Method for judging formation causes of organic pores in dessert section of shale gas and gold target body

Abstract

The invention provides a method for judging formation causes of organic pores in a shale gas dessert section and a gold target body. The method for judging the formation cause of the organic pores in the shale gas dessert section comprises the following steps: acquiring a target shale gas dessert section rock sample; determining the organic matter type of the target shale gas dessert section rock sample: determining the thermal evolution process of the organic matter based on the organic matter type of the shale gas dessert section rock sample, thereby determining the cause of the organic pores developed in the organic matter. The method for judging the gold target body of the shale gas dessert section comprises the following steps: acquiring a rock sample of a target shale gas dessert section; determining the mesoporous organic pore porosity of the target shale gas dessert section rock sample; and determining the target shale gas dessert section gold target based on the mesoporous organic pore porosity. According to the technical scheme provided by the invention, the organic pore formation cause of the shale gas dessert section and the gold target body of the shale gas dessert section can be judged, so that the economic targets of fine evaluation of the shale gas dessert section, cost reduction, efficiency improvement and exploration and development of shale gas are assisted.

Description

Technical Field

[0001] The present invention belongs to the technical field of shale gas exploration and development, and particularly relates to a method for judging the origin of organic pores in shale gas sweet spots and a method for judging the golden target body of shale gas sweet spots. Background Art

[0002] Shale oil and gas with rich resource endowments have gradually become the focus of oil and gas exploration and development. Honeycomb-like nano organic pores, as the main reservoir space and important seepage channels of shale oil and gas, have attracted the attention of the global oil and gas industry. The combined use of techniques such as argon ion polishing, MAPS, and FIB to characterize the occurrence states of organic pores such as morphology, size, and connectivity has promoted the large-scale exploration and development of shale oil and gas, but the understanding of the origin of organic pores is still lacking.

[0003] The results of thermal simulation experiments on immature or low-maturity organic matter shale suggest that organic pores develop inside residual kerogen. The hypothetical conditions for this understanding are that the shale has been dense and pore-free when or before the sedimentary organic matter is transformed into kerogen, and all the hydrocarbons formed by the thermal degradation of kerogen are expelled from the shale. The deficiencies of this view are as follows: ① For marine black shale, the sedimentary organic matter is mainly composed of organic matter formed after the death of microorganisms. When the kerogen is thermally evolved into pre-oil bitumen, the kerogen has been completely transformed into pre-oil bitumen and disappeared. Therefore, there is no residual kerogen or honeycomb-like nano pores developed in the residual kerogen; ② During the process of the sedimentary organic matter being thermally evolved into pre-oil bitumen and petroleum by kerogen, there may still be remaining primary pores in the shale, and the pre-oil bitumen and petroleum are filled in these remaining primary pores. Therefore, the view that the shale has been dense and pore-free when or before the sedimentary organic matter is transformed into kerogen is one-sided and does not conform to the actual geological situation.

[0004] The "bubble-to-pore" experiment of petroleum thermal simulation found that during the process of petroleum being thermally evolved into pyrobitumen and natural gas, the liquid petroleum is gradually transformed into solid pyrobitumen, and a part of the generated natural gas is locked in the pyrobitumen to form "bubble pores", that is, honeycomb-like pores are developed in the pyrobitumenized petroleum. However, petrological evidence shows that there are no pores in the pyrobitumenized petroleum. Therefore, the "bubble-to-pore" experiment of petroleum is not the origin of the pores in the pyrobitumenized petroleum in shale. That is to say, the origin of organic pores given by the results of the "bubble-to-pore" thermal simulation experiment of petroleum does not conform to petrological evidence, and the development of pores in the pyrobitumenized petroleum is one-sided and does not conform to the actual situation.

[0005] Some researchers combined the argon ion polishing technology and the high-resolution scanning electron microscopy technology to classify the pores in shale reservoirs, and believed that organic pores developed inside the residual kerogen. The hypothetical conditions for this understanding are as follows: when or before the sedimentary organic matter was transformed into kerogen, the shale was already dense and pore-free, and all the hydrocarbons formed by the thermal degradation of kerogen were discharged; then, according to the law of conservation of mass, honeycomb-like nanopores developed in the residual kerogen. The deficiencies of this view are as follows: ① For marine black shale, the sedimentary organic matter is mainly composed of organic matter formed after the death of microorganisms. When the kerogen is thermally evolved into pre-oil bitumen, the kerogen has been completely transformed into pre-oil bitumen and disappeared. Therefore, there is no residual kerogen or honeycomb-like nanopores developed in the residual kerogen; ② During the process of the sedimentary organic matter being thermally evolved into pre-oil bitumen and petroleum by kerogen, there may still be remaining primary pores in the shale, and the pre-oil bitumen and petroleum are filled in these remaining primary pores. Therefore, the view that the shale was already dense and pore-free when or before the sedimentary organic matter was transformed into kerogen is one-sided and does not conform to the actual geological situation.

[0006] Some researchers used synchrotron scanning transmission X-ray microscopy (STXM) to observe shale reservoirs and found that honeycomb-like pores developed in pyritized petroleum, while pyritized sedimentary organic matter lacked pores. However, the lack of pores in pyritized sedimentary organic matter is due to the low resolution of this experiment, which is not sufficient to resolve honeycomb-like mesopores and misleads people into thinking that pyritized sedimentary organic matter lacks pores. Therefore, this view is one-sided, partial and even misleading.

[0007] Some researchers, under the constraint of the conceptual model of shale diagenesis sequence, classified organic matter into in-situ organic matter and migrating organic matter, and found that organic pores developed in migrating organic matter, while in-situ organic matter lacked pores. The deviation of this understanding mainly lies in that the conceptual model of shale diagenesis sequence does not conform to the actual geological situation: in the conceptual model of diagenesis sequence, minerals such as secondary quartz enlargement, calcite, and dolomite are cements, and the formation time of these cements is later than the time when the sedimentary organic matter settled to the seabed and became part of the sediment and earlier than the formation time of migrating organic matter (pre-oil bitumen or petroleum). Then, the organic matter in contact with cements such as secondary quartz enlargement, calcite, and dolomite is migrating organic matter, and the organic matter in contact with other minerals (mainly clay minerals) is in-situ organic matter. However, the actual situation is that the formation time of secondary quartz enlargement, calcite, and dolomite is the same as the formation time of the sedimentary organic matter, that is to say, in-situ organic matter is in direct contact with these cements, and migrating organic matter may also be in direct contact with these minerals. Therefore, this view is one-sided, partial and even misleading.

[0008] Reviewing previous related achievements, it is found that all research results on the origin of organic pores in shale come from the understanding at the "point" level. There is no research on the origin of organic pores from the perspective of the sweet spot section of shale, that is, it is defaulted that the origin of organic pores in the sweet spot section of shale is the same, which is the fundamental reason for the multiple interpretations of the origin of organic pores.

[0009] In summary, there is still a need to study the distribution law of organic pores in the sweet spot section of shale gas, in order to contribute to the fine evaluation of the sweet spot section of shale gas and the economic goal of exploration and development of shale gas with cost reduction and efficiency increase. Summary of the Invention

[0010] The purpose of the present invention is to provide a technical solution capable of judging the origin of organic pores in the sweet spot section of shale gas and judging the golden target body of the sweet spot section of shale gas, so as to contribute to the fine evaluation of the sweet spot section of shale gas and the economic goal of exploration and development of shale gas with cost reduction and efficiency increase.

[0011] In order to achieve the above purpose, the present invention provides the following two aspects of technical solutions.

[0012] In the first aspect, the present invention provides a method for judging the origin of organic pores in the sweet spot section of shale gas, wherein the method includes:

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

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

[0015] Based on the organic matter type of the rock samples of the sweet spot section of shale gas, determine the thermal evolution process of the organic matter, so as to determine the origin of the organic pores developed in the organic matter.

[0016] According to the specific implementation manner of the first aspect, preferably, the organic matter types include macroporous organic clay complexes filling primary pores, macro-mesoporous organic clay complexes filling primary pores, mesoporous organic clay 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, pore-free pure organic matter filling primary pores, pore-free pure organic matter filling secondary pores, and pore-free pure organic matter filling fractures.

[0017] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the rock samples of the sweet spot section of shale gas, determining the thermal evolution process of the organic matter, so as to determine the origin of the organic pores developed in the organic matter includes:

[0018] When the organic matter type is macroporous organic clay complexes filling primary pores:

[0019] The thermal evolution process of organic matter is as follows: water-rich clay filling the primary pores evolves into oil-water clay filling the primary pores, and then evolves into macroporous pyrobitumen clay complex filling the primary pores;

[0020] The formation reason of the organic pores developed in organic matter is as follows: during the process of oil-water clay filling the primary pores evolving into macroporous pyrobitumen clay complex 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 the specific implementation manner of the first aspect, preferably, based on the organic matter type of the shale gas sweet spot rock sample, the thermal evolution process of organic matter is determined, so as to determine that the formation reasons of the organic pores developed in organic matter include:

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

[0023] The thermal evolution process of organic matter is as follows: sedimentary organic clay complex filling the primary pores evolves into kerogen clay complex filling the primary pores, then evolves into pre-bitumen clay complex with water droplets wrapped filling the primary pores, further evolves into solid bitumen petroleum clay complex with water droplets wrapped filling the primary pores, and then evolves into macro-mesoporous pyrobitumen clay complex filling the primary pores;

[0024] The formation reason of the organic pores developed in organic matter is as follows: during the process of pre-bitumen clay complex with water droplets wrapped filling the primary pores evolving into solid bitumen petroleum clay complex with water droplets wrapped filling the primary pores, the generation of petroleum expansion causes the formation of organic pores in solid bitumen, which is one of the main reservoir spaces of shale oil; during the process of solid bitumen petroleum clay complex with water droplets wrapped filling the primary pores evolving into macro-mesoporous pyrobitumen clay complex filling the primary pores, solid bitumen thermally degrades to generate natural gas and is converted into pyrobitumen at the same time. The generation of natural gas expansion causes the formation of mesopores in pyrobitumen. Natural gas coexists in the mesopores in an adsorbed state and a free state, water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0025] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the shale gas sweet spot rock sample, the thermal evolution process of organic matter is determined, so as to determine that the formation reasons of the organic pores developed in organic matter include:

[0026] When the organic matter type is mesoporous organic clay complex filling the primary pores:

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

[0028] The origin of the organic pores developed in the organic matter is as follows: during the evolution of the oil-pre-bitumen clay complex filling the primary pores into the solid bitumen - petroleum clay complex filling the primary pores, the generation of petroleum causes expansion, resulting in 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 complex filling the primary pores into the mesoporous pyrobitumen clay complex filling the primary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The expansion of the generated natural gas causes the formation of mesopores in the pyrobitumen, and the natural gas coexists in the mesopores in the adsorbed state and the free state.

