Method for judging organic pore genesis and golden target body of shale gas sweet spot section

Abstract

The present application provides a method for judging the cause of organic pores in a shale gas sweet spot section and a golden target body. The method for judging the cause of organic pores in a shale gas sweet spot section comprises: obtaining a rock sample of a target shale gas sweet spot section; determining the type of organic matter of the rock sample of the target shale gas sweet spot section; determining the thermal evolution history of the organic matter based on the type of organic matter of the rock sample of the shale gas sweet spot section, thereby determining the cause of the organic pores developed in the organic matter. The method for judging the golden target body of a shale gas sweet spot section comprises: obtaining a rock sample of a target shale gas sweet spot section; determining the mesopore organic pore porosity of the rock sample of the target shale gas sweet spot section; determining the golden target body of the target shale gas sweet spot section based on the mesopore organic pore porosity. The technical scheme provided by the present application can realize the judgment of the cause of organic pores in a shale gas sweet spot section and the judgment of the golden target body of a shale gas sweet spot section, thereby helping the fine evaluation of a shale gas sweet spot section and the economic goal of cost reduction and efficiency improvement in the exploration and development of shale gas.

Description

Technical Field

[0001] This invention belongs to the field of shale gas exploration and development technology, specifically relating to a method for determining the organic porosity of shale gas sweet spots and a method for determining gold targets in shale gas sweet spots. 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, serving 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, our understanding of the genesis of organic pores remains lacking.

[0003] Thermal simulation experiments on immature or low-maturity shale with organic matter suggest that organic pores develop within residual kerogen. This understanding assumes that the shale is already dense and non-porous when or before the conversion of sedimentary organic matter into kerogen, and that all hydrocarbons formed from the thermal degradation of kerogen are expelled from the shale. However, this viewpoint has several shortcomings: ① For marine black shale, sedimentary organic matter mainly consists of organic matter formed after the death of microorganisms. During the thermal evolution of kerogen into pre-oil bitumen, the kerogen is completely converted and disappears, thus there is no residual kerogen or honeycomb-like nanopores within it; ② During the thermal evolution of sedimentary organic matter into pre-oil bitumen and petroleum, the shale may still have residual primary pores. These pre-oil bitumen and petroleum fill these residual primary pores. Therefore, the conclusion that the shale is already dense and non-porous when or before the conversion of sedimentary organic matter into kerogen is a biased and incomplete view, not consistent with actual geological conditions.

[0004] Petroleum thermal simulation experiments using the "bubble-to-porosity" model revealed that during the thermal evolution of petroleum into pitch and natural gas, liquid petroleum gradually transforms into solid pitch. A portion of the generated natural gas is trapped within the pitch, forming "bubble pores," indicating the development of honeycomb-like pores in pitched petroleum. However, petrological evidence suggests a lack of porosity in pitched petroleum. Therefore, the "bubble-to-porosity" experiment is not the cause of porosity in pitched petroleum within shale. In other words, the organic pore formation attributed to the petroleum "bubble-to-porosity" thermal simulation results does not conform to petrological evidence, and the development of porosity in pitched petroleum is a partial and incomplete generalization.

[0005] Some researchers have combined argon ion polishing and high-resolution scanning electron microscopy to classify shale reservoir porosity, suggesting that organic pores develop within residual kerogen. This understanding assumes that the shale is already dense and non-porous when or before the conversion of sedimentary organic matter into kerogen, and that all hydrocarbons formed from the thermal degradation of kerogen are expelled. Therefore, according to the law of conservation of mass, honeycomb-like nanopores should develop within the residual kerogen. However, this viewpoint has several shortcomings: ① For marine black shale, sedimentary organic matter mainly consists of organic matter formed after the death of microorganisms. During the thermal evolution of kerogen into pre-oil bitumen, the kerogen is completely converted and disappears, thus there is no residual kerogen or honeycomb-like nanopores within it; ② During the thermal evolution of sedimentary organic matter into pre-oil bitumen and petroleum, the shale may still have residual primary pores. These pre-oil bitumen and petroleum fill these residual primary pores. Therefore, the assumption that the shale is already dense and non-porous before or after the conversion of sedimentary organic matter into kerogen is a biased and incomplete view, not consistent with actual geological conditions.

[0006] Researchers using simultaneous scanning transmission X-ray microscopy (STXM) to observe shale reservoirs have found that asphalt-bituminized petroleum exhibits honeycomb-like pores, while asphalt-bituminized organic matter lacks porosity. However, the apparent lack of porosity in asphalt-bituminized organic matter is due to the low resolution of this experiment, which is insufficient to distinguish the honeycomb-like mesopores, leading to the misconception that asphalt-bituminized organic matter lacks porosity. Therefore, this viewpoint is characterized by its biased interpretation, incomplete understanding, and even misleading nature.

[0007] Some researchers, constrained by a conceptual model of shale diagenesis sequence, have divided organic matter into in-situ organic matter and migrated organic matter, finding that organic pores are developed in migrated organic matter, while in-situ organic matter lacks porosity. This misconception stems primarily from the fact that the conceptual model of shale diagenesis sequence does not reflect actual geological conditions: in this model, minerals such as secondary quartz overgrowth, calcite, and dolomite act as cementing agents. These cements form after the sedimentary organic matter settles to the seabed and forms part of the sediment, but before the formation of migrated organic matter (pre-oil bitumen or petroleum). Therefore, organic matter in contact with these cements is considered migrated organic matter, while organic matter in contact with other minerals (mainly clay minerals) is considered in-situ organic matter. However, in reality, the formation time of secondary quartz overgrowth, calcite, and dolomite coincides with the formation time of sedimentary organic matter. This means that in-situ organic matter is in direct contact with these cements, and migrated organic matter may also be in direct contact with these minerals. Therefore, this viewpoint has the characteristics of generalizing from a single point, making sweeping generalizations based on limited information, and even confusing the public.

[0008] A review of previous research reveals that all studies on the genesis of organic pores in shale have focused on specific points in the spectrum, with no research conducted from the perspective of sweet spots in shale. This implies an assumption that the genesis of organic pores in sweet spots is the same, which is the fundamental reason for the ambiguity in the genesis of organic pores.

[0009] In summary, further research is needed on the distribution patterns of organic pores in shale gas sweet spots in order to facilitate the precise evaluation of shale gas sweet spots and achieve the economic goals of cost reduction and efficiency improvement in shale gas exploration and development. Summary of the Invention

[0010] The purpose of this invention is to provide a technical solution that enables the determination of the organic porosity of shale gas sweet spots and the identification of gold targets within shale gas sweet spots, thereby contributing to the precise evaluation of shale gas sweet spots and the economic goals of cost reduction and efficiency improvement in shale gas exploration and development.

[0011] To achieve the above objectives, the present invention provides the following two technical solutions.

[0012] In a first aspect, the present invention provides a method for determining the organic porosity of sweet spots in shale gas, wherein the method includes:

[0013] Obtain rock samples from the sweet spot segment of the target shale gas;

[0014] Determine the type of organic matter in the target shale gas sweet spot rock sample:

[0015] Based on the organic matter type of rock samples from sweet spots of shale gas, the thermal evolution process of organic matter was determined, thereby determining the origin of organic pores developed in the organic matter.

[0016] According to a specific embodiment of the first aspect, preferably, the organic matter type includes macroporous organic clay particle complexes filling primary pores, macro-mesoporous organic clay particle complexes filling primary pores, mesoporous organic clay particle complexes filling primary pores, macroporous pure organic matter filling primary pores, macroporous pure organic matter filling secondary pores, macro-mesoporous pure organic matter filling primary pores, macro-mesoporous pure organic matter filling secondary pores, mesoporous pure organic matter filling primary pores, mesoporous pure organic matter filling secondary pores, non-porous pure organic matter filling primary pores, non-porous pure organic matter filling secondary pores, and non-porous pure organic matter filling cracks.

[0017] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0018] When the organic matter type is a macroporous organic-mucinous complex that fills the primary pores:

[0019] The thermal evolution process of organic matter is as follows: water-rich clay filling the original pores evolves into oil-water clay filling the original pores, and then evolves into macroporous coke-asphalt clay-particle composite filling the original pores.

[0020] The organic pores developed in organic matter are formed as follows: during the process of oil-water clay filling the primary pores evolving into macroporous pyroasphalt clay-particle complexes filling the primary pores, water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0021] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0022] When the organic matter type is a macroporous-mesoporous organic-clay complex filling the primary pores:

[0023] The thermal evolution process of organic matter is as follows: the sedimentary organic clay particle complex filling the primary pores evolves into the kerogen clay particle complex filling the primary pores, then evolves into the pre-asphalt clay particle complex containing water droplets filling the primary pores, then evolves into the solid asphalt petroleum clay particle complex containing water droplets filling the primary pores, and then evolves into the macroporous-mesoporous coke asphalt clay particle complex filling the primary pores.

[0024] The formation of organic pores in organic matter is due to the following: During the evolution of the pre-water droplet-encapsulated asphalt-petroleum clay-particle complex filling the primary pores into a pre-water droplet-encapsulated solid asphalt-petroleum clay-particle complex filling the primary pores, the expansion of generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces for shale oil; During the evolution of the pre-water droplet-encapsulated solid asphalt-petroleum clay-particle complex filling the primary pores into a macro-mesoporous pyro-asphalt-petroleum clay-particle complex filling the primary pores, the solid asphalt undergoes thermal degradation to generate natural gas and is converted into pyro-asphalt. The expansion of generated natural gas leads to the formation of mesopores in the pyro-asphalt. Natural gas exists in both adsorbed and free states in the mesopores, while water droplets vaporize into water vapor to form macropores. Water vapor exists in the macropores in a free state.

