Method and system for calculating rock porosity based on clastic rock thin section identification data

Abstract

The present application relates to a rock porosity calculation method and system based on clastic rock thin section identification data, and belongs to the technical field of oil and gas exploration and geology engineering. The method comprises the following steps: obtaining a first compaction rate according to the carbonate content data in the current clastic rock thin section identification data and the fitting relationship between the carbonate content and the compaction rate in the historical data; obtaining a second compaction rate according to the clay contribution rate obtained from the current clastic rock thin section identification data and the fitting relationship between the clay contribution rate and the compaction rate obtained from the historical data; obtaining a comprehensive compaction rate by weighted average of the first and second compaction rates; obtaining a modified compaction rate by modifying the comprehensive compaction rate according to the ratio of clay to initial porosity and the ratio of carbonate to initial porosity; determining the calculated porosity by using the modified compaction rate; and obtaining the rock porosity by modifying the calculated porosity according to the dissolution and cementation of the thin section. The clay contribution rate is the ratio of the square root of the clay content to the sum of the clay content and the carbonate content.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration and geological engineering technology, specifically relating to a method and system for calculating rock porosity based on clastic thin section identification data. Background Technology

[0002] In geological exploration and rock engineering, accurate assessment of rock properties is crucial. Currently, common methods for determining rock porosity include direct and indirect methods. The direct method involves saturating different fluid media and calculating the pore volume by measuring the volume of the medium. However, this method is time-consuming due to the lengthy vacuuming and pressurization saturation processes, resulting in a long testing cycle. The paper titled "Research on Improving the Efficiency and Accuracy of Helium Method for Porosity Detection," published by Li Jianzhi in the October 2023 issue of *China Petroleum and Chemical Standards and Quality*, employs the indirect method. The indirect method calculates rock pore volume by measuring the apparent volume and skeletal volume of the rock, primarily using the helium method. However, for some rocks, it is difficult to accurately measure the apparent volume, leading to significant measurement errors. Both methods are significantly affected by human factors and equipment limitations, especially when samples are difficult to obtain again, making it impossible to determine the pore size.

[0003] To address the above issues, the authors Zhang Chuang, Sun Wei, and Gao Hui, in their 2014 paper titled "A Quantitative Calculation Method for Sandstone Reservoir Porosity Evolution Based on Cast Thin Section Data—Taking the Chang 8 Reservoir in the Huanjiang Area of ​​the Ordos Basin as an Example," published in *Acta Sedimentologica Sinica*, calculated the porosity of clastic sandstone based on the effects of compaction, early cementation, dissolution, and late cementation during the diagenetic evolution path. The authors Zeng Binxin, Xiao Hui, and Hao Zimei, in their 2024 paper titled "Reservoir Porosity Prediction Based on the VAE-BiGRU-Attention Model—Taking Medium-to-Low Permeability Sandstone Reservoirs as an Example," used well logging curves to continuously explore the relationship between well logging information and porosity, optimizing the algorithm to improve data representation capabilities and extrapolate porosity. While these methods can solve the problems of being affected by human and equipment factors in existing technologies, the large amount of data involved in the calculation process leads to low computational efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for calculating rock porosity based on clastic thin section identification data, in order to solve the problem of low calculation efficiency caused by the large amount of calculation data in the prior art.

[0005] To address the aforementioned technical problems, this invention provides a method for calculating rock porosity based on clastic thin section identification data. The method includes: obtaining a first compaction rate based on the fitted relationship between carbonate content data from current clastic thin section identification data and the compaction rate from historical clastic thin section identification data; obtaining a second compaction rate based on the fitted relationship between the clay contribution rate from current clastic thin section identification data and the compaction rate from historical clastic thin section identification data; performing a weighted average of the first and second compaction rates to obtain a comprehensive compaction rate; correcting the comprehensive compaction rate based on the ratio of clay to initial porosity and the ratio of carbonate to initial porosity to obtain a corrected compaction rate; determining the calculated porosity using the corrected compaction rate; and further correcting the calculated porosity based on the dissolution and cementation conditions of the thin section to obtain the rock porosity. The clay contribution rate is the contribution rate of clay to resist compaction.