[0029] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the shale gas sweet spot rock sample, the thermal evolution history of the organic matter is determined, so as to determine that the origin of the organic pores developed in the organic matter includes:

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

[0031] The thermal evolution history of the organic matter is: the water - droplet - wrapped petroleum filling the primary pores evolves into macroporous pyrobitumen filling the primary pores;

[0032] The origin of the organic pores developed in the organic matter is as follows: during the evolution of the water - droplet - wrapped petroleum filling the primary pores into macroporous pyrobitumen filling the primary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state.

[0033] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the shale gas sweet spot rock sample, the thermal evolution history of the organic matter is determined, so as to determine that the origin of the organic pores developed in the organic matter includes:

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

[0035] The thermal evolution history of the organic matter is: the water - droplet - wrapped petroleum filling the secondary pores evolves into macroporous pyrobitumen filling the secondary pores;

[0036] The origin of the organic pores developed in the organic matter is as follows: during the evolution of the water - droplet - wrapped petroleum filling the secondary pores into macroporous pyrobitumen filling the secondary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state.

[0037] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the shale gas sweet spot rock sample, the thermal evolution history of the organic matter is determined, so as to determine that the origin of the organic pores developed in the organic matter includes:

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

[0039] The thermal evolution process of organic matter is as follows: the pre-bitumen with water droplets filling the primary pores evolves into solid bitumen with water droplets filling the primary pores, then into petroleum, and finally into macro-mesoporous pyrobitumen filling the primary pores;

[0040] The formation reason of the organic pores developed in organic matter is as follows: during the process of the pre-bitumen with water droplets filling the primary pores evolving into solid bitumen with water droplets filling the primary pores and then into petroleum, the generated petroleum expands, causing the solid bitumen to generate organic pores, which is one of the main reservoir spaces of shale oil; during the process of the solid bitumen with water droplets filling the primary pores and petroleum evolving into macro-mesoporous pyrobitumen filling the primary pores, the solid bitumen thermally degrades to generate natural gas while being transformed into pyrobitumen. The generated natural gas expands, causing the pyrobitumen to form mesopores. The natural gas coexists in the mesopores in the adsorbed state and the free state. The water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state.

[0041] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the rock sample in the shale gas sweet spot section, the thermal evolution process of the organic matter is determined, and thus the formation reasons of the organic pores developed in the organic matter include:

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

[0043] The thermal evolution process of the organic matter is as follows: the pre-bitumen with water droplets filling the secondary pores evolves into solid bitumen with water droplets filling the secondary pores, then into petroleum, and finally into macro-mesoporous pyrobitumen filling the secondary pores;

[0044] The formation reason of the organic pores developed in the organic matter is as follows: during the process of the pre-bitumen with water droplets filling the secondary pores evolving into solid bitumen with water droplets filling the secondary pores and then into petroleum, the generated petroleum expands, causing the solid bitumen to generate organic pores, which is one of the main reservoir spaces of shale oil; during the process of the solid bitumen with water droplets filling the secondary pores and petroleum evolving into macro-mesoporous pyrobitumen filling the secondary pores, the solid bitumen thermally degrades to generate natural gas while being transformed into pyrobitumen. The generated natural gas expands, causing the pyrobitumen to form mesopores. The natural gas coexists in the mesopores in the adsorbed state and the free state. The water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state.

[0045] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the rock sample in the shale gas sweet spot section, the thermal evolution process of the organic matter is determined, and thus the formation reasons of the organic pores developed in the organic matter include:

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

[0047] The thermal evolution process of organic matter is as follows: the pre-oil asphalt filling the primary pores evolves into solid asphalt petroleum filling the primary pores, and then evolves into mesoporous pyrobitumen filling the primary pores;

[0048] The formation reason of the organic pores developed in organic matter is as follows: during the process of the pre-oil asphalt filling the primary pores evolving into solid asphalt petroleum filling the primary pores, the generated petroleum expands, causing the solid asphalt to generate organic pores, which is one of the main reservoir spaces of shale oil; during the process of the solid asphalt petroleum filling the primary pores evolving into mesoporous pyrobitumen filling the primary pores, the solid asphalt thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen, and the generated natural gas expands, causing the pyrobitumen to form mesopores, and the natural gas coexists in the mesopores in the adsorbed state and the free state.

[0049] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the shale gas sweet spot rock sample, determine the thermal evolution process of the organic matter, so as to determine that the formation reasons of the organic pores developed in the organic matter include:

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

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

[0052] The formation reason of the organic pores developed in the organic matter is as follows: during the process of the pre-oil asphalt filling the secondary pores evolving into solid asphalt petroleum filling the secondary pores, the generated petroleum expands, causing the solid asphalt to generate organic pores, which is one of the main reservoir spaces of shale oil; during the process of the solid asphalt petroleum filling the secondary pores evolving into mesoporous pyrobitumen filling the secondary pores, the solid asphalt thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen, and the generated natural gas expands, causing the pyrobitumen to form mesopores, and the natural gas coexists in the mesopores in the adsorbed state and the free state.

[0053] According to the specific implementation manner of the first aspect, preferably, based on the organic matter type of the shale gas sweet spot rock sample, determine the thermal evolution process of the organic matter, so as to determine that the formation reasons of the organic pores developed in the organic matter include:

[0054] When the organic matter type is pore-free pure organic matter filling primary pores:

[0055] The thermal evolution process of the organic matter is as follows: the petroleum filling the primary pores evolves into pore-free pyrobitumen filling the primary pores;

[0056] No organic pores are developed.

[0057] According to the specific embodiments of the first aspect, preferably, based on the organic matter type of the rock samples in the shale gas sweet spot section, the thermal evolution history of the organic matter is determined, and thus the origin of the organic pores developed in the organic matter includes:

[0058] When the organic matter type is pore-free pure organic matter filling secondary pores:

[0059] The thermal evolution history of the organic matter is: the petroleum filling secondary pores evolves into pore-free pyrobitumen filling secondary pores;

[0060] No organic pores are developed.

[0061] According to the specific embodiments of the first aspect, preferably, based on the organic matter type of the rock samples in the shale gas sweet spot section, the thermal evolution history of the organic matter is determined, and thus the origin of the organic pores developed in the organic matter includes:

[0062] When the organic matter type is pore-free pure organic matter filling fractures:

[0063] The thermal evolution history of the organic matter is: the petroleum filling fractures evolves into pore-free pyrobitumen filling fractures;

[0064] No organic pores are developed.

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

[0066] Making an argon ion polished section of the target shale gas sweet spot section rock using the target shale gas sweet spot section rock sample;

[0067] Collecting the MAPS rock image data volume of the argon ion polished section of the target shale gas sweet spot section rock;

[0068] Based on the collected MAPS rock image data volume of the argon ion polished section of the target shale gas sweet spot section rock, describing the organic matter type of the target shale gas sweet spot section rock sample;

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

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

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

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

[0073] More preferably, the top and bottom surfaces of the argon ion polished slice of the target shale gas sweet spot section rock are parallel to the top and bottom surfaces of the target shale gas sweet spot section rock sample in the underground state;

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

[0075] More preferably, during the process of collecting the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock, the top surface of the argon ion polished slice of the target shale gas sweet spot section rock is located above the field of view, and the bottom surface of the argon ion polished slice of the target shale gas sweet spot section rock is located below the field of view, so as to ensure that all phenomena observed in the collected MAPS rock image data volume are only magnifications of natural phenomena.

[0076] In a second aspect, the present invention provides a method for judging the gold target body of the shale gas sweet spot section, wherein the method includes:

[0077] Obtaining a target shale gas sweet spot section rock sample;

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

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

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

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

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

[0083] According to the specific implementation manner of the second aspect, preferably, the mesoporous organic pores are mesopores developed in organic matters of macro-mesoporous organic clay complexes filling primary pores, mesoporous organic clay complexes filling primary pores, macro-mesoporous pure organic matters filling primary pores, macro-mesoporous pure organic matters filling secondary pores, mesoporous pure organic matters filling primary pores, and mesoporous pure organic matters filling secondary pores.

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

[0085] Fabricating an argon ion polished section of the rock of the target shale gas sweet spot section with the rock sample of the target shale gas sweet spot section;

[0086] Collecting the MAPS rock image data volume of the argon ion polished section of the rock of the target shale gas sweet spot section;

[0087] Based on the collected MAPS rock image data volume of the argon ion polished section of the rock of the target shale gas sweet spot section, counting the mesoporous organic pore surface area ratio in the rock sample of the target shale gas sweet spot section, which is the mesoporous organic pore porosity of the rock sample of the target shale gas sweet spot section;

[0088] More preferably, counting the mesoporous organic pore surface area ratio in the rock sample of the target shale gas sweet spot section is performed by the "phase plane method";

[0089] More preferably, the resolution of the collected MAPS rock image data volume of the argon ion polished section of the rock of the target shale gas sweet spot section is 1-10 nm resolution;

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

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

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

[0093] More preferably, the top surface and the bottom surface of the argon ion polished section of the rock of the target shale gas sweet spot section are parallel to the top surface and the bottom surface of the rock sample of the target shale gas sweet spot section in the underground state, so as to better reveal the underground state information of the rock, so as to better ensure that the observed microscopic phenomena are only the magnification of the underground state of the rock;

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

[0095] More preferably, during the process of collecting the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock, the top surface of the argon ion polished slice of the target shale gas sweet spot section rock is located above the field of view, and the bottom surface of the argon ion polished slice of the target shale gas sweet spot section rock is located below the field of view, so as to ensure that all the phenomena observed in the collected MAPS rock image data volume are only the magnification of natural phenomena.

