Method, system, electronic device and storage medium for determining contribution rate of shale components to composite porosity

Abstract

The present invention provides a method, system, electronic device, and storage medium for determining the contribution rate of shale components to composite porosity. The method includes: obtaining images of each composite pore in a target shale sample and the shale components that make up each composite pore in the target shale; classifying the various shale components into N categories, where N is greater than 2; depicting the boundaries of each shale component in each composite pore in each composite pore image in the target shale sample; and determining the tortuosity of the boundaries of each shale component in each composite pore; determining the contribution rate of each shale component in each composite pore based on the tortuosity of the boundaries of each shale component in each composite pore and the radius of the minimum circumscribed circle of each composite pore; and determining the contribution rate of each shale component in each composite pore in the target shale sample to the composite porosity based on the contribution rate of each shale component in each composite pore.

Description

Technical Field

[0001] The present invention relates to a method, system, electronic equipment and storage medium for determining the contribution rate of shale components to composite porosity. Background Art

[0002] Shale oil and gas are a significant component of global oil and gas resources, possessing significant exploration and development value, and have already yielded considerable economic benefits. Porosity is the reservoir of shale oil and gas, and composite pores are the primary pore type in shale reservoirs. Composite pores are composed of multiple shale components. Due to the complex and variable composition of shale and the irregular shapes of composite pores, the contribution of different shale components to composite pores is difficult to effectively assess. Clarifying the contribution of different shale components to composite pores will help reveal the genetic mechanism of shale pores. Furthermore, composite pores composed of minerals such as quartz and feldspar are more susceptible to fracturing, facilitating the recovery of oil and gas within them. However, the unclear contribution of minerals such as quartz and feldspar to composite pores has hindered the accurate evaluation of the fracturing effect of shale oil and gas. Therefore, determining the contribution of shale components to composite pores can more effectively evaluate the genetic mechanism and fracturing effect of shale oil and gas, providing important support for shale oil and gas exploration and development.

[0003] Shale reservoirs develop both single pores and composite pores, with composite pores playing a dominant role in the storage and flow of shale oil and gas. Composite pores are characterized by varying sizes, shapes, and complex mineral contact relationships. Existing techniques typically characterize composite pores by their area and shape factor, determining their contribution to the overall shale porosity. However, analysis of the components of composite pores is lacking, leaving the contribution of shale components to composite pores unclear. Furthermore, composite pores are composed of multiple components, and cannot be simply attributed to the contribution of a single component.

[0004] In summary, current technical means cannot meet the requirements for accurately evaluating the genesis mechanism and fracturing transformation effect of shale oil and gas. It is urgent to develop a method to determine the contribution rate of shale components to composite porosity. Summary of the Invention

[0005] The object of the present invention is to provide a method, system, electronic equipment and storage medium capable of determining the contribution rate of shale components to composite porosity.

[0006] In order to achieve the above objectives, the present invention provides the following four technical solutions.

[0007] In a first aspect, the present invention provides a method for determining the contribution rate of shale components to composite porosity, wherein the method comprises:

[0008] Acquire images of each composite pore in the target shale sample and shale components constituting each composite pore in the target shale;

[0009] Classify various shale components into N categories where N is greater than 2, and depict the boundaries of various shale components in each composite pore in each composite pore image in the target shale sample, thereby determining the tortuosity of the boundaries of various shale components in each composite pore;

[0010] Based on the tortuosity of the boundaries of various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution rate of each shale component in each composite pore is determined respectively;

[0011] Based on the contribution rate of each shale component in each composite pore, the contribution rate of each shale component in the target shale sample to the composite pore is determined.