[0006] Furthermore, the method for correcting the overall compaction rate based on the clay-to-initial-porosity ratio and the carbonate-to-initial-porosity ratio to obtain the corrected compaction rate includes: if the clay-to-initial-porosity ratio is greater than or equal to a set value, the overall compaction rate is reduced to the current value by a first set percentage; if the clay-to-initial-porosity ratio is less than the set value, the overall compaction rate remains unchanged; if the carbonate-to-initial-porosity ratio is greater than or equal to the first set value and less than the second set value, the overall compaction rate is increased. If the ratio of carbonate to initial porosity is greater than or equal to the second set value but less than the third set value, the overall compaction rate will be reduced to the third set value. If the ratio of carbonate to initial porosity is greater than or equal to the third set value, the overall compaction rate will be reduced to the fourth set value. The second, third, and fourth set values ​​decrease sequentially. If the ratio of carbonate to initial porosity is less than the first set value, the overall compaction rate remains unchanged.

[0007] Furthermore, the method of correcting the calculated porosity to obtain the rock porosity based on the dissolution and cementation of the thin section includes: if the clastic rock thin section exhibits dissolution, the calculated porosity value is increased to a fifth preset proportion of the current value; if the clastic rock thin section does not exhibit dissolution, the calculated porosity value remains unchanged; if the ratio of carbonate to initial porosity is greater than or equal to a first preset cementation correction value and less than a second preset cementation correction value, the calculated porosity value is decreased to a sixth preset proportion of the current value; if the ratio of carbonate to initial porosity is greater than or equal to a second preset cementation correction value, the calculated porosity value is decreased to a seventh preset proportion of the current value; the seventh preset proportion is less than the sixth preset proportion; if the ratio of carbonate to initial porosity is less than a first preset cementation correction value, the calculated porosity value remains unchanged.

[0008] Furthermore, methods for determining calculated porosity using the corrected compaction rate include: determining calculated porosity based on initial porosity, carbonate content, clay content, and the corrected compaction rate.

[0009] Furthermore, methods for determining porosity based on initial porosity, carbonate content, clay content, and corrected compaction ratio include:

[0010] POR = OP-CC 粘 -COR*(OP-C 粘 )

[0011] In the formula: POR is the calculated porosity, OP is the initial porosity, C is the carbonate content, and C 粘 COR represents the clay content, and COR is the corrected compaction rate.

[0012] Furthermore, the clay contribution rate was determined by the clay content and carbonate content.

[0013] Furthermore, methods for determining the clay contribution rate through clay content and carbonate content include:

[0014]

[0015] In the formula, CCR is the clay contribution rate, C is the carbonate content, and CCR is the ore content. 粘 This represents the clay content.

[0016] To address the aforementioned technical problems, the present invention also provides a rock porosity calculation system based on clastic rock thin section identification data, including a processor for executing a computer program to implement the steps of a rock porosity calculation method based on clastic rock thin section identification data.

[0017] The beneficial effects of the above technical solution are as follows: This invention provides a method for calculating rock porosity based on clastic rock thin section identification data. It calculates the corresponding first and second compaction rates based on carbonate content and clay contribution rate, respectively. The first and second compaction rates are then weighted and averaged to obtain the comprehensive compaction rate. This involves using the relationship between the two factors with the best correlation to the compaction rate, obtained through historical data fitting, to calculate the comprehensive compaction rate. This makes the calculated comprehensive compaction rate more consistent with actual conditions. The comprehensive compaction rate is then corrected based on the geological basis of the clay and carbonate content that resists compaction. Based on the actual clay and carbonate content and its resistance to compaction, the compaction rate is adjusted accordingly for correction. The corrected compaction rate is then used to determine the calculated porosity. The calculated porosity is further corrected based on the dissolution and cementation conditions of the thin section to obtain the rock porosity. Dissolution increases porosity while cementation reduces porosity; therefore, the calculated porosity can be adjusted accordingly based on the actual degree of dissolution and cementation of the thin section. It is evident that this rock porosity calculation method can obtain the rock porosity by calculating and correcting the relevant parameters of carbonate and clay content in the clastic rock thin section identification data. While ensuring accuracy, it solves the problem of low calculation efficiency caused by the large amount of calculation data in existing technologies. Attached Figure Description

[0018] Figure 1 A schematic diagram illustrating the process of calculating rock porosity based on clastic rock thin section identification data, as described in this invention.

[0019] Figure 2 This is a fitting diagram of the coupling relationship between carbonate content and compaction rate in the rock porosity calculation method based on clastic rock thin section identification data, according to an embodiment of the present invention.

[0020] Figure 3 This is a fitting diagram of the coupling relationship between clay contribution rate and compaction rate in the rock porosity calculation method based on clastic rock thin section identification data, according to an embodiment of the present invention.