[0025] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0026] When the organic matter type is a mesoporous organic-mucinous complex filling the primary pores:

[0027] The thermal evolution process of organic matter is as follows: the sedimentary organic clay particle complex filling the primary pores evolves into the kerogen clay particle complex filling the primary pores, then evolves into the pre-oil bitumen clay particle complex filling the primary pores, then evolves into the solid bitumen petroleum clay particle complex filling the primary pores, and then evolves into the mesoporous coke bitumen clay particle complex filling the primary pores.

[0028] The formation of organic pores in organic matter is due to the following: During the evolution of the pre-oil bitumen clay particle complex that fills the primary pores into the solid bitumen petroleum clay particle complex that fills the primary pores, the expansion of generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main reservoir spaces for shale oil; During the evolution of the solid bitumen petroleum clay particle complex that fills the primary pores into the mesoporous pyroasphalt clay particle complex that fills the primary pores, the thermal degradation of solid bitumen generates natural gas and is converted into pyroasphalt. The expansion of generated natural gas leads to the formation of mesopores in the pyroasphalt, and natural gas exists in both adsorbed and free states in the mesopores.

[0029] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0030] When the organic matter type is macroporous pure organic matter filling the original pores:

[0031] The thermal evolution process of organic matter is as follows: petroleum droplets filled with primary pores evolve into macroporous tar pitch filled with primary pores;

[0032] The organic pores developed in organic matter are formed as follows: during the process of petroleum encapsulating water droplets filling the primary pores evolving into macroporous tar pitch filling the primary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0033] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0034] When the organic matter type is macroporous pure organic matter filling secondary pores:

[0035] The thermal evolution process of organic matter is as follows: petroleum droplets filled with secondary pores evolve into macroporous tar pitch filled with secondary pores.

[0036] The organic pores developed in organic matter are formed as follows: during the process of petroleum encapsulated in secondary pores evolving into macroporous tar pitch that fills secondary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0037] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0038] When the organic matter type is macroporous-mesoporous pure organic matter filling the primary pores:

[0039] The thermal evolution process of organic matter is as follows: pre-asphalt filled with water droplets and filled with primary pores evolves into solid asphalt petroleum filled with water droplets and filled with primary pores, and then evolves into macroporous-mesoporous coke asphalt filled with primary pores.

[0040] The formation of organic pores in organic matter is due to the following: During the evolution of asphalt into solid asphalt oil that fills the primary pores and encapsulates water droplets, the expansion of the generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main storage spaces for shale oil. During the evolution of solid asphalt oil that fills the primary pores and encapsulates water droplets into macroporous-mesoporous tar pitch that fills the primary pores, the solid asphalt undergoes thermal degradation to generate natural gas and is converted into tar pitch. The expansion of the generated natural gas leads to the formation of mesopores in the tar pitch. Natural gas exists in both adsorbed and free states in the mesopores. Water droplets vaporize into water vapor to form macropores, and water vapor exists in the macropores in a free state.

[0041] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0042] When the organic matter type is macroporous-mesoporous pure organic matter filling secondary pores:

[0043] The thermal evolution process of organic matter is as follows: pre-asphalt filled with water droplets that fills secondary pores evolves into solid asphalt petroleum filled with water droplets that fills secondary pores, and then evolves into macroporous-mesoporous coke pitch that fills secondary pores.

[0044] The formation of organic pores in organic matter is due to the following: During the evolution of asphalt into solid asphalt oil filled with water droplets before filling secondary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces for shale oil. During the evolution of solid asphalt oil filled with water droplets into macroporous-mesoporous tar pitch filled with secondary pores, the solid asphalt undergoes thermal degradation to generate natural gas and is converted into tar pitch. The expansion of the generated natural gas leads to the formation of mesopores in the tar pitch. Natural gas exists in both adsorbed and free states in the mesopores. Water droplets vaporize into water vapor to form macropores, and water vapor exists in the macropores in a free state.

[0045] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0046] When the organic matter type is mesoporous pure organic matter filling the primary pores:

[0047] The thermal evolution process of organic matter is as follows: pre-oil bitumen filling the original pores evolves into solid bitumen filling the original pores, and then evolves into mesoporous coke bitumen filling the original pores.

[0048] The formation of organic pores in organic matter is due to the following: During the evolution of pre-oil bitumen filling primary pores into solid bitumen filling primary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main storage spaces for shale oil; During the evolution of solid bitumen filling primary pores into mesoporous pyrophage filling primary pores, the solid bitumen undergoes thermal degradation to generate natural gas and is converted into pyrophage. The expansion of the generated natural gas leads to the formation of mesopores in the pyrophage, and natural gas exists in both adsorbed and free states in the mesopores.

[0049] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0050] When the organic matter type is mesoporous pure organic matter filling secondary pores:

[0051] The thermal evolution process of organic matter is as follows: pre-oil bitumen filling secondary pores evolves into solid asphalt petroleum filling secondary pores, and then evolves into mesoporous coke bitumen filling secondary pores.

[0052] The formation of organic pores in organic matter is due to the following: During the evolution of pre-oil bitumen filling secondary pores into solid bitumen filling secondary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main storage spaces for shale oil; During the evolution of solid bitumen filling secondary pores into mesoporous pyrophage filling secondary pores, the solid bitumen undergoes thermal degradation to generate natural gas and is converted into pyrophage. The expansion of the generated natural gas leads to the formation of mesopores in the pyrophage, and natural gas exists in both adsorbed and free states in the mesopores.

[0053] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0054] When the organic matter type is non-porous pure organic matter filling the original pores:

[0055] The thermal evolution process of organic matter is as follows: petroleum that fills the primary pores evolves into non-porous pyroasphalt that fills the primary pores.

[0056] It does not develop organic pores.

[0057] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0058] When the organic matter type is non-porous pure organic matter filling secondary pores:

[0059] The thermal evolution process of organic matter is as follows: petroleum filling secondary pores evolves into non-porous tar pitch filling secondary pores.

[0060] It does not develop organic pores.

[0061] According to a specific implementation of the first aspect, preferably, the thermal evolution process of organic matter is determined based on the type of organic matter in the rock sample of the sweet spot of shale gas, thereby determining the origin of the organic pores developed in the organic matter, including:

[0062] When the organic matter type is non-porous pure organic matter filling cracks:

[0063] The thermal evolution process of organic matter is as follows: petroleum filling cracks evolves into non-porous pyroasphalt filling cracks.

[0064] It does not develop organic pores.

[0065] According to a specific implementation of the first aspect, preferably, determining the organic matter type of the target shale gas sweet spot rock sample includes:

[0066] 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.

[0067] MAPS rock image data of argon-ion polished sections of target shale gas sweet spot rock were acquired;

[0068] Based on the MAPS rock image data of the argon-ion polished sections of the target shale gas sweet spot rock, the organic matter type of the target shale gas sweet spot rock sample is described.

[0069] More preferably, the resolution of the MAPS rock image data volume of the argon-ion polished slide of the target shale gas sweet spot rock is 4 resolution;

[0070] More preferably, the length of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.8-2 cm;

[0071] More preferably, the width of the argon-ion polished sheet for the sweet spot segment of the target shale gas is 0.8-2 cm;

[0072] More preferably, the thickness of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.3-0.8 cm;

[0073] More preferably, the top and bottom surfaces of the argon-ion polished sheet 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;

[0074] More preferably, the acquisition of MAPS rock image data volume of argon-ion polished sheet of target shale gas sweet spot rock includes: selecting an area with a length and width not exceeding 400 μm on the polished surface of argon-ion polished sheet of target shale gas sweet spot rock, and acquiring MAPS rock image data volume;

[0075] More preferably, during the acquisition of MAPS rock image data volumes from argon-ion polished sheets of target shale gas sweet spots, the top surface of the argon-ion polished sheet of the target shale gas sweet spot is located above the field of view, and the bottom surface of the argon-ion polished sheet of the target shale gas sweet spot is located below the field of view, thereby ensuring that all phenomena observed in the acquired MAPS rock image data volumes are merely magnified versions of natural phenomena.

[0076] Secondly, the present invention provides a method for identifying a gold target in the sweet spot segment of shale gas, wherein the method includes:

[0077] Obtain rock samples from the sweet spot segment of the target shale gas;

[0078] Determine the mesoporous organic porosity of the target shale gas sweet spot rock sample;

[0079] Based on the mesoporous organic porosity of the target shale gas sweet spot rock sample, determine whether the target shale gas sweet spot is a gold target.

[0080] According to a specific implementation of the second aspect, preferably, determining whether a target shale gas sweet spot is a gold target based on the mesoporous organic porosity of the target shale gas sweet spot rock sample includes:

[0081] When the mesoporous organic porosity of the target shale gas sweet spot rock sample is ≥1.0%, the target shale gas sweet spot is a gold target.

[0082] When the mesoporous organic porosity of the target shale gas sweet spot rock sample is less than 1.0%, the target shale gas sweet spot is not a gold target.

