A method for determining shale multi-component matrix porosity and an oil and gas reservoir evaluation method

Abstract

The present invention provides a method for determining multi-component matrix porosity in shale and a method for evaluating oil and gas reservoirs. The method comprises: obtaining a matrix porosity value, rock density, and the mass percentages of each component; substituting the matrix porosity value, rock density, and mass percentages of each component of the shale sample into a preset first formula to obtain the unit mass pore volume of each component in the shale; and using a preset second formula to obtain the matrix porosity of each component in the shale. This method can calculate the multi-component matrix porosity, helping to understand the degree of shale pore development and its controlling factors, clarifying the size and proportion of the multi-component matrix porosity in the shale layer, and facilitating the calculation of rock reservoir space, fluid saturation, and geological reserves. The method is highly operational, computationally efficient, and accurate.

Description

Technical Field

[0001] The present invention belongs to the technical field of geological exploration, and in particular relates to a method for determining the porosity of a shale multi-component matrix and a method for evaluating an oil and gas reservoir. Background Art

[0002] Shale gas is a type of unconventional natural gas resource, characterized by its self-generation and self-storage. my country boasts abundant shale gas resources. After nearly a decade of development, shale gas has now been industrialized, with national shale gas production reaching 22.8 billion cubic meters in 2021. Shale gas has become a key area of ​​growth in my country's natural gas production, and vigorous development of shale gas is crucial for meeting my country's rapidly growing energy demand and promoting clean energy utilization.

[0003] Shale generally contains three types of matrices: brittle minerals (quartz, feldspar, etc.), clay minerals (illite, chlorite, etc.), and organic matter. The pores developed in shale are also primarily related to these three types of minerals and can be divided into brittle mineral pores, clay mineral pores, and organic pores. Some literature collectively refers to brittle mineral pores and clay mineral pores as inorganic pores. The development of inorganic and organic pores varies in shales at different depths and in different strata. The development of inorganic pores is primarily influenced by diagenesis, while the development of organic pores is primarily influenced by the maturity of organic matter and hydrocarbon generation.

[0004] Porosity is a key parameter in oil and gas reservoir evaluation, crucial for determining rock reservoir space, fluid saturation, and calculating geological reserves. Shale is dense, primarily characterized by micro- and nano-pores, resulting in lower porosity and permeability than conventional reservoirs. Numerous methods exist for shale porosity testing, including gas injection porosimetry (GIP), water immersion porosimetry (WIP), and nuclear magnetic resonance (NMR). Summary of the Invention

[0005] In order to enrich the porosity testing methods and apply them to more application scenarios, the present invention proposes a method for determining the multi-component matrix porosity of shale, including:

[0006] Prepare shale samples in a number not less than the number of shale components, and prepare each shale sample into two types: plug samples and particle samples;

[0007] A preset first experiment was conducted on the plug sample of each shale sample to obtain the total matrix porosity value and rock density;

[0008] Performing a preset second experiment on a particle sample of each shale sample to obtain the mass percentage of each component in the shale, wherein the components include at least brittle minerals, clay minerals, and organic matter;

[0009] Substitute the matrix porosity values, rock density, and mass percentages of each component of all shale samples into the preset first formula to obtain the unit mass pore volume of each component in the shale. The preset first formula is:

[0010]

[0011] The matrix porosity of each component in the shale is obtained using the preset second formula, which is:

[0012]

[0013] in, is the total matrix porosity, is the porosity of brittle minerals, is the porosity of clay minerals, is the organic matter porosity%; V p is the total matrix pore volume, m 3 ; V t is the total rock volume, m 3 ; V pb is the pore volume of brittle minerals per unit mass, m 3 / t;V pc is the pore volume per unit mass of clay minerals, m 3 / t;V po is the pore volume of organic matter per unit mass, m 3 / t;m s is the total rock mass, t; m b is the mass percentage of brittle minerals in shale, %; m c is the mass percentage of clay minerals in shale, %; m o is the mass percentage of organic matter in shale, %; ρ s is the density of shale rock, t / m 3 .

[0014] Furthermore, a preset first experiment is conducted on the plug sample of each shale sample to obtain the matrix porosity value and rock density, including;

[0015] Helium porosity testing was performed on a portion of the plunger samples to obtain total matrix porosity values;

[0016] The rock density of another part of the plunger samples was measured to obtain the determined rock density.

