A shale gas dessert section compaction strength evaluation method and reservoir quality evaluation method

Abstract

The present application provides a shale gas dessert section compaction strength evaluation method and a reservoir quality evaluation method. The shale gas dessert section compaction strength evaluation method comprises determining the compaction strength of organic matter in the target shale gas dessert section rock sample based on the organic pores and organic matter occurrence state of the target shale gas dessert section rock sample. The method for evaluating the reservoir quality of the shale gas dessert section comprises determining the organic pores and organic matter occurrence state of the target shale gas dessert section rock sample, and then determining the content of mesopore organic matter and the content of non-pore organic clay particle complex in the mesopore organic matter and non-pore organic clay particle complex of the target shale gas dessert section rock sample, and then evaluating the reservoir quality of the target shale gas dessert section. The technical scheme provided by the present application can realize the compaction strength evaluation and reservoir quality evaluation of the shale gas dessert section based on the organic pores and organic matter occurrence state, thereby promoting the fine evaluation of the shale reservoir and the efficient exploration and development of the shale gas.

Description

Technical Field

[0001] This invention belongs to the field of shale oil and gas exploration and development technology, specifically involving a method for evaluating the compaction intensity of sweet spots in shale gas and a method for evaluating reservoir quality based on organic pores and organic matter occurrence. Background Technology

[0002] Shale oil and gas, rich in resources, has gradually become a key focus of oil and gas exploration and development. Honeycomb-like nanopores, as the main reservoir space and important seepage channels for shale oil and gas, have attracted global attention from the oil and gas industry. The combined use of techniques such as argon ion polishing, MAPS, and FIB to characterize the occurrence state of organic pores, such as morphology, size, and connectivity, has driven large-scale exploration and development of shale oil and gas. However, the understanding of the occurrence state of organic pores and organic matter is inconsistent and even contradictory.

[0003] Thermal simulation experiments on immature or low-maturity shale suggest that organic matter with organic pores is either residual kerogen or pyrolyzed petroleum. Petroleum thermal simulation experiments demonstrating "bubble-to-porosity" revealed that during the conversion of petroleum into pyrolyzed bitumen and natural gas, honeycomb-like nano-gas bubbles develop within the bitumen. Some researchers have combined argon ion polishing technology with high-resolution scanning electron microscopy to classify shale reservoir porosity, identifying residual kerogen as the organic matter with organic pores. Other researchers have used simultaneous scanning transmission X-ray microscopy (STXM) to observe that genomic pores in shale reservoirs are developed in migrating organic matter, while in-situ organic matter lacks organic pores. Previous studies have generally identified the organic matter types in shale gas reservoirs as peat-pyrified kerogen (in-situ organic matter) and peat-pyrified petroleum (migrated organic matter). Some researchers believe that peat-pyrified kerogen possesses honeycomb-like organic pores while peat-pyrified petroleum lacks them, while others believe that peat-pyrified kerogen lacks organic pores while peat-pyrified petroleum possesses honeycomb-like organic pores. These conflicting viewpoints indicate a lack of clarity regarding the organic pores and the occurrence state of organic matter in shale gas reservoirs. Furthermore, intense compaction can lead to the closure and disappearance of organic pores, resulting in the perception that "peat-pyrified kerogen possesses..." Scholars holding the view that "pyrene has honeycomb-like organic pores while pyrene-asphalted petroleum lacks organic pores" mistakenly identify pyrene-asphalted kerogen, whose pores have disappeared due to compaction, as pyrene-asphalted petroleum. Conversely, scholars holding the view that "pyrene-asphalted kerogen lacks organic pores while pyrene-asphalted petroleum has honeycomb-like organic pores" mistakenly identify pyrene-asphalted petroleum, whose organic pores have disappeared due to compaction, as pyrene-asphalted kerogen. This leads to confusion in the identification of organic pores and the occurrence state of organic matter. The "unclear understanding of organic matter types" coupled with "compaction causing confusion in organic matter types" has resulted in even greater confusion in the understanding of organic pores, seriously affecting shale gas reservoir evaluation and efficient exploration and development.

[0004] Therefore, only by clarifying the relationship between organic pores and the occurrence of organic matter and the intensity of compaction can we accurately evaluate shale gas reservoirs and guide the efficient exploration and development of shale gas.

[0005] Recently, researchers, using MAPS technology, discovered in over-mature radiolarian siliceous shale that the radiolarian silica shell cavity organosilica particle complex and the organoclay particle complex outside the radiolarian silica shell are transformed from sedimentary organosilica particle complexes and sedimentary organoclay particle complexes (collectively referred to as sedimentary organomineral particle complexes). Sedimentary organic matter undergoes thermal evolution through kerogen, pre-oil bitumen, solid bitumen, and petroleum to become tar pitch and natural gas. Correspondingly, the sedimentary organomineral particle complex transforms into tar pitch particle complexes through kerogen particle complexes, pre-oil bitumen particle complexes, and solid bitumen particle complexes. Pre-oil bitumen migrating from the original organic matter undergoes thermal evolution through solid bitumen and petroleum to become tar pitch and natural gas, while petroleum migrating from pre-oil bitumen transforms into tar pitch. Notably, the tar pitched organomineral particle complexes and tar pitched solid bitumen exhibit organic pores, while tar pitched petroleum lacks organic pores. This clarifies the fundamental relationship between organic matter type and organic pores, providing the necessary prerequisites for the analysis of the relationship between organic pores, organic matter occurrence state, and compaction intensity in this invention.

[0006] In summary, there is still a need to study technical solutions for analyzing the compaction intensity of shale gas sweet spots based on the relationship between organic pores and the occurrence state of organic matter and compaction intensity, so as to promote the fine evaluation of shale reservoirs and the efficient exploration and development of shale gas. Summary of the Invention

[0007] The purpose of this invention is to provide a technical solution that enables the evaluation of the compaction intensity of shale gas sweet spots and reservoir quality based on organic pores and the occurrence state of organic matter, thereby promoting the refined evaluation of shale reservoirs and the efficient exploration and development of shale gas.

[0008] To achieve the above objectives, the present invention provides the following two technical solutions.

[0009] On the one hand, the present invention provides a method for evaluating the compaction intensity of sweet spots in shale gas formations, the method comprising:

[0010] Obtain rock samples from the sweet spot segment of the target shale gas;

[0011] Determine the organic pore and organic matter occurrence state of the target shale gas sweet spot rock sample;

[0012] Based on the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample, the compaction intensity of organic matter in the target shale gas sweet spot rock sample was determined.

[0013] Among them, the compaction intensity of organic matter with abundant macroporous organic pores distributed within the silicon shell is low; the pure organic matter with abundant macroporous organic pores distributed outside the silicon shell is not sensitive to the compaction intensity; the pure organic matter and organic clay particle complex with abundant macroporous organic pores and abundant mesoporous organic pores distributed outside the silicon shell (i.e., the pure organic matter with abundant macroporous organic pores and abundant mesoporous organic pores distributed outside the silicon shell and the organic clay particle complex with abundant macroporous organic pores and abundant mesoporous organic pores distributed outside the silicon shell) The compaction intensity of the clay-particle complex is medium; the compaction intensity of pure organic matter with rich mesoporous organic pores and the organic-clay-particle complex (i.e., pure organic matter with rich mesoporous organic pores and organic-clay-particle complex with rich mesoporous organic pores) is medium; the compaction intensity of non-porous pure organic matter is not sensitive to the compaction intensity; the compaction intensity of non-porous organic-clay-particle complex is high; the compaction intensity of non-porous organosilicon particle complex is high.

[0014] Secondly, the present invention provides a method for evaluating the quality of sweet spot reservoirs in shale gas, the method comprising:

[0015] Obtain rock samples from the sweet spot segment of the target shale gas;

[0016] The organic pore and organic matter occurrence states of rock samples from the sweet spot segment of the target shale gas were determined, and then the contents of mesoporous organic matter and non-porous organic clay complex in the mesoporous organic matter and non-porous organic clay complex in the target shale gas sweet spot segment rock samples were determined. Among them, mesoporous organic matter includes pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, as well as pure organic matter and organic clay complex with developed mesoporous organic pores that are simultaneously developed outside the silica shell.

[0017] The reservoir quality of the target shale gas sweet spot is evaluated based on the content of mesoporous organic matter and non-porous organic clay complex in the rock samples.

[0018] The technical solution provided by this invention enables the determination of the relationship between the organic porosity and organic matter occurrence state and the compaction intensity of shale gas sweet spots, as well as the evaluation of shale gas sweet spot reservoir quality, thereby contributing to the economic goals of cost reduction and efficiency improvement in shale gas exploration and development. Specifically, this invention establishes a technical solution for determining the compaction intensity based on the organic porosity and organic matter occurrence state of shale, providing scientific data support for strata evaluation and area selection during the shale gas exploration stage and for refined sweet spot evaluation during the development stage. This invention also establishes a method for evaluating shale gas sweet spot reservoir quality based on the organic porosity and organic matter occurrence state of shale combined with the constraints of shale gas sweet spot compaction, providing important information for the selection of shale gas horizontal well targets and guiding efficient shale gas exploration and development. Attached Figure Description

[0019] Figure 1a This is a longitudinal section view of the core sample from Example 1.

[0020] Figure 1b This is a diagram of the intact silica shell and its cavity calcite (Ca) and organosilicon particle complex in the target core sample of Example 1.

[0021] Figure 1c for Figure 1b Enlarged view of the organosilicon particle complex located in the red box.

[0022] Figure 1d This is a diagram of the residual silica shell and its cavity calcite (Ca) and organosilicon particle complex in the target core sample of Example 1.

[0023] Figure 1e for Figure 1d Enlarged view of the organosilicon particle complex at the location marked in red box ①.

