Gas-water distribution analysis method, device, equipment and medium for braided river sandstone gas reservoir

Abstract

This invention discloses a method, apparatus, equipment, and medium for analyzing the gas-water distribution in braided river sandstone gas reservoirs. The method includes: establishing a high-frequency sequence stratigraphy framework for the target layer based on the lithology of the core sample of the target layer in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves; performing sedimentary facies profile distribution analysis on the target layer; analyzing the gas reservoir type based on the results of the high-frequency sequence stratigraphy framework and sedimentary facies profile distribution analysis; and determining the gas-water distribution boundaries and gas layer units according to the gas reservoir type. Using this invention, the gas-water distribution in braided river sandstone gas reservoirs can be analyzed, solving the problem of complex gas-water distribution and difficulty in accurately determining the gas-water distribution in braided river sandstone gas reservoirs.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration technology, and in particular to a method, apparatus, equipment and medium for analyzing the gas-water distribution in braided river sandstone gas reservoirs. Background Technology

[0002] Braided river deposits exhibit rapid changes in hydrodynamic conditions and complex, diverse lithology, with sandstone reservoirs and mudstone interlayers intermingling, resulting in strong heterogeneity. The resulting thin, interbedded, low-permeability, tight sandstone reservoirs generally possess high water saturation and low resistivity, leading to low well production and significant development challenges. Practice has shown that the study of low-permeability tight sandstone gas reservoirs and the gas-water distribution relationship during their formation directly impacts the success or failure of oil and gas exploration and development.

[0003] There are numerous studies both domestically and internationally on the gas-water distribution patterns in conventional sandstone gas reservoirs, and the controlling factors are relatively simple. It is generally believed that structure and reservoir distribution are the key factors controlling the gas-water distribution in conventional gas reservoirs. However, research on the gas-water distribution in low-permeability tight sandstone gas reservoirs is relatively insufficient, and there are more controlling factors; structure is no longer the sole factor controlling gas-water distribution.

[0004] Currently, most experts both domestically and internationally believe that the water content in low-permeability tight gas reservoirs is mainly due to insufficient natural gas accumulation momentum, and that the natural gas accumulation process is a continuous process of migration force overcoming migration resistance. However, many factors influence the migration force and resistance of natural gas in low-permeability tight sandstone reservoirs. Changes in reservoir properties, sand body thickness and distribution, hydrocarbon generation intensity, and structural conditions can also cause changes in the migration force and resistance of natural gas, thus affecting the gas-water distribution pattern. Among the many factors influencing the gas-water distribution in low-permeability tight sandstone water-bearing gas reservoirs, reservoir heterogeneity is clearly one of the key factors.

[0005] The above studies on gas and water distribution in low-permeability tight sandstone mainly focus on the control factors or distribution patterns. However, due to the complexity of gas and water distribution patterns in low-permeability tight sandstone water-bearing gas reservoirs and the influence of reservoir heterogeneity, no unified gas and water distribution model has been summarized, and there is a lack of accurate analysis schemes for gas and water distribution in braided river sandstone gas reservoirs. Summary of the Invention

[0006] The technical problem to be solved by this invention is that there is a lack of accurate analysis schemes for the gas and water distribution of braided river sandstone gas reservoirs in the prior art.

[0007] To address the aforementioned technical problems, this invention provides a method, apparatus, equipment, and medium for analyzing the gas-water distribution in braided river sandstone gas reservoirs.

[0008] A method for analyzing the gas-water distribution in braided river sandstone gas reservoirs, comprising:

[0009] Based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves of the braided river sandstone gas reservoir, a high-frequency sequence grid of the target layer is established.

[0010] The sedimentary facies profile distribution of the target layer was analyzed.

[0011] Based on the results of the high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer, the gas reservoir type of the braided river sandstone gas reservoir is analyzed.

[0012] The gas-water distribution boundary and gas layer unit are determined based on the gas reservoir type.

[0013] Optionally, before establishing the high-frequency sequence framework of the target layer based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed and the corresponding well logging curves of the braided river sandstone gas reservoir, the method further includes:

[0014] Determine the lithology and sedimentary facies of the target layer core in the braided river sandstone gas reservoir to be analyzed;

[0015] If the sedimentary facies is braided river sedimentary, then the step of establishing a high-frequency sequence framework for the target layer based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed and the corresponding well logging curves of the braided river sandstone gas reservoir is performed.