[0017] Furthermore, a preset second experiment is performed on the particle sample of each shale sample to obtain the mass percentage of each component in the shale, including:

[0018] X-ray diffraction experiments were conducted on some particle samples to obtain the mass percentage of brittle minerals and clay minerals;

[0019] Another part of the particle samples was subjected to carbon and sulfur element analysis experiments, and the particle samples after the experiment were burned at high temperature to obtain the mass percentage of organic matter.

[0020] Furthermore, each shale sample is prepared into two types: plug sample and particle sample, including:

[0021] Using shale samples, a plug sample of a predetermined length is prepared;

[0022] The remaining shale samples were crushed into particle samples;

[0023] Dry plunger samples and particle samples.

[0024] Furthermore, helium porosity tests were performed on some of the plunger samples to obtain the total matrix porosity values, including:

[0025] Place the plunger sample into the gas porosimeter, remove the air in the pores of the plunger sample, and apply helium at a preset pressure without applying confining pressure, so that the helium enters the pores of the plunger sample;

[0026] After the pressure in the pores of the plunger sample reaches equilibrium, the total matrix porosity value is calculated using Boyle's law.

[0027] Furthermore, the rock density of another part of the plunger samples is measured to determine the rock density, including:

[0028] The plunger sample is placed in a rock density meter and the rock density is determined by taking the average value of multiple measurements.

[0029] Furthermore, X-ray diffraction experiments were performed on some particle samples to obtain the mass percentage of brittle minerals and clay minerals, including:

[0030] The particle sample is placed in an X-ray diffractometer to obtain a diffraction pattern;

[0031] Importing the diffraction pattern into a preset software, comparing the measurement results obtained based on the diffraction pattern with the standard library data of the preset software to determine the mineral composition;

[0032] The mass percentage of brittle minerals and clay minerals was determined based on the peak areas in the diffraction pattern.

[0033] Furthermore, another part of the pellet samples was subjected to carbon and sulfur element analysis experiments. The pellet samples after the experiment were burned at high temperature to obtain the mass percentage of organic matter, including:

[0034] Conduct carbon and sulfur elemental analysis experiments to remove inorganic carbon from particle samples;

[0035] Perform high-temperature combustion to convert the carbon element in the particle sample into CO2;

[0036] Measure CO2 content;

[0037] The mass percentage of organic matter is obtained based on the carbon content in CO2 and the mass of the particle sample.

[0038] Furthermore, the matrix porosity values, rock density, and mass percentages of each component of all shale samples are substituted into the preset first formula to obtain the unit mass pore volume of each component in the shale, including:

[0039] The pore volume V per unit mass of brittle minerals pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po Set to unknown parameters;

[0040] The matrix porosity values ​​of all shale samples Rock density ρ s 、Mass percentage of brittle minerals in shale m b , Mass percentage of clay minerals in shale m c , mass percentage of organic matter in shale m o Substitute the preset first formula to obtain a set of pore volume V per unit mass of brittle minerals: pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po The linear equations of ;

[0041] The linear equations were solved using the multivariate linear regression method to obtain the pore volume V per unit mass of brittle minerals. pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po .

[0042] On the other hand, the present invention also discloses an oil and gas reservoir evaluation method, which uses the above-mentioned shale multi-component matrix porosity determination method to determine rock storage space, fluid saturation and geological reserve calculation.

[0043] Based on the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0044] The present invention establishes a shale multi-component matrix porosity interpretation model, clarifying that the matrix porosity of each component is related to parameters such as total matrix porosity, the porosity volume of each component mineral, the mass percentage of each component mineral, and shale rock density. The shale multi-component matrix porosity determination method proposed in the present invention can measure multiple shale samples at the same horizon. Using parameters such as total matrix porosity, the porosity volume of each component mineral, the mass percentage of each component mineral, and shale rock density, the multi-component matrix porosity can be calculated. This helps understand the degree of shale pore development and its controlling factors, and clarifies the size and proportion of multi-component matrix porosity in the shale at that horizon. The method is suitable for determining the matrix porosity of each component in shale across major blocks, facilitating the calculation of rock reservoir space, fluid saturation, and geological reserves. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 A schematic flow chart of a method for determining shale multi-component matrix porosity provided in an embodiment of the present invention;

[0047] Figure 2 1 is a flow chart of step S140 in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The inventors found that existing porosity testing methods can only obtain the porosity value of shale, and cannot effectively distinguish the porosity of the above-mentioned mineral components. It is impossible to clearly determine the porosity and proportion of each mineral component, which is not conducive to the calculation of rock storage space, fluid saturation and geological reserves. Therefore, the inventors made the present invention after further research and development.