[0012] In a second aspect, the present invention provides a system for determining the contribution of shale components to composite porosity, wherein the system comprises:

[0013] Data acquisition module: used to obtain images of each composite pore in the target shale sample and the shale components that constitute each composite pore in the target shale;

[0014] Tortuosity determination module: used to classify various shale components into N categories (where N is greater than 2), depict the boundaries of various shale components in each composite pore in the image of each composite pore in the target shale sample, and then determine the tortuosity of the boundaries of various shale components in each composite pore;

[0015] Contribution rate determination module for each component in each pore: used to determine the contribution rate of each shale component in each composite pore based on the tortuosity of the boundaries of each shale component in each composite pore and the radius of the minimum circumscribed circle of each composite pore;

[0016] Contribution rate determination module of each component to pores: used to determine the contribution rate of each shale component to the composite pores in the target shale sample based on the contribution rate of each shale component in each composite pore.

[0017] In a third aspect, the present invention provides an electronic device comprising a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method for determining the contribution rate of shale components to composite porosity in the first aspect are implemented.

[0018] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for determining the contribution rate of shale components to composite porosity in the first aspect.

[0019] The technical solution provided by the present invention can determine the contribution rate of shale components to composite porosity, providing more accurate technical support for shale oil and gas genesis analysis and fracturing transformation effect evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the image of the first composite pore.

[0021] Figure 2 This is the shale component diagram of the first complex pore.

[0022] Figure 3 Schematic diagram of the boundaries of various shale components in the first composite pore.

[0023] Figure 4 Schematic diagram of the contribution of each boundary of the first composite pore to the minimum circumscribed circle. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] A specific embodiment of the present invention provides a method for determining the contribution rate of shale components to composite porosity, wherein the method comprises:

[0026] Step S1: acquiring images of each composite pore in the target shale sample and shale components constituting each composite pore in the target shale;

[0027] Step S2: Classify various shale components into N categories where N is greater than 2, and depict the boundaries of various shale components in each composite pore in each composite pore image in the target shale sample, thereby determining the tortuosity of the boundaries of various shale components in each composite pore;

[0028] Step S3: Based on the tortuosity of the boundaries of the various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution rate of each shale component in each composite pore is determined respectively;

[0029] Step S4: Based on the contribution rate of each shale component in each composite pore, the contribution rate of each shale component in the target shale sample to the composite pore is determined.

[0030] This method can be used to determine the contribution of shale components to composite porosity, providing more accurate technical support for shale oil and gas genesis analysis and fracturing transformation effect evaluation.

[0031] In one embodiment, the images of each composite pore in the target shale sample and the shale components constituting each composite pore in the target shale are determined by a scanning electron microscope and a mineral quantitative evaluation system;

[0032] For example: using the high-resolution mode of a scanning electron microscope, images of no less than 100 composite pores in the target shale sample are obtained; and the shale components that make up all the composite pores in the corresponding image are obtained through a mineral quantitative evaluation system.

[0033] In one embodiment, the number of the composite pores is not less than 100.

[0034] In one embodiment, step S2, classifying various shale components into N categories where N is greater than 2, and depicting the boundaries of various shale components in each composite pore in each composite pore image in the target shale sample, and then determining the tortuosity of the boundaries of various shale components in each composite pore, includes:

[0035] The shale components are divided into N categories; where N is greater than 2;

[0036] In each composite pore image in the target shale sample, the boundaries of each shale component of each composite pore are depicted respectively; wherein each composite pore is composed of 2-N types of shale components, and the number of boundaries of each shale component of any composite pore is 2-N;

[0037] Based on the boundaries of various shale components of each composite pore obtained by characterization, the length and straight-line distance of the boundaries of various shale components of each composite pore are determined respectively;

[0038] Determining the tortuosity of the boundaries of the various shale components in each composite pore based on the length and straight-line distance of the boundaries of the various shale components in each composite pore;

[0039] Furthermore, shale components are divided into six categories: quartz, feldspar (including potassium feldspar and plagioclase), carbonate minerals (including calcite and dolomite), clay minerals (including kaolinite, illite, mixed layers of illite and smectite, chlorite), heavy minerals (including pyrite and barite), and organic matter.

[0040] Furthermore, the tortuosity is determined by the following formula:

[0041] When the i-th composite pore contains the j-th type of shale component, τ ij =Lt ij ÷L0 ij

[0042] When the i-th composite pore does not contain the j-th type of shale component, τ ij =0

[0043] Where, τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; Lt ij L0 is the length of the boundary of the j-th shale component of the i-th composite pore; ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; j is a natural number less than or equal to N.

