Method for calculating mechanical weight coefficients of different types of amorphous rocks

Abstract

The invention discloses a method for calculating mechanical weight coefficients of different types of amorphous rocks, and relates to the technical field of oil and gas reservoir exploration and research. The method comprises the following steps: selecting a rock core sample, preparing a cylinder sample and two rock ground powder samples, and respectively carrying out a rock mechanics experiment, an X-ray diffraction experiment and a carbon-sulfur analysis experiment to obtain the contents of amorphous organic matters and inorganic matters in the samples; and establishing an amorphous weight coefficient and correction coefficient solving equation by using the rock brittleness indexes of a rock mechanics weight method and a mineral composition method, establishing a plurality of solving equations according to the plurality of samples, and solving to obtain the rock mechanics weight coefficient of the amorphous substance in the rock sample. According to the method, independent calculation of the rock mechanics weight coefficients of the amorphous organic matter and the amorphous inorganic matter can be achieved, so that the contribution effect of different types of amorphous matter on rock brittleness or plasticity is accurately analyzed, and oil and gas reservoir evaluation, reservoir fracturing and transformation, geotechnical engineering research and other work are better guided.

Description

Technical Field

[0001] This invention relates to the field of oil and gas reservoir exploration and research technology, and more specifically to a method for calculating the mechanical weight coefficients of different types of amorphous rocks. Background Technology

[0002] The high-yield industrial gas flow detected in the DY1H well, a risk exploration well in the Wujiaping Formation of the Permian in the Sichuan Basin, marks a significant breakthrough in the exploration of a new marine shale gas stratum in the Sichuan Basin. Unlike the marine shale gas of the Maxi Formation of the Silurian, this stratum is a deep-water shelf facies shale with a more complex rock composition. Due to its proximity to a marine-continental transitional sedimentary system and the influence of volcanic activity, the rocks contain not only amorphous organic matter (kerogen) but also amorphous inorganic matter (glassy matter), resulting in a significant difference in brittleness compared to conventional marine shale. Existing research has found that the presence of amorphous materials can reduce the strength and hardness of the rocks, making them more prone to fracture, while also potentially increasing their toughness, thus enhancing their resistance to fracturing. The rock brittleness index is a key parameter affecting the effectiveness of reservoir fracturing. There are two main methods for its determination and evaluation: the rock mechanics method and the mineral composition method. The rock mechanics method is a direct measurement method that directly measures the rock's mechanical parameters using experimental instruments. The rock brittleness index is calculated based on Young's modulus and Poisson's ratio. This method directly reflects the overall mechanical properties of the rock, but it cannot directly determine the influence of individual minerals within the rock. The mineral composition method is an indirect calculation method. It is a weighted analysis method that comprehensively considers the influence of the content and corresponding mechanical properties of each mineral on shale brittleness. This method can clearly analyze the contribution of each mineral component to the overall brittleness of the rock based on the weight coefficients of each mineral. However, when the rock contains a large amount of amorphous material, its brittleness weight coefficient cannot be calculated, making it impossible to analyze its influence on rock brittleness.

[0003] Currently, there are many methods for calculating rock and mineral weight coefficients, including empirical formulas, comprehensive weighting methods, regression analysis, numerical simulation, neural networks, and experimental simulation. Among these, the empirical formula method is the most direct and simplest. It typically relies on the experience and knowledge of geological experts, who subjectively judge the weight coefficients of rocks and minerals and then establish empirical formulas to estimate them. This method inherently involves a degree of subjectivity. The comprehensive weighting method statistically analyzes various physical parameters and mineral composition data of standard samples to summarize the relationship between mineral content and rock physical properties, determining the weight coefficients through this method. It is currently the most commonly used method, but the discrepancies between actual samples and standard samples often lead to errors in the analysis results. Regression analysis utilizes statistical regression methods to establish mathematical models based on known rock and mineral compositions and corresponding standard sample physical property data to predict weight coefficients. This method is often difficult to apply due to the lack of universality in the mathematical models. The neural network method is a machine learning method that simulates the structure of the human brain's neural network. It can automatically adjust weight coefficients by continuously learning from a large amount of sample data. This method has advantages in handling complex and nonlinear problems, but it requires a large amount of training data and computational resources. Experimental simulation methods involve conducting physical simulation experiments, such as uniaxial or triaxial compression tests, to obtain the stress-strain curves of rocks. This allows for the calculation of the rock's elastic modulus and Poisson's ratio. These experimental parameters, along with the physical parameters of corresponding mineral standards, are then used to calculate weighting coefficients. It can be seen that to obtain the rock mechanics weighting coefficients of different minerals in rocks, apart from empirical formulas heavily influenced by human experience and neural network methods heavily influenced by data training, other methods all rely heavily on the physical parameters of the corresponding mineral standards. Because amorphous materials in rocks lack a fixed crystalline structure, and the composition of different types of amorphous materials is extremely complex, they cannot be analyzed as single minerals. There are no corresponding standard materials, making it impossible to obtain the corresponding physical parameters. Furthermore, existing research on the mechanical properties of amorphous rocks, both domestically and internationally, is extremely limited, lacking experimental data suitable for statistical analysis and neural network training. Therefore, the aforementioned methods cannot calculate the rock mechanics weighting coefficients of amorphous materials in rock composition, and thus cannot evaluate the influence of amorphous materials on rock mechanical properties.