[0049] Specifically, the inventors found in further research that the matrix in shale is divided into three categories: brittle minerals, clay minerals and organic matter. Since pores are developed in these three types of matrices, the pore composition can be classified.

[0050] Based on the above three-component classification method, the inventors established a shale matrix pore volume composition model. The total matrix pore volume consists of three parts, which can be expressed as:

[0051] V p =V pb ×m s ×m b +V pc ×ms ×m c +V po ×m s ×m o (1)

[0052] The shale matrix porosity is the ratio of the matrix pore volume to the rock volume. Combining equation (1), it can be expressed as:

[0053]

[0054] V t =m s / ρ s (3)

[0055]

[0056] Therefore, the shale matrix porosity composition model is finally established as follows:

[0057]

[0058] In the above equation, is the total matrix porosity of shale, %; V p is the total matrix pore volume, m 3 ; V t is the total rock volume, m 3 ; V pb is the pore volume of brittle minerals per unit mass, m 3 / t;V pc is the pore volume per unit mass of clay minerals, m 3 / t;V po is the pore volume of organic matter per unit mass, m 3 / t;m s is the total rock mass, t; m b is the mass percentage of brittle minerals in shale, %; m c is the mass percentage of clay minerals in shale, %; m o is the mass percentage of organic matter in shale, %; ρ s is the density of shale rock, t / m 3 .

[0059] According to the above theoretical deduction, if parameters such as total matrix porosity, porosity volume of each component mineral, mass percentage of each component mineral, and shale rock density can be obtained, multi-component matrix porosity can be calculated, which helps to understand the degree of shale pore development and its controlling factors, and is conducive to the calculation of rock reservoir space, fluid saturation, and geological reserves.

[0060] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0061] The embodiment of the present invention provides a method for determining the porosity of a shale multi-component matrix. Figure 1 As shown, it includes steps S110 to S150, specifically:

[0062] Step S110 , preparing shale samples in a number not less than the number of shale components, and preparing each shale sample into two types: a plug sample and a particle sample.

[0063] In this example, the matrix in shale is divided into three categories: brittle minerals, clay minerals, and organic matter. Therefore, at least three shale samples were required. For each shale sample, a 3-4 cm long plug was prepared. The remaining sample was then crushed into 40-80 mesh particles and dried.

[0064] Step S120 : performing a preset first experiment on the plug sample of each shale sample to obtain a total matrix porosity value and a rock density.

[0065] Performing a preset first experiment on the plug sample of each shale sample may include: performing a helium porosity test on a portion of the plug samples to obtain a total matrix porosity value, and performing a rock density measurement on another portion of the plug samples to obtain a determined rock density.

[0066] Specifically, a portion of the plunger sample is placed in a gas porosimeter, the air in the pores of the plunger sample is removed, and helium of a preset pressure is applied without applying confining pressure, so that the helium enters the pores of the plunger sample; after the pressure in the pores of the plunger sample reaches equilibrium (when the equilibrium conditions are set artificially, the porosimeter device will generally automatically determine whether the pressure is balanced, such as the pressure change within 10 minutes is less than 1 psi), the porosimeter system analysis software can use Boyle's law to set the initial gas pressure and make the helium expand isothermally into the core chamber. The gas continuously diffuses into the pores inside the core, and the total matrix porosity value can be calculated based on the pressure change characteristics, the core chamber volume and the gas state equation. In specific applications, the gas porosimeter can test the sample under both confining pressure and no confining pressure. Under confining pressure, the sample is affected by the external pressure, the pores are compressed, and the measured porosity is not the total porosity. Therefore, in this embodiment, it is necessary to obtain the total porosity value under no confining pressure. For another part of the plunger samples, the plunger samples need to be placed in a rock density meter and the rock density is determined by taking the average value through multiple measurements.