[0024] Figure 1f for Figure 1d Enlarged view of the organosilicon particle complex at position ② (red box in the middle).

[0025] Figure 1g for Figure 1d Enlarged view of the organosilicon particle complex at position ③ (red box in the middle).

[0026] Figure 1h for Figure 1d Enlarged view of the organosilicon particle complex at position ④ (red box in the middle).

[0027] Figure 1i This is a diagram of the organic matter between the skeletons in the target core sample of Example 1.

[0028] Figure 1j for Figure 1i Enlarged view of the organic clay particle complex at the location marked in red box ①.

[0029] Figure 1k for Figure 1iEnlarged view of the pure organic matter at the location marked in red box ②.

[0030] Figure 11 This is a diagram of the pure organic matter between the skeletons in the target core sample of Example 1.

[0031] Figure 1m This is a diagram of the pure organic matter between the skeletons in the target core sample of Example 1.

[0032] Figure 1n This is a diagram of the residual silica shell and its cavity calcite (Ca) and organosilicon particle complex in the target core sample of Example 1.

[0033] Figure 1o for Figure 1n Enlarged view of the calcite and organosilicon particle complex located at the position in the red box ①.

[0034] Figure 1p This is a diagram of the organic clay particle complex between the skeleton particles in the target core sample of Example 1.

[0035] Figure 1q This is a diagram of the pure organic matter and banded organic clay particle complex between the skeletons of the target core sample in Example 1.

[0036] Figure 1r for Figure 1q Enlarged view of the pure organic matter and banded organic clay particle complex between the skeletons in the area within the red box.

[0037] Figure 1s This is a diagram of the pure organic matter in strips without pores between the skeletons of the target core sample in Example 1.

[0038] Figure 1t This is a diagram of the organic matter filling the intercrystalline pores of berry-like pyrite in the target core sample of Example 1.

[0039] Figure 1u for Figure 1t Enlarged view of the organic matter in the intercrystalline pores of berry-like pyrite located in the red box.

[0040] Figure 2a This is a longitudinal section view of the core sample from Example 2.

[0041] Figure 2b This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 2.

[0042] Figure 2c This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 2.

[0043] Figure 2d This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 2.

[0044] Figure 2eThis is a diagram of the organic matter between the skeleton particles in the target core sample of Example 2.

[0045] Figure 3a This is a longitudinal section view of the core sample from Example 3.

[0046] Figure 3b This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 3.

[0047] Figure 3c This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 3.

[0048] Figure 3d This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 3.

[0049] Figure 3e This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 3.

[0050] Figure 3f This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 3.

[0051] Figure 3g This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 3.

[0052] Figure 3h This is a diagram of the organic matter between the skeleton particles in the target core sample of Example 3.

[0053] Figure 3i This is a diagram of the organic matter between mineral grains in the target core sample of Example 3.

[0054] Figure 3j This is a diagram of the organic matter between mineral grains in the target core sample of Example 3.

[0055] Figure 3k This is a diagram of the organic matter in the intercrystalline pores of berry-like pyrite in the target core sample of Example 3.

[0056] Figure 4a This is a longitudinal section view of the core sample from Example 4.

[0057] Figure 4b This is a diagram of the organic matter between mineral grains in the target core sample of Example 4.

[0058] Figure 4c This is a diagram of the organic matter between mineral grains in the target core sample of Example 4.

[0059] Figure 4d This is a diagram of the organic matter between mineral grains in the target core sample of Example 4.

[0060] Figure 4e This is a diagram of the organic matter between mineral grains in the target core sample of Example 4.

[0061] Figure 4f This is a diagram of the organic matter in the intercrystalline pores of berry-like pyrite in the target core sample of Example 4. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0063] MAPS stands for Modular Automated Processing System. MAPS technology divides the argon-polished surface of a sample into a series of regular grids, scans and images each grid, and stitches together the images of all grids to obtain a two-dimensional large field-of-view scan image data volume, which is the MAPS data volume.

[0064] The "phase surface method" is used to calculate the normalized content of mesoporous organic matter and non-porous organoclay complexes: The "phase surface method" estimates the volume percentage content of mesoporous organic matter and non-porous organoclay complexes in each grid rock image in the 4nm MAPS data volume. The volume percentage content of mesoporous organic matter and non-porous organoclay complexes in different grid rock images is added together to obtain their volume percentage content in all grids of mesoporous organic matter and non-porous organoclay complexes, which is then normalized to the volume percentage content of mesoporous organic matter and non-porous organoclay complexes.

[0065] The term "silicone shell" refers to the silicon shell of a radiolarian; a complete silicon shell refers to a silicon shell in which more than two-thirds of the silicon shell and more than two-thirds of the filling material in the silicon shell cavity are preserved; a damaged silicon shell refers to a silicon shell in which less than two-thirds of the silicon shell and less than two-thirds of the filling material in the silicon shell cavity are preserved.

[0066] Shell debris refers to silicon shell residues that were not preserved from the silicon shell cavity filling material.

[0067] The skeletal particles include rigid mineral particles such as quartz, calcite, dolomite, and pyrite, but do not include clay minerals (plastic mineral components). Among them, quartz includes biomass silica (such as silica shells and shell fragments) and terrigenous quartz, and pyrite includes pyrite particles and berry-like pyrite.

[0068] The mineral particles include rigid mineral particles such as quartz, calcite, dolomite, and pyrite, as well as clay minerals (plastic mineral components). Among them, quartz includes biomass silica (such as silica shells and shell fragments) and terrigenous quartz, and pyrite includes pyrite particles and berry-like pyrite.

[0069] Clumpy organic matter refers to organic matter with a length-to-height ratio ≤ 5, while strip-shaped organic matter refers to organic matter with a length-to-height ratio > 5.

[0070] Organic pores refer to the pores that develop in organic matter, organic clay particle complexes, or organosilicon particle complexes.

[0071] Mesopores refer to pores with a diameter of less than 50 nm and greater than 4 μm.

[0072] Macropores refer to pores with a diameter greater than or equal to 50 nm.

[0073] Organic clay-cement complexes refer to complexes formed by the mixing of organic matter and clay.

[0074] Organosilicon particle complexes refer to complexes formed by the mixing of organic matter and silicon particles.

[0075] Pure organic matter refers to organic matter that is not mixed with minerals such as clay and silica.

[0076] Macroporous organic pores refer to organic pores with macropore density of not less than 3 pores / μm. 2 .

[0077] Mesoporous organic pores refer to organic pores that have developed mesopores and whose pore density is not less than 3 pores / μm. 2 .

[0078] The inventors of this invention analyzed the organic porosity and organic matter occurrence state of shale gas sweet spots, clarifying the relationship between these states and compaction intensity. Using the "phase surface method," they statistically analyzed the normalized content of mesoporous organic matter and non-porous organic clay aggregate complexes in shale gas sweet spots, identifying the compaction intensity characteristics and evaluating reservoir quality. This pioneering approach to evaluating shale gas sweet spot reservoir quality based on compaction intensity characteristics is a first. By constraining compaction intensity analysis with organic porosity and organic matter occurrence state, the method reduces the ambiguity of the relationship between these states and compaction intensity, thus guiding efficient shale gas exploration and development. Furthermore, based on the inventors' research findings, this invention provides a method for evaluating the compaction intensity of shale gas sweet spots and a method for evaluating shale gas sweet spot reservoir quality, providing crucial information for selecting targets in shale gas horizontal wells and guiding efficient shale gas exploration and development.

[0079] In one specific embodiment, the present invention provides a method for evaluating the compaction intensity of sweet spots in shale gas formations, the method comprising:

[0080] S1: Obtain rock samples from the sweet spot segment of the target shale gas;

[0081] S2: Determine the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample;

[0082] S3: Based on the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample, determine the compaction intensity of organic matter in the target shale gas sweet spot rock sample;

[0083] Among them, the compaction intensity of organic matter with abundant macroporous organic pores distributed within the silicon shell is low; the pure organic matter with abundant macroporous organic pores distributed outside the silicon shell is not sensitive to the compaction intensity; the pure organic matter and organic clay particle complex with abundant macroporous organic pores and abundant mesoporous organic pores distributed outside the silicon shell (i.e., the pure organic matter with abundant macroporous organic pores and abundant mesoporous organic pores distributed outside the silicon shell and the organic clay particle complex with abundant macroporous organic pores and abundant mesoporous organic pores distributed outside the silicon shell) The compaction intensity of the clay-particle complex is medium; the compaction intensity of pure organic matter with rich mesoporous organic pores and the organic-clay-particle complex (i.e., pure organic matter with rich mesoporous organic pores and organic-clay-particle complex with rich mesoporous organic pores) is medium; the compaction intensity of non-porous pure organic matter is not sensitive to the compaction intensity; the compaction intensity of non-porous organic-clay-particle complex is high; the compaction intensity of non-porous organosilicon particle complex is high.

[0084] Organic matter with abundant macroporous organic pores distributed within the silicon shell (referring to organic matter distributed within the silicon shell with a pore diameter of not less than 50 μm and a pore density of not less than 3 pores / μm) 2 The organic matter is formed from the organic pores of the coking asphalt that has developed organic pores, which is derived from solid asphalt petroleum. The rock micro-regions where the organic pores and organic matter are located have a strong ability to resist compaction. The rock skeleton particles bear all the pressure of the overlying strata, while the organic matter does not bear the pressure of the overlying strata, and the organic pores are protected and remain in their original state.

