Method, system, equipment and medium for area selection of secondary gas reservoir

Abstract

The invention belongs to the technical field of natural gas exploration and development, and relates to a secondary gas reservoir area selection method, system, equipment and medium. According to the method, the comprehensive evaluation factor data of a plurality of secondary gas reservoirs of the destination stratum of the research block is acquired, so that the favorable target area for exploration and development can be accurately acquired. A corresponding secondary gas reservoir evaluation chart is obtained according to the secondary gas reservoir comprehensive evaluation factor data, and quantitative comparison of the physical properties of the reservoir stratum is facilitated. According to all the secondary gas reservoir evaluation maps, a region with a gas-bearing distribution intersection exceeding a threshold value is selected as a favorable target region for exploration and development, and the favorable target region for exploration and development is comprehensively obtained through various secondary gas reservoir comprehensive evaluation factors, so that the selection precision of the target region is improved; the geological basis is provided for exploration and development block optimal well position deployment and natural gas favorable enrichment area searching, and efficient and high-quality exploration and development of natural gas are boosted.

Description

Technical Field

[0001] This invention belongs to the field of natural gas exploration and development technology, and relates to a method, system, equipment and medium for selecting areas for secondary gas reservoirs. Background Technology

[0002] In recent years, finding high-efficiency and high-quality reserves and implementing low-cost and high-efficiency oil and gas exploration and development has become an important direction for oil and gas resources. With the continuous advancement of oil and gas reservoir exploration and development, secondary oil and gas reservoirs have been discovered to be shallowly buried, with good physical properties, high production capacity, rapid production establishment, and high utilization rate. They are typical high-efficiency and high-quality resources and are an important area for low-cost and high-efficiency exploration and development in the near future. Secondary gas reservoirs are proposed to distinguish them from primary oil and gas reservoirs. Primary oil and gas reservoirs are regarded as the parent oil and gas reservoirs. New oil and gas reservoirs formed by the re-migration and accumulation of primary oil and gas reservoirs are called secondary gas reservoirs. See: [HORSTAD I 1997, HIGLEY DK 2009, UNDERDOWN R 2008, Ping Hongwei 2009].

[0003] Secondary oil and gas reservoirs are widely distributed. See also: [Yan Xiaoxiong 2005, Qin Shengfei 2007, Xu Guosheng 2009, Ping Hongwei 2009, Wang Xingmou 2015, Tao Shizhen 2017, Sun Wentie 2020, Wang Yuzhen 2021], which conducted detailed research and analysis on the geological characteristics, accumulation conditions, resource potential, distribution patterns, and exploration prospects of secondary oil and gas reservoirs; [Wang Feiyu 2006], who used fluid history analysis (FHA) technology to determine the origin and charging history of secondary oil and gas reservoirs; and applied hydrocarbon accumulation chronology theory to determine the secondary oil and gas... For the formation period of secondary gas reservoirs, see [Zhang Youyu 2002]; some scholars have also summarized the main geological controlling factors of sweet spots in Jurassic secondary tight sandstone gas reservoirs by analyzing the formation process, fault sequence, source-reservoir configuration and formation efficiency of secondary gas reservoirs, and established a comprehensive evaluation standard for sweet spots in secondary tight sandstone gas reservoirs by combining geophysical, engineering, and economic sweet spot evaluation results, see: [Fu Ju 2019]; however, due to the limited comprehensive evaluation factors of secondary gas reservoirs, it cannot be accurately applied to the selection of favorable target areas for secondary gas reservoir exploration and development.