[0044] In one embodiment, step S3, based on the tortuosity of the boundaries of the various shale components in each composite pore and in combination with the radius of the minimum circumscribed circle of each composite pore, determines the contribution rate of each shale component in each composite pore, including:

[0045] Based on the tortuosity of the boundaries of various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution of the boundaries of various shale components in each composite pore to the minimum circumscribed circle is determined respectively;

[0046] Based on the contribution of the boundaries of various shale components in each composite pore to the minimum circumscribed circle, the contribution rate of each shale component in each composite pore is determined respectively;

[0047] Furthermore, the contribution of the boundaries of various shale components in each composite pore to the minimum circumscribed circle is determined by the following formula:

[0048] C ij =τ ij ×θ ij , where θ ij =2×arcsin(L0 ij ÷2r i )

[0049] Where C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; θ ij Lt is the angle of the minimum circumscribed circle occupied by the boundary of the j-th shale component of the i-th composite pore; ij L0 is the length of the boundary of the j-th shale component of the i-th composite pore; ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; r i is the radius of the minimum circumscribed circle of the i-th composite pore; j is a natural number less than or equal to N;

[0050] Furthermore, the contribution rate of each shale component in each composite pore is determined by the following formula:

[0051] R ij =C ij ÷(Ci1 +C i2 +…+C iN )

[0052] Where R ij is the contribution rate of the boundary of the j-th type of shale component in the i-th composite pore; C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; j is a natural number less than or equal to N.

[0053] In one embodiment, step S4, based on the contribution rate of each shale component in each composite pore, determining the contribution rate of each shale component in the target shale sample to the composite pores includes:

[0054] For each type of shale component, the contribution rate of this type of shale component in each composite pore is summed and averaged to obtain the contribution rate of this type of shale component to the composite pores in the target shale sample;

[0055] Furthermore, the contribution rate of a certain type of shale component in the target shale sample to the composite porosity is determined by the following formula:

[0056]

[0057] Where, P j is the contribution rate of the jth type of shale component to the composite porosity; R ij is the contribution rate of the boundary of the j-th type of shale component to the i-th composite pore; m is the number of composite pores.

[0058] The present invention also provides a specific embodiment of a system for determining the contribution of shale components to composite porosity. The system is used to implement the above-mentioned method for determining the contribution of shale components to composite porosity. The system includes:

[0059] Data acquisition module 21: used to obtain images of each composite pore in the target shale sample and shale components constituting each composite pore in the target shale;

[0060] Tortuosity determination module 22: used to classify various shale components into N categories (where N is greater than 2), depict the boundaries of various shale components in each composite pore in each composite pore image in the target shale sample, and then determine the tortuosity of the boundaries of various shale components in each composite pore;

[0061] Contribution rate determination module 23 for each component in each pore: used to determine the contribution rate of each shale component in each composite pore based on the tortuosity of the boundary of each shale component in each composite pore and the radius of the minimum circumscribed circle of each composite pore;

[0062] The contribution rate determination module 24 of each component to the pores is used to determine the contribution rate of each shale component to the composite pores in the target shale sample based on the contribution rate of each shale component in each composite pore.

[0063] In one embodiment, the images of each composite pore in the target shale sample and the shale components constituting each composite pore in the target shale are determined by a scanning electron microscope and a mineral quantitative evaluation system;

[0064] For example: using the high-resolution mode of a scanning electron microscope, images of no less than 100 composite pores in the target shale sample are obtained; and the shale components that make up all the composite pores in the corresponding image are obtained through a mineral quantitative evaluation system.

[0065] In one embodiment, the number of the composite pores is not less than 100.

[0066] In one embodiment, the tortuosity determination module 22 includes:

[0067] Shale component classification submodule 221: used to classify shale components into N categories; wherein N is greater than 2;

[0068] Boundary determination submodule 222: for depicting the boundaries of each shale component in each composite pore in the target shale sample. Each composite pore is composed of 2-N types of shale components, and the number of boundaries of each shale component in any composite pore is 2-N.