[0067] Step S130 : performing a preset second experiment on the particle sample of each shale sample to obtain the mass percentage of each component in the shale, wherein the components at least include brittle minerals, clay minerals, and organic matter.

[0068] The predetermined second experiment for the particle samples of each shale sample may include: performing an X-ray diffraction experiment on a portion of the particle samples to determine the mass percentage of brittle minerals and clay minerals; performing a carbon and sulfur elemental analysis experiment on another portion of the particle samples; and performing high-temperature combustion on the particle samples after the experiment to determine the mass percentage of organic matter.

[0069] Specifically, part of the particle sample is placed in an X-ray diffractometer. After the X-ray diffraction experiment is completed, the obtained diffraction pattern can be imported into the corresponding software. The measurement results obtained according to the diffraction pattern are compared with the standard library data of the preset software to determine the mineral composition. The mineral content is determined according to the area of ​​the peak in the spectrum to obtain the mass percentage of brittle minerals and the mass percentage of clay minerals.

[0070] Another portion of the pellet samples was subjected to carbon and sulfur elemental analysis. After removing inorganic carbon with hydrochloric acid, the pellets were burned at high temperatures to convert the carbon in the samples into CO2. The CO2 content was determined by infrared detection based on the intensity of light absorbed by the gas. By dividing the carbon content in the gas by the mass of the shale sample, the total organic carbon content in the shale sample was obtained, and thus the mass percentage of organic matter (mo).

[0071] Step S140: Substitute the matrix porosity values, rock density, and mass percentages of each component of all shale samples into a preset first formula to obtain the unit mass pore volume of each component in the shale. The preset first formula is:

[0072]

[0073] in, is the total matrix porosity; V p is the total matrix pore volume, m 3 ; V t is the total rock volume, m 3 ; V pb is the pore volume of brittle minerals per unit mass, m 3 / t;V pc is the pore volume per unit mass of clay minerals, m 3 / t;V po is the pore volume of organic matter per unit mass, m 3 / t;m s is the total rock mass, t; m b is the mass percentage of brittle minerals in shale, %; m c is the mass percentage of clay minerals in shale, %; m ois the mass percentage of organic matter in shale, %; ρ s is the density of shale rock, t / m 3 .

[0074] Specifically, the matrix porosity values ​​φ and rock density ρ of all shale samples are s , the mass percentage of each component is substituted into the preset first formula to obtain the unit mass pore volume of each component in the shale, including steps S141 to S143, combined with Figure 2 As shown:

[0075] Step S141: The pore volume V of the brittle mineral per unit mass is pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po Set to unknown parameters.

[0076] Step S142: The matrix porosity values ​​of all shale samples are Rock density ρ s 、Mass percentage of brittle minerals in shale m b , Mass percentage of clay minerals in shale m c , mass percentage of organic matter in shale m o Substitute the preset first formula to obtain a set of pore volume V per unit mass of brittle minerals: pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po Preferably, the number of linear equations in the linear equation system is consistent with the number of samples.

[0077] Step S143, using the multivariate linear regression method to solve the linear equations, and obtain the unit mass brittle mineral pore volume V pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po .

[0078] Step S150: derive the matrix porosity of each component in the shale using a preset second formula. The preset second formula is:

[0079]

[0080] in, is the porosity of brittle minerals, is the porosity of clay minerals, is the organic matter porosity%; V p is the total matrix pore volume, m 3 ; V t is the total rock volume, m3 ; V pb is the pore volume of brittle minerals per unit mass, m 3 / t;V pc is the pore volume per unit mass of clay minerals, m 3 / t;V po is the pore volume of organic matter per unit mass, m 3 / t;m s is the total rock mass, t; m b is the mass percentage of brittle minerals in shale, %; m c is the mass percentage of clay minerals in shale, %; m o is the mass percentage of organic matter in shale, %; ρ s is the density of shale rock, t / m 3 .

[0081] After obtaining the pore volume V per unit mass of brittle minerals pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po Then, the matrix porosity of each component in the shale can be obtained by combining the total matrix porosity value obtained in step S120, the rock density, and the mass percentage of each component in the shale obtained in step S130 using the preset second formula.

[0082] The inventors conducted multiple experiments using the method disclosed in this embodiment. The experimental results show that the method for determining the multi-component matrix porosity of shale proposed in this embodiment is highly operable, computationally efficient, and accurate. Table 1 shows some of the experimental results.