[0083] According to a specific embodiment of the second aspect, preferably, the mesoporous organic pores are mesopores developed in organic matter of the following types: macroporous-mesoporous organic-mucinous complexes filling primary pores, mesoporous organic-mucinous complexes filling primary pores, macroporous-mesoporous pure organic matter filling primary pores, macroporous-mesoporous pure organic matter filling secondary pores, mesoporous pure organic matter filling primary pores, and mesoporous pure organic matter filling secondary pores.

[0084] According to a specific implementation of the second aspect, preferably, determining the mesoporous organic porosity of the target shale gas sweet spot rock sample includes:

[0085] 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.

[0086] MAPS rock image data of argon-ion polished sections of target shale gas sweet spot rock were acquired;

[0087] Based on the MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock, the mesoporous organic porosity of the target shale gas sweet spot rock sample is calculated.

[0088] More preferably, the organic porosity of intermediate pores in rock samples from the sweet spot segment of the target shale gas was statistically analyzed using the "phase surface method".

[0089] More preferably, 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.

[0090] More preferably, the length of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.8-2 cm;

[0091] More preferably, the width of the argon-ion polished sheet for the sweet spot segment of the target shale gas is 0.8-2 cm;

[0092] More preferably, the thickness of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.3-0.8 cm;

[0093] More preferably, the top and bottom surfaces of the argon-ion polished sheet 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.

[0094] More preferably, the acquisition of MAPS rock image data volume of argon-ion polished sheet of target shale gas sweet spot rock includes: selecting an area with a length and width not exceeding 400 μm on the polished surface of argon-ion polished sheet of target shale gas sweet spot rock, and acquiring MAPS rock image data volume;

[0095] More preferably, during the acquisition of MAPS rock image data volumes from argon-ion polished sheets of target shale gas sweet spots, the top surface of the argon-ion polished sheet of the target shale gas sweet spot is located above the field of view, and the bottom surface of the argon-ion polished sheet of the target shale gas sweet spot is located below the field of view, thereby ensuring that all phenomena observed in the acquired MAPS rock image data volumes are merely magnified versions of natural phenomena.

[0096] The technical solution provided by this invention enables the determination of the organic porosity of sweet spots in shale gas and the identification of optimal targets within these sweet spots, thereby contributing to the refined evaluation of sweet spots and the economic goals of cost-effective and efficient shale gas exploration and development. Specifically, this invention establishes a technical solution capable of determining the organic porosity of over-mature shale, providing scientific data support for stratigraphic evaluation and site selection during shale gas exploration and for refined evaluation of sweet spots during development. This invention also establishes a method for identifying optimal targets within shale gas sweet spots, providing crucial information for selecting targets in shale gas horizontal wells and guiding efficient shale gas exploration and development. Attached Figure Description

[0097] Figure 1 This is a map showing the location and coding of rock samples from the sweet spot segment of the target shale gas in Examples 1, 2, and 3 of this invention.

[0098] Figure 2 This is a map showing the organic matter type and stratigraphic distribution of the target shale gas sweet spot in Examples 1, 2, and 3 of the present invention.

[0099] Figure 3 This is a typical image of nanorock of organic matter type in the sweet spot segment of the target shale gas of Embodiment 1 of the present invention.

[0100] Figure 4 This is a typical image of nanorock of organic matter type in the sweet spot segment of the target shale gas of Embodiment 2 of the present invention.

[0101] Figure 5 This is a typical image of nanorock of organic matter type in the sweet spot segment of the target shale gas of Example 3 of the present invention. Detailed Implementation

[0102] 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.

[0103] 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.

[0104] The "phase surface method" is used to calculate the porosity of mesoporous organic pores: The "phase surface method" estimates the porosity of mesoporous organic pores in each grid rock image in a 4nm MAPS data volume. The porosity of mesoporous organic pores in different grid rock images is added together to obtain the sum of the porosity of mesoporous organic pores in all grids. The percentage of the sum of porosity of this porosity to the total grid area is the porosity of mesoporous organic pores in the rock sample.

[0105] The products of thermal evolution of deposited organic matter are, in order: deposited organic matter → kerogen → pre-oil bitumen → solid bitumen and petroleum → coking bitumen and natural gas.

[0106] In-situ organic matter: settled organic clay particle complex, kerogen clay particle complex, pre-oil bitumen clay particle complex, solid bitumen petroleum clay particle complex, and coke bitumen clay particle complex.

[0107] Migrating organic matter: Organic matter that migrates from sedimentary organic clay complexes or kerogen clay complexes, such as pre-oil bitumen, solid bitumen, petroleum, coking asphalt solid bitumen petroleum, and coking asphalt petroleum.

[0108] Mesopores refer to pores with a diameter of 4-50 nm.

[0109] Macropores refer to pores with a diameter greater than 50 nm.

[0110] Organic pores refer to the pores that develop in organic matter or organic clay particle complexes.

[0111] The inventors of this invention conducted research on organic matter types in shale gas sweet spots, clarifying the thermal evolution process of organic matter types, identifying the genesis and gas-bearing properties of macropores and mesopores, and using the "phase surface method" to statistically analyze the porosity of mesopores in shale gas sweet spots. This method identifies prime targets within shale gas sweet spots, pioneering a new approach to determining the genesis of organic matter and identifying prime targets within these sweet spots by dividing them into smaller layers. This extends previous research on the genesis of organic pores from a "point" perspective to a "line" and "surface" perspective, reducing the ambiguity of organic pore formation and thus guiding the efficient exploration and development of shale gas. Furthermore, based on the inventors' research findings, this invention provides a method for determining the genesis of organic pores in shale gas sweet spots and a method for identifying prime targets within these sweet spots, providing crucial information for selecting targets in shale gas horizontal wells and guiding the efficient exploration and development of shale gas.

[0112] In one specific embodiment, the method for determining the organic porosity of shale gas sweet spots provided by the present invention includes:

[0113] Obtain rock samples from the sweet spot segment of the target shale gas;

[0114] Determine the type of organic matter in the target shale gas sweet spot rock sample:

[0115] Based on the organic matter type of rock samples from sweet spots of shale gas, the thermal evolution process of organic matter was determined, thereby determining the origin of organic pores developed in the organic matter.

[0116] Furthermore, the organic matter types include macroporous organic-clay composites filling primary pores, macro-mesoporous organic-clay composites filling primary pores, mesoporous organic-clay composites filling primary pores, macroporous pure organic matter filling primary pores (pure organic matter corresponds to organic-clay composites and refers to organic matter that does not mix with clay to form organic-clay composites), macroporous pure organic matter filling secondary pores, macro-mesoporous pure organic matter filling primary pores, macro-mesoporous pure organic matter filling secondary pores, mesoporous pure organic matter filling primary pores, mesoporous pure organic matter filling secondary pores, non-porous pure organic matter filling primary pores, non-porous pure organic matter filling secondary pores, and non-porous pure organic matter filling cracks.

[0117] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0118] When the organic matter type is a macroporous organic-mucinous complex that fills the primary pores:

[0119] The thermal evolution process of organic matter is as follows: water-rich clay filling the original pores evolves into oil-water clay filling the original pores, and then evolves into macroporous coke-asphalt clay-particle composite filling the original pores.

[0120] The organic pores developed in organic matter are formed as follows: during the process of water-rich clay filling the primary pores evolving into macroporous pyroasphalt clay-particle complexes filling the primary pores, water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0121] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0122] When the organic matter type is a macroporous-mesoporous organic-clay complex filling the primary pores:

[0123] The thermal evolution process of organic matter is as follows: pre-asphalt containing water droplets that fills the original pores evolves into a solid asphalt-petroleum particle complex containing water droplets that fills the original pores, and then evolves into a macroporous-mesoporous coke-asphalt particle complex that fills the original pores.

[0124] The formation of organic pores in organic matter is due to the following: During the evolution of the pre-water droplet-encapsulated asphalt-petroleum clay-particle complex filling the primary pores into a pre-water droplet-encapsulated solid asphalt-petroleum clay-particle complex filling the primary pores, the expansion of generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces for shale oil; During the evolution of the pre-water droplet-encapsulated solid asphalt-petroleum clay-particle complex filling the primary pores into a macro-mesoporous pyro-asphalt-petroleum clay-particle complex filling the primary pores, the solid asphalt undergoes thermal degradation to generate natural gas and is converted into pyro-asphalt. The expansion of generated natural gas leads to the formation of mesopores in the pyro-asphalt. Natural gas exists in both adsorbed and free states in the mesopores, while water droplets vaporize into water vapor to form macropores. Water vapor exists in the macropores in a free state.

[0125] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0126] When the organic matter type is a mesoporous organic-mucinous complex filling the primary pores:

[0127] The thermal evolution process of organic matter is as follows: the sedimentary organic clay particle complex filling the primary pores evolves into the kerogen clay particle complex filling the primary pores, then evolves into the pre-oil bitumen clay particle complex filling the primary pores, then evolves into the solid bitumen petroleum clay particle complex filling the primary pores, and then evolves into the mesoporous coke bitumen clay particle complex filling the primary pores.