[0004] In summary, existing technologies are inaccurate in the comprehensive evaluation of sweet spots in secondary tight sandstone gas reservoirs and cannot be accurately applied to the selection of favorable target areas for exploration and development of secondary gas reservoirs. Summary of the Invention

[0005] The purpose of this invention is to provide a method, system, equipment, and medium for selecting areas for secondary gas reservoirs, in order to overcome the technical problem of inaccurate evaluation results in the comprehensive evaluation of sweet spots in secondary tight sandstone gas reservoirs in the prior art. This invention integrates multiple secondary gas reservoir evaluation factors and can accurately obtain favorable target areas for exploration and development.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides a method for selecting a region of a secondary gas reservoir, comprising the following steps:

[0008] Obtain comprehensive evaluation data of several secondary gas reservoirs in the target layer of the research block;

[0009] Obtain the corresponding secondary gas reservoir evaluation map based on the comprehensive evaluation factor data of secondary gas reservoirs;

[0010] Based on all secondary gas reservoir evaluation maps, areas where the intersection of gas-bearing distributions exceeds a threshold are selected as favorable target areas for exploration and development.

[0011] Secondly, the present invention provides a system for selecting areas of secondary gas reservoirs, comprising a data acquisition module, an evaluation map acquisition module, and a target area acquisition module connected in sequence, wherein:

[0012] Data acquisition module: used to acquire comprehensive evaluation data of several secondary gas reservoirs in the target layer of the research block;

[0013] Evaluation map acquisition module: used to obtain the corresponding secondary gas reservoir evaluation map based on the comprehensive evaluation factor data of secondary gas reservoirs;

[0014] Target Area Acquisition Module: Used to select areas where the intersection of gas-bearing distributions exceeds a threshold as favorable target areas for exploration and development based on all secondary gas reservoir evaluation maps.

[0015] Thirdly, the present invention provides an electronic device, comprising: a processor; a memory for storing computer program instructions; and steps for implementing a method for selecting a secondary reservoir when executing the computer program.

[0016] Fourthly, the present invention provides a storage medium storing computer program instructions, which, when loaded and executed by a processor, enable the processor to perform a method for selecting a region of a secondary reservoir.

[0017] Fifthly, the present invention provides a computer program product comprising computer instructions that instruct a computer to perform a method for selecting a region of a secondary reservoir.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. This invention facilitates the precise identification of favorable target areas for exploration and development by acquiring comprehensive evaluation data of several secondary gas reservoir factors in the target strata of the study block. Based on the comprehensive evaluation data, corresponding secondary gas reservoir evaluation maps are obtained, enabling quantitative comparison of reservoir properties. Areas where the intersection of gas-bearing distributions exceeds a threshold are selected as favorable target areas for exploration and development based on all secondary gas reservoir evaluation maps. The comprehensive identification of favorable target areas through multiple secondary gas reservoir evaluation factors improves the accuracy of target area selection, provides geological basis for optimal well location deployment and the search for favorable natural gas enrichment areas in the exploration and development block, and promotes efficient and high-quality natural gas exploration and development.

[0020] 2. This invention, by comprehensively studying seven main controlling factors—porosity data, permeability data, thickness of the main gas-bearing sand body, fracture density of the lower strata, sealing index of the mudstone caprock, peak gas measurement value of each well, and number of gas-bearing layers in the lower strata—can accurately predict the sweet spot of natural gas in secondary gas reservoirs. This provides a geological basis for optimizing well site deployment and finding favorable areas for natural gas enrichment in exploration and development blocks, thus promoting efficient and high-quality exploration and development of natural gas.

[0021] 3. The system of this invention includes a data acquisition module, an evaluation map acquisition module, and a target area acquisition module connected in sequence. Specifically: the data acquisition module acquires comprehensive evaluation factor data for several secondary gas reservoirs in the target stratum of the study block; the evaluation map acquisition module acquires corresponding secondary gas reservoir evaluation maps based on the comprehensive evaluation factor data; and the target area acquisition module selects areas where the intersection of gas-bearing distributions exceeds a threshold as favorable target areas for exploration and development based on all secondary gas reservoir evaluation maps. The various modules of this invention cooperate with each other to accurately acquire favorable target areas for exploration and development.