[0069] Boundary parameter determination submodule 223: for determining the length and straight-line distance of the boundaries of the various shale components in each composite pore based on the boundaries of the various shale components in each composite pore obtained by characterization;

[0070] The tortuosity determination submodule 224 is configured to determine the tortuosity of the boundaries of each shale component in each composite pore based on the length and straight-line distance of the boundaries of each shale component in each composite pore;

[0071] Furthermore, the shale component classification submodule 221 is used to classify shale components into six categories: quartz, feldspar (including potassium feldspar and plagioclase, etc.), carbonate minerals (including calcite and dolomite, etc.), clay minerals (including kaolinite, illite, mixed layer of illite and smectite, chlorite, etc.), heavy minerals (including pyrite and barite, etc.), and organic matter;

[0072] Furthermore, the tortuosity is determined by the following formula:

[0073] When the i-th composite pore contains the j-th type of shale component, τ ij =Lt ij ÷L0 ij

[0074] When the i-th composite pore does not contain the j-th type of shale component, τ ij =0

[0075] Where, τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; Lt ij L0 is the length of the boundary of the j-th shale component of the i-th composite pore; ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; j is a natural number less than or equal to N.

[0076] In one embodiment, the module 23 for determining the contribution rate of each component in each pore includes:

[0077] The first determination submodule 231 is configured to determine the contribution of the boundaries of the various shale components in each composite pore to the minimum circumscribed circle based on the tortuosity of the boundaries of the various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore;

[0078] The second determining submodule 232 is configured to determine the contribution rate of each shale component in each composite pore based on the contribution of the boundary of each shale component in each composite pore to the minimum circumscribed circle;

[0079] Furthermore, the contribution of the boundaries of various shale components in each composite pore to the minimum circumscribed circle is determined by the following formula:

[0080] C ij =τ ij ×θ ij , where θ ij =2×arcsin(L0 ij ÷2r i )

[0081] Where C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; θ ij Lt is the angle of the minimum circumscribed circle occupied by the boundary of the j-th shale component of the i-th composite pore; ij L0 is the length of the boundary of the j-th shale component of the i-th composite pore; ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; r i is the radius of the minimum circumscribed circle of the i-th composite pore; j is a natural number less than or equal to N;

[0082] Furthermore, the contribution rate of each shale component in each composite pore is determined by the following formula:

[0083] Rij =C ij ÷(C i1 +C i2 +…+C iN )

[0084] Where R ij is the contribution rate of the boundary of the j-th type of shale component in the i-th composite pore; C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; j is a natural number less than or equal to N.

[0085] In one embodiment, the contribution rate determination module 24 of each component to the pores is specifically configured to, for each type of shale component, sum and average the contribution rates of the shale component of that type in each composite pore to obtain the contribution rate of the shale component of that type to the composite pores in the target shale sample;

[0086] Furthermore, the contribution rate of a certain type of shale component in the target shale sample to the composite porosity is determined by the following formula:

[0087]

[0088] Where, P j is the contribution rate of the jth type of shale component to the composite porosity; R ij is the contribution rate of the boundary of the j-th type of shale component to the i-th composite pore; m is the number of composite pores.

[0089] The embodiments of the present invention also provide a specific implementation of an electronic device capable of implementing all steps of the method for determining the contribution rate of shale components to composite porosity in the above embodiment. The electronic device specifically includes the following contents:

[0090] processors, memories, communication interfaces, and buses;

[0091] The processor, memory, and communication interface communicate with each other via a bus; the communication interface is used to implement information transmission between the server-side device and the client-side device and other related devices; the processor is used to call the computer program in the memory. When the processor executes the computer program, all steps of the method for determining the contribution rate of shale components to composite porosity in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0092] Step S1: acquiring images of each composite pore in the target shale sample and shale components constituting each composite pore in the target shale;

[0093] Step S2: Classify various shale components into N categories where N is greater than 2, and depict the boundaries of various shale components in each composite pore in each composite pore image in the target shale sample, thereby determining the tortuosity of the boundaries of various shale components in each composite pore;

[0094] Step S3: Based on the tortuosity of the boundaries of the various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution rate of each shale component in each composite pore is determined respectively;

[0095] Step S4: Based on the contribution rate of each shale component in each composite pore, the contribution rate of each shale component in the target shale sample to the composite pore is determined.