[0004] The existing standard, "Method for Determination and Evaluation of Shale Brittleness Index: NB / T 10248-2019," does not consider the influence of the content and properties of organic and inorganic matter in amorphous rocks. This inevitably leads to a significant deviation between the brittleness index determined by the mineral composition method and the brittleness index determined by the rock mechanics method. Furthermore, existing methods for studying rock brittleness are primarily limited to research based on rock mechanical properties. Due to the lack of methods for calculating the weighting coefficients for amorphous rocks, it is impossible to analyze the influence of amorphous organic matter and amorphous inorganic matter on rock brittleness. Summary of the Invention

[0005] To overcome the defects and shortcomings of the existing technology, this invention provides a method for calculating the mechanical weighting coefficients of different types of amorphous rocks. The purpose of this invention is to solve the problem that existing methods cannot calculate the rock mechanical weighting coefficients of amorphous substances in rock composition and cannot evaluate the influence of amorphous substances on rock mechanical properties. This invention conducts rock mechanics experiments and X-ray diffraction experiments on rock samples to calculate the rock brittleness index and the content of different types of amorphous substances. Using both rock mechanics and mineral composition methods, multiple equations are constructed and solved physically to establish a mathematical matrix model. Through mathematical physics calculations, the rock mechanical weighting coefficients of amorphous organic matter and amorphous inorganic matter, as well as new correction constants, are obtained.

[0006] To address the problems existing in the prior art, the present invention is achieved through the following technical solution.

[0007] A method for calculating the mechanical weighting coefficients of different types of amorphous rocks includes the following steps:

[0008] S1. Select core samples and prepare cylindrical samples and two rock powder samples;

[0009] S2. The rock strain characteristics under triaxial stress conditions of the cylindrical sample in S1 were measured using a longitudinal and transverse wave combined measurement system to obtain Young's modulus and Poisson's ratio.

[0010] S3. Use a carbon-sulfur analyzer to measure the organic carbon content in the S1 rock powder sample, and multiply the organic carbon content by the organic matter content conversion coefficient to determine the amorphous organic matter content in the sample.

[0011] S4. Measure the X-ray diffraction pattern of rock powder sample S1 using an X-ray diffractometer;

[0012] Then, based on the X-ray diffraction pattern, the content of each mineral component in the sample was obtained by full-spectrum fitting, and the total amount of amorphous matter in the sample was obtained by internal standard method.

[0013] S5. Subtract the amorphous organic matter content in the sample obtained in S3 from the total amorphous matter content in the sample obtained in S4 to obtain the amorphous inorganic matter content in the sample.

[0014] S6. Based on Young's modulus and Poisson's ratio described in S2, calculate the rock brittleness index using the rock mechanics weighting method.

[0015] S7. Based on the rock brittleness index obtained in S6, the content of each mineral component in the sample obtained in S4, the content of amorphous organic matter obtained in S3, and the content of amorphous inorganic matter obtained in S5, the amorphous weighting coefficient and correction coefficient are established using the mineral component method to solve the equation.

[0016] S8. Select two core samples from the same stratum as the core sample described in S1, repeat steps S1-S7, establish two more equations for solving the amorphous weight coefficient and correction coefficient, and then solve the amorphous weight coefficient and correction coefficient based on the equations for solving the amorphous weight coefficient and correction coefficient established from the three core samples. Use the solution results as the rock mechanical weight coefficients of amorphous materials in the rock samples.

[0017] In S3, the organic carbon content in the S1 rock powder sample measured by the carbon-sulfur analyzer should meet the technical requirements of "Determination of Total Organic Carbon in Sedimentary Rocks: GB / T19145-2022".

[0018] In step S3, the content of amorphous organic matter in the sample is calculated using the following formula:

[0019] X organic =P*Q TOC Formula 1

[0020] In Equation 1, X organic The content of amorphous organic matter in the sample is given by P, where P is the conversion coefficient between organic carbon and organic matter content, and Q is the value of Q. TOC This represents the organic carbon content in the sample.

[0021] The conversion coefficient between organic carbon and organic matter content meets the technical requirements of "Soil Testing Part 6: Determination of Soil Organic Matter: NY / T 1121.6-2006" and is set to 1.724.