[0016] Optionally, the sedimentary facies profile distribution analysis of the target layer includes:

[0017] The identification and analysis of sedimentary subfacies and microfacies markers were carried out, well logging facies and seismic facies were calibrated, the relationship between lithofacies, well logging facies and seismic facies was established, and the distribution analysis of sedimentary microfacies was conducted under the constraints of well logging facies and seismic facies.

[0018] Optionally, the gas reservoir type includes tectonic gas reservoir, lithologic gas reservoir, and tectonic-lithologic gas reservoir.

[0019] Optionally, determining the gas-water distribution boundary and gas layer unit based on the gas reservoir type includes:

[0020] For different types of gas reservoirs, the gas-water distribution interface must be determined;

[0021] Based on the gas-water distribution boundary, different interconnected gas layer units are determined.

[0022] A gas-water distribution analysis device for braided river sandstone gas reservoirs includes:

[0023] The sequence grid establishment module is used to establish a high-frequency sequence grid for the target layer based on the lithology of the core of the target layer in the braided river sandstone gas reservoir to be analyzed and the corresponding well logging curve of the braided river sandstone gas reservoir.

[0024] The profile distribution analysis module is used to perform sedimentary facies profile distribution analysis on the target layer.

[0025] The gas reservoir type analysis module is used to analyze the gas reservoir type of the braided river sandstone gas reservoir based on the results of the high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer.

[0026] The gas-water distribution determination module is used to determine the gas-water distribution boundary and gas layer unit according to the gas reservoir type.

[0027] Optionally, the above-mentioned braided river sandstone gas reservoir gas-water distribution analysis device further includes a target layer analysis module, used to determine the lithology and sedimentary facies of the target layer core in the braided river sandstone gas reservoir to be analyzed; if the sedimentary facies is braided river sediment, the sequence grid establishment module performs the corresponding function.

[0028] Optionally, the gas-water distribution determination module is used to determine the gas-water distribution interface for different gas reservoir types; and to determine different interconnected gas layer units based on the gas-water distribution boundary.

[0029] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program performing the following steps:

[0030] Based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves of the braided river sandstone gas reservoir, a high-frequency sequence grid of the target layer is established.

[0031] The sedimentary facies profile distribution of the target layer was analyzed.

[0032] Based on the results of the high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer, the gas reservoir type of the braided river sandstone gas reservoir is analyzed.

[0033] The gas-water distribution boundary and gas layer unit are determined based on the gas reservoir type.

[0034] A computer-readable storage medium having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0035] Based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves of the braided river sandstone gas reservoir, a high-frequency sequence grid of the target layer is established.

[0036] The sedimentary facies profile distribution of the target layer was analyzed.

[0037] Based on the results of the high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer, the gas reservoir type of the braided river sandstone gas reservoir is analyzed.

[0038] The gas-water distribution boundary and gas layer unit are determined based on the gas reservoir type.

[0039] Compared with the prior art, one or more embodiments of the above solutions may have the following advantages or beneficial effects:

[0040] Based on high-frequency sequence stratigraphy and sedimentary facies profile analysis, gas reservoir types can be determined. Based on these reservoir types, gas-water distribution boundaries and gas-bearing units can be identified. This allows for the analysis of the gas level distribution in braided river sandstone gas reservoirs, solving the problem of complex gas-water distribution and difficulty in accurately determining its location. The method is highly operable, conforms to the principles of sequence stratigraphy and sedimentology, and can effectively describe the gas level distribution in complex braided river water-bearing gas reservoirs, laying a solid foundation for further development and evaluation of clastic rock gas reservoirs. Attached Figure Description

[0041] The scope of this disclosure can be better understood by reading the following detailed description of exemplary embodiments in conjunction with the accompanying drawings. The accompanying drawings are:

[0042] Figure 1 This is a flowchart illustrating a method for analyzing the gas-water distribution in braided river sandstone gas reservoirs in one embodiment.

[0043] Figure 2 This is a structural block diagram of a gas-water distribution analysis device for a braided river sandstone gas reservoir in one embodiment.

[0044] Figure 3 This is a schematic diagram of the operational logic of a method for analyzing the gas-water distribution in braided river sandstone gas reservoirs in one embodiment.