[0083] Table 1

[0084]

[0085] The inventors discovered that existing porosity testing methods can only obtain the porosity value of shale, but cannot effectively distinguish the porosity of the above-mentioned mineral components, nor can they clearly determine the porosity and proportion of each mineral component. Therefore, through further research and development, a shale multi-component matrix porosity interpretation model was established, which clarified that the matrix porosity of each component is related to parameters such as total matrix porosity, the porosity volume of each component mineral, the mass percentage of each component mineral, and the shale rock density. The shale multi-component matrix porosity determination method proposed in the present invention can measure multiple shale samples at the same horizon. Using parameters such as total matrix porosity, the porosity volume of each component mineral, the mass percentage of each component mineral, and the shale rock density, the multi-component matrix porosity can be calculated. This helps to understand the degree of shale pore development and its controlling factors, and clarifies the size and proportion of multi-component matrix porosity in the shale at that horizon. It is suitable for determining the matrix porosity of each component shale in major blocks, and is conducive to the calculation of rock reservoir space, fluid saturation, and geological reserves.

[0086] It is understood that in other embodiments, the matrix porosity values, rock density, and mass percentages of each component of all shale samples can also be obtained by other methods. The embodiments of the present invention do not limit the specific means of obtaining the parameters. After obtaining the above parameter values, the above parameters can be substituted into the preset first formula to obtain the unit mass pore volume of each component in the shale. The preset first formula is:

[0087]

[0088] The matrix porosity of each component in the shale is obtained using the preset second formula, which is:

[0089]

[0090] in, is the total matrix porosity, is the porosity of brittle minerals, is the porosity of clay minerals, is the organic matter porosity%; V p is the total matrix pore volume, m 3 ; V t is the total rock volume, m 3 ; V pb is the pore volume of brittle minerals per unit mass, m 3 / t;V pc is the pore volume per unit mass of clay minerals, m 3 / t;V po is the pore volume of organic matter per unit mass, m 3 / t;m s is the total rock mass, t; m bis the mass percentage of brittle minerals in shale, %; m c is the mass percentage of clay minerals in shale, %; m o is the mass percentage of organic matter in shale, %; ρ s is the density of shale rock, t / m 3 .

[0091] In the foregoing detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the invention comprises less than all the features of any individual disclosed embodiment. The appended claims are therefore hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0092] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purposes of describing the above embodiments, but it will be appreciated by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to encompass all such changes, modifications and variations that fall within the scope of the appended claims. Furthermore, to the extent that the term "comprising" is used in the specification or claims, the term is intended to be encompassed in a manner similar to the term "including," as explained by "including," when used as a transitional word in the claims. Furthermore, any use of the term "or" in the specification of the claims is intended to mean a "non-exclusive or."

Claims

1. A method for determining shale multi-component matrix porosity, characterized in that: The following steps are involved: Prepare shale samples in a number not less than the number of shale components, and prepare each shale sample into two types: plug samples and particle samples; A preset first experiment was conducted on the plug sample of each shale sample to obtain the total matrix porosity value and rock density; Performing a preset second experiment on a particle sample of each shale sample to obtain the mass percentage of each component in the shale, wherein the components include at least brittle minerals, clay minerals, and organic matter; Substitute the matrix porosity values, rock density, and mass percentages of each component of all shale samples into the preset first formula to obtain the unit mass pore volume of each component in the shale. The preset first formula is: The matrix porosity of each component in the shale is obtained using the preset second formula, which is: in, is the total matrix porosity, is the porosity of brittle minerals, is the porosity of clay minerals, is the organic matter porosity%; V p is the total matrix pore volume; V t is the total rock volume; V pb V is the pore volume of brittle minerals per unit mass; pc is the pore volume per unit mass of clay minerals; V po is the pore volume of organic matter per unit mass; m s is the total rock mass; m b is the mass percentage of brittle minerals in shale; m c is the mass percentage of clay minerals in shale; m o is the mass percentage of organic matter in shale; ρ s is the density of shale rock.

2. The method according to claim 1, wherein The predetermined first experiment is performed on the plug sample of each shale sample to obtain the matrix porosity value and rock density, including: Helium porosity testing was performed on a portion of the plunger samples to obtain total matrix porosity values; The rock density of another part of the plunger samples was measured to obtain the determined rock density.