[0085] For pure organic matter with abundant macropores distributed outside the silicon shell (referring to organic matter distributed outside the silicon shell with a pore diameter of not less than 50 μm and a pore density of not less than 3 pores / μm), 2 The organic pores and organic matter are formed by the transformation of petroleum into asphalt that encapsulates water droplets. Asphalt-encapsulated petroleum has no pores, and water droplets vaporize into water vapor to form organic pores. The rock micro-regions where the organic pores and organic matter are located are micro-regions with low, medium, or high compaction intensity.

[0086] For pure organic matter and organic clay particle complexes distributed outside the silicon shell that simultaneously develop macroporous and mesoporous organic pores (referring to pore diameters greater than 50 μm and pore density not less than 3 pores / μm distributed outside the silicon shell), 2 Organic pores with diameters less than 50 μm and greater than 4 μm, and pore density not less than 3 pores / μm 2The organic pores are nested within organic matter. The organic pores and organic matter are formed from pyroasphalt, a solid asphalt petroleum that encapsulates water droplets. Water droplets vaporize into water vapor, forming macropores. Under moderate compaction, the pyroasphalt-derived solid asphalt petroleum forms mesopores. The rock micro-regions containing these organic pores and organic matter possess moderate resistance to compaction. The rock skeleton particles, along with the organic pores and organic matter, bear part of the overlying strata pressure. The organic pores formed by water droplet vaporization have a diameter greater than 50 μm and a pore density of not less than 3 pores / μm. 2 The pressure of the overlying strata caused the pore diameter of the coking asphalt solid asphalt petroleum to change from greater than 50 μm to less than 50 μm but greater than 4 μm, while the pore density did not change significantly.

[0087] For pure organic matter and organic clay particle complexes with rich mesoporous organic pores (referring to pore diameters less than 50 μm and greater than 4 μm, and pore density not less than 3 pores / μm), 2 Pure organic matter with pore diameters less than 50 μm and greater than 4 μm, and a pore density of not less than 3 pores / μm 2 The organic clay-particle complex is formed by mesoporous organic pores formed by coking asphalt solid asphalt under medium compaction intensity. The rock micro-regions where the organic pores and organic matter are located have the ability to resist compaction. The rock skeleton particles and the organic pores and organic matter respectively bear part of the pressure of the overlying strata, which causes the pore diameter of the organic pores to change from greater than 50 μm to less than 50 μm but greater than 4 μm, while the pore density does not change significantly.

[0088] For pure organic matter without pores, its formation is asphaltified petroleum, which is without pores; the rock micro-region where pure organic matter without pores is located is a micro-region with low, medium or high compaction intensity.

[0089] For non-porous organic-clay composites, their formation is due to the high-compaction intensity of pyroasphalt-clay composites and solid bitumen-petroleum clay composites. The rock micro-regions containing non-porous organic-clay composites have a weak resistance to compaction. The organic pores and organic matter, like mineral particles, bear the entire overlying formation pressure, resulting in pore diameters greater than 50 μm and pore densities of not less than 3 pores / μm in the pyroasphalt-clay composites and solid bitumen-petroleum clay composites. 2 The organic pores are crushed and disappear.

[0090] For non-porous organosilicon particle complexes, their formation is due to the high-intensity compaction of pyroasphalt silica particle complexes into solid asphalt and petroleum silica particle complexes. The rock micro-regions containing non-porous organosilicon particle complexes have a weak ability to resist compaction. The organic pores and organic matter, like mineral particles, bear the entire overlying formation pressure, resulting in pore diameters greater than 50 μm and pore densities not less than 3 pores / μm in the pyroasphalt silica particle complexes into solid asphalt and petroleum silica particle complexes. 2 The organic pores are crushed and disappear.

[0091] Furthermore, the organic matter distributed within the silicon shell and containing macroporous organic pores also possesses the following characteristics: it is an organosilicon particle complex and / or a filling material within the cavity of a complete silicon shell.

[0092] Furthermore, the pure organic matter with abundant macropores distributed outside the silicon shell also possesses the following occurrence characteristics:

[0093] It exists in clumps between mineral grains.

[0094] Furthermore, the pure organic matter and organic clay particle complexes that simultaneously develop macroporous and mesoporous organic pores distributed outside the silicon shell also possess the following occurrence characteristics:

[0095] It exists in clumps between the rock skeleton grains.

[0096] Furthermore, the pure organic matter and organic clay particle complexes with rich mesoporous organic pores also possess the following occurrence characteristics:

[0097] It exists in the form of clumps between rock skeleton grains, or in the form of bands between rock skeleton grains, or as filling material for intergranular pores of berry-like pyrite, or as filling material for the cavity of a broken silica shell.

[0098] Furthermore, pure organic matter without pores also possesses the following characteristics:

[0099] It exists in the form of clumps between mineral grains, or in the form of bands between mineral grains, or as a filling material for the intergranular pores of berry-like pyrite.

[0100] Furthermore, the non-porous organic-mucilage complex also possesses the following characteristics:

[0101] It exists in the spaces between mineral grains in the form of clumps, bands, or disseminated particles.

[0102] Furthermore, the non-porous organosilicon particle complex also possesses the following characteristics:

[0103] The filling material inside the cavity of a damaged silicon shell.

[0104] Further, rock samples were obtained from the sweet spot segment of the target shale gas, including:

[0105] The rock sample collected from the sweet spot of the target shale gas is the rock sample of the target shale gas sweet spot.

[0106] Furthermore, the organic porosity and organic matter occurrence state of the target shale gas sweet spot rock samples were determined, including:

[0107] Argon-ion polished discs of the target shale gas sweet spot rock were prepared using rock samples from the target shale gas sweet spot segment.

[0108] MAPS rock image data of argon-ion polished sections of target shale gas sweet spot rock were acquired;

[0109] Based on the MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock, the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample were determined.

[0110] Furthermore, the resolution of the MAPS rock image data volume of the argon-ion polished slides of the target shale gas sweet spot rock is 1-10 nm (e.g., 4 nm resolution).

[0111] Furthermore, the length of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.8-2cm (e.g., 1cm);

[0112] Furthermore, the width of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.8-2cm (e.g., 1cm);

[0113] Furthermore, the thickness of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.3-0.8 cm (e.g., 0.5 cm);

[0114] Furthermore, the top and bottom surfaces of the argon-ion polished section of the target shale gas sweet spot rock are parallel to the top and bottom surfaces of the target shale gas sweet spot rock sample in its underground state, thereby better revealing the underground state information of the rock and ensuring that the observed microscopic phenomena are merely an amplification of the underground state of the rock.

[0115] Furthermore, the acquisition of MAPS rock image data from argon-ion polished sheets of the target shale gas sweet spot rock includes: selecting an area with a length and width not exceeding 400 μm on the polished surface of the argon-ion polished sheet of the target shale gas sweet spot rock, and acquiring MAPS rock image data.

[0116] Furthermore, during the acquisition of MAPS rock image data volumes from argon-ion polished sections of target shale gas sweet spots, the top surface of the argon-ion polished section of the target shale gas sweet spot is positioned above the field of view, and the bottom surface is positioned below the field of view. This ensures that all phenomena observed in the acquired MAPS rock image data volumes are merely magnified versions of natural phenomena.

[0117] In one specific embodiment, the method for evaluating the quality of sweet spot shale gas reservoirs provided by the present invention includes:

[0118] Obtain rock samples from the sweet spot segment of the target shale gas;

[0119] The organic pore and organic matter occurrence states of rock samples from the sweet spot segment of the target shale gas were determined, and then the contents of mesoporous organic matter and non-porous organic clay complex in the mesoporous organic matter and non-porous organic clay complex in the target shale gas sweet spot segment rock samples were determined. Among them, mesoporous organic matter includes pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, as well as pure organic matter and organic clay complex with developed mesoporous organic pores that are simultaneously developed outside the silica shell.

[0120] The reservoir quality of the target shale gas sweet spot is evaluated based on the content of mesoporous organic matter and non-porous organic clay complex in the rock samples.

[0121] Furthermore, based on the content of mesoporous organic matter and non-porous organic-clay composite in the rock samples of the target shale gas sweet spot, the reservoir quality of the target shale gas sweet spot is evaluated, including:

[0122] When the content of mesoporous organic matter in the rock sample of the sweet spot of the target shale gas is ≥95% and the content of non-porous organic clay composite is ≤5%, the sweet spot of the target shale gas exhibits the characteristics of medium compaction intensity, and the sweet spot of the target shale gas is a high-quality reservoir.

[0123] When the content of mesoporous organic matter in the rock sample of the sweet spot of the target shale gas is less than 95% and greater than or equal to 50%, while the content of non-porous organic clay composite is greater than 5% and less than or equal to 50%, the sweet spot of the target shale gas exhibits the characteristics of medium to high compaction intensity, and the sweet spot of the target shale gas is a general reservoir.

[0124] When the content of mesoporous organic matter in the rock sample of the sweet spot of the target shale gas is less than 50% and greater than or equal to 5% and the content of non-porous organic clay composite is greater than 50% and less than or equal to 95%, the sweet spot of the target shale gas exhibits the characteristics of medium compaction intensity, and the sweet spot of the target shale gas is a poor reservoir.

[0125] When the content of mesoporous organic matter in the rock sample of the sweet spot of the target shale gas is less than 5% and the content of non-porous organic clay composite is greater than 95%, the sweet spot of the target shale gas exhibits the characteristics of high-pressure compaction intensity, and the sweet spot of the target shale gas is a non-reservoir.

[0126] The sweet spot of the target shale gas is a high-quality reservoir, while ordinary reservoirs are suitable as targets for horizontal wells in shale gas.

[0127] Further, rock samples were obtained from the sweet spot segment of the target shale gas, including:

[0128] The rock sample collected from the sweet spot of the target shale gas is the rock sample of the target shale gas sweet spot.