[0045] Figure 4 This is a comparison diagram of the high-frequency sequence division results of the target layer in wells J1-J2-J3-J4-J5 in one embodiment;

[0046] Figure 5 This is a diagram illustrating the integrated response model of seismic facies, well logging facies, and lithofacies of the target layer in one embodiment;

[0047] Figure 6 This is a lateral comparison diagram of sedimentary microfacies in wells J1-J2-J3-J4-J5 in one embodiment;

[0048] Figure 7 This is a diagram showing the sedimentary distribution of the target layer based on a combination of well and seismic data in one embodiment.

[0049] Figure 8 This is a comparative result diagram of a complex water-bearing gas reservoir profile in one embodiment, based on well-seismic combination of high-frequency sequence stratigraphy and sedimentary microfacies constraints.

[0050] Figure 9This is another comparative result diagram of a complex water-bearing gas reservoir profile in one embodiment, based on well-seismic combination of high-frequency sequence stratigraphy and sedimentary microfacies constraints;

[0051] Figure 10 This is a planar gas-water distribution diagram of the target layer H12 sublayer based on the combination of planar section and well-seismic analysis, which are mutually constrained by structural-lithological water-bearing gas reservoirs in one embodiment.

[0052] Figure 11 This is a planar gas-water distribution diagram of the target layer H11 sublayer based on a combination of planar section and well-seismic analysis, with mutual constraints, in one embodiment.

[0053] Figure 12 This is a planar distribution diagram of the target stratum based on a combination of planar section and well-seismic analysis, which are mutually constrained in one embodiment.

[0054] Figure 13 This is a schematic diagram of the gas horizontal distribution characteristics of a complex water-bearing gas reservoir in the target stratigraphic segment of the study area, constrained by high-frequency sequence, sedimentary microfacies, gas reservoir type, and geophysical properties, in one embodiment. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the present invention clearer, the implementation method of the present invention will be described in detail below with reference to the accompanying drawings and embodiments, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0056] Practice has shown that the study of low-permeability tight sandstone gas reservoirs and the gas-water distribution relationship during their formation is directly related to the success or failure of oil and gas exploration and development. Currently developed low-permeability tight gas fields in China, such as the Xujiahe and Sulige gas fields in Sichuan, are characterized by generally low gas saturation, strong reservoir heterogeneity, frequent gas-water co-production, and complex and poorly identifiable gas-water relationships, which restricts further effective development of these gas fields and the study of their remaining reserve distribution. Therefore, a correct understanding of the gas and water distribution patterns is a crucial step in the scientific exploration and development of this type of gas reservoir.

[0057] Research on gas-water distribution in low-permeability tight sandstone gas reservoirs, both domestically and internationally, is relatively insufficient. Furthermore, numerous controlling factors exist, and tectonics is no longer the sole determinant of gas-water distribution. For instance, Zou et al. argue that multiple hydrocarbon systems exist within low-permeability reservoirs, and regional tectonics do not necessarily correlate with gas-water distribution; that is, gas can be present in lower regions, and water can be present in higher regions. Most low-permeability tight gas reservoirs lack clear structural zoning characteristics in their water content, resulting in complex gas-water relationships. Existing understanding is insufficient to accurately characterize gas-water distribution.

[0058] Currently, most experts at home and abroad believe that the water content in low-permeability tight gas reservoirs is mainly due to insufficient natural gas accumulation momentum. The natural gas accumulation process is a continuous process of migration force overcoming migration resistance. When the migration force is greater than the migration resistance, natural gas can displace water in the reservoir and continuously accumulate. When the migration force is less than the migration resistance, natural gas cannot enter the space occupied by water, and it is blocked, and the accumulated gas volume no longer increases. Fu Jinhua et al. believe that the uneven filling degree of natural gas in low-permeability tight lithologic gas reservoirs easily leads to the formation of poor gas layers, dry layers, or water layers. Wang Zemin et al.'s research suggests that the gas-water distribution in the Sulige Su20 block is affected by the distribution of source rocks. The hydrocarbon generation intensity in the Ordos Basin gradually decreases from southeast to northwest. They also emphasize that the Sulige gas field has always been in a westward-dipping monocline tectonic setting during the hydrocarbon generation and accumulation stages, and the western Su20 block is located in a structurally low position, thus unfavorable for natural gas accumulation. Dai Jinyou et al., through their research on the relationship between source rock thickness and gas-water distribution, indicated that the coal seams in the Benxi Formation and Shanxi Formation are unevenly distributed. In areas with well-developed coal seams, gas layers are well-developed, gas flow rates are high, and water production is low. In contrast, areas with underdeveloped coal seams have low gas production and high water production.