[0021] Figure 4 This invention relates to a method for calculating rock porosity based on clastic rock thin section identification data, and presents an error judgment table for the predicted rock porosity versus the measured rock porosity based on the method for calculating rock porosity based on clastic rock thin section identification data. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Example of a method for calculating rock porosity based on thin section identification data of clastic rocks:

[0024] This embodiment presents a method for calculating rock porosity based on clastic rock thin section identification data. It performs fitting analysis on factors and compaction rates of the clastic rock thin sections, identifying two influencing factors with the best correlation to compaction rates: carbonate content and clay contribution rate. Based on the carbonate content and clay contribution rate of the current clastic rock thin section, the corresponding compaction rates are calculated using their respective fitting relationships. Then, the compaction rates are adjusted accordingly based on the actual clay and carbonate contents and their resistance to compaction. The corrected compaction rates are then used to determine the calculated porosity. Since thin section dissolution increases porosity while cementation reduces it, the calculated porosity is corrected based on the actual degree of dissolution and cementation in the thin section to obtain the rock porosity. This method, while ensuring accuracy, solves the problem of low calculation efficiency due to the large amount of calculation data in existing technologies.

[0025] The method for calculating rock porosity based on clastic thin section identification data is as follows: Figure 1 As shown, it mainly includes:

[0026] The first compaction rate is obtained by fitting the relationship between carbonate content data from current clastic rock thin section identification data and compaction rate from historical clastic rock thin section identification data. The second compaction rate is obtained by fitting the relationship between clay contribution rate from current clastic rock thin section identification data and compaction rate from historical clastic rock thin section identification data. The first and second compaction rates are weighted and averaged to obtain the comprehensive compaction rate. The comprehensive compaction rate is then corrected based on the ratio of clay to initial porosity and the ratio of carbonate to initial porosity to obtain the corrected compaction rate. The calculated porosity is determined using the corrected compaction rate. The calculated porosity is then corrected based on the dissolution and cementation conditions of the thin section to obtain the rock porosity. The clay contribution rate is the contribution rate of clay to compaction.

[0027] This embodiment calculates the first and second compaction rates based on carbonate content and clay contribution rate, respectively. The first and second compaction rates are then weighted and averaged to obtain the comprehensive compaction rate. This involves using historical data fitting to obtain the relationship between the two factors with the best correlation to the compaction rate, as determined through comprehensive analysis, to calculate the comprehensive compaction rate. This ensures that the calculated comprehensive compaction rate better reflects actual conditions. The comprehensive compaction rate is then corrected based on the geological basis of the clay and carbonate content that resists compaction. The actual clay and carbonate content can be used to determine the degree of compaction. The degree of compaction is adjusted accordingly to correct the porosity. Then, the corrected compaction rate is used to determine the calculated porosity. The calculated porosity is further corrected based on the dissolution and cementation of the thin section to obtain the rock porosity. Dissolution increases porosity while cementation reduces porosity; therefore, the calculated porosity can be adjusted accordingly based on the degree of dissolution and cementation of the actual thin section. It is evident that this rock porosity calculation method only requires calculation and correction using relevant parameters such as carbonate and clay content from the clastic rock thin section identification data. While ensuring accuracy, it solves the problem of low calculation efficiency caused by the large amount of calculation data in existing technologies.

[0028] Specifically, the data from thin section identification of clastic rocks were fitted to the compaction rate. Through data fitting, parameters sensitive to the compaction rate were identified. These parameters included carbonate content and clay contribution rate. The fitting relationship between carbonate content and compaction rate is shown in [reference needed]. Figure 2 Correlation coefficient R 2 The value reached 0.8787, indicating a good coupling relationship between the two. Multiple parameters help eliminate the error of a single sensitive parameter; the fitting relationship between clay contribution rate and compaction rate is shown in [reference needed]. Figure 3 Correlation coefficient R 2 The value reached 0.7997, indicating that the two have a good coupling relationship.

[0029] In this embodiment, the clay contribution rate is determined by the clay content and carbonate content.

[0030] Methods for determining the clay contribution rate based on clay content and carbonate content include:

[0031]

[0032] In the formula, CCR is the clay contribution rate, C is the carbonate content, and CCR is the ore content. 粘 This represents the clay content.

[0033] Specifically, the clay contribution rate (CCR) refers to the reduction in operating pressure (OP) of post-depositional sandstone due to the presence of clay matrix, but it also contributes to reducing the compaction rate during later compaction. Clay and carbonates play a positive role in resisting compaction. Since the supporting effect of clay in resisting compaction is much smaller than that of carbonates, the square root of its content value is used in the calculation to have a better correlation with the compaction rate. Therefore, the square root of the clay content value is used here.