[0096] The technical solution provided by the present invention can realize the determination of the origin of organic pores in the shale gas sweet spot section and the determination of the golden target body in the shale gas sweet spot section, thus contributing to the fine evaluation of the shale gas sweet spot section and the economic goal of reducing costs and increasing efficiency in the exploration and development of shale gas. Specifically: The present invention has established a technical solution capable of determining the origin of organic pores in overmature shale, providing scientific data support for the evaluation of layer selection in the exploration stage of shale gas and the fine evaluation of sweet spot sections in the development stage. The present invention has established a method capable of determining the golden target body in the shale gas sweet spot section, providing important information for the selection of the target body of shale gas horizontal wells and guiding the efficient exploration and development of shale gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1 It is a position and coding diagram of the rock samples of the target shale gas sweet spot section in Embodiment 1, Embodiment 2, and Embodiment 3 of the present invention.

[0098] Figure 2 It is a distribution diagram of the organic matter type and the organic matter type horizon in the target shale gas sweet spot section in Embodiment 1, Embodiment 2, and Embodiment 3 of the present invention.

[0099] Figure 3 It is a typical nano-rock diagram of the organic matter type in the target shale gas sweet spot section in Embodiment 1 of the present invention.

[0100] Figure 4 It is a typical nano-rock diagram of the organic matter type in the target shale gas sweet spot section in Embodiment 2 of the present invention.

[0101] Figure 5 It is a typical nano-rock diagram of the organic matter type in the target shale gas sweet spot section in Embodiment 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0102] In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer and more understandable, the following further describes the embodiments of the present invention in detail with reference to the drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but not to limit the present invention.

[0103] MAPS: Modular Automated Processing System. MAPS technology divides the argon ion polished surface of the sample into a series of regular grids, scans and images each grid, and splices the images of all grids to obtain a two-dimensional large-viewing-area scanned image data volume, which is the MAPS data volume.

[0104] "Surface mapping method" counts the surface ratio of mesoporous organic pores: "Surface mapping method" estimates the surface ratio of mesoporous organic pores in each grid rock image in the 4nmMAPS data volume. The surface ratios of mesoporous organic pores in rock images of different grids are added to obtain the sum of the surface ratios of mesoporous organic pores in all grids. The percentage of the sum of the surface ratios to the total grid area is the surface ratio of mesoporous organic pores in the rock sample.

[0105] The products of thermal evolution of sedimentary organic matter are as follows: sedimentary organic matter → kerogen → pre-oil asphalt → solid asphalt and petroleum → pyroasphalt and natural gas.

[0106] In situ organic matter: sedimentary organic clay complex, kerogen clay complex, pre-oil asphalt clay complex, solid asphalt petroleum clay complex, pyroasphalt clay complex.

[0107] Migrated organic matter: organic matter that migrates from sedimentary organic clay complexes or kerogen clay complexes, such as pre-oil asphalt, solid asphalt, petroleum, tar-asphalted solid asphalt petroleum, and tar-asphalted petroleum.

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

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

[0110] Organic pores refer to pores developed in organic matter or organic clay complexes.

[0111] The inventors of the present invention have conducted research on organic matter types using shale gas sweet spots as research objects, clarified the thermal evolution process of organic matter types, identified the origins of macropores and mesopores and their gas content, used the "face method" to count the surface ratio of organic pores in mesopores in shale gas sweet spots, and searched for golden targets in shale gas sweet spots, creating a precedent for determining the origin of organic matter and golden targets in shale gas sweet spots by dividing them into small layers. The previous research on the origin of organic pores on "points" has been expanded to the research on the origin of organic pores on "lines" and "surfaces" in sweet spots, reducing the multi-solution nature of the origin of organic pores, and thus guiding the efficient exploration and development of shale gas. Furthermore, based on the inventors' research conclusions, the present invention provides a method for determining the origin of organic pores in shale gas sweet spots and a method for determining golden targets in shale gas sweet spots, providing important information for the selection of shale gas horizontal well targets and guiding the efficient exploration and development of shale gas.

[0112] In a specific embodiment, the method for determining the origin of organic pores in shale gas sweet spots provided by the present invention includes:

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

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

[0115] Based on the organic matter type of the rock samples of the shale gas sweet spot, determine the thermal evolution history of the organic matter, so as to determine the origin of the organic pores developed in the organic matter.

[0116] Furthermore, the organic matter types include macro-pore organic clay complexes filling primary pores, macro-meso-pore organic clay complexes filling primary pores, meso-pore organic clay complexes filling primary pores, macro-pore pure organic matter filling primary pores (pure organic matter corresponds to organic clay complexes, referring to organic matter that does not coexist with clay to form organic clay complexes), macro-pore pure organic matter filling secondary pores, macro-meso-pore pure organic matter filling primary pores, macro-meso-pore pure organic matter filling secondary pores, meso-pore pure organic matter filling primary pores, meso-pore pure organic matter filling secondary pores, poreless pure organic matter filling primary pores, poreless pure organic matter filling secondary pores, and poreless pure organic matter filling fractures.

[0117] Furthermore, based on the organic matter type of the rock samples of the shale gas sweet spot, determining the thermal evolution history of the organic matter, so as to determine the origin of the organic pores developed in the organic matter includes:

[0118] When the organic matter type is macro-pore organic clay complexes filling primary pores:

[0119] The thermal evolution history of the organic matter is: water-rich clay filling primary pores evolves into oil-water clay filling primary pores, and then evolves into macro-pore pyrobitumen clay complexes filling primary pores;

[0120] The origin of the organic pores developed in the organic matter is: during the process of water-rich clay filling primary pores evolving into macro-pore pyrobitumen clay complexes filling primary pores, water droplets vaporize into water vapor to form macro-pores, and the water vapor exists in the macro-pores in a free state.

[0121] Furthermore, based on the organic matter type of the rock samples of the shale gas sweet spot, determining the thermal evolution history of the organic matter, so as to determine the origin of the organic pores developed in the organic matter includes:

[0122] When the organic matter type is macro-meso-pore organic clay complexes filling primary pores:

[0123] The thermal evolution process of organic matter is as follows: the pre-bitumen of water-droplet-included oil filling the primary pores evolves into the solid-bitumen petroleum clay complex of water-droplet-included filling the primary pores, and then evolves into the macro-mesoporous pyrobitumen clay complex of water-droplet-included filling the primary pores;

[0124] The formation reason of the organic pores developed in organic matter is as follows: during the process of the pre-bitumen clay complex of water-droplet-included oil filling the primary pores evolving into the solid-bitumen petroleum clay complex of water-droplet-included filling the primary pores, the generated petroleum expands, resulting in the generation of organic pores in solid bitumen, which is one of the main reservoir spaces of shale oil; during the process of the solid-bitumen petroleum clay complex of water-droplet-included filling the primary pores evolving into the macro-mesoporous pyrobitumen clay complex of water-droplet-included filling the primary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The generated natural gas expands, leading to the formation of mesopores in pyrobitumen. The natural gas coexists in the mesopores in the adsorbed state and the free state. The water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state.

[0125] Furthermore, based on the organic matter type of the rock samples in the shale gas sweet spot section, the thermal evolution process of the organic matter is determined, and thus the formation reasons of the organic pores developed in the organic matter include:

[0126] When the organic matter type is the mesoporous organic clay complex of water-droplet-included filling the primary pores:

[0127] The thermal evolution process of the organic matter is as follows: the sedimentary organic clay complex of water-droplet-included filling the primary pores evolves into the kerogen clay complex of water-droplet-included filling the primary pores, then evolves into the pre-bitumen clay complex of water-droplet-included filling the primary pores, and further evolves into the solid-bitumen petroleum clay complex of water-droplet-included filling the primary pores, and then evolves into the mesoporous pyrobitumen clay complex of water-droplet-included filling the primary pores;

[0128] The formation reason of the organic pores developed in the organic matter is as follows: during the process of the pre-bitumen clay complex of water-droplet-included oil filling the primary pores evolving into the solid-bitumen petroleum clay complex of water-droplet-included filling the primary pores, the generated petroleum expands, resulting in the generation of organic pores in solid bitumen, which is one of the main reservoir spaces of shale oil; during the process of the solid-bitumen petroleum clay complex of water-droplet-included filling the primary pores evolving into the mesoporous pyrobitumen clay complex of water-droplet-included filling the primary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The generated natural gas expands, leading to the formation of mesopores in pyrobitumen. The natural gas coexists in the mesopores in the adsorbed state and the free state.

[0129] Furthermore, based on the organic matter type of the rock samples in the shale gas sweet spot section, the thermal evolution process of the organic matter is determined, and thus the formation reasons of the organic pores developed in the organic matter include:

[0130] When the organic matter type is the macroporous pure organic matter of water-droplet-included filling the primary pores:

[0131] The thermal evolution process of organic matter is as follows: the inclusion water droplets filled in the primary pores evolve into macro-pore pyrobitumen filled in the primary pores;

[0132] The formation reason of the organic pores developed in the organic matter is as follows: during the process of the inclusion water droplets filled in the primary pores evolving into macro-pore pyrobitumen filled in the primary pores, the water droplets vaporize into water vapor to form macro-pores, and the water vapor exists in the macro-pores in a free state.

[0133] Furthermore, based on the organic matter type of the shale gas reservoir rock samples, the thermal evolution process of the organic matter is determined, and thus the formation reasons of the organic pores developed in the organic matter include:

[0134] When the organic matter type is macro-pore pure organic matter filling secondary pores:

[0135] The thermal evolution process of the organic matter is as follows: the inclusion water droplets filled in the primary pores evolve into macro-pore pyrobitumen filled in the secondary pores;

[0136] The formation reason of the organic pores developed in the organic matter is as follows: during the process of the inclusion water droplets filled in the secondary pores evolving into macro-pore pyrobitumen filled in the secondary pores, the water droplets vaporize into water vapor to form macro-pores, and the water vapor exists in the macro-pores in a free state.