3. The method according to claim 1, wherein The second experiment is performed on the particle sample of each shale sample to obtain the mass percentage of each component in the shale, including: X-ray diffraction experiments were conducted on some particle samples to obtain the mass percentage of brittle minerals and clay minerals; Another part of the particle samples was subjected to carbon and sulfur element analysis experiments, and the particle samples after the experiment were burned at high temperature to obtain the mass percentage of organic matter.

4. The method according to claim 1, wherein Each shale sample is prepared into two types: a plug sample and a particle sample, including: Using shale samples, a plug sample of a predetermined length is prepared; The remaining shale samples were crushed into particle samples; Dry plunger samples and particle samples.

5. The method according to claim 2, wherein The helium porosity test is performed on a portion of the plunger samples to obtain a total matrix porosity value, including: Place the plunger sample into the gas porosimeter, remove the air in the pores of the plunger sample, and apply helium at a preset pressure without applying confining pressure, so that the helium enters the pores of the plunger sample; After the pressure in the pores of the plunger sample reaches equilibrium, the total matrix porosity value is calculated using Boyle's law.

6. The method according to claim 2, wherein The rock density of another part of the plunger samples was measured to determine the rock density, including: The plunger sample is placed in a rock density meter and the rock density is determined by taking the average value of multiple measurements.

7. The method according to claim 3, wherein X-ray diffraction experiments were performed on some particle samples to obtain the mass percentage of brittle minerals and clay minerals, including: The particle sample is placed in an X-ray diffractometer to obtain a diffraction pattern; Importing the diffraction pattern into a preset software, comparing the measurement results obtained based on the diffraction pattern with the standard library data of the preset software to determine the mineral composition; The mass percentage of brittle minerals and clay minerals was determined based on the peak areas in the diffraction pattern.

8. The method according to claim 3, wherein The carbon and sulfur element analysis experiment is performed on another part of the particle samples, and the particle samples after the experiment are burned at high temperature to obtain the mass percentage of organic matter, including: Conduct carbon and sulfur elemental analysis experiments to remove inorganic carbon from particle samples; Perform high-temperature combustion to convert the carbon element in the particle sample into CO2; Measure CO2 content; The mass percentage of organic matter is obtained based on the carbon content in CO2 and the mass of the particle sample.

9. The method according to claim 1, wherein Substituting the matrix porosity values, rock density, and mass percentages of each component of all shale samples into a preset first formula to obtain the unit mass pore volume of each component in the shale includes: The pore volume V per unit mass of brittle minerals pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po Set to unknown parameters; The matrix porosity values ​​of all shale samples Rock density ρ s 、Mass percentage of brittle minerals in shale m b , Mass percentage of clay minerals in shale m c , mass percentage of organic matter in shale m o Substitute the preset first formula to obtain a set of pore volume V per unit mass of brittle minerals: pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po The linear equations of ; The linear equations were solved using the multivariate linear regression method to obtain the pore volume V per unit mass of brittle minerals. pb 、Pore volume per unit mass of clay minerals V pc , organic pore volume per unit mass V po .

10. A method for determining shale multi-component matrix porosity, characterized in that: The following steps are involved: The matrix porosity value, rock density, and mass percentage of each component of all shale samples were obtained according to the preset rules; Substitute the matrix porosity values, rock density, and mass percentages of each component of all shale samples into the preset first formula to obtain the unit mass pore volume of each component in the shale. The preset first formula is: The matrix porosity of each component in the shale is obtained using the preset second formula, which is: in, is the total matrix porosity, is the porosity of brittle minerals, is the porosity of clay minerals, is the organic matter porosity%; V p is the total matrix pore volume; V t is the total rock volume; V pb V is the pore volume of brittle minerals per unit mass; pc is the pore volume per unit mass of clay minerals; V po is the pore volume of organic matter per unit mass; m s is the total rock mass; m b is the mass percentage of brittle minerals in shale; m c is the mass percentage of clay minerals in shale; m o is the mass percentage of organic matter in shale; ρ s is the density of shale rock.

11. A method for evaluating an oil and gas reservoir, characterized in that: The method comprises the method for determining the shale multi-component matrix porosity according to any one of claims 1 to 10.

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