[0022] In step S4, corundum is used as an internal standard to calculate the total amount of amorphous material in the sample:

[0023]

[0024] In Equation 2, W amor M represents the total amount of amorphous matter in the sample; M represents the total mass of the sample, in grams. corundum The mass of the pure corundum powder sample is expressed in g; K corundum The reference strength parameter for corundum is °cps; I corundum The integral intensity of the diffraction peak selected for corundum, °cps; I i The integral intensity of the diffraction peak selected for the i-th mineral in the sample, °cps; K i Let be the reference intensity parameter for the i-th mineral in the sample.

[0025] In step S5, the content of amorphous inorganic matter in the sample is calculated using the following formula:

[0026] X mineral =W amor -X organic Formula 3

[0027] In Equation 3, Xmineral X represents the content of amorphous inorganic matter in the sample. organic W represents the content of amorphous organic matter in the sample. amor This represents the total amount of amorphous matter in the sample.

[0028] In S7, based on the rock brittleness index obtained in S6, the content of each mineral component in the sample obtained in S4, the content of amorphous organic matter obtained in S3, and the content of amorphous inorganic matter obtained in S5, the equation for solving the amorphous weighting coefficient and correction coefficient is established using the mineral component method, including:

[0029] An equation for determining the brittleness index of rocks using the mineral composition method was established.

[0030] Using the rock brittleness index obtained from S6 as the result of the established equation, the equation for solving the amorphous weighting coefficient and correction coefficient is established.

[0031] The equation for determining the rock brittleness index using the mineral composition method is as follows:

[0032]

[0033] In Equation 4, B M1 X is the rock brittleness index, dimensionless; α is the weighting coefficient for quartz; quartz X represents the mass fraction of quartz in the sample, %; β is the weighting coefficient for dolomite; X do1omite γ is the mass fraction of dolomite in the sample; γ is the weighting coefficient of calcite; X calcite X represents the calcite mass fraction in the sample, in percent; η is the weighting coefficient for feldspar; X feldspar The mass fraction of feldspar in the sample, %; X is the weighting coefficient for pyrite; pyrite X represents the mass fraction of pyrite in the sample, in %; ω is the weighting coefficient for clay minerals; X clay Xx represents the mineral content of clay in the sample, in percentage (%); o represents the weighting coefficient of amorphous organic matter; Xx rganic X represents the content of amorphous organic matter in the sample; m is the weighting coefficient of amorphous inorganic matter; X mineral κ represents the content of amorphous inorganic matter in the sample; κ is the correction factor.

[0034] The equations for solving the amorphous weighting coefficient and correction coefficient are as follows:

[0035]

[0036] In Equation 5, B M1 X is the rock brittleness index, dimensionless; α is the weighting coefficient for quartz; quartz X represents the mass fraction of quartz in the sample, %; β is the weighting coefficient for dolomite; X dolomite γ is the mass fraction of dolomite in the sample; γ is the weighting coefficient of calcite; Xcalcite X represents the calcite mass fraction in the sample, in percent; η is the weighting coefficient for feldspar; X feldspar The mass fraction of feldspar in the sample, %; X is the weighting coefficient for pyrite; pyrite X represents the mass fraction of pyrite in the sample, in %; ω is the weighting coefficient for clay minerals; X clay X represents the mineral content of clay in the sample, in percentage (%); o represents the weighting coefficient of amorphous organic matter; X organic X represents the content of amorphous organic matter in the sample; m is the weighting coefficient of amorphous inorganic matter; X mineral κ represents the content of amorphous inorganic matter in the sample; κ is the correction factor.

[0037] In step S8, the solution for the amorphous weighting coefficient and correction coefficient based on the solution equations established from the three core samples includes:

[0038] make

[0039] The solution equations established based on the three core samples are as follows:

[0040]

[0041] Based on the system of equations, construct the matrix:

[0042]

[0043] Based on the matrix values, a program was written and substituted into Python software to calculate the weighting coefficient o of amorphous organic matter and the weighting coefficient m and correction coefficient k of amorphous inorganic matter, which were then used as the rock mechanical weighting coefficients of amorphous materials in the rock sample.

[0044] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0045] 1. This invention establishes for the first time a method for calculating the rock mechanical weight coefficient of amorphous rocks. Existing methods cannot calculate the rock mechanical weight coefficient due to the lack of experimental samples and standard materials. This invention overcomes the existing technical difficulties by establishing a brand-new experimental and calculation method, thus overcoming the problem that traditional techniques require experimental samples and standard materials, and fundamentally providing a solution for calculating the rock mechanical weight coefficient of amorphous rocks.

[0046] 2. This invention can calculate the mechanical weighting coefficients of two different types of amorphous rocks, and the calculation results provide greater support for practical work. Because different types of amorphous materials exhibit completely different brittle or ductile effects in rock mechanics, this invention avoids the problem of large analytical errors caused by calculating the total mechanical weighting coefficient of amorphous rocks using a single factor. It enables separate calculation of the mechanical weighting coefficients of amorphous organic and amorphous inorganic materials, thereby accurately analyzing the contribution of different types of amorphous materials to the brittleness or ductility of rocks, and better guiding work such as oil and gas reservoir evaluation, reservoir fracturing and stimulation, and geotechnical engineering research.