[0128] The formation of organic pores in organic matter is due to the following: During the evolution of the pre-oil bitumen clay particle complex that fills the primary pores into the solid bitumen petroleum clay particle complex that fills the primary pores, the expansion of generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main reservoir spaces for shale oil; During the evolution of the solid bitumen petroleum clay particle complex that fills the primary pores into the mesoporous pyroasphalt clay particle complex that fills the primary pores, the thermal degradation of solid bitumen generates natural gas and is converted into pyroasphalt. The expansion of generated natural gas leads to the formation of mesopores in the pyroasphalt, and natural gas exists in both adsorbed and free states in the mesopores.

[0129] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0130] When the organic matter type is macroporous pure organic matter filling the original pores:

[0131] The thermal evolution process of organic matter is as follows: petroleum droplets filled with primary pores evolve into macroporous tar pitch filled with primary pores;

[0132] The organic pores developed in organic matter are formed as follows: during the process of petroleum encapsulating water droplets filling the primary pores evolving into macroporous tar pitch filling the primary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0133] Furthermore, based on the organic matter type of shale gas reservoir rock samples, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed in the organic matter, including:

[0134] When the organic matter type is macroporous pure organic matter filling secondary pores:

[0135] The thermal evolution process of organic matter is as follows: water droplets filling primary pores evolve into macroporous pyrophage filling secondary pores;

[0136] The organic pores developed in organic matter are formed as follows: during the process of petroleum encapsulated in secondary pores evolving into macroporous tar pitch that fills secondary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0137] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0138] When the organic matter type is macroporous-mesoporous pure organic matter filling the primary pores:

[0139] The thermal evolution process of organic matter is as follows: pre-asphalt filled with water droplets that fills the original pores evolves into solid asphalt petroleum filled with water droplets that fills the original pores, and then evolves into macroporous-mesoporous coke pitch that fills the original pores.

[0140] The formation of organic pores in organic matter is due to the following: During the evolution of asphalt into solid asphalt oil filled with water droplets before filling the primary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main storage spaces for shale oil; During the evolution of solid asphalt oil filled with water droplets into macroporous-mesoporous tar pitch filled with primary pores, the solid asphalt undergoes thermal degradation to generate natural gas and is converted into tar pitch. The expansion of the generated natural gas leads to the formation of mesopores in the tar pitch. Natural gas exists in both adsorbed and free states in the mesopores, while water droplets vaporize into water vapor to form macropores. Water vapor exists in the macropores in a free state.

[0141] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0142] When the organic matter type is macroporous-mesoporous pure organic matter filling secondary pores:

[0143] The thermal evolution process of organic matter is as follows: pre-asphalt filled with water droplets that fills secondary pores evolves into solid asphalt petroleum filled with water droplets that fills secondary pores, and then evolves into macroporous-mesoporous coke pitch that fills secondary pores.

[0144] The formation of organic pores in organic matter is due to the following: During the evolution of asphalt into solid asphalt oil that fills secondary pores and encapsulates water droplets, the expansion of the generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces for shale oil. During the evolution of solid asphalt oil that fills secondary pores and encapsulates water droplets into macroporous-mesoporous tar pitch that fills secondary pores, the solid asphalt undergoes thermal degradation to generate natural gas and is converted into tar pitch. The expansion of the generated natural gas leads to the formation of mesopores in the tar pitch. Natural gas exists in both adsorbed and free states in the mesopores. Water droplets vaporize into water vapor to form macropores, and water vapor exists in the macropores in a free state.

[0145] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0146] When the organic matter type is mesoporous pure organic matter filling the primary pores:

[0147] The thermal evolution process of organic matter is as follows: pre-oil bitumen filling the original pores evolves into solid bitumen filling the original pores, and then evolves into mesoporous coke bitumen filling the original pores.

[0148] The formation of organic pores in organic matter is due to the following: During the evolution of pre-oil bitumen filling primary pores into solid bitumen filling primary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main storage spaces for shale oil; During the evolution of solid bitumen filling primary pores into mesoporous pyrophage filling primary pores, the solid bitumen undergoes thermal degradation to generate natural gas and is converted into pyrophage. The expansion of the generated natural gas leads to the formation of mesopores in the pyrophage, and natural gas exists in both adsorbed and free states in the mesopores.

[0149] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0150] When the organic matter type is mesoporous pure organic matter filling secondary pores:

[0151] The thermal evolution process of organic matter is as follows: pre-oil bitumen filling secondary pores evolves into solid asphalt petroleum filling secondary pores, and then evolves into mesoporous coke bitumen filling secondary pores.

[0152] The formation of organic pores in organic matter is due to the following: During the evolution of pre-oil bitumen filling secondary pores into solid bitumen filling secondary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main storage spaces for shale oil; During the evolution of solid bitumen filling secondary pores into mesoporous pyrophage filling secondary pores, the solid bitumen undergoes thermal degradation to generate natural gas and is converted into pyrophage. The expansion of the generated natural gas leads to the formation of mesopores in the pyrophage, and natural gas exists in both adsorbed and free states in the mesopores.

[0153] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0154] When the organic matter type is non-porous pure organic matter filling the original pores:

[0155] The thermal evolution process of organic matter is as follows: petroleum that fills the primary pores evolves into non-porous pyroasphalt that fills the primary pores.

[0156] It does not develop organic pores.

[0157] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0158] When the organic matter type is non-porous pure organic matter filling secondary pores:

[0159] The thermal evolution process of organic matter is as follows: petroleum filling secondary pores evolves into non-porous tar pitch filling secondary pores.

[0160] It does not develop organic pores.

[0161] Furthermore, based on the organic matter type of rock samples from shale gas sweet spots, the thermal evolution process of the organic matter was determined, thereby identifying the genesis of the organic pores developed within the organic matter, including:

[0162] When the organic matter type is non-porous pure organic matter filling cracks:

[0163] The thermal evolution process of organic matter is as follows: petroleum filling cracks evolves into non-porous pyroasphalt filling cracks.

[0164] It does not develop organic pores.

[0165] Further, rock samples were obtained from the sweet spot segment of the target shale gas, including:

[0166] The rock sample collected from the sweet spot of the target shale gas is the rock sample of the target shale gas sweet spot.

[0167] Furthermore, the organic matter type of the target shale gas sweet spot rock samples was determined, including:

[0168] 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.

[0169] MAPS rock image data of argon-ion polished sections of target shale gas sweet spot rock were acquired;

[0170] Based on the MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock, the organic matter type of the target shale gas sweet spot rock sample was determined.

[0171] Furthermore, the resolution of the MAPS rock image data volume of the argon-ion polished section of the target shale gas sweet spot rock is 4 resolution;

[0172] Furthermore, the length of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.8-2cm (e.g., 1cm);

[0173] Furthermore, the width of the argon-ion polished sheet of the target shale gas sweet spot rock is 0.8-2cm (e.g., 1cm);

[0174] 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);

[0175] 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.

[0176] 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.

[0177] 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.

[0178] In one specific embodiment, the method for determining the sweet spot gold target of shale gas provided by the present invention includes:

[0179] Obtain rock samples from the sweet spot segment of the target shale gas;

[0180] Determine the mesoporous organic porosity of the target shale gas sweet spot rock sample;

[0181] Based on the mesoporous organic porosity of the target shale gas sweet spot rock sample, determine whether the target shale gas sweet spot is a gold target.

[0182] Furthermore, based on the mesoporous-organic porosity of the target shale gas sweet spot rock sample, determining whether the target shale gas sweet spot is a gold target includes:

[0183] When the mesoporous organic porosity of the target shale gas sweet spot rock sample is ≥1.0%, the target shale gas sweet spot is a gold target.

[0184] When the mesoporous organic porosity of the target shale gas sweet spot rock sample is less than 1.0%, the target shale gas sweet spot is not a gold target.

[0185] Furthermore, the mesoporous organic pores are mesopores developed in organic matter of the following types: macroporous-mesoporous organic-mucinous complex filling primary pores, mesoporous organic-mucinous complex filling primary pores, macroporous-mesoporous pure organic matter filling primary pores, macroporous-mesoporous pure organic matter filling secondary pores, mesoporous pure organic matter filling primary pores, and mesoporous pure organic matter filling secondary pores.

[0186] Further, obtain rock samples from the target shale gas reservoir, including:

[0187] The rock samples collected from the target shale gas reservoir are called target shale gas reservoir rock samples.

[0188] Further, the porosity of the mesoporous organic pores in the target shale gas reservoir rock samples was determined, including:

[0189] Argon-ion polished discs of target shale gas reservoir rocks were prepared using rock samples from the target shale gas reservoir.

[0190] MAPS rock image data of argon-ion polished sections of rocks from the target shale gas reservoir were acquired.

[0191] Based on the MAPS rock image data of the argon-ion polished section of the target shale gas sweet spot rock, the mesoporous organic porosity of the target shale gas sweet spot rock sample is calculated.

[0192] Furthermore, the organic porosity of intermediate pores in rock samples from the sweet spot segment of the target shale gas was statistically analyzed using the "phase surface method".

[0193] Furthermore, the resolution of the MAPS rock image data volume of the argon-ion polished slides of the target shale gas reservoir rocks is 1-10 nm (preferably 4 nm).