[0059] However, many factors influence the migration force and resistance of natural gas in low-permeability tight sandstone reservoirs. Changes in reservoir properties, sand body thickness and distribution, hydrocarbon generation intensity, and structural conditions can also cause changes in natural gas migration force and resistance, thus affecting the gas-water distribution pattern. Yurewicz et al. studied the controlling factors of gas and water distribution in the central gas accumulation area of ​​the Mesa Verde Basin in the Pishens Basin, Colorado, and concluded that factors such as source rock distribution and faults affect the gas and water distribution patterns. Dou Weitan et al. studied the formation water genesis of the Sulige Gas Field in the Ordos Basin and analyzed the gas and water distribution patterns. They concluded that the gas reservoir has underdeveloped edge and bottom water, exhibiting strong concealment. The gas reservoir distribution is mainly controlled by reservoir heterogeneity (such as lithology and physical properties) and hydrocarbon generation intensity. Among these factors, hydrocarbon generation intensity controls the macroscopic pattern of gas and water distribution, while reservoir heterogeneity controls the degree of natural gas enrichment. Zhao Shuang et al. studied the tight sandstone gas field of the Chongxi-Xu section in central Sichuan and explored the distribution characteristics of gas and water. Based on its genesis, they concluded that the main controlling factors for gas and water distribution are tectonic activity, reservoir properties, faults, and fractures.

[0060] Among the many factors influencing the gas-water distribution in low-permeability tight sandstone gas reservoirs, reservoir heterogeneity is clearly a key factor. For example, in their study on the identification and genesis of water-rich layers in the Xiashihezi Formation gas reservoir in the Ordos Basin, Zhu Yadong, Wang Yuncheng, and others emphasized that under the condition of widely covered source rocks, the gas-water distribution mainly depends on the heterogeneity of the reservoir. In tight, low-permeability reservoirs, formation water flow is difficult, and water remaining in the channel sand bodies is hard to be displaced by natural gas, thus forming a residual movable water distribution zone. In Zhang Zhuang's study on the gas-water distribution in the Xujiahe Formation in the Dayi area, based on the complex internal structure and heterogeneous characteristics of the tight reservoir, it is believed that during natural gas migration, if the capillary saturation pressure of the reservoir is greater than the capillary breakthrough pressure of the upper interlayer, natural gas will continue to migrate upwards through the interlayer before the reservoir reaches the critical gas saturation (the gas saturation corresponding to the critical water saturation), resulting in the presence of movable water in the reservoir. Pang Xiongqi used physical simulation experiments to study the formation process and gas and water distribution patterns of tight sandstone gas reservoirs, pointing out that the heterogeneity of the reservoir is the main reason for the complex gas-water relationship.

[0061] The above studies on gas-water distribution in low-permeability tight sandstone mainly focus on controlling factors or distribution patterns. However, due to the complexity of gas-water distribution patterns in low-permeability tight sandstone water-bearing gas reservoirs and the influence of reservoir heterogeneity, a unified gas-water distribution model has not yet been summarized. Therefore, research on the macroscopic distribution of gas and water is more limited, and existing studies mostly utilize geophysical methods. For example, Huang et al. used continuous spectrum analysis technology to study the gas-water distribution and lateral reservoir prediction of the Carboniferous system in eastern Sichuan based on the gas-water distribution characteristics of traps. Tang Jianming, through detailed research on the geological characteristics of the Carboniferous reservoirs in the Tahe Oilfield, described the spatial distribution of reservoirs and the variation of hydrocarbon content based on high-precision 3D seismic data and seismic reservoir studies, and delineated the high-yield enrichment zone in the area. Peng Zhenming et al. used elastic impedance inversion technology to conduct fluid detection and gas-water identification in the Feixianguan Formation in central Sichuan. Although the above descriptions of the macroscopic distribution of gas and water have made some progress, the methods used are relatively simple and have certain limitations. Clearly, for water-bearing gas reservoirs in thin, interbedded, highly heterogeneous, low-permeability, and tight clastic rocks of braided river deposits, finding locally enriched gas layers within the gas-water distribution is the main challenge for development.

[0062] Through research, the inventors of this application, addressing the strong heterogeneity of braided river thin-layered interbedded low-permeability tight water-bearing gas reservoirs, have linked reservoir geology, well logging fluid identification, and geophysical gas-bearing prediction. By combining multiple disciplines to study the gas-water distribution of the gas reservoir, they have proposed a set of integrated geological, well logging, and geophysical methods to describe the gas horizontal distribution of braided river low-permeability tight gas reservoirs. This method solves the problem of the difficulty in studying the gas horizontal distribution of braided river low-permeability lithological water-bearing gas reservoirs and provides a basic basis for the effective development of gas fields.