[0034] In this embodiment, the method of determining the calculated porosity using the corrected compaction rate includes: determining the calculated porosity based on the initial porosity, carbonate content, clay content, and the corrected compaction rate.

[0035] Methods for determining porosity based on initial porosity, carbonate content, clay content, and corrected compaction ratio include:

[0036] POR = OP-CC 粘 -COR*(OP-C 粘 )

[0037] In the formula: POR is the calculated porosity, OP is the initial porosity, C is the carbonate content, and C 粘 COR represents the clay content, and COR is the corrected compaction rate.

[0038] Specifically, according to Figure 2 and Figure 3 The corresponding compaction rates are calculated based on the fitting relationships, and then weighted averaged according to their correlation coefficients (in this embodiment, the weight of carbonate content is 0.8; the weight of clay contribution rate is 0.2). The weighted average comprehensive compaction rate is then corrected, and the calculated porosity (POR) is calculated based on the corrected compaction rate (COR). Finally, the rock porosity is obtained by correcting the calculated porosity (POR).

[0039] In this embodiment, the method for correcting the overall compaction rate based on the clay-to-initial-porosity ratio and the carbonate-to-initial-porosity ratio to obtain the corrected compaction rate includes: if the clay-to-initial-porosity ratio is greater than or equal to a set value, the overall compaction rate is reduced to the current value by a first set percentage; if the clay-to-initial-porosity ratio is less than the set value, the overall compaction rate remains unchanged; if the carbonate-to-initial-porosity ratio is greater than or equal to a first set value and less than a second set value, the overall compaction rate is reduced by a certain percentage. The compaction rate is reduced to a second set percentage of the current value; if the ratio of carbonate to initial porosity is greater than or equal to the second set percentage but less than the third set percentage, the overall compaction rate is reduced to a third set percentage; if the ratio of carbonate to initial porosity is greater than or equal to the third set percentage, the overall compaction rate is reduced to a fourth set percentage; the second, third, and fourth set percentages decrease sequentially; if the ratio of carbonate to initial porosity is less than the first set percentage, the overall compaction rate remains unchanged. In this embodiment, the initial porosity ratio of clay is set to 0.2, the first set percentage is 0.99, the initial porosity ratio of carbonate is set to 0.1, the second set percentage of carbonate is set to 0.2, the second set percentage is set to 0.995, the third set percentage of carbonate is set to 0.4, the third set percentage is set to 0.99, and the fourth set percentage is set to 0.98, as shown in Table 1.

[0040] The method for adjusting the calculated porosity of rock based on the dissolution and cementation of thin sections includes: if the clastic rock thin section exhibits dissolution, the calculated porosity value is increased to a fifth preset proportion of the current value; if the clastic rock thin section does not exhibit dissolution, the calculated porosity value remains unchanged; if the ratio of carbonate to initial porosity is greater than or equal to a first cementation correction value but less than a second cementation correction value, the calculated porosity value is decreased to a sixth preset proportion of the current value; if the ratio of carbonate to initial porosity is greater than or equal to a second cementation correction value, the calculated porosity value is decreased to a seventh preset proportion of the current value; the seventh preset proportion is less than the sixth preset proportion; if the ratio of carbonate to initial porosity is less than a first cementation correction value, the calculated porosity value remains unchanged. In this embodiment, the fifth preset proportion is 1.03, the first cementation correction value is 0.2, the second cementation correction value is 0.4, the sixth preset proportion is 0.95, and the seventh preset proportion is 0.9, as shown in Table 1.

[0041] Specifically, the first round of correction targets the weighted average overall compaction rate (COR). The geological basis for this correction is the clay and carbonate content that resists compaction; however, higher is not necessarily better, as these elements, while resisting compaction, can also cement the sandstone, thus reducing porosity. The ratio of clay to initial porosity, R... 粘 and the ratio of carbonate to initial porosity R 碳 The correction factors are determined, as shown in Table 1. The second round of correction targets the calculated porosity (POR). After calculating the POR using the corrected compaction ratio (COR), dissolution correction and cementation correction are performed. Dissolution increases porosity while cementation decreases it. The dissolution correction factor is determined by observing thin sections of clastic rocks to identify the presence of dissolution phenomena; the cementation correction factor is based on the ratio of carbonate to initial porosity (R). 碳 The value determines this.