[0137] Furthermore, based on the organic matter type of the shale gas sweet spot rock samples, the thermal evolution process of the organic matter is determined, and thus the formation reasons of the organic pores developed in the organic matter include:

[0138] When the organic matter type is macro-meso-pore pure organic matter filling primary pores:

[0139] The thermal evolution process of the organic matter is as follows: the inclusion water droplets filled in the primary pores and pre-oil-bitumen evolve into inclusion water droplets filled in the primary pores and solid-bitumen oil, and then evolve into macro-meso-pore pyrobitumen filled in the primary pores;

[0140] The formation reason of the organic pores developed in the organic matter is as follows: during the process of the inclusion water droplets filled in the primary pores and pre-oil-bitumen evolving into inclusion water droplets filled in the primary pores and solid-bitumen oil, the generated oil expands, resulting in the formation of organic pores in the solid-bitumen, which is one of the main storage spaces for shale oil; during the process of the inclusion water droplets filled in the primary pores and solid-bitumen oil evolving into macro-meso-pore pyrobitumen filled in the primary pores, the solid-bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The generated natural gas expands to cause the formation of meso-pores in the pyrobitumen. The natural gas coexists in the meso-pores in an adsorbed state and a free state. The water droplets vaporize into water vapor to form macro-pores, and the water vapor exists in the macro-pores in a free state.

[0141] Furthermore, based on the organic matter type of the shale gas sweet spot rock samples, the thermal evolution process of the organic matter is determined, and thus the formation reasons of the organic pores developed in the organic matter include:

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

[0143] The thermal evolution process of the organic matter is as follows: the water-droplet-included oil-pre-bitumen filling secondary pores evolves into water-droplet-included solid bitumen petroleum filling secondary pores, and then evolves into macro-mesoporous pyrobitumen filling secondary pores;

[0144] The origin of the organic pores developed in the organic matter is as follows: during the process of the water-droplet-included oil-pre-bitumen filling secondary pores evolving into water-droplet-included solid bitumen petroleum filling secondary pores, the generated petroleum expands, causing the solid bitumen to generate organic pores, which is one of the main reservoir spaces of shale oil; during the process of the water-droplet-included solid bitumen petroleum filling secondary pores evolving into macro-mesoporous pyrobitumen filling secondary pores, the solid bitumen thermally degrades to generate natural gas while being transformed into pyrobitumen. The generated natural gas expands, causing the pyrobitumen to form mesopores. The natural gas coexists in the mesopores in both adsorbed and free states. The water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0145] Furthermore, based on the organic matter type of the rock samples in the shale gas sweet spot section, the thermal evolution process of the organic matter is determined, and thus the origin of the organic pores developed in the organic matter includes:

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

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

[0148] The origin of the organic pores developed in the organic matter is as follows: during the process of the oil-pre-bitumen filling primary pores evolving into solid bitumen petroleum filling primary pores, the generated petroleum expands, causing the solid bitumen to generate organic pores, which is one of the main reservoir spaces of shale oil; during the process of the solid bitumen petroleum filling primary pores evolving into mesoporous pyrobitumen filling primary pores, the solid bitumen thermally degrades to generate natural gas while being transformed into pyrobitumen. The generated natural gas expands, causing the pyrobitumen to form mesopores. The natural gas coexists in the mesopores in both adsorbed and free states.

[0149] Furthermore, based on the organic matter type of the rock samples in the shale gas sweet spot section, the thermal evolution process of the organic matter is determined, and thus the origin of the organic pores developed in the organic matter includes:

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

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

[0152] The origin of organic pores developed in organic matter is as follows: during the evolution of pre-oil asphalt filling secondary pores into solid asphalt petroleum filling secondary pores, the generation of petroleum causes expansion, resulting in the formation of organic pores in solid asphalt. This is one of the main reservoir spaces for shale oil. During the evolution of solid asphalt petroleum filling secondary pores into mesoporous pyrobitumen filling secondary pores, while solid asphalt thermally degrades to generate natural gas, it is transformed into pyrobitumen. The expansion of the generated natural gas leads to the formation of mesopores in pyrobitumen, and natural gas coexists in mesopores in the form of adsorbed state and free state.

[0153] Furthermore, based on the organic matter type of rock samples from the sweet spot section of shale gas, the thermal evolution process of organic matter is determined, and thus the origin of organic pores developed in organic matter includes:

[0154] When the organic matter type is pore-free pure organic matter filling primary pores:

[0155] The thermal evolution process of organic matter is: petroleum filling primary pores evolves into pore-free pyrobitumen filling primary pores;

[0156] No organic pores are developed.

[0157] Furthermore, based on the organic matter type of rock samples from the sweet spot section of shale gas, the thermal evolution process of organic matter is determined, and thus the origin of organic pores developed in organic matter includes:

[0158] When the organic matter type is pore-free pure organic matter filling secondary pores:

[0159] The thermal evolution process of organic matter is: petroleum filling secondary pores evolves into pore-free pyrobitumen filling secondary pores;

[0160] No organic pores are developed.

[0161] Furthermore, based on the organic matter type of rock samples from the sweet spot section of shale gas, the thermal evolution process of organic matter is determined, and thus the origin of organic pores developed in organic matter includes:

[0162] When the organic matter type is pore-free pure organic matter filling fractures:

[0163] The thermal evolution process of organic matter is: petroleum filling fractures evolves into pore-free pyrobitumen filling fractures;

[0164] No organic pores are developed.

[0165] Furthermore, obtaining rock samples from the target sweet spot section of shale gas includes:

[0166] Obtaining rock samples collected from the target sweet spot section of shale gas, which are the rock samples from the target sweet spot section of shale gas.

[0167] Further, determining the organic matter type of the rock sample in the target shale gas sweet spot section includes:

[0168] Fabricating an argon ion polished slice of the rock in the target shale gas sweet spot section using the rock sample in the target shale gas sweet spot section;

[0169] Collecting the MAPS rock image data volume of the argon ion polished slice of the rock in the target shale gas sweet spot section;

[0170] Based on the collected MAPS rock image data volume of the argon ion polished slice of the rock in the target shale gas sweet spot section, determining the organic matter type of the rock sample in the target shale gas sweet spot section;

[0171] Even further, the resolution of the collected MAPS rock image data volume of the argon ion polished slice of the rock in the target shale gas sweet spot section is 4 resolutions;

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

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

[0174] Even further, the thickness of the argon ion polished slice of the rock in the target shale gas sweet spot section is 0.3 - 0.8 cm (e.g., 0.5 cm);

[0175] Even further, the top and bottom surfaces of the argon ion polished slice of the rock in the target shale gas sweet spot section are parallel to the top and bottom surfaces of the rock sample in the underground state of the target shale gas sweet spot section, so as to better reveal the underground state information of the rock, in order to better ensure that the observed microscopic phenomena are only magnifications of the underground state of the rock;

[0176] Even further, collecting the MAPS rock image data volume of the argon ion polished slice of the rock in the target shale gas sweet spot section includes: selecting an area with a length and width not exceeding 400 μm in the polished surface of the argon ion polished slice of the rock in the target shale gas sweet spot section and collecting the MAPS rock image data volume;

[0177] Even further, during the process of collecting the MAPS rock image data volume of the argon ion polished slice of the rock in the target shale gas sweet spot section, the top surface of the argon ion polished slice of the rock in the target shale gas sweet spot section is located above the field of view, and the bottom surface of the argon ion polished slice of the rock in the target shale gas sweet spot section is located below the field of view, so as to ensure that all the phenomena observed in the collected MAPS rock image data volume are only magnifications of natural phenomena.

[0178] In a specific embodiment, the method for judging the golden target body in the shale gas sweet spot section provided by the present invention includes:

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

[0180] Determine the mesoporous organic pore porosity of the rock samples from the target shale gas sweet spot section;

[0181] Based on the mesoporous organic pore porosity of the rock samples from the target shale gas sweet spot section, determine whether the target shale gas sweet spot section is a golden target body.

[0182] Furthermore, determining whether the target shale gas sweet spot section is a golden target body based on the mesoporous organic pore porosity of the rock samples from the target shale gas sweet spot section includes:

[0183] When the mesoporous organic pore porosity of the rock samples from the target shale gas sweet spot section ≥ 1.0%, the target shale gas sweet spot section is a golden target body;

[0184] When the mesoporous organic pore porosity of the rock samples from the target shale gas sweet spot section is less than 1.0%, the target shale gas sweet spot section is not a golden target body.

[0185] Furthermore, the mesoporous organic pores are the mesopores developed in organic matters of the types of macro-mesoporous organic clay complex filling primary pores, mesoporous organic clay complex filling primary pores, macro-mesoporous pure organic matter filling primary pores, macro-mesoporous pure organic matter filling secondary pores, mesoporous pure organic matter filling primary pores, and mesoporous pure organic matter filling secondary pores.

[0186] Furthermore, obtaining rock samples from the target shale gas reservoir includes:

[0187] Obtain rock samples collected from the target shale gas reservoir, which are the rock samples from the target shale gas reservoir.

[0188] Furthermore, determining the porosity of the mesoporous organic pores of the rock samples from the target shale gas reservoir includes:

[0189] Use the rock samples from the target shale gas reservoir to make argon ion polished slices of the rock from the target shale gas reservoir;

[0190] Collect the MAPS rock image data volume of the argon ion polished slices of the rock from the target shale gas reservoir;

[0191] Based on the collected MAPS rock image data volume of the argon ion polished slices of the rock from the target shale gas sweet spot section, count the mesoporous organic pore area ratio in the rock samples from the target shale gas sweet spot section, which is the mesoporous organic pore porosity of the rock samples from the target shale gas sweet spot section;

[0192] Even further, the "phase surface method" is used to count the mesoporous organic pore area ratio in the rock samples from the target shale gas sweet spot section;

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

[0194] Furthermore, the length of the argon ion polished slice 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 slice 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 slice 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 slice of the target shale gas reservoir rock are parallel to the top and bottom surfaces of the target shale gas reservoir rock sample in the underground state, so as to better reveal the underground state information of the rock and ensure that the microscopic phenomena observed are only magnifications of the underground state of the rock.