[0194] Furthermore, the length of the argon-ion polished sheet of the target shale gas reservoir rock is 0.8-2 cm (e.g., 1 cm);

[0195] Furthermore, the width of the argon-ion polished sheet of the target shale gas reservoir rock is 0.8-2 cm (e.g., 1 cm);

[0196] Furthermore, the thickness of the argon-ion polished sheet of the target shale gas reservoir rock is 0.3-0.8 cm (e.g., 0.5 cm);

[0197] Furthermore, the top and bottom surfaces of the argon-ion polished section of the target shale gas reservoir rock are parallel to the top and bottom surfaces of the target shale gas reservoir 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.

[0198] Furthermore, the acquisition of MAPS rock image data from argon-ion polished sheets of target shale gas reservoir rocks 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 reservoir rocks, and acquiring MAPS rock image data.

[0199] Furthermore, during the acquisition of MAPS rock image data volumes from argon-ion polished sheets of target shale gas reservoir rocks, the top surface of the argon-ion polished sheets of target shale gas reservoir rocks is positioned above the field of view, and the bottom surface of the argon-ion polished sheets of target shale gas reservoir rocks is positioned below the field of view, thereby ensuring that all phenomena observed in the acquired MAPS rock image data volumes are merely magnified versions of natural phenomena.

[0200] Example 1:

[0201] This embodiment provides a method for determining the organic porosity of the sweet spot segment of shale gas in well H2 and a method for determining the gold target in the sweet spot segment of shale gas in well H2.

[0202] Methods for determining the organic porosity of the sweet spot section of shale gas in well H2 include:

[0203] 1. Obtain the sweet spot segment of shale gas from well H2 (Longyi 1) 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from the stratigraphic unit were selected as rock samples from the target shale gas sweet spot segment.

[0204] This embodiment collects shale gas sweet spot segment Longyi 1 from well H2. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from each stratigraphic layer. One sample was collected from each stratigraphic layer, for a total of four samples. Sample locations and codes are detailed below. Figure 1 .

[0205] 2. Prepare argon-ion polished discs of the target shale gas sweet spot rock sample using rock samples from the target shale gas sweet spot rock sample; wherein the length of the argon-ion polished disc of the target shale gas sweet spot rock sample is 1cm, the width is 1cm, and the thickness is 0.5cm; the top and bottom surfaces of the argon-ion polished disc of the target shale gas sweet spot rock sample are parallel to the top and bottom surfaces of the target shale gas sweet spot rock sample in its underground state, respectively.

[0206] 3. Select 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, and acquire MAPS rock image data volume with a resolution of 4 nm. During the acquisition of MAPS rock image data volume, the top surface of the argon-ion polished sheet of the target shale gas sweet spot is located above the field of view, and the bottom surface of the argon-ion polished sheet of the target shale gas sweet spot is located below the field of view, so as to ensure that all phenomena observed in the acquired MAPS rock image data volume are merely magnified natural phenomena.

[0207] 4. Based on the MAPS rock image data of the argon-ion polished sections of the target shale gas sweet spot rock, describe the types of organic matter in the target shale gas sweet spot rock samples, clarify the thermal evolution process of the organic matter types, and thus clarify the genesis of organic pores.

[0208] The organic matter types include macroporous organic-mucinous complex I1 filling primary pores, macro-mesoporous organic-mucinous complex I2 filling primary pores, mesoporous organic-mucinous complex I3 filling primary pores, and macroporous pure organic matter II1 filling primary pores. 1 Macroporous pure organic matter filling secondary pores II1 2 Macroporous-mesoporous pure organic matter II2 filling the original pores 1 Macroporous-mesoporous pure organic matter II2 filling secondary pores 2 Mesoporous pure organic matter II3 filling the original pores 1 Mesoporous pure organic matter II3 filling secondary pores 2 Non-porous pure organic matter II4 filling the original pores 1 Non-porous pure organic matter II4 filling secondary pores 2 1. Non-porous pure organic matter II4 for filling cracks 3 .

[0209] In this embodiment, the organic matter types in the sweet spot segment of shale gas are divided into 2 major categories, 7 subcategories, and 9 subcategories, such as... Figure 2 , Figure 3 Among them, the H2 well contains the Longyi 1 shale gas reservoir. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 See the types of organic matter in the strata. Figure 3 .

[0210] In macroporous organic-clay composites I1, where the organic matter type is filled with primary pores, clay generally exceeds 10%, and the organic matter and clay minerals are thoroughly mixed. The macropores have large pore size and low density (e.g., Figure 3 (a) In macroporous-mesoporous organic clay composite I2, where the organic matter type is filled with primary pores, clay minerals are scattered throughout the organic matter. Macropores are few in number and randomly distributed, while mesopores are dense and uniformly distributed (e.g., ...). Figure 3 (b) In the mesoporous organic clay-particle complex I3, where the organic matter type is filled with primary pores, clay minerals are scattered throughout the organic matter, and the mesoporous density is high and the distribution is uniform (e.g., Figure 3 (c)

[0211] The organic matter type is macroporous pure organic matter II1 that fills the original pores. 1 (like Figure 3 d) and organic matter type II1 are macroporous pure organic matter filling secondary pores. 2 (like Figure 3 In section e), the macropore density is high and the distribution is uniform. The organic matter type is macro-mesoporous pure organic matter II2 filling the primary pores. 1 (like Figure 3 f) and organic matter type II are macro-mesoporous pure organic matter filling secondary pores. 2 (like Figure 3 In the g group, macropores have low density and random distribution, while mesopores have high density and uniform distribution. The organic matter type is mesoporous pure organic matter II3 filling the primary pores. 1 (like Figure 3 h) and the organic matter type is mesoporous pure organic matter II3 filling secondary pores. 2 (like Figure 3 (i) The mesopore density is high and the distribution is uniform. The organic matter type is non-porous pure organic matter II4, which fills the original pores. 1 like Figure 3 As shown in j, the organic matter type is non-porous pure organic matter II4 that fills secondary pores. 2 like Figure 3 As shown in k, the organic matter type is non-porous pure organic matter II4 filling the cracks. 3 like Figure 3As shown in l in the figure.

[0212] H2 well shale gas sweet spot Duan Longyi 1 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 The types of organic matter vary considerably within the strata; see details below. Figure 2 The section on the distribution of organic matter types in stratigraphic layers shows that when the organic matter type is a macroporous organic-clay composite filling primary pores, the thermal evolution process of the organic matter is as follows: water-rich clay filling primary pores evolves into oil-water clay filling primary pores, and then evolves into a macroporous pyroasphalt clay composite filling primary pores. The organic pores developed in the organic matter are formed because, during the evolution from water-rich clay filling primary pores to macroporous pyroasphalt clay composites, water droplets vaporize into water vapor, forming macropores, and the water vapor exists in a free state within the macropores.

[0213] When the organic matter type is a macro-mesoporous organic clay particle complex that fills the primary pores, the thermal evolution process of the organic matter is as follows: the pre-asphalt containing water droplets that fills the primary pores evolves into a solid asphalt petroleum clay particle complex containing water droplets that fills the primary pores, and then evolves into a macro-mesoporous coke pitch clay particle complex that fills the primary pores. The formation of organic pores in organic matter is due to the following: During the evolution of the pre-water droplet-encapsulated asphalt-petroleum clay-particle complex filling the primary pores into a pre-water droplet-encapsulated solid asphalt-petroleum clay-particle complex filling the primary pores, the expansion of generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces for shale oil; During the evolution of the pre-water droplet-encapsulated solid asphalt-petroleum clay-particle complex filling the primary pores into a macro-mesoporous pyro-asphalt-petroleum clay-particle complex filling the primary pores, the solid asphalt undergoes thermal degradation to generate natural gas and is converted into pyro-asphalt. The expansion of generated natural gas leads to the formation of mesopores in the pyro-asphalt. Natural gas exists in both adsorbed and free states in the mesopores, while water droplets vaporize into water vapor to form macropores. Water vapor exists in the macropores in a free state.

[0214] When the organic matter is a mesoporous organic-clay composite filled with primary pores, the thermal evolution process of the organic matter is as follows: the mesoporous organic-clay composite filled with primary pores evolves into a kerogen clay composite filled with primary pores, then into a pre-oil bitumen clay composite filled with primary pores, further into a solid bitumen petroleum clay composite filled with primary pores, and finally into a mesoporous pyroasphalt clay composite filled with primary pores. The formation of organic pores in the organic matter is as follows: during the evolution of the pre-oil bitumen clay composite filled with primary pores into the solid bitumen petroleum clay composite filled with primary pores, the expansion of generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main reservoir spaces for shale oil; during the evolution of the solid bitumen petroleum clay composite filled with primary pores into the mesoporous pyroasphalt clay composite filled with primary pores, the thermal degradation of solid bitumen generates natural gas and is converted into pyroasphalt, and the expansion of generated natural gas leads to the formation of mesopores in the pyroasphalt, where natural gas exists in both adsorbed and free states.

[0215] When the organic matter is macroporous pure organic matter filling primary pores, the thermal evolution process of the organic matter is as follows: the encapsulated water droplets of petroleum filling primary pores evolve into macroporous tar pitch filling primary pores. The organic pores developed in the organic matter are formed because, during the process of the encapsulated water droplets of petroleum filling primary pores evolving into macroporous tar pitch filling primary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in a free state within the macropores.