[0022] 4. The equipment, media, and computer program products of this invention can also accurately acquire favorable target areas for exploration and development. Attached Figure Description

[0023] Figure 1 This is a contour map of the sealing index of mudstone from the lower strata of the 5th section of a basin in an embodiment of the present invention, specifically the 1st to 4th mudstone sections.

[0024] Figure 2 This is a contour map of fracture density in the lower strata of the 5th section of a certain basin in an embodiment of the present invention, specifically the 1-7 fracture density contour map.

[0025] Figure 3 This is a flowchart of the method of the present invention;

[0026] Figure 4 This is a system module diagram of the present invention. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings:

[0030] See Figure 3 This invention discloses a method for selecting a region for a secondary gas reservoir, comprising the following steps:

[0031] S1. Obtain comprehensive evaluation data of several secondary gas reservoirs in the target stratum of the study block. The comprehensive evaluation data of secondary gas reservoirs includes: porosity data, permeability data, thickness of the main gas-bearing sand body, fracture density of the lower strata, sealing index of mudstone caprock, peak gas measurement value of each well, and number of gas-bearing layers in the lower strata. By integrating the seven main controlling factors of secondary gas reservoirs, the sweet spot area of ​​natural gas in secondary gas reservoirs can be accurately predicted, providing geological basis for the optimal well location deployment and the search for favorable natural gas enrichment areas in the exploration and development block, and promoting the efficient and high-quality exploration and development of natural gas.

[0032] Preferably, the method for obtaining the fracture density in the lower strata is as follows:

[0033] Obtain the number of fractures and formation thickness for each well;

[0034] The fracture density of the lower strata is obtained based on the number of fractures developed in each well and the formation thickness.

[0035] Preferably, the formula for calculating the fracture density in the lower strata is as follows:

[0036] ρ=T / h

[0037] ρ: fracture density, in units of fractures / meter; T: number of fractures developed, in units of fractures; h: formation thickness, in units of meters.

[0038] S2. Obtain the corresponding secondary gas reservoir evaluation map based on the comprehensive evaluation factor data of secondary gas reservoirs;

[0039] Preferably, the secondary gas reservoir evaluation map includes: a porosity distribution map, a permeability distribution map, a thickness map of the main gas-bearing sand body, a straight line map of fracture density, a contour map of the mudstone capping closure index, a contour map of the gas-bearing layer's gas measurement peak value, and a distribution map of the number of gas-bearing layers.

[0040] Preferably, the method for obtaining the crack density line graph is as follows:

[0041] Obtain the comprehensive index of fracture development in the target stratum and the fracture density in the lower strata of the study block;

[0042] Linear graphs of fracture density were obtained based on the comprehensive fracture development index and the fracture density of the lower strata.

[0043] S3. Based on all secondary gas reservoir evaluation maps, select areas where the intersection of gas-bearing distributions exceeds a threshold as favorable target areas for exploration and development, as follows:

[0044] Based on the gas content of each secondary gas reservoir evaluation map of the target layer in the same study block, obtain the number of distribution intersections of the regions whose gas content in the secondary gas reservoir evaluation maps exceeds the threshold.

[0045] Areas with a distribution intersection number greater than or equal to the first threshold are classified as Category I target areas for exploration and development.

[0046] Areas with a distribution intersection number greater than or equal to the second threshold but less than the first threshold are classified as Category II target areas for exploration and development.

[0047] Areas with fewer than the second threshold distribution intersections are classified as Category III target areas for exploration and development.

[0048] See Figure 3In another feasible embodiment of the present invention, the following modifications are made as appropriate. The steps include: acquiring comprehensive evaluation data of several secondary gas reservoir factors for the target strata in the study block, facilitating the accurate identification of favorable target areas for exploration and development; obtaining corresponding secondary gas reservoir evaluation maps based on the comprehensive evaluation data, facilitating quantitative comparison of reservoir properties; selecting areas where the intersection of gas-bearing distributions exceeds a threshold as favorable target areas for exploration and development based on all secondary gas reservoir evaluation maps. By comprehensively identifying favorable target areas for exploration and development through multiple secondary gas reservoir evaluation factors, the accuracy of target area selection is improved, providing geological basis for optimal well location deployment and the search for favorable natural gas enrichment areas in the exploration and development block, thus promoting efficient and high-quality natural gas exploration and development.