[0042] Table 1

[0043]

[0044] The predicted rock porosity after two corrections was compared with the actual porosity of clastic rock thin sections. The absolute error ranged from -1.52% to 1.04%, with an average of -0.01%. The relative error ranged from a maximum of 0.15% to 21%, with an average of 10.28%, indicating good accuracy. (Specific details are as follows...) Figure 4 As shown.

[0045] Example of a rock porosity calculation system based on clastic thin section identification data:

[0046] A rock porosity calculation system based on clastic rock thin section identification data includes a processor. The processor executes a computer program to implement the steps of a rock porosity calculation method based on clastic rock thin section identification data. The specific process, principle, and effects of the rock porosity calculation system based on clastic rock thin section identification data have been described in detail in the embodiments of the rock porosity calculation method based on clastic rock thin section identification data, and will not be repeated here.

[0047] Specific implementation methods have been given above, but the present invention is not limited to the described implementation methods. The basic idea of ​​the present invention lies in the above basic scheme. For those skilled in the art, designing various modified models, formulas, and parameters based on the teachings of the present invention does not require creative effort. Changes, modifications, substitutions, and variations made to the implementation methods without departing from the principles and spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A method for calculating rock porosity based on thin section identification data of clastic rocks, characterized in that, The method includes: obtaining a first compaction rate based on the fitted relationship between carbonate content data from current clastic rock thin section identification data and compaction rate from historical clastic rock thin section identification data; obtaining a second compaction rate based on the fitted relationship between clay contribution rate from current clastic rock thin section identification data and compaction rate from historical clastic rock thin section identification data; obtaining a comprehensive compaction rate by weighted averaging the first and second compaction rates; obtaining a corrected compaction rate by correcting the comprehensive compaction rate based on the ratio of clay to initial porosity and the ratio of carbonate to initial porosity; determining the calculated porosity using the corrected compaction rate; and obtaining the rock porosity by correcting the calculated porosity based on the dissolution and cementation conditions of the thin section; the clay contribution rate is the contribution rate of clay to compaction. The formula for determining porosity using the corrected compaction ratio is as follows: In the formula: POR is the calculated porosity, OP is the initial porosity, and C is the carbonate content. COR represents the clay content, and COR is the corrected compaction rate.

2. The method for calculating rock porosity based on clastic thin section identification data according to claim 1, characterized in that, The method for correcting the overall compaction rate based on the clay-to-initial-porosity ratio and the carbonate-to-initial-porosity ratio to obtain the corrected compaction rate includes: if the clay-to-initial-porosity ratio is greater than or equal to a set value, the overall compaction rate is reduced to the current value by a first set percentage; if the clay-to-initial-porosity ratio is less than the set value, the overall compaction rate remains unchanged; if the carbonate-to-initial-porosity ratio is greater than or equal to the first set value and less than the second set value, the overall compaction rate is adjusted accordingly. If the value of the initial porosity is reduced to the second set percentage of the current value; if the ratio of carbonate to initial porosity is greater than or equal to the second set percentage but less than the third set percentage, the overall compaction rate is reduced to the third set percentage of the current value; if the ratio of carbonate to initial porosity is greater than or equal to the third set percentage, the overall compaction rate is reduced to the fourth set percentage; the second, third, and fourth set percentages decrease sequentially; if the ratio of carbonate to initial porosity is less than the first set percentage, the overall compaction rate remains unchanged.

3. The method for calculating rock porosity based on clastic thin section identification data according to claim 1 or 2, characterized in that, The method for correcting the calculated porosity of the rock based on the dissolution and cementation of the thin section includes: if the clastic rock thin section exhibits dissolution, the calculated porosity value is increased to a fifth preset proportion of the current value; if the clastic rock thin section does not exhibit dissolution, the calculated porosity value remains unchanged; if the ratio of carbonate to initial porosity is greater than or equal to a first preset cementation correction value and less than a second preset cementation correction value, the calculated porosity value is decreased to a sixth preset proportion of the current value; if the ratio of carbonate to initial porosity is greater than or equal to a second preset cementation correction value, the calculated porosity value is decreased to a seventh preset proportion of the current value; the seventh preset proportion is less than the sixth preset proportion; if the ratio of carbonate to initial porosity is less than a first preset cementation correction value, the calculated porosity value remains unchanged.