[0198] Furthermore, collecting the MAPS rock image data volume of the argon ion polished slice of the target shale gas reservoir rock includes: selecting an area with a length and width not exceeding 400 μm in the polished surface of the argon ion polished slice of the target shale gas reservoir rock and collecting the MAPS rock image data volume;

[0199] Furthermore, during the process of collecting the MAPS rock image data volume of the argon ion polished slice of the target shale gas reservoir rock, the top surface of the argon ion polished slice of the target shale gas reservoir rock is located above the field of view, and the bottom surface of the argon ion polished slice of the target shale gas reservoir rock is located below the field of view, so as to ensure that all phenomena observed in the collected MAPS rock image data volume are only magnifications of natural phenomena.

[0200] Example 1:

[0201] This example provides a method for judging the origin of organic pores in the sweet spot section of shale gas in Well H2 and a method for judging the gold target body in the sweet spot section of shale gas in Well H2.

[0202] The method for judging the origin of organic pores in the sweet spot section of shale gas in Well H2 includes:

[0203] 1. Obtain rock samples from the Longyi 1 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizon in the sweet spot section of shale gas in Well H2 as the target shale gas sweet spot section rock samples.

[0204] In this embodiment, rock samples of the Longyi 1 member in the sweet spot section of shale gas in Well H2 are collected. 1 For the Longyi 1 member 2 For the Longyi 1 member 3 For the Longyi 1 member 4 For the Longyi 1 member. One sample is collected for each member, and a total of 4 samples are collected. The sample locations and codes are shown in Figure 1 .

[0205] 2. Prepare argon ion polished slices of the rock in the target shale gas sweet spot section using the rock samples of the target shale gas sweet spot section; wherein, the length of the argon ion polished slice of the rock in the target shale gas sweet spot section is 1 cm, the width is 1 cm, and the thickness is 0.5 cm; the top and bottom surfaces of the argon ion polished slice of the rock in the target shale gas sweet spot section are parallel to the top and bottom surfaces of the rock sample in the target shale gas sweet spot section in the 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 slice of the target shale gas sweet spot section, and collect MAPS rock image data volume with a resolution of 4 nm; wherein, during the process of collecting the MAPS rock image data volume, the top surface of the argon ion polished slice of the target shale gas sweet spot section is located above the field of view, and the bottom surface of the argon ion polished slice of the target shale gas sweet spot section is located below the field of view, so as to ensure that all the phenomena observed in the collected MAPS rock image data volume are only the magnifications of natural phenomena.

[0207] 4. Based on the MAPS rock image data volume of the argon ion polished slice of the rock in the target shale gas sweet spot section collected, describe the organic matter types in the rock sample of the target shale gas sweet spot section, clarify the thermal evolution process of the organic matter types, and thus clarify the origin of the organic pores.

[0208] Among them, the organic matter types include macro-pore organic clay complex Ⅰ1 filling primary pores, macro-meso-pore organic clay complex Ⅰ2 filling primary pores, meso-pore organic clay complex Ⅰ3 filling primary pores, macro-pore pure organic matter Ⅱ1 filling primary pores 1 , macro-pore pure organic matter Ⅱ1 filling secondary pores 2 , macro-meso-pore pure organic matter Ⅱ2 filling primary pores 1 , macro-meso-pore pure organic matter Ⅱ2 filling secondary pores 2 , meso-pore pure organic matter Ⅱ3 filling primary pores 1 , meso-pore pure organic matter Ⅱ3 filling secondary pores 2 , pore-free pure organic matter Ⅱ4 filling primary pores 1 , pore-free pure organic matter Ⅱ4 filling secondary pores 2 , pore-free pure organic matter Ⅱ4 filling fractures 3 .

[0209] In this embodiment, the organic matter types in the shale gas sweet spot section are divided into 2 major categories, 7 categories, and 9 subcategories. For example, Figure 2 , Figure 3 . Among them, for the organic matter types in the Longyi 1 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, and Longyi 1 4 horizon, refer to Figure 3 .

[0210] For the macro-pore organic clay complex Ⅰ1 that fills the primary pores in the organic matter type, the clay generally exceeds 10%. The organic matter and clay minerals are fully mixed. The macro-pores have large pore diameters and low densities (such as Figure 3 a in). For the macro-mesopore organic clay complex Ⅰ2 that fills the primary pores in the organic matter type, the clay minerals are scattered in the organic matter. The number of macro-pores is small and randomly distributed. The mesopore density is large and evenly distributed (such as Figure 3 b in). For the mesopore organic clay complex Ⅰ3 that fills the primary pores in the organic matter type, the clay minerals are scattered in the organic matter. The mesopore density is large and evenly distributed (such as Figure 3 c in).

[0211] The organic matter type is the macro-pore pure organic matter Ⅱ1 that fills the primary pores 1 (such as Figure 3 d in) and the organic matter type is the macro-pore pure organic matter Ⅱ1 that fills the secondary pores 2 (such as Figure 3 e in), where the macro-pore density is large and evenly distributed. The organic matter type is the macro-mesopore pure organic matter Ⅱ2 that fills the primary pores 1 (such as Figure 3 f in) and the organic matter type is the macro-mesopore pure organic matter Ⅱ2 that fills the secondary pores 2 (such as Figure 3 g in), where the macro-pore density is small and randomly distributed, while the mesopore density is large and evenly distributed. The organic matter type is the mesopore pure organic matter Ⅱ3 that fills the primary pores 1 (such as Figure 3 h in) and the organic matter type is the mesopore pure organic matter Ⅱ3 that fills the secondary pores 2 (such as Figure 3 i in), where the mesopore density is large and evenly distributed. The organic matter type is the poreless pure organic matter Ⅱ4 that fills the primary pores 1 as shown in Figure 3 j, the organic matter type is the poreless pure organic matter Ⅱ4 that fills the secondary pores 2 as shown in Figure 3 k, and the organic matter type is the poreless pure organic matter Ⅱ4 that fills the fractures 3 as shown in Figure 3as shown in l in

[0212] Longyi-1 in the sweet spot section of shale gas in Well H2 1 Stratigraphic horizon, Longyi-1 2 Stratigraphic horizon, Longyi-1 3 Stratigraphic horizon, Longyi-1 4 There are significant differences in the organic matter types in the stratigraphic horizon. See the column of the stratigraphic horizons where the organic matter types are distributed in Figure 2 When the organic matter type is the macro-pore organic clay complex filling the primary pores, the thermal evolution process of the organic matter is as follows: the water-rich clay filling the primary pores evolves into the oil-water clay filling the primary pores, and then evolves into the macro-pore pyrobitumen clay complex filling the primary pores. The formation reason of the organic pores developed in the organic matter is as follows: during the process of the water-rich clay filling the primary pores evolving into the macro-pore pyrobitumen clay complex filling the primary pores, water droplets vaporize into water vapor to form macro-pores, and the water vapor exists in the macro-pores in a free state.

[0213] When the organic matter type is the macro-meso-pore organic clay complex filling the primary pores, the thermal evolution process of the organic matter is as follows: the pre-bitumen with water droplets filling the primary pores evolves into the solid bitumen-petroleum clay complex with water droplets filling the primary pores, and then evolves into the macro-meso-pore pyrobitumen clay complex filling the primary pores. The formation reason of the organic pores developed in the organic matter is as follows: during the process of the pre-bitumen clay complex with water droplets filling the primary pores evolving into the solid bitumen-petroleum clay complex with water droplets filling the primary pores, the generation of petroleum causes expansion, resulting in the formation of organic pores in the solid bitumen, which is one of the main reservoir spaces for shale oil; during the process of the solid bitumen-petroleum clay complex with water droplets filling the primary pores evolving into the macro-meso-pore pyrobitumen clay complex filling the primary pores, the solid bitumen thermally degrades to generate natural gas and is converted into pyrobitumen at the same time. The generation of natural gas causes expansion, resulting in the formation of meso-pores in the pyrobitumen. Natural gas coexists in the meso-pores 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.

[0214] When the organic matter type is mesoporous organic clay complex filling primary pores, the thermal evolution process of the organic matter is as follows: the sedimentary organic clay complex filling primary pores evolves into kerogen clay complex filling primary pores, then into pre-oil asphalt clay complex filling primary pores, and further into solid asphalt petroleum clay complex filling primary pores, and then into mesoporous pyrobitumen clay complex filling primary pores. The formation reason of the organic pores developed in the organic matter is as follows: during the process of the pre-oil asphalt clay complex filling primary pores evolving into the solid asphalt petroleum clay complex filling primary pores, the generation of petroleum expansion causes the solid asphalt to generate organic pores, which is one of the main reservoir spaces of shale oil; during the process of the solid asphalt petroleum clay complex filling primary pores evolving into the mesoporous pyrobitumen clay complex filling primary pores, the solid asphalt thermally degrades to generate natural gas and is converted into pyrobitumen at the same time. The generation of natural gas expansion causes the pyrobitumen to form mesopores, and the natural gas coexists in the mesopores in the adsorbed state and the free state.

[0215] When the organic matter type is macroporous pure organic matter filling primary pores, the thermal evolution process of the organic matter is as follows: the petroleum with water droplets wrapped filling primary pores evolves into macroporous pyrobitumen filling primary pores. The formation reason of the organic pores developed in the organic matter is as follows: during the process of the petroleum with water droplets wrapped filling primary pores evolving into macroporous pyrobitumen filling primary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state.

[0216] When the organic matter type is macroporous pure organic matter filling secondary pores, the thermal evolution process of the organic matter is as follows: the water droplets wrapped filling primary pores evolve into macroporous pyrobitumen filling secondary pores. The formation reason of the organic pores developed in the organic matter is as follows: during the process of the petroleum with water droplets wrapped filling secondary pores evolving into macroporous pyrobitumen filling secondary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state.