[0049] Example 1:

[0050] This embodiment discloses a method for selecting areas of a secondary gas reservoir, see [link to relevant documentation]. Figure 3 This includes the following steps:

[0051] Step 1: Collect porosity data of the gas-bearing reservoir in the target formation of the study block and draw a porosity distribution map. Areas with large porosity values ​​have good reservoir properties and better gas content; areas with small porosity values ​​have poor reservoir properties and worse gas content.

[0052] Step 2: Collect permeability data of the gas-bearing strata in the target formation of the study block and draw a permeability distribution map. Areas with high permeability values ​​have good reservoir properties and better gas content; areas with low permeability values ​​have poor reservoir properties and worse gas content.

[0053] Step 3: Statistically analyze the thickness of the main gas-bearing sand body in the target layer of the research block, and draw an isopyrograph of the main gas-bearing sand body. The greater the thickness of the main gas-bearing sand body, the larger the space for storing natural gas in the reservoir and the better the gas content; the smaller the thickness of the main gas-bearing sand body, the smaller the space for storing natural gas in the reservoir and the worse the gas content.

[0054] Step 4: Study the development of fractures and faults in the lower layer of the target layer of the secondary gas reservoir, calculate the comprehensive fracture development index, obtain the number of fractures T in each well, and calculate the fracture density in the lower layer of the target layer using the following formula.

[0055] ρ=T / h

[0056] ρ: fracture density, in units of fractures / meter; T: number of fractures developed, in units of fractures; h: formation thickness, in units of meters.

[0057] Based on the calculation results, a linear graph of fracture density was plotted. The greater the fracture density in the lower layers of the target layer, the more developed the fractures, and the easier it is for natural gas to migrate upwards along the fractures, resulting in better gas-bearing properties in the target layer. Conversely, the smaller the fracture density in the lower layers, the less developed the fractures, making it relatively difficult for natural gas to migrate upwards, resulting in relatively poor gas-bearing properties in the target layer.

[0058] Step 5: Investigate the sealing properties of the mudstone caprock above the target layer of the secondary gas reservoir, calculate its sealing index, and draw a contour map of the sealing index. The larger the sealing index of the mudstone caprock above the target layer, the better the sealing properties and the better the gas content of the target layer; the smaller the sealing index, the worse the sealing properties and the worse the gas content of the target layer.

[0059] Step 6: Statistically analyze the peak gas readings of each well in the target layer of the research block, and draw a contour map of the peak gas readings of the gas-bearing layers. Areas with larger peak gas readings have better gas-bearing properties, while areas with smaller peak gas readings have worse gas-bearing properties.

[0060] Step 7: Count the number of gas-bearing layers in the lower layer of the target layer in the research block, and draw a distribution map of the number of gas-bearing layers. The more gas-bearing layers there are in the lower layer of the target layer, the higher the gas saturation in the area, which is conducive to the accumulation of natural gas in the target layer and the better the gas content. Conversely, the fewer gas-bearing layers there are, the worse the gas content.

[0061] Step 8: Combine the gas-bearing comprehensive evaluation map obtained from steps 1, 2, 3, 4, 5, 6 and 7 to determine the favorable target areas for exploration and development in the study area, namely Class I, Class II and Class III areas, based on the intersection of the map distribution. Wells are placed in the Class I area.

