis method, the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data of core analysis was established. Based on the aforementioned correspondence, the permeability of the entire well section of the target layer is calculated during logging.

2. The method according to claim 1, characterized in that, The calculation method further includes: The reliability of the permeability was verified by comparing and analyzing the permeability data from the core analysis.

3. The method according to claim 1, characterized in that, The method of classifying the T2 spectrum distribution of different pore structure components based on nuclear magnetic resonance logging T2 spectrum distribution curves includes: Based on the T2 spectrum distribution curve of nuclear magnetic resonance logging, the cutoff values ​​for bound water in carbonate mudstone and capillary bound water were determined.

4. The method according to claim 3, characterized in that, The determination of the cutoff values ​​for bound water in carbonate mudstone and capillary bound water includes: Based on the cutoff values ​​of bound water in carbonate mudstone and capillary bound water, the distribution curves of T2 spectrum based on nuclear magnetic resonance logging are classified.

5. The method according to claim 4, characterized in that, The classification based on the T2 spectrum distribution curves of nuclear magnetic resonance logging includes: The T2 spectrum distribution curve of nuclear magnetic resonance logging is divided into mudstone bound water, capillary bound water and free fluid components.

6. The method according to claim 1, characterized in that, The establishment of the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data from core analysis includes: By comparing the porosity results in the permeability data from core analysis with the porosity results from the well logging curves, we ensured that the calibration and well logging depth were consistent, thus verifying the consistency between the permeability results from core analysis and the well logging depth analysis results. Establish the correspondence between the T2 spectrum distribution of capillary bound water, mudstone bound water and free fluid and the permeability of core analysis.

7. The method according to claim 2, characterized in that, The verification of the reliability of the penetration rate includes: The permeability was compared with the permeability data from core analysis by cross-plotting, and the correlation coefficient between the permeability and the permeability data from core analysis was obtained, thereby verifying the reliability of the permeability.

8. A permeability calculation system for carbonate reservoirs, characterized in that, include: The classification module is used to classify the T2 spectrum distribution of components with different pore structures; The analysis module is used to establish the correspondence between the T2 spectrum distribution of different pore structure components and the permeability data from core analysis. The calculation module is used to calculate the permeability of the entire well section of the target layer based on the correspondence. The verification module is used to verify the correlation between the permeability and the permeability data from core analysis.

9. A device, characterized in that, Includes a processor, which is coupled to a memory; The processor is configured to read and execute the computer program stored in the memory to implement the permeability calculation method for carbonate reservoirs as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The system stores a program or instructions that, when executed on a computer, cause the computer to perform the permeability calculation method for carbonate reservoirs as described in any one of claims 1-7.

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