[0129] Furthermore, the organic pore and organic matter occurrence states of the target shale gas sweet spot rock samples are determined, thereby determining the content of mesoporous organic matter and the content of non-porous organic clay complex in the target shale gas sweet spot rock samples, including:

[0130] Argon-ion polished discs of the target shale gas sweet spot rock were prepared using rock samples from the target shale gas sweet spot segment.

[0131] MAPS rock image data of argon-ion polished sections of target shale gas sweet spot rock were acquired;

[0132] Based on the MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock, the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample are determined, and then the contents of mesoporous organic matter and non-porous organic clay complex in the target shale gas sweet spot rock sample are statistically analyzed.

[0133] Furthermore, the content of mesoporous organic matter and the content of non-porous organic clay complex in the sweet spot rock samples of the target shale gas were statistically analyzed using the "phase surface method".

[0134] Furthermore, the resolution of the MAPS rock image data volume of the argon-ion polished slide of the target shale gas sweet spot rock is 1-10 nm (preferably 4 nm).

[0135] Furthermore, the length of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.8-2cm (e.g., 1cm);

[0136] Furthermore, the width of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.8-2cm (e.g., 1cm);

[0137] Furthermore, the thickness of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.3-0.8 cm (e.g., 0.5 cm);

[0138] Furthermore, the top and bottom surfaces of the argon-ion polished section of the target shale gas sweet spot rock are parallel to the top and bottom surfaces of the target shale gas sweet spot rock sample in its underground state, thereby better revealing the underground state information of the rock and ensuring that the observed microscopic phenomena are merely an amplification of the underground state of the rock.

[0139] Furthermore, the acquisition of MAPS rock image data from argon-ion polished sheets of the target shale gas sweet spot rock includes: selecting an area with a length and width not exceeding 400 μm on the polished surface of the argon-ion polished sheet of the target shale gas sweet spot rock, and acquiring MAPS rock image data.

[0140] Furthermore, during the acquisition of MAPS rock image data volumes from argon-ion polished sections of target shale gas sweet spots, the top surface of the argon-ion polished section of the target shale gas sweet spot is positioned above the field of view, and the bottom surface is positioned below the field of view. This ensures that all phenomena observed in the acquired MAPS rock image data volumes are merely magnified versions of natural phenomena.

[0141] Example 1:

[0142] This embodiment provides a method for evaluating the compaction intensity of sweet spots in shale gas reservoirs and a method for evaluating the quality of sweet spot reservoirs in shale gas reservoirs.

[0143] Methods for evaluating the compaction intensity of sweet spots in shale gas formations include:

[0144] 1. Obtain rock samples from the sweet spot segment of the target shale gas.

[0145] In this embodiment, observing the longitudinal section of a core sample collected from the sweet spot segment of Shale A in Area A revealed a 2.5 mm thick radiolarian siliceous shale lamellarity. This lamellarity is characterized by a layer of white spots the size of a pen tip appearing within a black shale devoid of any texture (e.g., ...). Figure 1a (As shown); take the radiolarian siliceous shale lamellar rock sample as the target shale gas sweet spot rock sample.

[0146] 2. Prepare argon-ion polished discs of the target shale gas sweet spot rock sample using the target shale gas sweet spot rock sample; wherein the length of the argon-ion polished disc is 1cm, the width is 1cm, and the thickness is 0.5cm; the top and bottom surfaces of the argon-ion polished disc are parallel to the top and bottom surfaces of the target shale gas sweet spot rock sample in its underground state, respectively.

[0147] 3. Acquire MAPS rock image data at a resolution of 4nm on the polished surface of the argon-ion polished sheet of the target shale gas sweet spot rock. During the acquisition of MAPS rock image data, the top surface of the argon-ion polished sheet is located above the field of view and the bottom surface is located below the field of view, so as to ensure that all phenomena observed in the acquired MAPS rock image data are merely magnified natural phenomena.

[0148] 4. The MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock was collected to determine the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample; based on the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample, the compaction intensity of organic matter in the target shale gas sweet spot rock sample was determined.

[0149] Specifically, if the organic matter is distributed within the silicon shell and has abundant macropores, then the organic matter has low compaction strength; if the organic matter is distributed outside the silicon shell and has abundant macropores, then the organic matter is unrelated to compaction strength; if the organic matter is distributed outside the silicon shell and is a composite of pure organic matter and organic particles with both abundant macropores and mesopores, then the organic matter has medium compaction strength; if the organic matter is a composite of pure organic matter and organic particles with abundant mesopores, then the organic matter has medium compaction strength; if the organic matter is pure and non-porous, then the organic matter is unrelated to compaction strength; if the organic particle composite is non-porous, then the organic matter has high compaction strength; if the organic silicon particle composite is non-porous, then the organic matter has high compaction strength.

[0150] In this embodiment, based on the MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock, it was observed that: the target shale gas sweet spot rock consists of a complete silica shell and its cavity-filling material, a fragmented silica shell and its cavity-filling material, and shell fragments, forming the main skeleton of the rock. The spaces between the skeleton particles are filled with organic matter, clay, and pyrite; the complete silica shell and its strong filling material is a composite of calcite and organosilicon particles (such as...). Figure 1b (as shown); the incomplete silica cavity filling material is a composite of calcite and organosilicon particles (such as...). Figure 1d , Figure 1n (as shown); the organic matter filling the spaces between the skeletal particles is pure organic matter (such as...). Figure 1i Organic matter outside the area enclosed by the green coil shown Figure 11, Figure 1m , Figure 1r The red arrow points to... Figure 1s (as shown) and organic clay complexes (such as) Figure 1i The organic matter within the area enclosed by the green coil shown Figure 1p , Figure 1r (as indicated by the blue arrow); the clay between the skeleton particles exists in the form of agglomerated organic-clay composites (such as...). Figure 1i The organic matter within the area enclosed by the green coil shown is either in the form of a strip-shaped organic-mucilage complex. Figure 1p , Figure 1r (As indicated by the blue arrow) exists; the pyrite filling the spaces between the skeletons can be divided into pyrite particles (such as...). Figure 1q , Figure 1r (as shown) exists and berry-like pyrite (such as Figure 1t (As shown) exists; the intergranular pores of strawberry-like pyrite are filled with organic matter (such as... Figure 1t , Figure 1u As shown). Specifically:

[0151] In this embodiment, the target shale gas sweet spot rock development includes: (1) organic matter filling the intact silica shell cavity (such as...). Figure 1b , Figure 1c (as shown), the organic matter is an organic matter with low compaction strength; (2) the organic matter filling the defective silicon shell cavity (such as Figure 1d As shown), a portion of the organic matter is organic matter with medium compaction intensity (such as...). Figure 1e , Figure 1f As shown), another part of the organic matter is organic matter with high compaction intensity (such as...). Figure 1g , Figure 1h (as shown); (3) Organic matter filling the defective silicon shell cavity (such as...) Figure 1n , Figure 1o (as shown), the organic matter is organic matter with high compaction strength; (4) organic matter between skeletal particles (such as Figures 1i-1l , Figure 1r (As indicated by the red arrow), this organic matter is organic matter with medium compaction intensity; (5) Organic matter between skeletal particles (such as...) Figure 1m , Figure 1s As shown), the occurrence state of this organic matter is independent of the compaction intensity; (6) Organic clay-particle complexes between skeleton particles (such as...) Figure 1p , Figure 1r (As indicated by the blue arrow), the organic-mucilage complex is an organic material with high compaction strength; (7) organic material filling the intercrystalline pores of berry-like pyrite (such as... Figure 1t , Figure 1u As shown in the figure, the organic matter is of medium compaction strength.

[0152] In this embodiment, the organic matter with low compaction intensity in the sweet spot rock of the target shale gas is specifically the organic matter filling intact silica cavities. The specific occurrence state of the organic matter filling intact silica cavities is as follows: Figure 1b , Figure 1c As shown, the complete silica cavity filling material is a complex of calcite (Ca) and organosilicon particles. The organosilicon particle complex has a diameter of not less than 50 μm and a density of not less than 3 pores / μm. 2 The organic pores are essentially a composite of coking asphalt and silica particles, and the pores remain in their original state without being significantly affected by compaction.

[0153] In this embodiment, the organic matter with medium compaction intensity developed in the sweet spot rock of the target shale gas includes organic matter partially filling the incomplete silica shell cavity, organic matter between framework grains, and organic matter filling the intergranular pores of berry-like pyrite. Its specific occurrence state is described below. The organic matter partially filling the incomplete silica shell cavity is an organosilicon particle complex with a pore diameter less than 50 μm and greater than 4 μm, and a pore density of not less than 3 pores / μm. 2 Organic pores (such as) Figure 1e , Figure 1f The organic matter between the skeletal particles in this part is characterized by a diameter of less than 50 μm and greater than 4 μm, and a density of not less than 3 pores / μm. 2 Pure organic matter with organic pores (such as) Figure 1i Organic matter outside the green coil Figure 1k , Figure 11 , Figure 1r (as indicated by the red arrow) and organic clay complex ( Figure 1i Organic matter within the green coil Figure 1j (As shown). The organic matter filling the intergranular pores of berry-like pyrite consists of well-developed pores with a diameter less than 50 μm and greater than 4 μm, and a density of not less than 3 pores / μm. 2 Pure organic matter with organic pores (such as) Figure 1t , Figure 1u (As shown). The pores in the above organic matter exist in a state where the coking asphalt solid asphalt petroleum has a diameter greater than 50 μm and a density of not less than 3 pores / μm. 2 The manifestation of organic pores under medium compaction intensity.