[0047] 3. This invention establishes a highly efficient method that can be directly calculated using software programs. This invention utilizes mathematical physics calculation methods, establishing and solving a system of equations, and using a matrix model to calculate the mechanical weighting coefficients of amorphous rocks. This method can be programmed directly using Python software, quickly yielding the desired optimal results.

[0048] 4. This invention integrates multiple experimental techniques and mathematical physics analysis techniques, achieving technological integration and innovation. It integrates X-ray diffraction analysis, carbon and sulfur elemental analysis, and rock mechanics parameter analysis methods based on combined P-wave and S-wave measurements. Building upon existing standard calculation methods, it incorporates mathematical physics equation-solving methods, achieving integrated innovation of experiment and theory.

[0049] 5. This invention has wide applicability and significant economic and social benefits. It can be applied to the calculation of mechanical parameters of amorphous rocks of various rock types. Since the content of amorphous materials of different types in various lithologies often varies greatly, the mechanical properties of rocks may also vary greatly. Therefore, the amorphous weighting coefficient calculated by one type of lithology cannot represent all lithologies. After all, there is no standard material for amorphous materials. Therefore, it is necessary to use the approach provided by this invention to carry out targeted experiments and theoretical calculations based on different rock cores to meet the needs of actual analysis. Attached Figure Description

[0050] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0051] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0052] Example 1

[0053] As a preferred embodiment of the present invention, this embodiment discloses a method for calculating the mechanical weighting coefficients of different types of amorphous rocks, the method comprising the following steps:

[0054] S1. Select core samples, prepare cylindrical samples and two rock powder samples, and conduct rock mechanics experiments, X-ray diffraction experiments and carbon-sulfur analysis experiments respectively.

[0055] S2. The rock strain characteristics under triaxial stress conditions of the cylindrical sample in S1 were measured using a longitudinal and transverse wave combined measurement system to obtain Young's modulus and Poisson's ratio.

[0056] S3. Use a carbon-sulfur analyzer to measure the organic carbon content in the S1 rock powder sample, and multiply the organic carbon content by the organic matter content conversion coefficient to determine the amorphous organic matter content in the sample.

[0057] S4. Measure the X-ray diffraction pattern of rock powder sample S1 using an X-ray diffractometer;

[0058] Then, based on the X-ray diffraction pattern, the content of each mineral component in the sample was obtained by full-spectrum fitting, and the total amount of amorphous matter in the sample was obtained by internal standard method.

[0059] S5. Subtract the amorphous organic matter content in the sample obtained in S3 from the total amorphous matter content in the sample obtained in S4 to obtain the amorphous inorganic matter content in the sample.

[0060] S6. Based on Young's modulus and Poisson's ratio described in S2, calculate the rock brittleness index using the rock mechanics weighting method.

[0061] S7. Based on the rock brittleness index obtained in S6, the content of each mineral component in the sample obtained in S4, the content of amorphous organic matter obtained in S3, and the content of amorphous inorganic matter obtained in S5, the amorphous weighting coefficient and correction coefficient are established using the mineral component method to solve the equation.

[0062] S8. Select two core samples from the same stratum as the core sample described in S1, repeat steps S1-S7, establish two more equations for solving the amorphous weight coefficient and correction coefficient, and then solve the amorphous weight coefficient and correction coefficient based on the equations for solving the amorphous weight coefficient and correction coefficient established from the three core samples. The solution results are used as the rock mechanical weight coefficients of amorphous materials in the rock samples.

[0063] This embodiment establishes for the first time a method for calculating the rock mechanical weighting coefficient of amorphous rocks. Existing methods cannot calculate the rock mechanical weighting coefficient due to the lack of experimental samples and standard materials. This invention overcomes the existing technical difficulties by establishing a brand-new experimental and calculation method, thus overcoming the problem that traditional techniques require experimental samples and standard materials, and fundamentally providing a solution for calculating the rock mechanical weighting coefficient of amorphous rocks.

[0064] Example 2

[0065] As another preferred embodiment of the present invention, this embodiment discloses a method for calculating the mechanical weighting coefficients of different types of amorphous rocks, the method comprising the following steps:

[0066] S1. Select core samples, prepare cylindrical samples and two rock powder samples, and conduct rock mechanics experiments, X-ray diffraction experiments and carbon-sulfur analysis experiments respectively.

[0067] S2. The rock strain characteristics under triaxial stress conditions of the cylindrical sample in S1 were measured using a longitudinal and transverse wave combined measurement system to obtain Young's modulus and Poisson's ratio.