[0216] When the organic matter is macroporous pure organic matter filling secondary pores, the thermal evolution process of the organic matter is as follows: encapsulated water droplets filling primary pores evolve into macroporous tar pitch filling secondary pores. The formation of organic pores in the organic matter is as follows: during the evolution of petroleum encapsulated water droplets filling secondary pores into macroporous tar pitch filling secondary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in a free state within the macropores.

[0217] When the organic matter is pure macro-mesoporous organic matter filling primary pores, the thermal evolution process of the organic matter is as follows: pre-oil asphalt containing water droplets filling primary pores evolves into solid asphalt petroleum containing water droplets filling primary pores, and then evolves into macro-mesoporous pyrophage filling primary pores. The formation of organic pores in the organic matter is as follows: During the evolution of pre-oil asphalt containing water droplets filling primary pores into solid asphalt petroleum containing water droplets filling primary pores, the expansion of generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces of shale oil; During the evolution of solid asphalt petroleum containing water droplets filling primary pores into macro-mesoporous pyrophage filling primary pores, the solid asphalt thermally degrades to generate natural gas and is converted into pyrophage. The expansion of generated natural gas leads to the formation of mesopores in the pyrophage. Natural gas exists in the mesopores in both adsorbed and free states, while water droplets vaporize into water vapor to form macropores, and water vapor exists in the macropores in a free state.

[0218] When the organic matter is pure macro-mesoporous organic matter filling secondary pores, the thermal evolution process of the organic matter is as follows: the pre-oil asphalt containing water droplets filling secondary pores evolves into solid asphalt petroleum containing water droplets filling secondary pores, and then evolves into macro-mesoporous pyrophage filling secondary pores. The formation of organic pores in the organic matter is as follows: during the evolution of pre-oil asphalt containing water droplets filling secondary pores into solid asphalt petroleum containing water droplets filling secondary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces of shale oil; during the evolution of solid asphalt petroleum containing water droplets filling secondary pores into macro-mesoporous pyrophage filling secondary pores, the solid asphalt thermally degrades to generate natural gas and is converted into pyrophage. The expansion of the generated natural gas leads to the formation of mesopores in the pyrophage. Natural gas exists in both adsorbed and free states in the mesopores, and water droplets vaporize into water vapor to form macropores. Water vapor exists in the macropores in a free state.

[0219] When the organic matter is mesoporous pure organic matter filling primary pores, the thermal evolution process of the organic matter is as follows: pre-oil bitumen filling primary pores evolves into solid bitumen filling primary pores, and then evolves into mesoporous pyrophage filling primary pores. The formation of organic pores in the organic matter is due to the following: during the evolution of pre-oil bitumen filling primary pores into solid bitumen filling primary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main reservoir spaces for shale oil; during the evolution of solid bitumen filling primary pores into mesoporous pyrophage filling primary pores, the solid bitumen undergoes thermal degradation to generate natural gas and is simultaneously converted into pyrophage. The expansion of the generated natural gas leads to the formation of mesopores in the pyrophage, and the natural gas exists in both adsorbed and free states within the mesopores.

[0220] When the organic matter is mesoporous pure organic matter filling secondary pores, the thermal evolution process of the organic matter is as follows: pre-oil bitumen filling secondary pores evolves into solid bitumen filling secondary pores, and then evolves into mesoporous pyrophage filling secondary pores. The formation of organic pores in the organic matter is as follows: during the evolution of pre-oil bitumen filling secondary pores into solid bitumen filling secondary pores, the expansion of the generated petroleum leads to the formation of organic pores in the solid bitumen, which is one of the main reservoir spaces of shale oil; during the evolution of solid bitumen filling secondary pores into mesoporous pyrophage filling secondary pores, the solid bitumen thermally degrades to generate natural gas and is converted into pyrophage. The expansion of the generated natural gas leads to the formation of mesopores in the pyrophage, and natural gas exists in both adsorbed and free states in the mesopores.

[0221] When the organic matter is a non-porous pure organic matter filling the primary pores, the thermal evolution process of the organic matter is as follows: petroleum filling the primary pores evolves into non-porous tar pitch filling the primary pores. No organic pores are developed.

[0222] When the organic matter is a non-porous pure organic matter filling secondary pores, the thermal evolution process of the organic matter is as follows: petroleum filling secondary pores evolves into non-porous tar pitch filling secondary pores. No organic pores are developed.

[0223] When the organic matter type is non-porous pure organic matter filling cracks, the thermal evolution process of the organic matter is as follows: the petroleum filling cracks evolves into non-porous pyroasphalt filling cracks. No organic pores are developed.

[0224] Methods for identifying the sweet spot of shale gas in well H2 include:

[0225] 1. Obtain the sweet spot segment of shale gas from well H2 (Longyi 1) 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from the stratigraphic unit were used as rock samples for the target shale gas sweet spot. Argon-ion polished sections of the target shale gas sweet spot rocks were prepared using the rock samples from the target shale gas sweet spot. A region with a length and width not exceeding 400 μm was selected on the polished surface of the argon-ion polished section of the target shale gas sweet spot, and MAPS rock image data volumes with a resolution of 4 nm were acquired.

[0226] Here, we can directly use the MAPS rock image data obtained in step 3 of the method for determining the organic porosity of the sweet spot segment of shale gas in well H2.

[0227] 2. Based on the acquired MAPS rock image data, the "facies surface method" was used to statistically analyze the sweet spot segment of the H2 shale gas, Long-1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 The interpore organic porosity of rock samples from the stratigraphic layer is used as a reference for the sweet spot segment of shale gas in well H2, Long-1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Mesoporous organic porosity of rock samples from different stratigraphic layers.

[0228] In this embodiment, the sweet spot segment of shale gas in well H2 is Longyi 1. 1 、Dragon 1 2 、Dragon 1 3 、Dragon 1 4 The porosity of mesoporous and organic pores varies considerably across the strata. (Longyi 1) 1 The porosity of the mesoporous organic pores in the strata is 1.86%, Longyi 1 2 The porosity of the mesoporous organic pores in the strata is 1.27%, Longyi 1 3 The porosity of the mesoporous organic pores in the strata is 0.75%, Longyi 1 4The porosity of the mesoporous organic pores in the strata is 0%.

[0229] 3. Based on the sweet spot segment of shale gas in well H2, Longyi 1 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 The mesoporous organic porosity of rock samples from the stratigraphic layer was used to determine the sweet spot segment of shale gas in well H2, Long-1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Is the layer a golden target?

[0230] Specifically, when the mesoporous-organic porosity of the target shale gas sweet spot rock sample is ≥1.0%, the target shale gas sweet spot is a gold target; when the mesoporous-organic porosity of the target shale gas sweet spot rock sample is less than 1.0%, the target shale gas sweet spot is not a gold target.

[0231] Dragon 1 1 Layer, Dragon 1 2 The mesoporous organic pore porosity of the layer is greater than or equal to 1.0%, therefore Longyi 1 1 Layer, Dragon 1 2 The stratigraphic position is a prime target for the sweet spot segment of shale gas in well H2. Higher mesoporous organic pore porosity indicates a higher content of adsorbed and free natural gas within these pores. Therefore, Longyi 1 serves as a prime target for the sweet spot segment of shale gas in well H2. 1 The tier is also better than Longyi 1 2 Layers.

[0232] Example 2

[0233] This embodiment provides a method for determining the organic porosity of the sweet spot segment of shale gas in well H4 and a method for determining the gold target in the sweet spot segment of shale gas in well H4.

[0234] The method for determining the organic porosity of the sweet spot segment in the H4 shale gas well differs from the method for determining the organic porosity of the sweet spot segment in the H2 shale gas well in Example 1 only in the following aspects:

[0235] The rock samples used were collected from the sweet spot segment of shale gas in well H4, Long-1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from each stratigraphic layer (one sample was collected from each stratigraphic layer, for a total of four samples; sample locations and codes are detailed in [link to sample information]). Figure 1 It was not collected from the sweet spot segment of shale gas in well H2, Longyi 1. 1 Layer, Dragon 1 2 Layer, Dragon 13 Layer, Dragon 1 4 Rock samples from the stratigraphic layer.

[0236] In this embodiment, the organic matter type of the sweet spot segment of shale gas in well H4 is divided into 2 major categories, 7 subcategories, and 9 subcategories, such as... Figure 2 , Figure 4 Among them, the H4 well has a sweet spot segment for shale gas, Longyi 1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 See the types of organic matter in the strata. Figure 4 .

[0237] In macroporous organic-clay composites I1, where the organic matter type is filled with primary pores, clay generally exceeds 10%, and the organic matter and clay minerals are thoroughly mixed. The macropores have large pore size and low density (e.g., Figure 4 (a) In macroporous-mesoporous organic clay composite I2, where the organic matter type is filled with primary pores, clay minerals are scattered throughout the organic matter. Macropores are few in number and randomly distributed, while mesopores are dense and uniformly distributed (e.g., ...). Figure 4 (b) In the mesoporous organic clay-particle complex I3, where the organic matter type is filled with primary pores, clay minerals are scattered throughout the organic matter, and the mesoporous density is high and the distribution is uniform (e.g., Figure 4 (c)

[0238] The organic matter type is macroporous pure organic matter II1 that fills the original pores. 1 (like Figure 4 d) and organic matter type II1 are macroporous pure organic matter filling secondary pores. 2 (like Figure 4 In section e), the macropore density is high and the distribution is uniform. The organic matter type is macro-mesoporous pure organic matter II2 filling the primary pores. 1 (like Figure 4 f) and organic matter type II are macro-mesoporous pure organic matter filling secondary pores. 2 (like Figure 4 In the g group, macropores have low density and random distribution, while mesopores have high density and uniform distribution. The organic matter type is mesoporous pure organic matter II3 filling the primary pores. 1 (like Figure 4 h) and the organic matter type is mesoporous pure organic matter II3 filling secondary pores. 2 (like Figure 4 (i) The mesopore density is high and the distribution is uniform. The organic matter type is non-porous pure organic matter II4, which fills the original pores. 1 like Figure 4 As shown in j, the organic matter type is non-porous pure organic matter II4 that fills secondary pores. 2 like Figure 4As shown in k, the organic matter type is non-porous pure organic matter II4 filling the cracks. 3 like Figure 4 As shown in l in the figure.