[0154] In this embodiment, the high-compact organic matter developed in the sweet spot rock of the target shale gas includes partially filled organosilicon particle complexes in the incomplete silica shell cavity and partially between framework particles, and its specific occurrence state is described below. The partially filled organosilicon particle complexes in the incomplete silica shell cavity exhibit partial non-porosity (e.g., ...). Figure 1d , Figure 1g , Figure 1h (as shown) or all organosilicon particle complexes are non-porous (e.g. Figure 1n , Figure 1o As shown). This part of the skeleton particles' organic-mucilage complex is non-porous and exists in a clump-like form (e.g. Figure 1p (as shown) or exists in a strip-like form (such as...) Figure 1q , Figure 1r (As indicated by the blue arrow). The portion filling the incomplete silica shell cavity with organosilicon particle composite is a high-pressure compaction strength coking asphalt silica particle composite solid asphalt petroleum silica particle composite. The portion with organic clay particle composite between the skeleton particles is a high-pressure compaction strength coking asphalt clay particle composite solid asphalt petroleum clay particle composite. Under high-pressure compaction strength, the pore diameter in the coking asphalt solid asphalt petroleum is greater than 50 μm, and the pore density is not less than 3 pores / μm. 2 The organic pores are crushed and disappear.

[0155] In this embodiment, the organic matter developed in the sweet spot rock of the target shale gas, which is unrelated to the compaction intensity, is pure organic matter between some framework particles, and its specific occurrence state is as follows. This pure organic matter between framework particles is non-porous and exists in a clump or banded form. Among them, the non-porous clump-shaped pure organic matter between framework particles is as follows: Figure 1m As shown, the pure organic matter in the strips without pores between the skeletal particles is like... Figure 1s As shown, the pure organic matter without pores between the skeleton particles is originally non-porous asphalt-refined petroleum, and is unrelated to the compaction strength.

[0156] Methods for evaluating the quality of sweet spot reservoirs in shale gas include:

[0157] 1. Obtain rock samples from the sweet spot section of shale gas in area A as the target sweet spot rock samples. Prepare argon-ion polished sections of the target sweet spot rock samples. Select an area with a length and width not exceeding 400 μm on the polished surface of the argon-ion polished section of the target sweet spot rock samples, and acquire MAPS rock image data volumes with a resolution of 4 nm.

[0158] Here, we can directly use the MAPS rock image data obtained in step 3 of the evaluation method for the compaction intensity of shale gas sweet spot segment in Example 1.

[0159] 2. Based on the acquired MAPS rock image data, determine the organic pore and organic matter occurrence state of the target shale gas sweet spot rock sample, and then determine the content of mesoporous organic matter and non-porous organic clay complex in the target shale gas sweet spot rock sample; wherein, mesoporous organic matter includes pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, as well as pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, and organic matter in the portion of pure organic matter and organic clay complex with developed macroporous organic pores and mesoporous organic pores.

[0160] In this embodiment, the content of mesoporous organic matter in the target shale gas sweet spot rock sample and the content of non-porous organic clay composite are 68% and 32%, respectively.

[0161] 3. Evaluate the reservoir quality of the target shale gas sweet spot based on the content of mesoporous organic matter and non-porous organic clay composite in the rock samples of the target shale gas sweet spot.

[0162] Specifically, when the content of mesoporous organic matter in the mesoporous organic-clay composite of the target shale gas sweet spot rock sample is ≥95% and the content of non-porous organic-clay composite is ≤5%, the target shale gas sweet spot exhibits medium compaction intensity characteristics and is a high-quality reservoir; when the content of mesoporous organic matter in the mesoporous organic-clay composite of the target shale gas sweet spot rock sample is less than 95% but greater than or equal to 50% and the content of non-porous organic-clay composite is greater than 5% but less than or equal to 50%, the target shale gas sweet spot exhibits medium to high compaction intensity characteristics and is a general reservoir. Layer; when the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is less than 50% and greater than or equal to 5% and the content of non-porous organic clay composite is greater than 50% and less than or equal to 95%, the target shale gas sweet spot exhibits characteristics of moderate to high-pressure compaction intensity, and the target shale gas sweet spot is a poor reservoir; when the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is less than 5% and the content of non-porous organic clay composite is greater than 95%, the target shale gas sweet spot exhibits characteristics of high-pressure compaction intensity, and the target shale gas sweet spot is a non-reservoir.

[0163] In this embodiment, the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is 68%, and the content of non-porous organic clay composite is 32%. Therefore, the target shale gas sweet spot has the characteristics of medium to high compaction intensity, and the target shale gas sweet spot is evaluated as a general reservoir.

[0164] Example 2

[0165] This embodiment provides a method for evaluating the compaction intensity of sweet spots in shale gas reservoirs and a method for evaluating the quality of sweet spot reservoirs in shale gas reservoirs.

[0166] Methods for evaluating the compaction intensity of sweet spots in shale gas formations include:

[0167] 1. Obtain rock samples from the sweet spot segment of the target shale gas.

[0168] In this embodiment, observing the longitudinal section of the core collected from the sweet spot segment of shale gas in area A, it was found that the core was black shale without any texture (such as...). Figure 2a (As shown); select one as the target shale gas sweet spot rock sample.

[0169] 2. Prepare argon-ion polished discs of the target shale gas sweet spot rock sample using the target shale gas sweet spot rock sample; wherein the length of the argon-ion polished disc is 1cm, the width is 1cm, and the thickness is 0.5cm; the top and bottom surfaces of the argon-ion polished disc are parallel to the top and bottom surfaces of the target shale gas sweet spot rock sample in its underground state, respectively.

[0170] 3. Acquire MAPS rock image data at a resolution of 4nm on the polished surface of the argon-ion polished sheet of the target shale gas sweet spot rock. During the acquisition of MAPS rock image data, the top surface of the argon-ion polished sheet is located above the field of view and the bottom surface is located below the field of view, so as to ensure that all phenomena observed in the acquired MAPS rock image data are merely magnified natural phenomena.

[0171] 4. The MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock was collected to determine the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample; based on the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample, the compaction intensity of organic matter in the target shale gas sweet spot rock sample was determined.

[0172] Specifically, if the organic matter is distributed within the silicon shell and has abundant macropores, then the organic matter has low compaction strength; if the organic matter is distributed outside the silicon shell and has abundant macropores, then the organic matter is unrelated to compaction strength; if the organic matter is distributed outside the silicon shell and is a composite of pure organic matter and organic particles with both abundant macropores and mesopores, then the organic matter has medium compaction strength; if the organic matter is a composite of pure organic matter and organic particles with abundant mesopores, then the organic matter has medium compaction strength; if the organic matter is pure and non-porous, then the organic matter is unrelated to compaction strength; if the organic particle composite is non-porous, then the organic matter has high compaction strength; if the organic silicon particle composite is non-porous, then the organic matter has high compaction strength.

[0173] In this embodiment, based on the MAPS rock image data of the argon-ion polished slide of the target shale, it was observed that: the gas sweet spot of the target shale has biomass silica as the main rock skeleton, and the spaces between the skeleton particles are filled with organic matter; wherein, the organic matter between the skeleton particles has a pore diameter of less than 50 μm and greater than 4 μm, and a pore density of not less than 3 pores / μm. 2 clumps of pure organic matter (such as) Figure 2b , Figure 2c , Figure 2d Organic matter within the white coil is shown) and non-porous, clump-like pure organic matter (such as...). Figure 2d Organic matter outside the white coil Figure 2e (As shown).

[0174] Specifically:

[0175] In this embodiment, the target shale gas sweet spot rock development is as follows: (1) the organic matter between the skeleton particles has a pore diameter of less than 50 μm and greater than 4 μm, and a pore density of not less than 3 pores / μm. 2 clumps of pure organic matter (such as) Figure 2b , Figure 2c , Figure 2d (1) Organic matter within the white coil, which is organic matter with medium compaction strength; (2) Pure organic matter in the form of clumps without pores between the skeleton particles (such as...). Figure 2d Organic matter outside the white coil Figure 2e As shown in the figure, the organic matter is organic matter that is unrelated to the intensity of compaction.

[0176] In this embodiment, the organic matter with medium compaction strength developed in the sweet spot rock of the target shale gas specifically refers to some intergranular organic matter, namely, coking soot petroleum with medium compaction strength, and its specific occurrence state is as follows. This part of the intergranular organic matter (such as...) Figure 2b , Figure 2c , Figure 2d The organic matter within the white circle (shown as pure organic matter) is characterized by pore diameters less than 50 μm and greater than 4 μm, and a pore density of not less than 3 pores / μm. 2 The organic pores exist in aggregate form.

[0177] In this embodiment, the organic matter in the sweet spot rock of the target shale gas that is unrelated to the compaction intensity specifically refers to some intergranular organic matter, i.e., asphaltified petroleum unrelated to the compaction intensity, and its specific occurrence state is described below. This part of the intergranular organic matter (such as...) Figure 2d Organic matter outside the white coil Figure 2e The substance shown is pure organic matter, without pores, and exists in clumps.

[0178] Methods for evaluating the quality of sweet spot reservoirs in shale gas include:

[0179] 1. Obtain rock samples from the B sweet spot section of shale gas in area A as the target shale gas sweet spot rock samples. Prepare argon-ion polished sections of the target shale gas sweet spot rock samples. Select an area with a length and width not exceeding 400 μm on the polished surface of the argon-ion polished section of the target shale gas sweet spot rock samples, and acquire MAPS rock image data volumes with a resolution of 4 nm.

[0180] Here, we can directly use the MAPS rock image data obtained in step 3 of the evaluation method for the compaction intensity of shale gas sweet spot segment in Example 2.