[0068] S3. Using a carbon-sulfur analyzer, the organic carbon content in the S1 rock powder sample can be measured according to the relevant methods in "Determination of Total Organic Carbon in Sedimentary Rocks: GB / T19145-2022". The content of amorphous organic matter in the sample can be obtained by combining the conversion coefficient between organic carbon and organic matter content.

[0069] Furthermore, the content of amorphous organic matter in the sample is calculated using the following formula:

[0070] X organic =P*Q TOC Formula 1

[0071] In Equation 1, X organic ρ represents the content of amorphous organic matter in the sample; P is the conversion coefficient between organic carbon and organic matter content, which is taken as 1.724 according to "Soil Testing Part 6: Determination of Soil Organic Matter: NY / T 1121.6-2006"; Q TOC This refers to the organic carbon content in the sample.

[0072] S4. Measure the X-ray diffraction pattern of rock powder sample S1 using an X-ray diffractometer;

[0073] Then, based on the X-ray diffraction pattern, the content of each mineral component in the sample was obtained by full-spectrum fitting method, and the total amount of amorphous matter in the sample was obtained by using the internal standard method with corundum as the internal standard.

[0074]

[0075] In Equation 2, W amor M represents the total amount of amorphous matter in the sample; M represents the total mass of the sample, in grams. corundum The mass of the pure corundum powder sample is expressed in g; K corundum The reference strength parameter for corundum is °cps; I corundum The integral intensity of the diffraction peak selected for corundum, °cps; I iThe integral intensity of the diffraction peak selected for the i-th mineral in the sample, °cps; K i Let be the reference intensity parameter for the i-th mineral in the sample;

[0076] S5. Subtract the amorphous organic matter content in the sample obtained in S3 from the total amorphous matter content in the sample obtained in S4 to obtain the amorphous inorganic matter content in the sample.

[0077] X mineral =W amor -X organic Formula 3

[0078] In Equation 3, X mineral X represents the content of amorphous inorganic matter in the sample. organic W represents the content of amorphous organic matter in the sample. amor This represents the total amount of amorphous matter in the sample.

[0079] S6. Using the rock mechanics weighting method, calculate the rock brittleness index using Young's modulus and Poisson's ratio obtained in S2;

[0080] S7. Based on the rock brittleness index obtained in S6, the content of each mineral component in the sample obtained in S4, the content of amorphous organic matter obtained in S3, and the content of amorphous inorganic matter obtained in S5, establish the amorphous weighting coefficient and correction coefficient using the mineral component method to solve the equation; including:

[0081] An equation for determining the brittleness index of rocks using the mineral composition method was established.

[0082]

[0083] In Equation 4, B M1 X is the rock brittleness index, dimensionless; α is the weighting coefficient for quartz; quartz X represents the mass fraction of quartz in the sample, %; β is the weighting coefficient for dolomite; X dolomite γ is the mass fraction of dolomite in the sample; γ is the weighting coefficient of calcite; X calcite X represents the calcite mass fraction in the sample, in percent; η is the weighting coefficient for feldspar; X feldspar The mass fraction of feldspar in the sample, %; X is the weighting coefficient for pyrite; pyrite X represents the mass fraction of pyrite in the sample, in %; ω is the weighting coefficient for clay minerals; X clay X represents the mineral content of clay in the sample, in percentage (%); o represents the weighting coefficient of amorphous organic matter; X organic X represents the content of amorphous organic matter in the sample; m is the weighting coefficient of amorphous inorganic matter; X mineral The content of amorphous inorganic matter in the sample is represented by κ; κ is a correction factor.

[0084] Using the rock brittleness index obtained from S6 as the result of the established equation, the equation is solved by establishing the amorphous weighting coefficient and correction coefficient:

[0085]

[0086] In Equation 5, B M1 X is the rock brittleness index, dimensionless; α is the weighting coefficient for quartz; quartz X represents the mass fraction of quartz in the sample, %; β is the weighting coefficient for dolomite; X dolomite γ is the mass fraction of dolomite in the sample; γ is the weighting coefficient of calcite; X calcite X represents the calcite mass fraction in the sample, in percent; η is the weighting coefficient for feldspar; X feldspar The mass fraction of feldspar in the sample, %; X is the weighting coefficient for pyrite; pyrite X represents the mass fraction of pyrite in the sample, in %; ω is the weighting coefficient for clay minerals; X clay X represents the mineral content of clay in the sample, in percentage (%); o represents the weighting coefficient of amorphous organic matter; X organic X represents the content of amorphous organic matter in the sample; m is the weighting coefficient of amorphous inorganic matter; X mineral The content of amorphous inorganic matter in the sample is represented by κ; κ is a correction factor.

[0087] S8. Select two core samples from the same stratum as the core sample described in S1, repeat steps S1-S7, establish two more equations for solving the amorphous weight coefficient and correction coefficient, and then solve the amorphous weight coefficient and correction coefficient based on the equations for solving the amorphous weight coefficient and correction coefficient established from the three core samples. Use the solution results as the rock mechanical weight coefficients of amorphous materials in the rock samples.