[0096] An embodiment of the present invention also provides a computer-readable storage medium capable of implementing all steps of the method for determining the contribution rate of shale components to composite porosity in the above embodiment. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the computer program implements all steps of the method for determining the contribution rate of shale components to composite porosity in the above embodiment. For example, when the processor executes the computer program, the following steps are implemented:

[0097] Step S1: acquiring images of each composite pore in the target shale sample and shale components constituting each composite pore in the target shale;

[0098] Step S2: Classify various shale components into N categories where N is greater than 2, and depict the boundaries of various shale components in each composite pore in each composite pore image in the target shale sample, thereby determining the tortuosity of the boundaries of various shale components in each composite pore;

[0099] Step S3: Based on the tortuosity of the boundaries of the various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution rate of each shale component in each composite pore is determined respectively;

[0100] Step S4: Based on the contribution rate of each shale component in each composite pore, the contribution rate of each shale component in the target shale sample to the composite pore is determined.

[0101] Example 1

[0102] This embodiment provides a method for determining the contribution rate of shale components to composite porosity. The method is used to determine the contribution rate of shale components to composite porosity for continental shale in area A.

[0103] The method includes:

[0104] (1) First, a scanning electron microscope (SEM) high-resolution mode was used to obtain images of 125 composite pores in the target shale sample. The shale components that constituted all the composite pores in the corresponding images were obtained using a mineral quantitative evaluation system. Figure 1 Shown is the first of 125 composite pores.

[0105] (2) The shale components are divided into 6 types, namely quartz, feldspar (including potassium feldspar and plagioclase, etc.), carbonate minerals (including calcite and dolomite, etc.), clay minerals (including kaolinite, illite, illite-montmorillonite, chlorite, etc.), heavy minerals (including pyrite and barite, etc.), and organic matter. Among them, the first composite pore is composed of 3 components, namely quartz, feldspar and carbonate minerals (such as Figure 2 shown).

[0106] (3) In each composite pore image in the target shale sample, the boundaries of each shale component of each composite pore are respectively depicted, and based on the depicted boundaries of each shale component of each composite pore, the length and straight-line distance of the boundaries of each shale component of each composite pore are respectively determined; based on the length and straight-line distance of the boundaries of each shale component of each composite pore, the tortuosity of the boundaries of each shale component of each composite pore is respectively determined; wherein the tortuosity is determined by the following formula:

[0107] When the i-th composite pore contains the j-th type of shale component, τ ij =Lt ij ÷L0 ij

[0108] When the i-th composite pore does not contain the j-th type of shale component, τ ij =0

[0109] Where, τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; Lt ij L0 is the length of the boundary of the j-th shale component of the i-th composite pore; ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; j is a natural number less than or equal to N.

[0110] Take the first pore as an example: In the first composite pore, the boundary of quartz is Lt 11 , the straight-line distance L0 between the two end points of the boundary 11 The boundary of feldspar is Lt 12 , the straight-line distance L0 between the two end points of the boundary 12 The boundary of carbonate minerals is Lt 13 , the straight-line distance L0 between the two end points of the boundary 13 (See Figure 3The lengths and linear distances of the boundaries of quartz, feldspar, and carbonate minerals are shown in Table 1. Based on the lengths and linear distances of each composite pore boundary, the tortuosity of each boundary was calculated (Table 2). The tortuosity of the quartz boundary was 1.035, the feldspar boundary was 1.040, and the carbonate mineral boundary was 1.430.