[0181] 2. Based on the acquired MAPS rock image data, determine the organic pore and organic matter occurrence state of the target shale gas sweet spot rock sample, and then determine the content of mesoporous organic matter and non-porous organic clay complex in the target shale gas sweet spot rock sample; wherein, mesoporous organic matter includes pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, as well as pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, and organic matter in the portion of pure organic matter and organic clay complex with developed macroporous organic pores and mesoporous organic pores.

[0182] In this embodiment, the content of mesoporous organic matter in the target shale gas sweet spot rock sample and the content of non-porous organic clay composite are 100% and 0% respectively.

[0183] 3. Evaluate the reservoir quality of the target shale gas sweet spot based on the content of mesoporous organic matter and non-porous organic clay composite in the rock samples of the target shale gas sweet spot.

[0184] Specifically, when the content of mesoporous organic matter in the mesoporous organic-clay composite of the target shale gas sweet spot rock sample is ≥95% and the content of non-porous organic-clay composite is ≤5%, the target shale gas sweet spot exhibits medium compaction intensity characteristics and is a high-quality reservoir; when the content of mesoporous organic matter in the mesoporous organic-clay composite of the target shale gas sweet spot rock sample is less than 95% but greater than or equal to 50% and the content of non-porous organic-clay composite is greater than 5% but less than or equal to 50%, the target shale gas sweet spot exhibits medium to high compaction intensity characteristics and is a general reservoir. Layer; when the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is less than 50% and greater than or equal to 5% and the content of non-porous organic clay composite is greater than 50% and less than or equal to 95%, the target shale gas sweet spot exhibits characteristics of moderate to high-pressure compaction intensity, and the target shale gas sweet spot is a poor reservoir; when the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is less than 5% and the content of non-porous organic clay composite is greater than 95%, the target shale gas sweet spot exhibits characteristics of high-pressure compaction intensity, and the target shale gas sweet spot is a non-reservoir.

[0185] In this embodiment, the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is 100%, and the content of non-porous organic clay composite is 0%. Therefore, the target shale gas sweet spot has the characteristics of medium compaction intensity and is a high-quality reservoir.

[0186] Example 3

[0187] This embodiment provides a method for evaluating the compaction intensity of sweet spots in shale gas reservoirs and a method for evaluating the quality of sweet spot reservoirs in shale gas reservoirs.

[0188] Methods for evaluating the compaction intensity of sweet spots in shale gas formations include:

[0189] 1. Obtain rock samples from the sweet spot segment of the target shale gas.

[0190] In this embodiment, observing the longitudinal section of the core collected from the sweet spot segment of shale gas in area A, it was found that the core was black shale without any texture (such as...). Figure 3a (As shown); select one as the target shale gas sweet spot rock sample.

[0191] 2. Prepare argon-ion polished discs of the target shale gas sweet spot rock sample using the target shale gas sweet spot rock sample; wherein the length of the argon-ion polished disc is 1cm, the width is 1cm, and the thickness is 0.5cm; the top and bottom surfaces of the argon-ion polished disc are parallel to the top and bottom surfaces of the target shale gas sweet spot rock sample in its underground state, respectively.

[0192] 3. Acquire MAPS rock image data at a resolution of 4nm on the polished surface of the argon-ion polished sheet of the target shale gas sweet spot rock. During the acquisition of MAPS rock image data, the top surface of the argon-ion polished sheet is located above the field of view and the bottom surface is located below the field of view, so as to ensure that all phenomena observed in the acquired MAPS rock image data are merely magnified natural phenomena.

[0193] 4. The MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock was collected to determine the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample; based on the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample, the compaction intensity of organic matter in the target shale gas sweet spot rock sample was determined.

[0194] Specifically, if the organic matter is distributed within the silicon shell and has abundant macropores, then the organic matter has low compaction strength; if the organic matter is distributed outside the silicon shell and has abundant macropores, then the organic matter is unrelated to compaction strength; if the organic matter is distributed outside the silicon shell and is a composite of pure organic matter and organic particles with both abundant macropores and mesopores, then the organic matter has medium compaction strength; if the organic matter is a composite of pure organic matter and organic particles with abundant mesopores, then the organic matter has medium compaction strength; if the organic matter is pure and non-porous, then the organic matter is unrelated to compaction strength; if the organic particle composite is non-porous, then the organic matter has high compaction strength; if the organic silicon particle composite is non-porous, then the organic matter has high compaction strength.

[0195] In this embodiment, based on the MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock, the following were observed: organic matter between framework grains, organic matter between mineral grains, and organic matter in the intercrystalline pores of berry-like pyrite. Among these, the organic matter between framework grains consists of pores with a diameter greater than 50 μm and a pore density of not less than 3 pores / μm. 2 Pure organic matter (such as Figure 3b (as shown), and has a pore diameter greater than 50 μm and a pore density of not less than 3 pores / μm. 2 Organic pores with diameters less than 50 μm and greater than 4 μm, and pore density not less than 3 pores / μm 2 Pure organic matter with nested organic pores (such as Figure 3c (as shown) and organic clay complexes (such as) Figure 3d (as shown), and has a pore diameter of less than 50 μm and greater than 4 μm, and a pore density of not less than 3 pores / μm. 2 Pure organic matter (such as Figure 3e(as shown) and organic clay complexes (such as) Figure 3f As shown), and non-porous, clump-like pure organic matter (such as... Figure 3g (as shown) and strip-shaped pure organic matter (such as...) Figure 3h As shown). The organic matter between the mineral particles is a disseminated, non-porous organic-clay composite (such as...). Figure 3i , Figure 3j (As shown). Among them, the intercrystalline porous organic matter of berry-like pyrite has a pore diameter of less than 50 μm and greater than 4 μm, and a pore density of not less than 3 pores / μm. 2 Pure organic matter (such as Figure 3k As shown). Specifically:

[0196] In this embodiment, the target shale gas sweet spot rock development is as follows: (1) The organic matter between the skeleton particles has a pore diameter greater than 50 μm and a pore density of not less than 3 pores / μm. 2 Pure organic matter (such as Figure 3b (as shown), the organic matter is organic matter that is unrelated to the compaction intensity; (2) the organic matter between the skeleton particles is organic matter with a pore diameter greater than 50 μm and a pore density of not less than 3 pores / μm. 2 Organic pores with diameters less than 50 μm and greater than 4 μm, and pore density not less than 3 pores / μm 2 Pure organic matter with nested organic pores (such as Figure 3c (as shown) and organic clay complexes (such as) Figure 3d (as shown), the organic matter is organic matter with medium compaction strength; (3) the organic matter between the skeleton particles is organic matter with a pore diameter of less than 50 μm and greater than 4 μm and a pore density of not less than 3 pores / μm. 2 Pure organic matter (such as Figure 3e (as shown) and organic clay complexes (such as) Figure 3f (as shown), the organic matter is organic matter with medium compaction strength; (4) the organic matter between the skeleton particles is pure organic matter in the form of non-porous clumps (such as...). Figure 3g (as shown) and strip-shaped pure organic matter (such as...) Figure 3h (as shown), the organic matter is organic matter unrelated to the compaction intensity; (5) the organic matter between mineral particles is a disseminated, non-porous organic-clay composite (such as... Figure 3i , Figure 3j (as shown), the organic matter is an organic matter with high compaction strength; (6) the intercrystalline pore organic matter of berry-like pyrite is an organic matter with a pore diameter of less than 50 μm and greater than 4 μm and a pore density of not less than 3 pores / μm. 2 Pure organic matter (such as Figure 3k As shown in the figure, the organic matter is of medium compaction strength.

[0197] In this embodiment, the organic matter developed in the sweet spot rock of the target shale gas, which is unrelated to the compaction intensity, specifically includes pure organic matter between some framework particles, and its specific occurrence state is described below. A portion of this pure organic matter between framework particles is non-porous, exists in a clump-like form, or exists in a banded form (e.g., Figure 3g As shown), it is essentially non-porous coking petroleum. Another portion develops a pore density of not less than 3 pores / μm. 2 Organic pores with a diameter greater than 50 μm (such as...) Figure 3b As shown), it is essentially petroleum with water droplets encapsulated in asphalt coking, which is independent of the compaction strength. The water droplets vaporize into water vapor, forming a structure with a diameter greater than 50 μm and a pore density of not less than 3 pores / μm. 2 Organic pores.

[0198] In this embodiment, the organic matter with medium compaction intensity developed in the sweet spot rock of the target shale gas includes some intergranular organic matter of the framework and organic matter filling the intergranular pores of berry-like pyrite, and its specific occurrence state is described below. A portion of this intergranular organic matter of the framework has a diameter greater than 50 μm and a pore density of not less than 3 pores / μm. 2 Organic pores with diameters less than 50 μm and greater than 4 μm, and a density of not less than 3 pores / μm 2 A complex of pure organic matter and organic clay particles with nested organic pores (such as...) Figure 3c , 3d As shown), it is essentially solid asphalt petroleum with medium compaction strength, consisting of coking asphalt encapsulating water droplets. The water droplets vaporize into water vapor, forming a structure with a diameter greater than 50 μm and a pore density of not less than 3 pores / μm. 2 The organic pores of coking asphalt solid petroleum under medium compaction strength have a diameter of less than 50 μm and greater than 4 μm, and a density of not less than 3 pores / μm. 2 The organic pores; another part of the organic matter between the framework particles consists of pores with a diameter less than 50 μm and greater than 4 μm, and a density of not less than 3 pores / μm. 2 Pure organic matter with organic pores (such as) Figure 3e (as shown) and organic clay complexes (such as) Figure 3f As shown), it is essentially solid asphalt petroleum formed by coking and refining under medium compaction intensity. The organic matter filling the intercrystalline pores of the berry-like pyrite is pure organic matter, with a diameter less than 50 μm and greater than 4 μm, and a density of not less than 3 pores / μm. 2 Organic pores (such as) Figure 3k (As shown).