4. The method for calculating rock porosity based on clastic thin section identification data according to claim 2, characterized in that, The initial porosity ratio of clay is set to 0.2, the first set ratio is 0.99, the initial porosity ratio of carbonate is set to 0.1, the initial porosity ratio of carbonate is set to 0.2, the second set ratio is 0.995, the initial porosity ratio of carbonate is set to 0.4, the third set ratio is 0.99, and the fourth set ratio is 0.

98.

5. The method for calculating rock porosity based on clastic thin section identification data according to claim 3, characterized in that, The fifth setting ratio is 1.03, the first setting value for bonding correction is 0.2, the second setting value for bonding correction is 0.4, the sixth setting ratio is 0.95, and the seventh setting ratio is 0.

9.

6. The method for calculating rock porosity based on clastic thin section identification data according to claim 1 or 2, characterized in that, The clay contribution rate is determined by the clay content and carbonate content.

7. The method for calculating rock porosity based on clastic thin section identification data according to claim 6, characterized in that, The methods for determining the clay contribution rate by clay content and carbonate content include: In the formula, CCR is the clay contribution rate, and C is the carbonate content. This represents the clay content.

8. A rock porosity calculation system based on clastic rock thin section identification data, comprising a processor, characterized in that, The processor is used to execute a computer program to implement the steps of the rock porosity calculation method based on clastic rock thin section identification data as described in claim 1.

9. The rock porosity calculation system based on clastic rock thin section identification data according to claim 8, characterized in that, The method for correcting the overall compaction rate based on the clay-to-initial-porosity ratio and the carbonate-to-initial-porosity ratio to obtain the corrected compaction rate includes: if the clay-to-initial-porosity ratio is greater than or equal to a set value, the overall compaction rate is reduced to the current value by a first set percentage; if the clay-to-initial-porosity ratio is less than the set value, the overall compaction rate remains unchanged; if the carbonate-to-initial-porosity ratio is greater than or equal to the first set value and less than the second set value, the overall compaction rate is adjusted accordingly. If the value of the initial porosity is reduced to the second set percentage of the current value; if the ratio of carbonate to initial porosity is greater than or equal to the second set percentage but less than the third set percentage, the overall compaction rate is reduced to the third set percentage of the current value; if the ratio of carbonate to initial porosity is greater than or equal to the third set percentage, the overall compaction rate is reduced to the fourth set percentage; the second, third, and fourth set percentages decrease sequentially; if the ratio of carbonate to initial porosity is less than the first set percentage, the overall compaction rate remains unchanged.

10. The rock porosity calculation system based on clastic thin section identification data according to claim 8 or 9, characterized in that, The method for correcting the calculated porosity of the rock based on the dissolution and cementation of the thin section includes: if the clastic rock thin section exhibits dissolution, the calculated porosity value is increased to a fifth preset proportion of the current value; if the clastic rock thin section does not exhibit dissolution, the calculated porosity value remains unchanged; if the ratio of carbonate to initial porosity is greater than or equal to a first preset cementation correction value and less than a second preset cementation correction value, the calculated porosity value is decreased to a sixth preset proportion of the current value; if the ratio of carbonate to initial porosity is greater than or equal to a second preset cementation correction value, the calculated porosity value is decreased to a seventh preset proportion of the current value; the seventh preset proportion is less than the sixth preset proportion; if the ratio of carbonate to initial porosity is less than a first preset cementation correction value, the calculated porosity value remains unchanged.

11. The rock porosity calculation system based on clastic thin section identification data according to claim 9, characterized in that, The initial porosity ratio of clay is set to 0.2, the first set ratio is 0.99, the initial porosity ratio of carbonate is set to 0.1, the initial porosity ratio of carbonate is set to 0.2, the second set ratio is 0.995, the initial porosity ratio of carbonate is set to 0.4, the third set ratio is 0.99, and the fourth set ratio is 0.

98.

12. The rock porosity calculation system based on clastic rock thin section identification data according to claim 10, characterized in that, The fifth setting ratio is 1.03, the first setting value for bonding correction is 0.2, the second setting value for bonding correction is 0.4, the sixth setting ratio is 0.95, and the seventh setting ratio is 0.

9.

13. The rock porosity calculation system based on clastic rock thin section identification data according to claim 8 or 9, characterized in that, The clay contribution rate is determined by the clay content and carbonate content.

14. The rock porosity calculation system based on clastic rock thin section identification data according to claim 13, characterized in that, The methods for determining the clay contribution rate by clay content and carbonate content include: In the formula, CCR is the clay contribution rate, and C is the carbonate content. This represents the clay content.

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