[0062] This invention is a method for selecting areas for secondary gas reservoirs. Based on a comprehensive analysis of source rocks, drainage systems, reservoir control factors, and mudstone caprock sealing properties, it meticulously studies seven key controlling factors of secondary gas reservoirs: porosity, permeability, thickness of the main sandstone body, fracture density, mudstone sealing properties, gas detection peak value, and multi-layer gas-bearing properties. This innovative method for selecting areas for secondary gas reservoirs accurately predicts natural gas sweet spots, providing geological basis for optimizing well site deployment and finding favorable natural gas enrichment areas in exploration and development blocks, and promoting efficient and high-quality exploration and development of natural gas.

[0063] Example 2:

[0064] This will be further illustrated by a specific example of a typical secondary gas reservoir in a certain area of ​​a basin, specifically section 5.

[0065] Outcrop, core, seismic, and imaging logging data indicate that the 5th stratum in a certain area of ​​a basin is a secondary gas reservoir. Natural fractures serve as important pathways for the upward migration of natural gas. Therefore, conducting the selection of favorable target areas for the 5th stratum is of great significance for promoting natural gas exploration and development in this area. This invention's method is used to select areas for the 5th stratum in this region. (See attached...) Figure 3 This includes the following specific steps:

[0066] Step 1: Collect porosity data of the gas-bearing strata in a certain area of ​​a basin and draw a porosity distribution map. Areas with larger porosity values ​​have better reservoir properties and better gas-bearing capacity; areas with smaller porosity values ​​have poorer reservoir properties and poorer gas-bearing capacity.

[0067] Step 2: Collect permeability data of the gas-bearing strata in the Qian5 section of the study area and draw a permeability distribution map. Areas with high permeability values ​​have good reservoir properties and better gas content; areas with low permeability values ​​have poor reservoir properties and worse gas content.

[0068] Step 3: Calculate the thickness of the main gas-bearing sand body in the Qian 5 section of the study area and draw an isopyrograph of the main gas-bearing sand body. The greater the thickness of the main gas-bearing sand body, the larger the space for storing natural gas in the reservoir and the better the gas content; the smaller the thickness of the main gas-bearing sand body, the smaller the space for storing natural gas in the reservoir and the worse the gas content.

[0069] Step 4: Analyze the fracture development of the drainage system in the lower layer of Qian 5 section, Box 1-Box 7, in the study area, calculate the comprehensive fracture development index of Box 1-Box 7 for each well, obtain the number of fractures T in Box 1-Box 7 for each well, and calculate the fracture density of Box 1-Box 7 in the lower layer of Qian 5 section in the study area using the following formula.

[0070] ρ=T / h

[0071] ρ: fracture density, in units of fractures / meter; T: number of fractures developed, in units of fractures; h: formation thickness, in units of meters.

[0072] Based on the calculation results, a linear graph showing the crack density of segments 1-7 was plotted. (See attached graph) Figure 2 In the study area, the higher the fracture density in the lower strata of the Qian5 section, the more developed the fractures, the easier it is for natural gas to migrate upwards along the fractures, and the better the gas content of the Qian5 section. Conversely, the lower the fracture density in the He1-He7 sections, the less developed the fractures, the more difficult it is for natural gas to migrate upwards, and the worse the gas content of the Qian5 section.

[0073] Step 5: Investigate the sealing properties of the mudstone caprock of the upper strata of the Qian 5 member in the study area, calculate its mudstone sealing index, and draw contour maps of the mudstone sealing index of the Qian 1-Qian 4 members. (See attached map) Figure 1The larger the sealing index of the mudstone caprock in sections 1-4, the better the sealing performance, and the better the gas content of section 5; the smaller the sealing index of the mudstone caprock in sections 1-4, the worse the sealing performance, and the worse the gas content of section 5.

[0074] Step 6: Statistically analyze the peak gas readings of each well in the gas-bearing strata of the Qian5 section in the study area, and draw a contour map of the peak gas readings for the gas-bearing strata. Areas with larger peak gas readings in the Qian5 section have better gas-bearing properties; areas with smaller peak gas readings have worse gas-bearing properties.