[0199] In this embodiment, the high-pressure compaction intensity organic matter developed in the sweet spot rock of the target shale gas is specifically the organic matter between mineral grains, and its specific occurrence state is described below. This organic matter between mineral grains is specifically an organic clay-particle complex, non-porous, and disseminated between mineral grains (e.g., Figure 3i , Figure 3j As shown in the figure, it is essentially a coking pitch clay-particle composite solid asphalt petroleum clay-particle composite with high pressure compaction strength.

[0200] Methods for evaluating the quality of sweet spot reservoirs in shale gas include:

[0201] 1. Obtain rock samples from the sweet spot section of shale gas in area A (C section) as the target sweet spot rock samples. Prepare argon-ion polished sections of the target sweet spot rocks using the target sweet spot rock samples. Select an area with a length and width not exceeding 400 μm on the polished surface of the argon-ion polished section of the target sweet spot rocks, and acquire MAPS rock image data at a resolution of 4 nm.

[0202] Here, we can directly use the MAPS rock image data obtained in step 3 of the evaluation method for the compaction intensity of shale gas sweet spot segment in Example 3.

[0203] 2. Based on the acquired MAPS rock image data, determine the organic pore and organic matter occurrence state of the target shale gas sweet spot rock sample, and then determine the content of mesoporous organic matter and non-porous organic clay complex in the target shale gas sweet spot rock sample; wherein, mesoporous organic matter includes pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, as well as pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, and organic matter in the portion of pure organic matter and organic clay complex with developed macroporous organic pores and mesoporous organic pores.

[0204] In this embodiment, the content of mesoporous organic matter in the target shale gas sweet spot rock sample and the content of non-porous organic clay composite are 31% and 69%, respectively.

[0205] 3. Evaluate the reservoir quality of the target shale gas sweet spot based on the content of mesoporous organic matter and non-porous organic clay composite in the rock samples of the target shale gas sweet spot.

[0206] Specifically, when the content of mesoporous organic matter in the mesoporous organic-clay composite of the target shale gas sweet spot rock sample is ≥95% and the content of non-porous organic-clay composite is ≤5%, the target shale gas sweet spot exhibits medium compaction intensity characteristics and is a high-quality reservoir; when the content of mesoporous organic matter in the mesoporous organic-clay composite of the target shale gas sweet spot rock sample is less than 95% but greater than or equal to 50% and the content of non-porous organic-clay composite is greater than 5% but less than or equal to 50%, the target shale gas sweet spot exhibits medium to high compaction intensity characteristics and is a general reservoir. Layer; when the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is less than 50% and greater than or equal to 5% and the content of non-porous organic clay composite is greater than 50% and less than or equal to 95%, the target shale gas sweet spot exhibits characteristics of moderate to high-pressure compaction intensity, and the target shale gas sweet spot is a poor reservoir; when the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is less than 5% and the content of non-porous organic clay composite is greater than 95%, the target shale gas sweet spot exhibits characteristics of high-pressure compaction intensity, and the target shale gas sweet spot is a non-reservoir.

[0207] In this embodiment, the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is 31%, and the content of non-porous organic clay composite is 69%. Therefore, the target shale gas sweet spot has the characteristics of medium compaction intensity and is a poor reservoir.

[0208] Example 4

[0209] A method for evaluating the compaction intensity of sweet spots in shale gas reservoirs and a method for evaluating the quality of sweet spots in shale gas reservoirs.

[0210] Methods for evaluating the compaction intensity of sweet spots in shale gas formations include:

[0211] 1. Obtain rock samples from the sweet spot segment of the target shale gas.

[0212] In this embodiment, observing the longitudinal section of the core collected from the sweet spot segment of shale gas in area A revealed that the core was black shale without any texture (such as...). Figure 4a (As shown); select one as the target shale gas sweet spot rock sample.

[0213] 2. Prepare argon-ion polished discs of the target shale gas sweet spot rock sample using the target shale gas sweet spot rock sample; wherein the length of the argon-ion polished disc is 1cm, the width is 1cm, and the thickness is 0.5cm; the top and bottom surfaces of the argon-ion polished disc are parallel to the top and bottom surfaces of the target shale gas sweet spot rock sample in its underground state, respectively.

[0214] 3. Acquire MAPS rock image data at a resolution of 4nm on the polished surface of the argon-ion polished sheet of the target shale gas sweet spot rock. During the acquisition of MAPS rock image data, the top surface of the argon-ion polished sheet is located above the field of view and the bottom surface is located below the field of view, so as to ensure that all phenomena observed in the acquired MAPS rock image data are merely magnified natural phenomena.

[0215] 4. The MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock was collected to determine the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample; based on the organic pores and organic matter occurrence state of the target shale gas sweet spot rock sample, the compaction intensity of organic matter in the target shale gas sweet spot rock sample was determined.

[0216] Specifically, if the organic matter is distributed within the silicon shell and has abundant macropores, then the organic matter has low compaction strength; if the organic matter is distributed outside the silicon shell and has abundant macropores, then the organic matter is unrelated to compaction strength; if the organic matter is distributed outside the silicon shell and is a composite of pure organic matter and organic particles with both abundant macropores and mesopores, then the organic matter has medium compaction strength; if the organic matter is a composite of pure organic matter and organic particles with abundant mesopores, then the organic matter has medium compaction strength; if the organic matter is pure and non-porous, then the organic matter is unrelated to compaction strength; if the organic particle composite is non-porous, then the organic matter has high compaction strength; if the organic silicon particle composite is non-porous, then the organic matter has high compaction strength.

[0217] In this embodiment, based on the MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock, the following were observed: organic matter between mineral grains and organic matter in the intercrystalline pores of berry-like pyrite in the target shale gas sweet spot rock; wherein, the organic matter between mineral grains is a non-porous, agglomerated, pure organic matter (such as... Figure 4b (as shown) and non-porous, strip-shaped pure organic matter (such as...) Figure 4c (as shown) and impregnated non-porous organic clay particle complexes (such as...) Figure 4d , Figure 4e As shown). The organic matter filling the intergranular pores of the berry-like pyrite is pure organic matter without pores (e.g., Figure 4f As shown). Specifically:

[0218] In this embodiment, the target shale gas sweet spot rock development is as follows: (1) the organic matter between mineral grains is a non-porous, agglomerated, pure organic matter (such as... Figure 4d(as shown), the organic matter is organic matter unrelated to the compaction intensity; (2) the organic matter between mineral particles is pure organic matter in the form of non-porous bands (such as...). Figure 4c (as shown), the organic matter is organic matter unrelated to the compaction intensity; (3) the organic matter between mineral particles is a disseminated, non-porous organic clay composite (such as... Figure 4d , Figure 4e (as shown), the organic matter is organic matter with high compressive strength; (5) the organic matter in the intercrystalline pores of berry-like pyrite is pure organic matter without pores (such as... Figure 4f As shown in the figure, the organic matter is organic matter that is unrelated to the intensity of compaction.

[0219] In this embodiment, the organic matter developed in the sweet spot rock of the target shale gas, which is unrelated to the compaction intensity, specifically includes some intergranular organic matter and intercrystalline porous organic matter in berry-like pyrite, and its specific occurrence state is described below. This intergranular organic matter is pure organic matter, without pores, and some is stored in aggregate form (e.g., ...). Figure 4d As shown), some exist in strip-like shapes (e.g. Figure 4c As shown), it is essentially non-porous asphalt peat. The intercrystalline pores of the berry-like pyrite contain pure organic matter, without pores (as shown). Figure 4f (As shown).

[0220] In this embodiment, the organic matter exhibiting high-pressure compaction intensity in the target shale gas sweet spot rock is part of the intergranular organic matter, and its specific occurrence state is described below. This part of the intergranular organic matter is an organic clay-granule complex, without pores, and is distributed in a disseminated manner between the mineral particles (e.g., Figure 4d , Figure 4e As shown in the figure, it is essentially a coking pitch clay-particle composite solid asphalt petroleum clay-particle composite with high pressure compaction strength.

[0221] Methods for evaluating the quality of sweet spot reservoirs in shale gas include:

[0222] 1. Obtain rock samples from the sweet spot section of shale gas in area A (D) as the target sweet spot rock samples. Prepare argon-ion polished sections of the target sweet spot rock samples. Select an area with a length and width not exceeding 400 μm on the polished surface of the argon-ion polished section of the target sweet spot rock samples, and acquire MAPS rock image data volumes with a resolution of 4 nm.

[0223] Here, we can directly use the MAPS rock image data obtained in step 3 of the evaluation method for the compaction intensity of shale gas sweet spot segment in Example 4.

[0224] 2. Based on the acquired MAPS rock image data, determine the organic pore and organic matter occurrence state of the target shale gas sweet spot rock sample, and then determine the content of mesoporous organic matter and non-porous organic clay complex in the target shale gas sweet spot rock sample; wherein, mesoporous organic matter includes pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, as well as pure organic matter and organic clay complex with developed mesoporous organic pores distributed outside the silica shell, and organic matter in the portion of pure organic matter and organic clay complex with developed macroporous organic pores and mesoporous organic pores.

[0225] In this embodiment, the content of mesoporous organic matter in the target shale gas sweet spot rock sample and the content of non-porous organic clay composite are 0% and 100% respectively.

[0226] 3. Evaluate the reservoir quality of the target shale gas sweet spot based on the content of mesoporous organic matter and non-porous organic clay composite in the rock samples of the target shale gas sweet spot.