[0088] This embodiment integrates X-ray diffraction analysis, carbon and sulfur elemental analysis, and rock mechanics parameter analysis using combined P-wave and S-wave measurements. It incorporates mathematical physics equation solving methods into existing standard calculation methods, achieving integrated innovation of experiment and theory. It avoids the problem of large analytical errors caused by calculating the weighting coefficients of total amorphous rock mechanics alone, and enables separate calculation of the weighting coefficients of amorphous organic and amorphous inorganic rock mechanics. This allows for accurate analysis of the contribution of different types of amorphous materials to the brittleness or plasticity of rocks, better guiding work in oil and gas reservoir evaluation, reservoir fracturing and stimulation, and geotechnical engineering research.

[0089] Example 3

[0090] As another preferred embodiment of the present invention, this embodiment discloses a method for calculating the mechanical weighting coefficients of different types of amorphous rocks, the method comprising the following steps:

[0091] S1. Select core samples, prepare cylindrical samples and two rock powder samples, and conduct rock mechanics experiments, X-ray diffraction experiments and carbon-sulfur analysis experiments respectively.

[0092] S2. The rock strain characteristics under triaxial stress conditions of the cylindrical sample in S1 were measured using a longitudinal and transverse wave combined measurement system to obtain Young's modulus and Poisson's ratio.

[0093] S3. Using a carbon-sulfur analyzer, the organic carbon content in the S1 rock powder sample can be measured according to the relevant methods in "Determination of Total Organic Carbon in Sedimentary Rocks: GB / T19145-2022". The content of amorphous organic matter in the sample can be obtained by combining the conversion coefficient between organic carbon and organic matter content.

[0094] Furthermore, the content of amorphous organic matter in the sample is calculated using the following formula:

[0095] X organic =P*Q TOC Formula 1

[0096] In Equation 1, X organic ρ represents the content of amorphous organic matter in the sample; P is the conversion coefficient between organic carbon and organic matter content, which is taken as 1.724 according to "Soil Testing Part 6: Determination of Soil Organic Matter: NY / T 1121.6-2006"; Q TOC This refers to the organic carbon content in the sample.

[0097] S4. Measure the X-ray diffraction pattern of rock powder sample S1 using an X-ray diffractometer;

[0098] Then, based on the X-ray diffraction pattern, the content of each mineral component in the sample was obtained by full-spectrum fitting method, and the total amount of amorphous matter in the sample was obtained by using the internal standard method with corundum as the internal standard.

[0099]

[0100] In Equation 2, W amor M represents the total amount of amorphous matter in the sample; M represents the total mass of the sample, in grams. corundum The mass of the pure corundum powder sample is expressed in g; K corundum The reference strength parameter for corundum is °cps; I corundum The integral intensity of the diffraction peak selected for corundum, °cps; I i The integral intensity of the diffraction peak selected for the i-th mineral in the sample, °cps; K i Let be the reference intensity parameter for the i-th mineral in the sample;

[0101] S5. Subtract the amorphous organic matter content in the sample obtained in S3 from the total amorphous matter content in the sample obtained in S4 to obtain the amorphous inorganic matter content in the sample.

[0102] X mineral =W amor -X organic Formula 3

[0103] In Equation 3, X mineral X represents the content of amorphous inorganic matter in the sample. organic W represents the content of amorphous organic matter in the sample. amor This represents the total amount of amorphous matter in the sample.

[0104] S6. Using the rock mechanics weighting method, calculate the rock brittleness index using Young's modulus and Poisson's ratio obtained in S2;

[0105] S7. Based on the rock brittleness index obtained in S6, the content of each mineral component in the sample obtained in S4, the content of amorphous organic matter obtained in S3, and the content of amorphous inorganic matter obtained in S5, establish the amorphous weighting coefficient and correction coefficient using the mineral component method to solve the equation; including:

[0106] An equation for determining the brittleness index of rocks using the mineral composition method was established.

[0107]

[0108] In Equation 4, B M1 X is the rock brittleness index, dimensionless; α is the weighting coefficient for quartz; quartz X represents the mass fraction of quartz in the sample, %; β is the weighting coefficient for dolomite; X dolomite γ is the mass fraction of dolomite in the sample; γ is the weighting coefficient of calcite; X calcite X represents the calcite mass fraction in the sample, in percent; η is the weighting coefficient for feldspar; X feldspar The mass fraction of feldspar in the sample, %; X is the weighting coefficient for pyrite; pyrite X represents the mass fraction of pyrite in the sample, in %; ω is the weighting coefficient for clay minerals; X clay X represents the mineral content of clay in the sample, in percentage (%); o represents the weighting coefficient of amorphous organic matter; X organic X represents the content of amorphous organic matter in the sample; m is the weighting coefficient of amorphous inorganic matter; X mineral The content of amorphous inorganic matter in the sample is represented by κ; κ is a correction factor.