[0111] (4) Based on the tortuosity of the boundaries of each shale component in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution of the boundaries of each shale component in each composite pore to the minimum circumscribed circle is determined; based on the contribution of the boundaries of each shale component in each composite pore to the minimum circumscribed circle, the contribution rate of each shale component in each composite pore is determined;

[0112] The contribution of the boundaries of various shale components in each composite pore to the minimum circumscribed circle is determined by the following formula:

[0113] C ij =τ ij ×θ ij , where θ ij =2×arcsin(L0 ij ÷2r i )

[0114] Where C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; θ ij Lt is the angle of the minimum circumscribed circle occupied by the boundary of the j-th shale component of the i-th composite pore; ij L0 is the length of the boundary of the j-th shale component of the i-th composite pore; ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; r i is the radius of the minimum circumscribed circle of the i-th composite pore; j is a natural number less than or equal to N;

[0115] The contribution rate of each shale component in each composite pore is determined by the following formula:

[0116] R ij =C ij ÷(C i1 +C i2 +…+C iN )

[0117] Where R ij is the contribution rate of the boundary of the j-th type of shale component in the i-th composite pore; C ijis the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; j is a natural number less than or equal to N.

[0118] Take the first pore as an example: draw the minimum circumscribed circle of the composite pore, and obtain the radius r1 of the minimum circumscribed circle as 738nm. Place the two end points of the boundary on the minimum circumscribed circle, and the straight line distance L0 1j The angle of the circle occupied θ 1j =2×arcsin(L0 1j ÷r1). The angle of the circle occupied by quartz is 111°, the angle of the circle occupied by feldspar is 146°, and the angle of the circle occupied by carbonate minerals is 103° (see Table 3). The contribution of each boundary to the minimum circumscribed circle C 1j =τ 1j ×θ 1j , where θ 1j =2×arcsin(L0 1j ÷2r1), see Figure 4 The contribution of quartz to the minimum circumscribed circle is 114.91, the contribution of feldspar to the minimum circumscribed circle is 151.83, and the contribution of carbonate minerals to the minimum circumscribed circle is 147.26 (see Table 4). The contribution rate of each shale component in the composite pore is determined by the following formula: 1j =C 1j ÷(C 11 +C 12 +C 13 The contribution rate of quartz to the composite pores is 0.28, the contribution rate of feldspar to the composite pores is 0.37, and the contribution rate of carbonate minerals to the composite pores is 0.36 (see Table 5).

[0119] (5) For each type of shale component, the contribution rate of the shale component in each composite pore is summed and averaged to obtain the contribution rate of the shale component in the target shale sample to the composite pore; wherein, the contribution rate of a certain type of shale component in the target shale sample to the composite pore is determined by the following formula:

[0120]

[0121] Where, P j is the contribution rate of the jth type of shale component to the composite porosity; R ij is the contribution rate of the boundary of the jth type of shale component in the i-th composite pore; m is the number of composite pores (see Table 6 for the results).

[0122] The contribution rate of quartz to the composite pores of shale is 0.27, the contribution rate of feldspar to the composite pores of shale is 0.18, the contribution rate of carbonate minerals to the composite pores of shale is 0.23, the contribution rate of clay minerals to the composite pores of shale is 0.19, the contribution rate of heavy minerals to the composite pores of shale is 0.05, and the contribution rate of organic matter to the composite pores of shale is 0.08.

[0123] Table 1

[0124] shale components quartz feldspar carbonate minerals Clay minerals heavy minerals organic matter Boundary length (nm) 1294 1484 1677 0 0 0 Linear distance (nm) 1250 1427 1173 0 0 0

[0125] Table 2

[0126] shale components quartz feldspar carbonate minerals Clay minerals heavy minerals organic matter Tortuosity 1.035 1.040 1.430 0 0 0

[0127] Table 3

[0128] shale components quartz feldspar carbonate minerals Clay minerals heavy minerals organic matter Angle (°) 111 146 103 0 0 0

[0129] Table 4

[0130] shale components quartz feldspar carbonate minerals Clay minerals heavy minerals organic matter Contribution of the boundary to the minimum circumcircle 114.91 151.83 147.26 0 0 0