[0227] Specifically, when the content of mesoporous organic matter in the mesoporous organic-clay composite of the target shale gas sweet spot rock sample is ≥95% and the content of non-porous organic-clay composite is ≤5%, the target shale gas sweet spot exhibits medium compaction intensity characteristics and is a high-quality reservoir; when the content of mesoporous organic matter in the mesoporous organic-clay composite of the target shale gas sweet spot rock sample is less than 95% but greater than or equal to 50% and the content of non-porous organic-clay composite is greater than 5% but less than or equal to 50%, the target shale gas sweet spot exhibits medium to high compaction intensity characteristics and is a general reservoir. Layer; when the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is less than 50% and greater than or equal to 5% and the content of non-porous organic clay composite is greater than 50% and less than or equal to 95%, the target shale gas sweet spot exhibits characteristics of moderate to high-pressure compaction intensity, and the target shale gas sweet spot is a poor reservoir; when the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is less than 5% and the content of non-porous organic clay composite is greater than 95%, the target shale gas sweet spot exhibits characteristics of high-pressure compaction intensity, and the target shale gas sweet spot is a non-reservoir.

[0228] In this embodiment, the content of mesoporous organic matter in the rock sample of the target shale gas sweet spot is 0%, and the content of non-porous organic clay composite is 100%. Therefore, the target shale gas sweet spot has the characteristics of high-pressure compaction intensity and is not a reservoir.

[0229] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating compaction strength of a shale gas dessert section, the method comprising: obtaining a rock sample of a target shale gas dessert section; determining organic pores and organic matter occurrence state of the rock sample of the target shale gas dessert section; determining compaction strength of organic matter in the rock sample of the target shale gas dessert section based on the organic pores and the organic matter occurrence state of the rock sample of the target shale gas dessert section; wherein the compaction strength of the organic matter with developed macroporous organic pores distributed in the siliceous shell is low compaction strength; the pure organic matter with developed macroporous organic pores distributed outside the siliceous shell is not sensitive to compaction strength; the compaction strength of the pure organic matter and organic clay particle complex with developed macroporous organic pores and mesoporous organic pores distributed outside the siliceous shell is medium compaction strength; the compaction strength of the pure organic matter and organic clay particle complex with developed mesoporous organic pores is medium compaction strength; the pure organic matter without pores is not sensitive to compaction strength; the compaction strength of the organic clay particle complex without pores is high compaction strength; and the compaction strength of the organic siliceous particle complex without pores is high compaction strength; wherein the determination of the organic pores and the organic matter occurrence state of the rock sample of the target shale gas dessert section comprises: preparing an argon ion polished slice of the rock of the target shale gas dessert section using the rock sample of the target shale gas dessert section; collecting a MAPS rock image data volume of the argon ion polished slice of the rock of the target shale gas dessert section; determining the organic pores and the organic matter occurrence state of the rock sample of the target shale gas dessert section based on the collected MAPS rock image data volume of the argon ion polished slice of the rock of the target shale gas dessert section.

2. The method of claim 1, wherein the organic matter with developed macroporous organic pores distributed in the siliceous shell further has the following occurrence characteristics: being an organic siliceous particle complex and / or being a filling in a siliceous shell cavity of an intact siliceous shell; and / or the pure organic matter with developed macroporous organic pores distributed outside the siliceous shell further has the following occurrence characteristics: being in a lump shape between mineral particles; and / or the pure organic matter and the organic clay particle complex with developed macroporous organic pores and mesoporous organic pores distributed outside the siliceous shell further has the following occurrence characteristics: being in a lump shape between rock framework particles; and / or the pure organic matter and the organic clay particle complex with developed mesoporous organic pores further has the following occurrence characteristics: being in a lump shape between rock framework particles, or being in a strip shape between rock framework particles, or being a filling in intercrystalline pores of raspberry pyrite, or being a filling in a siliceous shell cavity of a broken siliceous shell; and / or the pure organic matter without pores further has the following occurrence characteristics: being in a lump shape between mineral particles, or being in a strip shape between mineral particles, or being a filling in intercrystalline pores of raspberry pyrite; and / or the organic clay particle complex without pores further has the following occurrence characteristics: being in a lump shape between mineral particles, or being in a strip shape between mineral particles, or being in a disseminated state between mineral particles; and / or the organic siliceous particle complex without pores further has the following occurrence characteristics: being a filling in a siliceous shell cavity of a broken siliceous shell. ​ ​ ​ ​ ​ ​ ​ ​ 3. The method of claim 1, wherein, The MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock comprises: selecting an area with a length and a width of no more than 400 μm in the polishing surface of the argon ion polished slice of the target shale gas sweet spot section rock, and collecting the MAPS rock image data volume.

4. The method of claim 1, wherein, The argon ion polished slice of the target shale gas sweet spot section rock has a length of 0.8-2 cm, a width of 0.8-2 cm, and a thickness of 0.3-0.8 cm.

5. The method of claim 1, wherein, The resolution of the collected MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock is 1-10 nm.

6. The method of claim 1, wherein, The top surface and the bottom surface of the argon ion polished slice of the target shale gas sweet spot section rock are parallel to the top surface and the bottom surface of the target shale gas sweet spot section rock sample in the underground state; and / or During the collection of the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock, the top surface of the argon ion polished slice of the target shale gas sweet spot section rock is located above the field of view, and the bottom surface of the argon ion polished slice of the target shale gas sweet spot section rock is located below the field of view.

7. A method of evaluating reservoir quality in a shale gas sweet spot interval, wherein, The method comprises: obtaining a target shale gas sweet spot section rock sample; determining the organic pore and organic matter occurrence state of the target shale gas sweet spot section rock sample, and further determining the content of mesopore organic matter and the content of non-pore organic clay complex in the mesopore organic matter and the non-pore organic clay complex of the target shale gas sweet spot section rock sample; wherein the mesopore organic matter includes pure organic matter and organic clay complex that develop rich mesopore organic pores outside the silica shell, and the organic matter that develops rich mesopore organic pores in the pure organic matter and the organic clay complex that develop rich macropore organic pores and rich mesopore organic pores outside the silica shell; based on the content of mesopore organic matter and the content of non-pore organic clay complex in the mesopore organic matter and the non-pore organic clay complex of the target shale gas sweet spot section rock sample, evaluating the reservoir quality of the target shale gas sweet spot section; wherein determining the organic pore and organic matter occurrence state of the target shale gas sweet spot section rock sample, and further determining the content of mesopore organic matter and the content of non-pore organic clay complex in the mesopore organic matter and the non-pore organic clay complex of the target shale gas sweet spot section rock sample, comprises: using the target shale gas sweet spot section rock sample to make an argon ion polished slice of the target shale gas sweet spot section rock; collecting a MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock; based on the collected MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock, determining the organic pore and organic matter occurrence state of the target shale gas sweet spot section rock sample, and further determining the content of mesopore organic matter and the content of non-pore organic clay complex in the mesopore organic matter and the non-pore organic clay complex of the target shale gas sweet spot section rock sample; wherein based on the content of mesopore organic matter and the content of non-pore organic clay complex in the mesopore organic matter and the non-pore organic clay complex of the target shale gas sweet spot section rock sample, evaluating the reservoir quality of the target shale gas sweet spot section comprises: When the content of mesopore organic matter in the mesopore organic matter and non-pore organic clay complex of the rock sample of the target shale gas sweet spot section is greater than or equal to 95% and the content of the non-pore organic clay complex is less than or equal to 5%, the target shale gas sweet spot section presents a medium compaction strength feature, and the target shale gas sweet spot section is a high-quality reservoir. When the content of mesopore organic matter in the mesopore organic matter and non-pore organic clay complex of the rock sample of the target shale gas sweet spot section is less than 95% and greater than or equal to 50% and the content of the non-pore organic clay complex is greater than 5% and less than or equal to 50%, the target shale gas sweet spot section presents a medium compaction strength feature, and the target shale gas sweet spot section is a general reservoir. When the content of mesopore organic matter in the mesopore organic matter and non-pore organic clay complex of the rock sample of the target shale gas sweet spot section is less than 50% and greater than or equal to 5% and the content of the non-pore organic clay complex is greater than 50% and less than or equal to 95%, the target shale gas sweet spot section presents a high compaction strength feature, and the target shale gas sweet spot section is a poor reservoir. When the content of mesopore organic matter in the mesopore organic matter and non-pore organic clay complex of the rock sample of the target shale gas sweet spot section is less than 5% and the content of the non-pore organic clay complex is greater than 95%, the target shale gas sweet spot section presents a high compaction strength feature, and the target shale gas sweet spot section is a non-reservoir.

8. The method of claim 7, wherein, The argon ion polished slice of the rock of the target shale gas sweet spot section has a length of 0.8-2 cm, a width of 0.8-2 cm, and a thickness of 0.3-0.8 cm.

9. The method of claim 7, wherein, The process of collecting the MAPS rock image data body of the argon ion polished slice of the rock of the target shale gas sweet spot section includes: selecting an area with a length and a width of not more than 400 μm in the polishing surface of the argon ion polished slice of the rock of the target shale gas sweet spot section, and collecting the MAPS rock image data body.

10. The method of claim 7, wherein, The resolution of the collected MAPS rock image data body of the argon ion polished slice of the rock of the target shale gas sweet spot section is 1-10 nm.

11. The method of claim 7, wherein, The top surface and the bottom surface of the argon ion polished slice of the rock of the target shale gas sweet spot section are parallel to the top surface and the bottom surface of the rock sample of the target shale gas sweet spot section in an underground state; and / or During the process of collecting the MAPS rock image data body of the argon ion polished slice of the rock of the target shale gas sweet spot section, the top surface of the argon ion polished slice of the rock of the target shale gas sweet spot section is located above the field of view, and the bottom surface of the argon ion polished slice of the rock of the target shale gas sweet spot section is located below the field of view.

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