[0217] When the organic matter type is macro-mesoporous pure organic matter filling primary pores, the thermal evolution process of the organic matter is as follows: the pre-oil asphalt with water droplets wrapped filling primary pores evolves into solid asphalt petroleum with water droplets wrapped filling primary pores, and then into macro-mesoporous pyrobitumen filling primary pores. The formation reason of the organic pores developed in the organic matter is as follows: during the process of the pre-oil asphalt with water droplets wrapped filling primary pores evolving into solid asphalt petroleum with water droplets wrapped filling primary pores, the generation of petroleum expansion causes the solid asphalt to generate organic pores, which is one of the main reservoir spaces of shale oil; during the process of the solid asphalt petroleum with water droplets wrapped filling primary pores evolving into macro-mesoporous pyrobitumen filling primary pores, the solid asphalt thermally degrades to generate natural gas and is converted into pyrobitumen at the same time. The generation of natural gas expansion causes the pyrobitumen to form mesopores, and the natural gas coexists in the mesopores in the adsorbed state and the free state. The water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state.

[0218] When the organic matter type is macro-mesoporous pure organic matter filling secondary pores, the thermal evolution process of the organic matter is as follows: the pre-bitumen with water droplets filling secondary pores evolves into solid bitumen petroleum with water droplets filling secondary pores, and then evolves into macro-mesoporous pyrobitumen filling secondary pores. The reason for the formation of organic pores developed in the organic matter is as follows: during the evolution of the pre-bitumen with water droplets filling secondary pores into solid bitumen petroleum with water droplets filling secondary pores, the generation of petroleum causes expansion, resulting in 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 petroleum with water droplets filling secondary pores into macro-mesoporous pyrobitumen filling secondary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The expansion of the generated natural gas causes the formation of mesopores in the pyrobitumen. The natural gas coexists in the mesopores in both adsorbed and free states. The water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state.

[0219] When the organic matter type is mesoporous pure organic matter filling primary pores, the thermal evolution process of the organic matter is as follows: the pre-bitumen filling primary pores evolves into solid bitumen petroleum filling primary pores, and then evolves into mesoporous pyrobitumen filling primary pores. The reason for the formation of organic pores developed in the organic matter is as follows: during the evolution of the pre-bitumen filling primary pores into solid bitumen petroleum filling primary pores, the generation of petroleum causes expansion, resulting in 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 petroleum filling primary pores into mesoporous pyrobitumen filling primary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The expansion of the generated natural gas causes the formation of mesopores in the pyrobitumen. The natural gas coexists in the mesopores in both adsorbed and free states.

[0220] When the organic matter type is mesoporous pure organic matter filling secondary pores, the thermal evolution process of the organic matter is as follows: the pre-bitumen filling secondary pores evolves into solid bitumen petroleum filling secondary pores, and then evolves into mesoporous pyrobitumen filling secondary pores. The reason for the formation of organic pores developed in the organic matter is as follows: during the evolution of the pre-bitumen filling secondary pores into solid bitumen petroleum filling secondary pores, the generation of petroleum causes expansion, resulting in 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 petroleum filling secondary pores into mesoporous pyrobitumen filling secondary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The expansion of the generated natural gas causes the formation of mesopores in the pyrobitumen. The natural gas coexists in the mesopores in both adsorbed and free states.

[0221] When the organic matter type is pore-free pure organic matter filling primary pores, the thermal evolution process of the organic matter is as follows: the petroleum filling primary pores evolves into pore-free pyrobitumen filling primary pores. No organic pores are developed.

[0222] When the organic matter type is pore-free pure organic matter filling secondary pores, the thermal evolution process of the organic matter is as follows: the petroleum filling secondary pores evolves into pore-free pyrobitumen filling secondary pores. Organic pores are not developed.

[0223] When the organic matter type is pore-free pure organic matter filling fractures, the thermal evolution process of the organic matter is as follows: the petroleum filling fractures evolves into pore-free pyrobitumen filling fractures. Organic pores are not developed.

[0224] The method for judging the gold target body of the shale gas sweet spot in Well H2 includes:

[0225] 1. Obtain rock samples from the Longyi-1 1 horizon, Longyi-1 2 horizon, Longyi-1 3 horizon, Longyi-1 4 horizon of the shale gas sweet spot in Well H2 as the rock samples of the target shale gas sweet spot. Use the rock samples of the target shale gas sweet spot to make argon ion polished slices of the rocks in the target shale gas sweet spot. Select an area with a length and width not exceeding 400 μm in the polished surface of the argon ion polished slice of the target shale gas sweet spot, and collect a MAPS rock image data volume with a resolution of 4 nm.

[0226] Here, the MAPS rock image data volume obtained in step 3 of the method for judging the origin of organic pores in the shale gas sweet spot of Well H2 can be directly adopted.

[0227] 2. Based on the collected MAPS rock image data volume, use the "phase face method" to statistically analyze the mesoporous organic pore surface area ratio of the rock samples from the Longyi-1 1 horizon, Longyi-1 2 horizon, Longyi-1 3 horizon, Longyi-1 4 horizon of the shale gas sweet spot in Well H2 as the mesoporous organic pore porosity of the rock samples from the Longyi-1 1 horizon, Longyi-1 2 horizon, Longyi-1 3 horizon, Longyi-1 4 horizon of the shale gas sweet spot in Well H2.

[0228] In this embodiment, the mesoporous organic pore porosities of the Longyi-1 1 , Longyi-1 2 , Longyi-1 3 , Longyi-1 4 horizons in the shale gas sweet spot of Well H2 vary greatly. The mesoporous organic pore porosity of the Longyi-1 1 horizon is 1.86%, and the mesoporous organic pore porosity of the Longyi-1 2 horizon is 1.27%, and the mesoporous organic pore porosity of the Longyi-1 3 horizon is 0.75%, and the mesoporous organic pore porosity of the Longyi-1 4The mesoporous organic pore porosity of the horizon is 0%.

[0229] 3. Based on the Longyi 1 of the sweet spot section of shale gas in Well H2 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizon, determine whether the Longyi 1 of the sweet spot section of shale gas in Well H2 is a golden target body based on the mesoporous organic pore porosity of the rock samples of the Longyi 1 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizon is a golden target body;

[0230] Among them, when the mesoporous organic pore porosity of the rock samples of the target sweet spot section of shale gas ≥ 1.0%, the target sweet spot section of shale gas is a golden target body; when the mesoporous organic pore porosity of the rock samples of the target sweet spot section of shale gas is less than 1.0%, the target sweet spot section of shale gas is not a golden target body.

[0231] Longyi 1 1 horizon, Longyi 1 2 The mesoporous organic pore porosity of the horizon is greater than or equal to 1.0%, so the Longyi 1 1 horizon, Longyi 1 2 horizon is the golden target body of the sweet spot section of shale gas in Well H2. The higher the mesoporous organic pore porosity, the higher the content of natural gas existing in the mesoporous organic pores in the adsorbed state and the free state. Therefore, as the golden target body of the sweet spot section of shale gas in Well H2, the Longyi 1 1 horizon is superior to the Longyi 1 2 horizon.

[0232] Example 2

[0233] This example provides a method for judging the origin of organic pores in the sweet spot section of shale gas in Well H4 and a method for judging the golden target body of the sweet spot section of shale gas in Well H4.

[0234] The method for judging the origin of organic pores in the sweet spot section of shale gas in Well H4 is different from the method for judging the origin of organic pores in the sweet spot section of shale gas in Well H2 in Example 1 only in that:

[0235] The rock samples used are the rock samples collected from the Longyi 1 of the sweet spot section of shale gas in Well H4 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizon (1 sample is collected from each horizon, and a total of 4 samples are collected. The sample positions and codes are shown in Figure 1 ), rather than the rock samples collected from the Longyi 1 of the sweet spot section of shale gas in Well H2 1 horizon, Longyi 1 2 horizon, Longyi 13 Stratigraphic horizon, Longyi 1 4 Rock samples of the stratigraphic horizon

[0236] In this embodiment, the organic matter types in the sweet spot section of shale gas in Well H4 are divided into 2 categories, 7 types and 9 sub-types, as shown in Figure 2 , Figure 4 . Among them, for the Longyi 1 1 stratigraphic horizon, Longyi 1 2 stratigraphic horizon, Longyi 1 3 stratigraphic horizon, Longyi 1 4 stratigraphic horizon, the organic matter types can be seen in Figure 4 .

[0237] For the macro-pore organic clay complex Ⅰ1 filling the primary pores with the organic matter type, the clay generally exceeds 10%, the organic matter and clay minerals are fully mixed, and the macro-pores have large pore diameters and low densities (as shown in Figure 4 a in). For the macro-meso-pore organic clay complex Ⅰ2 filling the primary pores with the organic matter type, the clay minerals are scattered in the organic matter, the number of macro-pores is small and randomly distributed, and the meso-pore density is large and evenly distributed (as shown in Figure 4 b in). For the meso-pore organic clay complex Ⅰ3 filling the primary pores with the organic matter type, the clay minerals are scattered in the organic matter, and the meso-pore density is large and evenly distributed (as shown in Figure 4 c in).

[0238] For the macro-pore pure organic matter Ⅱ1 filling the primary pores with the organic matter type 1 (as shown in Figure 4 d in) and the macro-pore pure organic matter Ⅱ1 filling the secondary pores with the organic matter type 2 (as shown in Figure 4 e in), the macro-pore density is large and evenly distributed. For the macro-meso-pore pure organic matter Ⅱ2 filling the primary pores with the organic matter type 1 (as shown in Figure 4 f in) and the macro-meso-pore pure organic matter Ⅱ2 filling the secondary pores with the organic matter type 2 (as shown in Figure 4 g in), the macro-pore density is small and randomly distributed, while the meso-pore density is large and evenly distributed. For the meso-pore pure organic matter Ⅱ3 filling the primary pores with the organic matter type 1 (as shown in Figure 4 h in) and the meso-pore pure organic matter Ⅱ3 filling the secondary pores with the organic matter type 2 (as shown in Figure 4 i in), the meso-pore density is large and evenly distributed. For the pore-free pure organic matter Ⅱ4 filling the primary pores with the organic matter type 1 as shown in Figure 4 j shown, and for the pore-free pure organic matter Ⅱ4 filling the secondary pores with the organic matter type 2 as shown in Figure 4As shown by k, the organic matter type is pore-free pure organic matter Ⅱ4 filling the fractures 3 As Figure 4 shown by l in

[0239] Longyi 1 of the sweet spot section of shale gas in Well H4 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 There are significant differences in the organic matter types in the horizons of Longyi 1 in the sweet spot section of shale gas in Well H4. For details, see the column of horizons where the organic matter types are distributed in Figure 2 the organic matter type distribution horizons

[0240] The method for determining the golden target of the sweet spot section of shale gas in Well H4 is different from the method for determining the golden target of the sweet spot section of shale gas in Well H2 in Example 1 only in that

[0241] the rock samples used are the rock samples collected from Longyi 1 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizon of the sweet spot section of shale gas in Well H4 (1 sample is collected from each horizon, and a total of 4 samples are collected. The sample positions and codes are shown in Figure 1 ), rather than the rock samples collected from Longyi 1 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizon of the sweet spot section of shale gas in Well H2

[0242] In this embodiment, the mesoporous organic pore porosities of Longyi 1 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizons vary greatly. The mesoporous organic pore porosity of Longyi 1 1 horizon is 1.91%, and the mesoporous organic pore porosity of Longyi 1 2 horizon is 1.16%, and the mesoporous organic pore porosity of Longyi 1 3 horizon is 0.88%, and the mesoporous organic pore porosity of Longyi 1 4 horizon is 0%.