[0131] Table 5

[0132] shale components quartz feldspar carbonate minerals Clay minerals heavy minerals organic matter Contribution rate of shale components 0.28 0.37 0.36 0 0 0

[0133] Table 6

[0134] shale components quartz feldspar carbonate minerals Clay minerals heavy minerals organic matter Contribution rate of shale components to composite porosity 0.27 0.18 0.23 0.19 0.05 0.08

[0135] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for determining the contribution of shale components to composite porosity, wherein: The method includes: Acquire images of each composite pore in the target shale sample and shale components constituting each composite pore in the target shale; Classify various shale components into N categories where N is greater than 2, and depict the boundaries of various shale components in each composite pore in each composite pore image in the target shale sample, thereby determining the tortuosity of the boundaries of various shale components in each composite pore; Based on the tortuosity of the boundaries of various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution rate of each shale component in each composite pore is determined respectively; Based on the contribution rate of each shale component in each composite pore, the contribution rate of each shale component in the target shale sample to the composite pore is determined; Among them, based on the tortuosity of the boundaries of various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution rate of each shale component in each composite pore is determined respectively, including: Based on the tortuosity of the boundaries of various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore, the contribution of the boundaries of various shale components in each composite pore to the minimum circumscribed circle is determined respectively; Based on the contribution of the boundaries of various shale components in each composite pore to the minimum circumscribed circle, the contribution rate of each shale component in each composite pore is determined separately. The formula is as follows: C ij =t ij ×θ ij , among which, i ij =2×arcsin(L0 ij ÷2r i ) Where C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; θ ij L0 is the angle of the minimum circumscribed circle occupied by the boundary of the j-th shale component of the i-th composite pore; ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; r i is the radius of the minimum circumscribed circle of the i-th composite pore; j is a natural number less than or equal to N; Among them, based on the contribution rate of each shale component in each composite pore, the contribution rate of each shale component in the target shale sample to the composite pore is determined, including: For each type of shale component, the contribution rate of this type of shale component in each composite pore is summed and averaged to obtain the contribution rate of this type of shale component to the composite pores in the target shale sample. The formula is as follows: Where, P j is the contribution rate of the jth type of shale component to the composite porosity; R ij is the contribution rate of the boundary of the j-th type of shale component to the i-th composite pore; m is the number of composite pores.

2. The method according to claim 1, wherein Various shale components are classified into N categories where N is greater than 2. The boundaries of various shale components in each composite pore are depicted in each composite pore image in the target shale sample, and the tortuosity of the boundaries of various shale components in each composite pore is determined, including: The shale components are divided into N categories; where N is greater than 2; In each composite pore image in the target shale sample, the boundaries of each shale component of each composite pore are depicted respectively; wherein each composite pore is composed of N-2 types of shale components, and the number of boundaries of each shale component of any composite pore is N-2; Based on the boundaries of various shale components of each composite pore obtained by characterization, the length and straight-line distance of the boundaries of various shale components of each composite pore are determined respectively; Based on the length and straight-line distance of the boundaries of each shale component in each composite pore, the tortuosity of the boundaries of each shale component in each composite pore is determined respectively.

3. The method according to claim 2, wherein: Classifying shale components into N categories includes: classifying shale components into 6 categories: quartz, feldspar, carbonate minerals, clay minerals, heavy minerals and organic matter.

4. The method according to claim 2, wherein: The tortuosity is determined by the following formula: When the i-th composite pore contains the j-th type of shale component, τ ij =Lt ij ÷L0 ij When the i-th composite pore does not contain the j-th type of shale component, τ ij =0 Where, τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; Lt ij is the length of the boundary of the j-th shale component of the i-th composite pore; L0 ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; j is a natural number less than or equal to N.

5. The method according to claim 1, wherein The contribution rate of each shale component in each composite pore is determined by the following formula: R ij =C ij ÷(C i1 +C i2 +…+C iN ) Where R ij is the contribution rate of the boundary of the j-th type of shale component in the i-th composite pore; C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; j is a natural number less than or equal to N.