[0075] Step 7: Count the number of gas-bearing layers in the Benxi Formation-He 7 section of the lower Qian 5 section of the study area, and draw a distribution map of the number of gas-bearing layers. The more gas-bearing layers there are in the Benxi Formation-He 7 section of the lower Qian 5 section, the higher the gas saturation, which is conducive to natural gas accumulation and the better the gas content; conversely, the fewer the gas-bearing layers, the worse the gas content.

[0076] Step 8: Overlay the multiple maps obtained from Steps 1, 2, 3, 4, 5, 6, and 7 to obtain the comprehensive evaluation map of gas content in Section 5 of the study area. Based on the overlapping areas of the map distribution, determine the favorable target areas for exploration and development: Class I, Class II, and Class III areas. Wells are placed in the dominant areas of Class I.

[0077] Preferably, the Class I area is the overlap of the distribution of 6 or 7 or more secondary gas reservoir evaluation maps;

[0078] The Class II area is the intersection and overlap of the distribution of 4 or 5 secondary gas reservoir evaluation maps;

[0079] The Class III area consists of the overlapping distribution of evaluation maps of four or fewer secondary gas reservoirs;

[0080] The purpose of this invention is to provide an effective method for selecting areas for secondary gas reservoir exploration and development, accurately predicting sweet spots for enriched secondary gas reservoirs. Based on a comprehensive analysis of source rocks, conduit systems, reservoir controlling factors, and the sealing properties of mudstone caprocks, an innovative method for selecting areas for secondary gas reservoirs is established. This method overcomes the shortcomings of previous scholars' insufficient consideration of factors in evaluating secondary gas reservoirs, and possesses strong operability, practicality, and creativity. This invention can be effectively applied to secondary gas reservoir area selection, increasing the accuracy of identifying enriched secondary gas reservoirs, reducing the cost of natural gas exploration and development, and providing strong technical support for efficient and high-quality natural gas exploration and development. It can be applied to the efficient exploration and development of secondary gas reservoirs in other gas fields both domestically and internationally.

[0081] Based on a comprehensive analysis of previous research findings, this invention summarizes the selection methods for secondary gas reservoirs by considering factors such as source rocks, drainage systems, reservoir control factors, and the sealing properties of mudstone caprocks. This provides a new approach for finding high-efficiency exploration and development of "golden" secondary gas reservoirs. The invention is highly practical, reliable, and operable, reducing the blind spots and risks in natural gas exploration and development, and providing a geological basis for achieving low-cost and high-efficiency exploration and development.

[0082] Based on the above method, the present invention also discloses a system for selecting areas of secondary gas reservoirs, see [link to relevant documentation]. Figure 4 It includes a data acquisition module, an evaluation map acquisition module, and a target area acquisition module connected in sequence, wherein:

[0083] Data acquisition module: used to acquire comprehensive evaluation data of several secondary gas reservoirs in the target layer of the research block;

[0084] Evaluation map acquisition module: used to obtain the corresponding secondary gas reservoir evaluation map based on the comprehensive evaluation factor data of secondary gas reservoirs;

[0085] Target Area Acquisition Module: Used to select areas where the intersection of gas-bearing distributions exceeds a threshold as favorable target areas for exploration and development based on all secondary gas reservoir evaluation maps.

[0086] The various modules of the system of this invention work together to accurately identify favorable target areas for exploration and development.

[0087] An electronic device includes: a processor; a memory for storing computer program instructions; and steps for implementing a method for selecting a secondary reservoir when executing the computer program.

[0088] A storage medium storing computer program instructions, which, when loaded and executed by a processor, enable the processor to perform a method for selecting a region of a secondary reservoir.

[0089] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0090] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0091] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0092] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0093] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for selecting a region for a secondary gas reservoir, characterized in that, Includes the following steps: Obtain comprehensive evaluation data of several secondary gas reservoirs in the target layer of the research block; Obtain the corresponding secondary gas reservoir evaluation map based on the comprehensive evaluation factor data of secondary gas reservoirs; Based on all secondary gas reservoir evaluation maps, areas where the intersection of gas-bearing distributions exceeds a threshold are selected as favorable target areas for exploration and development.