[0243] Longyi 1 1 horizon, Longyi 1 2 The mesoporous organic pore porosity of the horizons is greater than or equal to 1.0%. Therefore, Longyi 1 1 horizon, Longyi 1 2The horizon is the golden target body of the shale gas sweet spot section of Well H4. The higher the porosity of mesoporous organic pores, the higher the content of natural gas present in the adsorbed and free states in the mesoporous organic pores. Therefore, as the golden target body of the shale gas sweet spot section of Well H4, Longyi-1 1 horizon is superior to Longyi-1 2 horizon.

[0244] Example 3

[0245] This example provides a method for judging the origin of organic pores in the shale gas sweet spot section of Well H5 and a method for judging the golden target body of the shale gas sweet spot section of Well H5.

[0246] The method for judging the origin of organic pores in the shale gas sweet spot section of Well H5 is different from the method for judging the origin of organic pores in the shale gas sweet spot section of Well H2 in Example 1 only in that:

[0247] The rock samples used are rock samples collected from the Longyi-1 1 horizon, Longyi-1 2 horizon, Longyi-1 3 horizon, Longyi-1 4 horizon of the shale gas sweet spot section of Well H5 (1 sample is collected from each horizon, a total of 4 samples are collected, and the sample positions and codes are shown in Figure 1 ), rather than rock samples from the Longyi-1 1 horizon, Longyi-1 2 horizon, Longyi-1 3 horizon, Longyi-1 4 horizon of the shale gas sweet spot section of Well H2.

[0248] In this example, the organic matter types in the shale gas sweet spot section of Well H5 are divided into 2 major categories, 7 categories, and 9 subcategories, such as Figure 2 , Figure 5 . Among them, for the organic matter types in the Longyi-1 1 horizon, Longyi-1 2 horizon, Longyi-1 3 horizon, Longyi-1 4 horizon of the shale gas sweet spot section of Well H5, refer to Figure 5 .

[0249] For the macro-porous organic clay complex Ⅰ1 that fills the primary pores in the organic matter type, the clay generally exceeds 10%, the organic matter and clay minerals are fully mixed, and the macro-pores have large pore diameters and low densities (such as Figure 5 a). For the macro-mesoporous organic clay complex Ⅰ2 that fills the primary pores in the organic matter type, the clay minerals are scattered in the organic matter, the number of macro-pores is small and randomly distributed, and the mesopore density is large and evenly distributed (such as Figure 5 b). For the mesoporous organic clay complex Ⅰ3 that fills the primary pores in the organic matter type, the clay minerals are scattered in the organic matter, and the mesopore density is large and evenly distributed (such asFigure 5 in c) of

[0250] The organic matter type is macro-porous pure organic matter Ⅱ1 filling primary pores 1 (such as Figure 5 in d) and the organic matter type is macro-porous pure organic matter Ⅱ1 filling secondary pores 2 (such as Figure 5 in e), the macro-porosity is large and the distribution is uniform. The organic matter type is macro-meso-porous pure organic matter Ⅱ2 filling primary pores 1 (such as Figure 5 in f) and the organic matter type is macro-meso-porous pure organic matter Ⅱ2 filling secondary pores 2 (such as Figure 5 in g), the macro-porosity is small and the distribution is random, while the meso-porosity is large and the distribution is uniform. The organic matter type is meso-porous pure organic matter Ⅱ3 filling primary pores 1 (such as Figure 5 in h) and the organic matter type is meso-porous pure organic matter Ⅱ3 filling secondary pores 2 (such as Figure 5 in i), the meso-porosity is large and the distribution is uniform. The organic matter type is non-porous pure organic matter Ⅱ4 filling primary pores 1 such as Figure 5 shown in j, and the organic matter type is non-porous pure organic matter Ⅱ4 filling secondary pores 2 such as Figure 5 shown in k, and the organic matter type is non-porous pure organic matter Ⅱ4 filling fractures 3 such as Figure 5 shown in l.

[0251] The sweet spot section of shale gas in Well H5, Longyi 1 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizons, there are significant differences in the organic matter types in the Longyi 1 Figure 2 horizons, specifically see the column of organic matter type distribution horizons in

[0252] The method for judging the golden target body of the sweet spot section of shale gas in Well H5 is different from the method for judging the golden target body of the sweet spot section of shale gas in Well H2 in Example 1 only in that:

[0253] The rock samples used are collected from the Longyi 1 1 horizon, Longyi 1 2 horizon, Longyi 1 3 horizon, Longyi 1 4 horizons of the rock samples (1 sample is collected from each horizon, a total of 4 samples are collected, and the sample positions and codes are shown in Figure 1 ), rather than being collected from the Longyi 1 sweet spot section of Well H21 Stratigraphic horizon, Longyi 1 2 Stratigraphic horizon, Longyi 1 3 Stratigraphic horizon, Longyi 1 4 Rock samples of the stratigraphic horizon.

[0254] In this embodiment, the sweet spot section of shale gas in Well H5, Longyi 1 1 Stratigraphic horizon, Longyi 1 2 Stratigraphic horizon, Longyi 1 3 Stratigraphic horizon, Longyi 1 4 There are significant differences in the mesoporous organic pore porosity of the stratigraphic horizons. Longyi 1 1 The mesoporous organic pore porosity of the stratigraphic horizon is 2.35%, Longyi 1 2 The mesoporous organic pore porosity of the stratigraphic horizon is 1.19%, Longyi 1 3 The mesoporous organic pore porosity of the stratigraphic horizon is 0.82%, Longyi 1 4 The mesoporous organic pore porosity of the stratigraphic horizon is 0%.

[0255] Longyi 1 1 Stratigraphic horizon, Longyi 1 2 The mesoporous organic pore porosity of the stratigraphic horizon is greater than or equal to 1.0%, so Longyi 1 1 Stratigraphic horizon, Longyi 1 2 The stratigraphic horizon is the golden target body of the sweet spot section of shale gas in Well H4. The higher the mesoporous organic pore surface area ratio, the higher the content of natural gas existing in the mesoporous organic pores in the adsorbed state and the free state. Therefore, as the golden target body of the sweet spot section of shale gas in Well H5, Longyi 1 1 The stratigraphic horizon is superior to Longyi 1 2 Stratigraphic horizon.

[0256] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for judging the origin of organic pores in shale gas sweet spots, wherein, The method includes: Obtaining a rock sample of the 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, so as to determine the origin of the organic pores developed in the organic matter.

2. The method according to claim 1, wherein, The organic matter types include macro-pore organic clay complexes filling primary pores, macro-meso-pore organic clay complexes filling primary pores, meso-pore organic clay complexes filling primary pores, macro-pore pure organic matter filling primary pores, macro-pore pure organic matter filling secondary pores, macro-meso-pore pure organic matter filling primary pores, macro-meso-pore pure organic matter filling secondary pores, meso-pore pure organic matter filling primary pores, meso-pore pure organic matter filling secondary pores, pore-free pure organic matter filling primary pores, pore-free pure organic matter filling secondary pores, and pore-free pure organic matter filling fractures.