[0109] Using the rock brittleness index obtained from S6 as the result of the established equation, the equation is solved by establishing the amorphous weighting coefficient and correction coefficient:

[0110]

[0111] In Equation 5, B M1 X is the rock brittleness index, dimensionless; α is the weighting coefficient for quartz; quartzX represents the mass fraction of quartz in the sample, %; β is the weighting coefficient for dolomite; X dolomite γ is the mass fraction of dolomite in the sample; γ is the weighting coefficient of calcite; X calcite X represents the calcite mass fraction in the sample, in percent; η is the weighting coefficient for feldspar; X feldspar The mass fraction of feldspar in the sample, %; X is the weighting coefficient for pyrite; pyrite X represents the mass fraction of pyrite in the sample, in %; ω is the weighting coefficient for clay minerals; X clay X represents the mineral content of clay in the sample, in percentage (%); o represents the weighting coefficient of amorphous organic matter; X organic X represents the content of amorphous organic matter in the sample; m is the weighting coefficient of amorphous inorganic matter; X mineral The content of amorphous inorganic matter in the sample is represented by κ; κ is a correction factor.

[0112] S8. Select two core samples from the same stratum as the core sample described in S1, repeat steps S1-S7, establish two more equations for solving the amorphous weight coefficient and correction coefficient, and then solve the amorphous weight coefficient and correction coefficient based on the equations for solving the amorphous weight coefficient and correction coefficient established from the three core samples. Use the solution results as the rock mechanical weight coefficient of amorphous material in the rock sample.

[0113] Furthermore, for the sake of simplified calculation, let

[0114] The solution equations established based on the three core samples are as follows:

[0115]

[0116] Based on the system of equations, construct the matrix:

[0117]

[0118] Based on the matrix values, a program was written and substituted into Python software to find the optimal solutions for the weighting coefficient o of amorphous organic matter and the weighting coefficient m and correction coefficient k of amorphous inorganic matter, which are then used as the rock mechanical weighting coefficients of amorphous materials in the rock sample.

[0119] This embodiment establishes an efficient method that can be directly calculated using software programs. This embodiment utilizes mathematical physics calculation methods, establishing and solving a system of equations, and using a matrix model to calculate the mechanical weighting coefficients of amorphous rocks. This method can be programmed directly using Python, quickly yielding the desired optimal results.

[0120] This invention can calculate the mechanical weighting coefficients for two different types of amorphous rocks, and the calculation results provide greater support for practical work. Because different types of amorphous materials exhibit completely different brittle or ductile effects in rock mechanics, this invention avoids the problem of large analytical errors caused by calculating the mechanical weighting coefficients of a single total amorphous rock. It enables separate calculation of the mechanical weighting coefficients for amorphous organic materials and amorphous inorganic materials, thereby accurately analyzing the contribution of different types of amorphous materials to the brittleness or ductility of rocks, and better guiding work such as oil and gas reservoir evaluation, reservoir fracturing and stimulation, and geotechnical engineering research.

Claims

1. A method for calculating the mechanical weighting coefficients of different types of amorphous rocks, comprising the following steps: S1. Select core samples, prepare cylindrical samples and two rock powder samples, and conduct rock mechanics experiments, X-ray diffraction experiments and carbon-sulfur analysis experiments respectively. S2. The rock strain characteristics under triaxial stress conditions of the cylindrical sample in S1 are measured using a longitudinal and transverse wave combined measurement system to obtain Young's modulus and Poisson's ratio; characterized in that it further includes: S3. Use a carbon-sulfur analyzer to measure the organic carbon content in the S1 rock powder sample, and multiply the organic carbon content by the organic matter content conversion coefficient to determine the amorphous organic matter content in the sample. S4. Measure the X-ray diffraction pattern of rock powder sample S1 using an X-ray diffractometer; Then, based on the X-ray diffraction pattern, the content of each mineral component in the sample was obtained by full-spectrum fitting, and the total amount of amorphous matter in the sample was obtained by internal standard method. S5. Subtract the amorphous organic matter content in the sample obtained in S3 from the total amorphous matter content in the sample obtained in S4 to obtain the amorphous inorganic matter content in the sample. S6. Based on Young's modulus and Poisson's ratio described in S2, calculate the rock brittleness index using the rock mechanics weighting method. S7. Based on the rock brittleness index obtained in S6, the content of each mineral component in the sample obtained in S4, the content of amorphous organic matter obtained in S3, and the content of amorphous inorganic matter obtained in S5, the amorphous weighting coefficient and correction coefficient are established using the mineral component method to solve the equation. S8. Select two core samples from the same stratum as the core sample described in S1, repeat steps S1-S7, establish two more equations for solving the amorphous weight coefficient and correction coefficient, and then solve the amorphous weight coefficient and correction coefficient based on the equations for solving the amorphous weight coefficient and correction coefficient established from the three core samples. Use the solution results as the rock mechanical weight coefficients of amorphous materials in the rock samples.

2. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 1, characterized in that: In S3, the organic carbon content in the S1 rock powder sample measured by the carbon-sulfur analyzer should meet the technical requirements of "Determination of Total Organic Carbon in Sedimentary Rocks: GB / T19145-2022".

3. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 1, characterized in that: In step S3, the content of amorphous organic matter in the sample is calculated using the following formula: X organic =P*Q TOC Formula 1 In Equation 1, X organic The content of amorphous organic matter in the sample is given by P, where P is the conversion coefficient between organic carbon and organic matter content, and Q is the value of Q. TOC This represents the organic carbon content in the sample.

4. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 3, characterized in that: The conversion coefficient between organic carbon and organic matter content meets the technical requirements of "Soil Testing Part 6: Determination of Soil Organic Matter: NY / T1121.6-2006" and has a value of 1.

724.

5. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 1, characterized in that: In step S4, corundum is used as an internal standard to calculate the total amount of amorphous material in the sample: In Equation 2, W amor M represents the total amount of amorphous matter in the sample; M represents the total mass of the sample, in grams. corundum The mass of the pure corundum powder sample is expressed in g; K corundum The reference strength parameter for corundum is °cps; l corundum The integral intensity of the diffraction peak selected for corundum, °cps; I i The integral intensity of the diffraction peak selected for the i-th mineral in the sample, °cps; K i Let be the reference intensity parameter for the i-th mineral in the sample.

6. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 1, characterized in that: In step S5, the content of amorphous inorganic matter in the sample is calculated using the following formula: X mineral =W amor -X organic Formula 3 In Equation 3, X mineral X represents the content of amorphous inorganic matter in the sample. organic W represents the content of amorphous organic matter in the sample. amor This represents the total amount of amorphous matter in the sample.

7. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 1, characterized in that: In S7, based on the rock brittleness index obtained in S6, the equations for solving the amorphous weighting coefficient and correction coefficient using the mineral composition method include: An equation for determining the brittleness index of rocks using the mineral composition method was established. Using the rock brittleness index obtained from S6 as the result of the established equation, the equation for solving the amorphous weighting coefficient and correction coefficient is established.

8. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 7, characterized in that: The equation for determining the rock brittleness index using the mineral composition method is as follows: In Equation 4, B M1 X is the rock brittleness index, dimensionless; α is the weighting coefficient for quartz; quartz X represents the mass fraction of quartz in the sample, %; β is the weighting coefficient for dolomite; X dolomite γ is the mass fraction of dolomite in the sample; γ is the weighting coefficient of calcite; X calcite X represents the calcite mass fraction in the sample, in percent; η is the weighting coefficient for feldspar; X feldspar denoted as feldspar mass fraction in the sample, %; ζ is the weighting coefficient for pyrite; X pyrite X represents the mass fraction of pyrite in the sample, in %; ω is the weighting coefficient for clay minerals; X clay X represents the mineral content of clay in the sample, in percentage (%); o represents the weighting coefficient of amorphous organic matter; X organic X represents the content of amorphous organic matter in the sample; m is the weighting coefficient of amorphous inorganic matter; X mineral denoted as the content of amorphous inorganic matter in the sample; k is a correction factor.

9. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 7, characterized in that: The equations for solving the amorphous weighting coefficient and correction coefficient are as follows: In Equation 5, B M1 X is the rock brittleness index, dimensionless; α is the weighting coefficient for quartz; quartz X represents the mass fraction of quartz in the sample, %; β is the weighting coefficient for dolomite; X dolomite γ is the mass fraction of dolomite in the sample; γ is the weighting coefficient of calcite; X calcite X represents the calcite mass fraction in the sample, in percent; η is the weighting coefficient for feldspar; X feldspar The mass fraction of feldspar in the sample, %; X is the weighting coefficient for pyrite; pyrite X represents the mass fraction of pyrite in the sample, in %; ω is the weighting coefficient for clay minerals; X clay X represents the mineral content of clay in the sample, in percentage (%); o represents the weighting coefficient of amorphous organic matter; X organic X represents the content of amorphous organic matter in the sample; m is the weighting coefficient of amorphous inorganic matter; X mineral κ represents the content of amorphous inorganic matter in the sample; κ is the correction factor.

10. The method for calculating the mechanical weighting coefficients of different types of amorphous rocks according to claim 1, characterized in that: In step S8, the solution for the amorphous weighting coefficient and correction coefficient based on the solution equations established from the three core samples includes: make The solution equations established based on the three core samples are as follows: Based on the system of equations, construct the matrix: Based on the matrix values, a program was written and substituted into Python software to calculate the weighting coefficient o of amorphous organic matter and the weighting coefficient m and correction coefficient k of amorphous inorganic matter, which were then used as the rock mechanical weighting coefficients of amorphous materials in the rock sample.

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