6. A system for determining the contribution of shale components to composite porosity, wherein: The system includes: Data acquisition module: used to obtain images of each composite pore in the target shale sample and the shale components that constitute each composite pore in the target shale; Tortuosity determination module: used to classify various shale components into N categories (where N is greater than 2), depict the boundaries of various shale components in each composite pore in the image of each composite pore in the target shale sample, and then determine the tortuosity of the boundaries of various shale components in each composite pore; Contribution rate determination module for each component in each pore: used to determine the contribution rate of each shale component in each composite pore based on the tortuosity of the boundaries of each shale component in each composite pore and the radius of the minimum circumscribed circle of each composite pore; Contribution rate determination module of each component to pores: used to determine the contribution rate of each shale component to the composite pores in the target shale sample based on the contribution rate of each shale component in each composite pore; Among them, the module for determining the contribution rate of each component in each pore includes: The first determination submodule is configured to determine the contribution of the boundaries of the various shale components in each composite pore to the minimum circumscribed circle based on the tortuosity of the boundaries of the various shale components in each composite pore and the radius of the minimum circumscribed circle of each composite pore; The second determination submodule is used to determine the contribution rate of each shale component in each composite pore based on the contribution of the boundaries of each shale component in each composite pore to the minimum circumscribed circle. The formula is as follows: C ij =t ij ×θ ij , among which, i ij =2×arcsin(L0 ij ÷2r i ) Where C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; θ ij L0 is the angle of the minimum circumscribed circle occupied by the boundary of the j-th shale component of the i-th composite pore; ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; r i is the radius of the minimum circumscribed circle of the i-th composite pore; j is a natural number less than or equal to N; The module for determining the contribution rate of each component to the pores is used to sum and average the contribution rates of each type of shale component in each composite pore to obtain the contribution rate of this type of shale component to the composite pores in the target shale sample. The formula is as follows: Where, P j is the contribution rate of the jth type of shale component to the composite porosity; R ij is the contribution rate of the boundary of the j-th type of shale component to the i-th composite pore; m is the number of composite pores.

7. The system according to claim 6, wherein: The tortuosity determination module includes: Shale component classification submodule: used to classify shale components into N categories; where N is greater than 2; Boundary determination submodule: used to depict the boundaries of various shale components in each composite pore in the target shale sample. Each composite pore is composed of N-2 types of shale components, and the number of boundaries of various shale components in any composite pore is N-2. Boundary parameter determination submodule: used to determine the length and straight-line distance of the boundaries of various shale components in each composite pore based on the boundaries of various shale components in each composite pore obtained by characterization; Tortuosity determination submodule: for determining the tortuosity of the boundaries of various shale components in each composite pore based on the length and straight-line distance of the boundaries of various shale components in each composite pore.

8. The system according to claim 7, wherein: The shale component classification submodule is used to classify shale components into six categories: quartz, feldspar, carbonate minerals, clay minerals, heavy minerals and organic matter.

9. The system according to claim 7, wherein: The tortuosity is determined by the following formula: When the i-th composite pore contains the j-th type of shale component, τ ij =Lt ij ÷L0 ij When the i-th composite pore does not contain the j-th type of shale component, τ ij =0 Where, τ ij is the tortuosity of the boundary of the j-th shale component in the i-th composite pore; Lt ij is the length of the boundary of the j-th shale component of the i-th composite pore; L0 ij is the straight-line distance to the boundary of the j-th shale component of the i-th composite pore; j is a natural number less than or equal to N.

10. The system according to claim 6, wherein the contribution rate of each shale component in each composite pore is determined by the following formula: R ij =C ij ÷(C i1 +C i2 +…+C iN ) Where R ij is the contribution rate of the boundary of the j-th type of shale component in the i-th composite pore; C ij is the contribution of the boundary of the j-th shale component of the i-th composite pore to the minimum circumscribed circle; j is a natural number less than or equal to N.

11. An electronic device comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for determining the contribution of shale components to composite porosity as claimed in any one of claims 1 to 5 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the computer program implements the steps of the method for determining the contribution rate of shale components to composite porosity according to any one of claims 1 to 5.

Images