3. The method according to claim 2, 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, so as to determine the origin of the organic pores developed in the organic matter includes: When the organic matter type is a macro-pore organic clay complex filling primary pores: The thermal evolution history of the organic matter is that the water-rich clay filling primary pores evolves into oil-water clay filling primary pores, and then evolves into a macro-pore pyrobitumen clay complex filling primary pores; The origin of the organic pores developed in the organic matter is that during the evolution of the oil-water clay filling primary pores into the macro-pore pyrobitumen clay complex filling primary pores, water droplets vaporize into water vapor to form macro-pores, and the water vapor exists in the macro-pores in a free state; And / or when the organic matter type is a macro-meso-pore organic clay complex filling primary pores: The thermal evolution history of the organic matter is that the sedimentary organic clay complex filling primary pores evolves into a kerogen clay complex filling primary pores, then evolves into a pre-bitumen clay complex with water droplets wrapped filling primary pores, and then evolves into a solid bitumen petroleum clay complex with water droplets wrapped filling primary pores, and then evolves into a macro-meso-pore pyrobitumen clay complex filling primary pores; The origin of the organic pores developed in the organic matter is that during the evolution of the pre-bitumen clay complex with water droplets wrapped filling primary pores into the solid bitumen petroleum clay complex with water droplets wrapped filling primary pores, the generation of petroleum expansion causes the solid bitumen to generate organic pores, which is one of the main reservoir spaces of shale oil; during the evolution of the solid bitumen petroleum clay complex with water droplets wrapped filling primary pores into the macro-meso-pore pyrobitumen clay complex filling primary pores, the solid bitumen thermally degrades to generate natural gas and is converted into pyrobitumen at the same time. The generation of natural gas expansion causes the pyrobitumen to form meso-pores, and the natural gas coexists in the meso-pores 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; And / or when the organic matter type is a meso-pore organic clay complex filling primary pores: The thermal evolution process of organic matter is as follows: The organic clay complex filling the primary pores evolves into the kerogen clay complex filling the primary pores, then evolves into the pre-oil asphalt clay complex filling the primary pores, and further evolves into the solid asphalt petroleum clay complex filling the primary pores, and then evolves into the mesoporous pyrobitumen clay complex filling the primary pores; The formation reason of the organic pores developed in organic matter is as follows: During the process of the pre-oil asphalt clay complex filling the primary pores evolving into the solid asphalt petroleum clay complex filling the primary pores, the generation of petroleum causes swelling, resulting in the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces for shale oil; During the process of the solid asphalt petroleum clay complex filling the primary pores evolving into the mesoporous pyrobitumen clay complex filling the primary pores, the solid asphalt thermally degrades to generate natural gas while being transformed into pyrobitumen. The generation of natural gas causes swelling, resulting in the formation of mesopores in the pyrobitumen. Natural gas coexists in the mesopores in the adsorbed state and the free state; And / or when the organic matter type is macroporous pure organic matter filling the primary pores: The thermal evolution process of organic matter is as follows: The petroleum containing water droplets filling the primary pores evolves into macroporous pyrobitumen filling the primary pores; The formation reason of the organic pores developed in organic matter is as follows: During the process of the petroleum containing water droplets filling the primary pores evolving into macroporous pyrobitumen filling the primary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state; And / or when the organic matter type is macroporous pure organic matter filling the secondary pores: The thermal evolution process of organic matter is as follows: The petroleum containing water droplets filling the secondary pores evolves into macroporous pyrobitumen filling the secondary pores; The formation reason of the organic pores developed in organic matter is as follows: During the process of the petroleum containing water droplets filling the secondary pores evolving into macroporous pyrobitumen filling the secondary pores, the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state; And / or when the organic matter type is macroporous-mesoporous pure organic matter filling the primary pores: The thermal evolution process of organic matter is as follows: The pre-oil asphalt containing water droplets filling the primary pores evolves into the solid asphalt petroleum containing water droplets filling the primary pores, and then evolves into macroporous-mesoporous pyrobitumen filling the primary pores; The formation reason of the organic pores developed in organic matter is as follows: During the process of the pre-oil asphalt containing water droplets filling the primary pores evolving into the solid asphalt petroleum containing water droplets filling the primary pores, the generation of petroleum causes swelling, resulting in the formation of organic pores in the solid asphalt, which is one of the main reservoir spaces for shale oil; During the process of the solid asphalt petroleum containing water droplets filling the primary pores evolving into macroporous-mesoporous pyrobitumen filling the primary pores, the solid asphalt thermally degrades to generate natural gas while being transformed into pyrobitumen. The generation of natural gas causes swelling, resulting in the formation of mesopores in the pyrobitumen. Natural gas coexists in the mesopores in the adsorbed state and the free state, and the water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in the free state; And / or when the organic matter type is macroporous-mesoporous pure organic matter filling the secondary pores: The thermal evolution process of organic matter is as follows: The pre-oil asphalt containing water droplets filling the secondary pores evolves into the solid asphalt petroleum containing water droplets filling the secondary pores, and then evolves into macroporous-mesoporous pyrobitumen filling the secondary pores; The formation reason of organic pores developed in organic matter is as follows: during the process of the pre-bitumen filled in secondary pores evolving into solid bitumen filled in secondary pores with water droplets and oil, and then evolving into petroleum, the generated petroleum expands, resulting in the generation of organic pores in the solid bitumen. This is one of the main reservoir spaces of shale oil; during the process of the solid bitumen filled in secondary pores with water droplets and oil evolving into macro-mesoporous pyrobitumen filled in secondary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The expansion of the generated natural gas leads to the formation of mesopores in the pyrobitumen. The natural gas coexists in the mesopores in both adsorbed and free states. The water droplets vaporize into water vapor to form macropores, and the water vapor exists in the macropores in a free state; and / or when the organic matter type is mesoporous pure organic matter filled in primary pores: The thermal evolution process of the organic matter is as follows: the pre-bitumen filled in primary pores evolves into solid bitumen filled in primary pores with water droplets and oil, and then evolves into mesoporous pyrobitumen filled in primary pores; The formation reason of organic pores developed in organic matter is as follows: during the process of the pre-bitumen filled in primary pores evolving into solid bitumen filled in primary pores with water droplets and oil, the generated petroleum expands, resulting in the generation of organic pores in the solid bitumen. This is one of the main reservoir spaces of shale oil; during the process of the solid bitumen filled in primary pores with water droplets and oil evolving into mesoporous pyrobitumen filled in primary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The expansion of the generated natural gas leads to the formation of mesopores in the pyrobitumen. The natural gas coexists in the mesopores in both adsorbed and free states; and / or when the organic matter type is mesoporous pure organic matter filled in secondary pores: The thermal evolution process of the organic matter is as follows: the pre-bitumen filled in secondary pores evolves into solid bitumen filled in secondary pores with water droplets and oil, and then evolves into mesoporous pyrobitumen filled in secondary pores; The formation reason of organic pores developed in organic matter is as follows: during the process of the pre-bitumen filled in secondary pores evolving into solid bitumen filled in secondary pores with water droplets and oil, the generated petroleum expands, resulting in the generation of organic pores in the solid bitumen. This is one of the main reservoir spaces of shale oil; during the process of the solid bitumen filled in secondary pores with water droplets and oil evolving into mesoporous pyrobitumen filled in secondary pores, the solid bitumen thermally degrades to generate natural gas and is simultaneously transformed into pyrobitumen. The expansion of the generated natural gas leads to the formation of mesopores in the pyrobitumen. The natural gas coexists in the mesopores in both adsorbed and free states; and / or when the organic matter type is pore-free pure organic matter filled in primary pores: The thermal evolution process of the organic matter is as follows: the petroleum filled in primary pores evolves into pore-free pyrobitumen filled in primary pores; No organic pores are developed; and / or when the organic matter type is pore-free pure organic matter filled in secondary pores: The thermal evolution process of the organic matter is as follows: the petroleum filled in secondary pores evolves into pore-free pyrobitumen filled in secondary pores; No organic pores are developed; and / or when the organic matter type is pore-free pure organic matter filled in fractures: The thermal evolution process of the organic matter is as follows: the petroleum filled in fractures evolves into pore-free pyrobitumen filled in fractures; No organic pores are developed.

4. The method according to any one of claims 1-3, wherein Determining the organic matter type of the rock sample in the target shale gas sweet spot section includes: Using the rock sample in the target shale gas sweet spot section to make an argon ion polished section of the rock in the target shale gas sweet spot section; Collecting the MAPS rock image data volume of the argon ion polished section of the rock in the target shale gas sweet spot section; Based on the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock obtained by collection, determine the organic matter type of the target shale gas sweet spot section rock sample.

5. The method according to claim 4, wherein, The resolution of the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock obtained by collection is 1 - 10 nm resolution; and / or The length of the argon ion polished slice of the target shale gas sweet spot section rock is 0.8 - 2 cm, the width is 0.8 - 2 cm, and the thickness is 0.3 - 0.8 cm; and / or The top and bottom surfaces of the argon ion polished slice of the target shale gas sweet spot section rock are parallel to the top and bottom surfaces of the target shale gas sweet spot section rock sample in the underground state; and / or Collecting the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock includes: selecting an area with a length and width not exceeding 400 μm in the polished surface of the argon ion polished slice of the target shale gas sweet spot section rock, and collecting the MAPS rock image data volume; and / or During the process of collecting the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock, the top surface of the argon ion polished slice of the target shale gas sweet spot section rock is located above the field of view, and the bottom surface of the argon ion polished slice of the target shale gas sweet spot section rock is located below the field of view.

6. A method for determining the golden target body of the target shale gas sweet spot section, wherein The method includes: Obtain a target shale gas sweet spot section rock sample; Determine the mesoporous organic pore porosity of the target shale gas sweet spot section rock sample; Based on the mesoporous organic pore porosity of the target shale gas sweet spot section rock sample, determine whether the target shale gas sweet spot section is a golden target.

7. The method according to claim 6, wherein, Determining whether the target shale gas sweet spot section is a golden target based on the mesoporous organic pore porosity of the target shale gas sweet spot section rock sample includes: When the mesoporous organic pore porosity of the target shale gas sweet spot section rock sample ≥ 1.0%, the target shale gas sweet spot section is a golden target; When the mesoporous organic pore porosity of the target shale gas sweet spot section rock sample is less than 1.0%, the target shale gas sweet spot section is not a golden target.

8. The method according to claim 6, wherein The mesoporous organic pores are mesopores developed in organic matters of macro-mesoporous organic clay complexes filling primary pores, mesoporous organic clay complexes filling primary pores, macro-mesoporous pure organic matters filling primary pores, macro-mesoporous pure organic matters filling secondary pores, mesoporous pure organic matters filling primary pores, and mesoporous pure organic matters filling secondary pores.

9. The method according to any one of claims 6 - 8, wherein, Determining the mesoporous organic pore porosity of the target shale gas sweet spot section rock sample includes: Using the target shale gas sweet spot section rock sample to make an argon ion polished slice of the target shale gas sweet spot section rock; Collecting the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock; Based on the MAPS rock image data volume of the argon ion polished slice of the target shale gas sweet spot section rock obtained by collection, statistically calculate the mesoporous organic pore surface area ratio in the target shale gas sweet spot section rock sample, which is the mesoporous organic pore porosity of the target shale gas sweet spot section rock sample.

10. The method according to claim 9, wherein, The resolution of the MAPS rock image data volume of the argon ion polished section of the target shale gas sweet spot rock obtained by collection is 1-10 nm resolution; and / or The length of the argon ion polished section of the target shale gas sweet spot rock is 0.8-2 cm, the width is 0.8-2 cm, and the thickness is 0.3-0.8 cm; and / or 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 the underground state; and / or Collecting the MAPS rock image data volume of the argon ion polished section of the target shale gas sweet spot rock includes: selecting an area with a length and width not exceeding 400 μm in the polished surface of the argon ion polished section of the target shale gas sweet spot rock and collecting the MAPS rock image data volume; and / or During the process of collecting the MAPS rock image data volume of the argon ion polished section of the target shale gas sweet spot rock, the top surface of the argon ion polished section of the target shale gas sweet spot rock is located above the field of view, and the bottom surface of the argon ion polished section of the target shale gas sweet spot rock is located below the field of view.

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