2. The method for selecting a secondary gas reservoir according to claim 1, characterized in that, The comprehensive evaluation factors for several secondary gas reservoirs include: porosity data, permeability data, thickness of the main gas-bearing sand body, fracture density of the lower strata, sealing index of the mudstone caprock, peak gas measurement value of the gas-bearing layer in each well, and the number of gas-bearing layers in the lower strata of the target formation in the study block.

3. The method for selecting a secondary gas reservoir according to claim 2, characterized in that, The method for obtaining the fracture density in the lower strata is as follows: Obtain the number of fractures and formation thickness for each well; The fracture density of the lower strata is obtained based on the number of fractures developed in each well and the formation thickness.

4. The method for selecting a secondary gas reservoir according to claim 3, characterized in that, The formula for calculating the fracture density in the lower strata is as follows: ρ=T / h ρ: fracture density, in units of fractures / meter; T: number of fractures developed, in units of fractures; h: formation thickness, in units of meters.

5. The method for selecting a region for a secondary gas reservoir according to claim 1, characterized in that, The secondary gas reservoir evaluation map includes: porosity distribution map, permeability distribution map, isopyrograph of the main gas-bearing sand body, isoline map of fracture density, isoline map of mudstone capping closure index, isoline map of gas-bearing peak gas measurement value, and distribution map of the number of gas-bearing layers.

6. The method for selecting a secondary gas reservoir according to claim 5, characterized in that, The method for obtaining the crack density contour plot is as follows: Obtain the comprehensive index of fracture development in the target stratum and the fracture density in the lower strata of the study block; Linear graphs of fracture density were obtained based on the comprehensive fracture development index and the fracture density of the lower strata.

7. The method for selecting a region for a secondary gas reservoir according to claim 1, characterized in that, The method for selecting areas where the intersection of gas-bearing distributions exceeds a threshold as favorable target areas for exploration and development based on all secondary gas reservoir evaluation maps is as follows: Based on the gas content of each secondary gas reservoir evaluation map of the target layer in the same study block, obtain the number of distribution intersections of the regions whose gas content in the secondary gas reservoir evaluation maps exceeds the threshold. Areas with a distribution intersection number greater than or equal to the first threshold are classified as Category I target areas for exploration and development. Areas with a distribution intersection number greater than or equal to the second threshold but less than the first threshold are classified as Category II target areas for exploration and development. Areas with fewer than the second threshold distribution intersections are classified as Category III target areas for exploration and development.

8. A system for selecting areas of a secondary gas reservoir, characterized in that, It includes a data acquisition module, an evaluation map acquisition module, and a target area acquisition module connected in sequence, wherein: Data acquisition module: used to acquire comprehensive evaluation data of several secondary gas reservoirs in the target layer of the research block; Evaluation map acquisition module: used to obtain the corresponding secondary gas reservoir evaluation map based on the comprehensive evaluation factor data of secondary gas reservoirs; Target Area Acquisition Module: Used to select areas where the intersection of gas-bearing distributions exceeds a threshold as favorable target areas for exploration and development based on all secondary gas reservoir evaluation maps.

9. An electronic device, comprising: A processor; a memory, an electronic device for storing computer program instructions; characterized in that the steps of implementing the method for selecting a secondary reservoir as described in any one of claims 1-7 when executing the computer program are included.

10. A storage medium storing computer program instructions, characterized in that, When the computer program instructions are loaded and run by the processor, the processor performs the method for selecting a region of a secondary reservoir as described in any one of claims 1-7.

11. A computer program product, said computer program product comprising computer instructions, characterized in that, The computer instructions instruct the computer to perform the method for selecting a region of a secondary gas reservoir as described in any one of claims 1-7.

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