[0239] H4 Well Shale Gas Sweet Spot Duan Longyi 1 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 The types of organic matter vary considerably within the strata; see details below. Figure 2 The column showing the distribution of organic matter types in the stratigraphic sequence.

[0240] The method for identifying the gold target in the sweet spot of shale gas in well H4 differs from the method for identifying the gold target in the sweet spot of shale gas in Example 1 only in that:

[0241] The rock samples used were collected from the sweet spot segment of shale gas in well H4, Long-1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from each stratigraphic layer (one sample was collected from each stratigraphic layer, for a total of four samples; sample locations and codes are detailed in [link to sample information]). Figure 1 It was not collected from the sweet spot segment of shale gas in well H2, Longyi 1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from the stratigraphic layer.

[0242] In this embodiment, the sweet spot segment of shale gas in well H4 is Longyi 1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 The porosity of mesoporous and organic pores varies considerably across the strata. (Longyi 1) 1 The porosity of the mesoporous organic pores in the strata is 1.91%, Longyi 1 2 The porosity of the mesoporous organic pores in the strata is 1.16%, Longyi 1 3 The porosity of the mesoporous organic pores in the strata is 0.88%, Longyi 1 4 The porosity of the mesoporous organic pores in the strata is 0%.

[0243] Dragon 1 1 Layer, Dragon 1 2 The mesoporous organic pore porosity of the layer is greater than or equal to 1.0%, therefore Longyi 1 1 Layer, Dragon 1 2The stratigraphic unit is a prime target for the sweet spot segment of shale gas in well H4. Higher mesoporous organic pore porosity indicates a higher content of adsorbed and free natural gas within these pores. Therefore, Longyi 1 serves as a prime target for the sweet spot segment of shale gas in well H4. 1 The tier is also better than Longyi 1 2 Layers.

[0244] Example 3

[0245] This embodiment provides a method for determining the organic porosity of the sweet spot segment of shale gas in well H5 and a method for determining the gold target in the sweet spot segment of shale gas in well H5.

[0246] The method for determining the organic porosity of the sweet spot section of shale gas in well H5 differs from the method for determining the organic porosity of the sweet spot section of shale gas in well H2 in Example 1 only in the following aspects:

[0247] The rock samples used were collected from the sweet spot segment of shale gas in well H5, specifically from the Long-1 shale gas well. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from each stratigraphic layer (one sample was collected from each stratigraphic layer, for a total of four samples; sample locations and codes are detailed in [link to sample information]). Figure 1 It was not collected from the sweet spot segment of shale gas in well H2, Longyi 1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from the stratigraphic layer.

[0248] In this embodiment, the organic matter type of the sweet spot segment of shale gas in well H5 is divided into 2 major categories, 7 subcategories, and 9 subcategories, such as... Figure 2 , Figure 5 Among them, the H5 well has a sweet spot segment for shale gas, Longyi 1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 See the types of organic matter in the strata. Figure 5 .

[0249] In macroporous organic-clay composites I1, where the organic matter type is filled with primary pores, clay generally exceeds 10%, and the organic matter and clay minerals are thoroughly mixed. The macropores have large pore size and low density (e.g., Figure 5 (a) In macroporous-mesoporous organic clay composite I2, where the organic matter type is filled with primary pores, clay minerals are scattered throughout the organic matter. Macropores are few in number and randomly distributed, while mesopores are dense and uniformly distributed (e.g., ...). Figure 5 (b) In the mesoporous organic clay-particle complex I3, where the organic matter type is filled with primary pores, clay minerals are scattered throughout the organic matter, and the mesoporous density is high and the distribution is uniform (e.g., Figure 5 (c)

[0250] The organic matter type is macroporous pure organic matter II1 that fills the original pores. 1 (like Figure 5 d) and organic matter type II1 are macroporous pure organic matter filling secondary pores. 2 (like Figure 5 In section e), the macropore density is high and the distribution is uniform. The organic matter type is macro-mesoporous pure organic matter II2 filling the primary pores. 1 (like Figure 5 f) and organic matter type II are macro-mesoporous pure organic matter filling secondary pores. 2 (like Figure 5 In the g group, macropores have low density and random distribution, while mesopores have high density and uniform distribution. The organic matter type is mesoporous pure organic matter II3 filling the primary pores. 1 (like Figure 5 h) and the organic matter type is mesoporous pure organic matter II3 filling secondary pores. 2 (like Figure 5 (i) The mesopore density is high and the distribution is uniform. The organic matter type is non-porous pure organic matter II4, which fills the original pores. 1 like Figure 5 As shown in j, the organic matter type is non-porous pure organic matter II4 that fills secondary pores. 2 like Figure 5 As shown in k, the organic matter type is non-porous pure organic matter II4 filling the cracks. 3 like Figure 5 As shown in l in the figure.

[0251] H5 Well Shale Gas Sweet Spot Duan Longyi 1 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 The types of organic matter vary considerably within the strata; see details below. Figure 2 The column showing the distribution of organic matter types in the stratigraphic sequence.

[0252] The method for identifying the gold target in the sweet spot of shale gas in well H5 differs from the method for identifying the gold target in the sweet spot of shale gas in Example 1 only in that:

[0253] The rock samples used were collected from the sweet spot segment of shale gas in well H5, specifically from the Long-1 shale gas well. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from each stratigraphic layer (one sample was collected from each stratigraphic layer, for a total of four samples; sample locations and codes are detailed in [link to sample information]). Figure 1 It was not collected from the sweet spot segment of shale gas in well H2, Longyi 1.1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 Rock samples from the stratigraphic layer.

[0254] In this embodiment, the sweet spot segment of shale gas in well H5 is Longyi 1. 1 Layer, Dragon 1 2 Layer, Dragon 1 3 Layer, Dragon 1 4 The porosity of mesoporous and organic pores varies considerably across the strata. (Longyi 1) 1 The porosity of the mesoporous organic pores in the strata is 2.35%, Longyi 1 2 The porosity of the mesoporous organic pores in the strata is 1.19%, Longyi 1 3 The porosity of the mesoporous organic pores in the strata is 0.82%, Longyi 1 4 The porosity of the mesoporous organic pores in the strata is 0%.

[0255] Dragon 1 1 Layer, Dragon 1 2 The mesoporous organic pore porosity of the layer is greater than or equal to 1.0%, therefore Longyi 1 1 Layer, Dragon 1 2 The stratigraphic unit is a prime target for the sweet spot segment of shale gas in well H4. The higher the porosity of the mesoporous organic pores, the higher the content of adsorbed and free natural gas within them. Therefore, as a prime target for the sweet spot segment of shale gas in well H5, Longyi 1... 1 The tier is also better than Longyi 1 2 Layers.

[0256] 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 of determining the origin of organic pores in a shale gas pay interval, wherein, The method comprises: acquiring a rock sample of a target shale gas sweet spot section; determining the organic matter type of the rock sample of the target shale gas sweet spot section: based on the organic matter type of the rock sample of the shale gas sweet spot section, determining the thermal evolution history of the organic matter, thereby determining the genesis of the organic pores developed in the organic matter; wherein the organic matter type comprises a macro-pore organic clay complex filling the primary pores, a macro-mesopore organic clay complex filling the primary pores, a mesopore organic clay complex filling the primary pores, a macro-pore pure organic matter filling the primary pores, a macro-pore pure organic matter filling the secondary pores, a macro-mesopore pure organic matter filling the primary pores, a macro-mesopore pure organic matter filling the secondary pores, a mesopore pure organic matter filling the primary pores, a mesopore pure organic matter filling the secondary pores, a non-pore pure organic matter filling the primary pores, a non-pore pure organic matter filling the secondary pores, and a non-pore pure organic matter filling the fractures; wherein, based on the organic matter type of the rock sample of the shale gas sweet spot section, determining the thermal evolution history of the organic matter, thereby determining the genesis of the organic pores developed in the organic matter comprises: when the organic matter type is a macro-pore organic clay complex filling the primary pores: the thermal evolution history of the organic matter is that water-rich clay filling the primary pores evolves into oil-water clay filling the primary pores, and then evolves into a macro-pore pyrobitumen clay complex filling the primary pores; the genesis of the organic pores developed in the organic matter is that water droplets vaporize into water vapor to form macro-pores in the process of the oil-water clay filling the primary pores evolving into the macro-pore pyrobitumen clay complex, and the water vapor exists in the macro-pores in a free state; when the organic matter type is a macro-mesopore organic clay complex filling the primary pores: the thermal evolution history of the organic matter is that the organic clay complex filling the primary pores evolves into a kerogen clay complex filling the primary pores, then evolves into an oil pre-bitumen clay complex filling the primary pores with water droplets, and further evolves into a solid bitumen oil clay complex filling the primary pores with water droplets, and then evolves into a macro-mesopore pyrobitumen clay complex filling the primary pores; the genesis of the organic pores developed in the organic matter is that the generation of oil swelling causes the solid bitumen to generate organic pores in the process of the oil pre-bitumen clay complex filling the primary pores with water droplets evolving into the solid bitumen oil clay complex filling the primary pores with water droplets, which is one of the main reservoir spaces of shale oil; in the process of the solid bitumen oil clay complex filling the primary pores with water droplets evolving into the macro-mesopore pyrobitumen clay complex filling the primary pores, the solid bitumen is converted into pyrobitumen while generating natural gas through thermal degradation, and the generation of natural gas swelling causes the pyrobitumen to form mesopores, and the natural gas exists in the mesopores in an adsorbed state and a free state, water droplets vaporize into water vapor to form macro-pores, and the water vapor exists in the macro-pores in a free state; when the organic matter type is a mesopore organic clay complex filling the primary pores: The thermal evolution process of the organic matter is that the organic matter filling the primary pores evolves into kerogen filling the primary pores, then into oil pre-bitumen filling the primary pores, further into solid bitumen oil filling the primary pores, and then into mesoporous pyrobitumen filling the primary pores; The organic pores in the organic matter are caused by the generation of oil expansion leading to the organic pores of the solid bitumen during the evolution of the oil pre-bitumen filling the primary pores into the solid bitumen oil filling the primary pores, which is one of the main reservoir spaces of shale oil; the natural gas expansion leading to the mesopores of the pyrobitumen during the evolution of the solid bitumen oil filling the primary pores into the mesoporous pyrobitumen filling the primary pores, the natural gas existing in the mesopores in the adsorbed state and the free state; When the organic matter type is the macro-pore pure organic matter filling the primary pores: The thermal evolution process of the organic matter is that the oil filling the primary pores wrapping water droplets evolves into the macro-pore pyrobitumen filling the primary pores; The organic pores in the organic matter are caused by the water droplets vaporizing into water vapor to form macro-pores during the evolution of the oil filling the primary pores wrapping water droplets into the macro-pore pyrobitumen filling the primary pores, the water vapor existing in the macro-pores in the free state; When the organic matter type is the macro-pore pure organic matter filling the secondary pores: The thermal evolution process of the organic matter is that the oil filling the secondary pores wrapping water droplets evolves into the macro-pore pyrobitumen filling the secondary pores; The organic pores in the organic matter are caused by the water droplets vaporizing into water vapor to form macro-pores during the evolution of the oil filling the secondary pores wrapping water droplets into the macro-pore pyrobitumen filling the secondary pores, the water vapor existing in the macro-pores in the free state; When the organic matter type is the macro-mesopore pure organic matter filling the primary pores: The thermal evolution process of the organic matter is that the oil pre-bitumen filling the primary pores wrapping water droplets evolves into the solid bitumen oil filling the primary pores wrapping water droplets, and then evolves into the macro-mesopore pyrobitumen filling the primary pores; The organic pores in the organic matter are caused by the generation of oil expansion leading to the organic pores of the solid bitumen during the evolution of the oil pre-bitumen filling the primary pores wrapping water droplets into the solid bitumen oil filling the primary pores wrapping water droplets, which is one of the main reservoir spaces of shale oil; the natural gas expansion leading to the mesopores of the pyrobitumen during the evolution of the solid bitumen oil filling the primary pores wrapping water droplets into the macro-mesopore pyrobitumen filling the primary pores, the natural gas existing in the mesopores in the adsorbed state and the free state, the water droplets vaporizing into water vapor to form macro-pores, the water vapor existing in the macro-pores in the free state; When the organic matter type is the macro-mesopore pure organic matter filling the secondary pores: The thermal evolution process of the organic matter is that the oil pre-bitumen filling the secondary pores wrapping water droplets evolves into the solid bitumen oil filling the secondary pores wrapping water droplets, and then evolves into the macro-mesopore pyrobitumen filling the secondary pores; The organic pores in the organic matter are caused by the generation of oil expansion leading to the organic pores of the solid bitumen during the evolution of the oil pre-bitumen filling the secondary pores wrapping water droplets into the solid bitumen oil filling the secondary pores wrapping water droplets, which is one of the main reservoir spaces of shale oil; the natural gas expansion leading to the mesopores of the pyrobitumen during the evolution of the solid bitumen oil filling the secondary pores wrapping water droplets into the macro-mesopore pyrobitumen filling the secondary pores, the natural gas existing in the mesopores in the adsorbed state and the free state, the water droplets vaporizing into water vapor to form macro-pores, the water vapor existing in the macro-pores in the free state. The cause of the organic pores developed in the organic matter is that in the process of the oil before filling the secondary pores of the water droplet oil before filling the secondary pores of the water droplet solid bitumen petroleum, the generation of the oil expansion causes the solid bitumen to produce the organic pores, which is one of the main reservoir spaces of the shale oil; in the process of the solid bitumen petroleum filling the secondary pores of the water droplet oil before filling the secondary pores of the water droplet solid bitumen petroleum evolving into the mesopore pyrobitumen filling the secondary pores, the solid bitumen thermal degradation generates the natural gas at the same time, and the solid bitumen is converted into the pyrobitumen, the natural gas expansion causes the pyrobitumen to form the mesopore, the natural gas exists in the mesopore in the adsorbed state and the free state, the water droplet is vaporized into the water vapor to form the macro-pore, and the water vapor exists in the macro-pore in the free state; When the organic matter type is the mesopore pure organic matter filling the primary pores: The thermal evolution process of the organic matter is that the oil before filling the primary pores of the oil before filling the primary pores of the solid bitumen petroleum evolves into the mesopore pyrobitumen filling the primary pores; The cause of the organic pores developed in the organic matter is that in the process of the oil before filling the primary pores of the oil before filling the primary pores of the solid bitumen petroleum, the generation of the oil expansion causes the solid bitumen to produce the organic pores, which is one of the main reservoir spaces of the shale oil; in the process of the solid bitumen petroleum filling the primary pores of the oil before filling the primary pores of the solid bitumen petroleum evolving into the mesopore pyrobitumen filling the primary pores, the solid bitumen thermal degradation generates the natural gas at the same time, and the solid bitumen is converted into the pyrobitumen, the natural gas expansion causes the pyrobitumen to form the mesopore, and the natural gas exists in the mesopore in the adsorbed state and the free state; When the organic matter type is the mesopore pure organic matter filling the secondary pores: The thermal evolution process of the organic matter is that the oil before filling the secondary pores of the oil before filling the secondary pores of the solid bitumen petroleum evolves into the mesopore pyrobitumen filling the secondary pores; The cause of the organic pores developed in the organic matter is that in the process of the oil before filling the secondary pores of the oil before filling the secondary pores of the solid bitumen petroleum, the generation of the oil expansion causes the solid bitumen to produce the organic pores, which is one of the main reservoir spaces of the shale oil; in the process of the solid bitumen petroleum filling the secondary pores of the oil before filling the secondary pores of the solid bitumen petroleum evolving into the mesopore pyrobitumen filling the secondary pores, the solid bitumen thermal degradation generates the natural gas at the same time, and the solid bitumen is converted into the pyrobitumen, the natural gas expansion causes the pyrobitumen to form the mesopore, and the natural gas exists in the mesopore in the adsorbed state and the free state; When the organic matter type is the non-porous pure organic matter filling the primary pores: The thermal evolution process of the organic matter is that the oil filling the primary pores of the oil evolves into the non-porous pyrobitumen filling the primary pores; No organic pores are developed; When the organic matter type is the non-porous pure organic matter filling the secondary pores: The thermal evolution process of the organic matter is that the oil filling the secondary pores of the oil evolves into the non-porous pyrobitumen filling the secondary pores; No organic pores are developed; When the organic matter type is the non-porous pure organic matter filling the cracks: The thermal evolution process of the organic matter is that the oil filling the cracks of the oil evolves into the non-porous pyrobitumen filling the cracks; No organic pores are developed.

2. The method of claim 1, wherein, The determination of the organic matter type of the rock sample of the target shale gas sweet spot section comprises: The rock sample of the target shale gas sweet spot section is used to make an argon ion polished section of the rock of the target shale gas sweet spot section; The MAPS rock image data body of the argon ion polished section of the rock of the target shale gas sweet spot section is collected; Based on the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot segment rock obtained by collection, the organic matter type of the target shale gas sweet spot segment rock sample is determined.

3. The method of claim 2, wherein, The resolution of the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot segment rock obtained by collection is 1-10 nm resolution; and / or The argon ion polished slice of the target shale gas sweet spot segment 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; and / or The top surface and the bottom surface of the argon ion polished slice of the target shale gas sweet spot segment rock are parallel to the top surface and the bottom surface of the target shale gas sweet spot segment rock sample in the underground state; and / or The collection of the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot segment rock includes: 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 segment rock, and collecting the MAPS rock image data volume; 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 segment rock, the top surface of the argon ion polished slice of the target shale gas sweet spot segment 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 segment rock is located below the field of view.

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