[0063] Example 1

[0064] like Figure 1 As shown, a method for analyzing the gas-water distribution in braided river sandstone gas reservoirs is provided, including the following steps:

[0065] S110: Based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves of the braided river sandstone gas reservoir, establish a high-frequency sequence grid for the target layer.

[0066] The braided river sandstone gas reservoir to be analyzed refers to a gas reservoir for which the gas-water distribution needs to be analyzed, specifically a low-permeability, tight braided river sandstone water-bearing gas reservoir. Specifically, core-logging curves can be used for mutual calibration, and sensitive curves reflecting lithology can be selected. The logging response characteristics of high-frequency sequence boundaries can be utilized, combining well and seismic logging, and under the constraint of seismic interfaces, high-frequency sequence boundaries can be identified and compared throughout the well section to establish a high-frequency sequence framework for the target layer.

[0067] S130: Perform sedimentary facies profile distribution analysis on the target layer.

[0068] S150: Based on the results of high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer, the gas reservoir type of braided river sandstone gas reservoir is analyzed.

[0069] S170: Determine the gas-water distribution boundary and gas layer unit based on the gas reservoir type.

[0070] The aforementioned method for analyzing gas-water distribution in braided river sandstone gas reservoirs, based on high-frequency sequence stratigraphy and sedimentary facies profile analysis to determine reservoir type, and based on reservoir type to determine gas-water distribution boundaries and gas-bearing units, enables the analysis of gas level distribution in braided river sandstone gas reservoirs. This solves the problem of complex gas-water distribution and difficulty in accurately determining the gas-water distribution in braided river sandstone gas reservoirs. This method is highly operable, conforms to the principles of sequence stratigraphy and sedimentology, and can effectively describe the gas level distribution in complex water-bearing gas reservoirs in braided rivers, laying a solid foundation for further development and evaluation of clastic rock gas reservoirs.

[0071] Optionally, before step S110, an analysis step is also included: determining the lithology and sedimentary facies of the target layer core in the braided river sandstone gas reservoir to be analyzed; if the sedimentary facies is braided river sediment, then step S110 is performed.

[0072] By determining the sedimentary facies of the target layer and analyzing whether it is braided river deposit, we can ensure the gas-water distribution analysis of low-permeability tight sandstone gas reservoirs in braided river deposits. Specifically, we can observe the core and thin sections of the target layer to determine the main lithology and rock type of the target layer, and analyze the sedimentary environment and sedimentary facies in conjunction with the regional sedimentary background.

[0073] Optionally, step S130 includes: identifying and analyzing sedimentary subfacies and microfacies markers, calibrating well logging facies and seismic facies, establishing the relationship between lithofacies, well logging facies and seismic facies, and conducting distribution analysis of sedimentary microfacies under the constraints of well logging facies and seismic facies.

[0074] For example, based on the analysis steps and step S110, further identification and analysis of sedimentary subfacies and microfacies markers based on core and thin section observations are carried out, well logging facies and seismic facies are calibrated in detail, the relationship between lithofacies, well logging facies and seismic facies is established, and under the constraints of well logging facies and seismic facies, the distribution of sedimentary microfacies is analyzed to determine favorable gas reservoir lithological units.

[0075] Optionally, gas reservoir types include tectonic gas reservoirs, lithologic gas reservoirs, and tectonic-lithologic gas reservoirs.

[0076] Step S150 can utilize the reservoir fluid logging interpretation results, placing the logging fluid interpretation results in single-well high-frequency sequence stratigraphy, sedimentary microfacies division, and well-to-well sedimentary microfacies comparison. Based on the target layer high-frequency sequence stratigraphy framework in step S110 and the sedimentary facies profile layout in step S130, well-seismic combination is used to draw gas reservoir profiles and summarize all gas reservoir types in the study area.

[0077] Optionally, step S170 includes: determining the gas-water distribution interface for different gas reservoir types; and determining different interconnected gas layer units based on the gas-water distribution boundary.

[0078] Specifically, based on the geophysical gas-bearing prediction results, and according to the different gas reservoir types determined in step S150, the gas-water distribution control factors of different gas reservoir types are analyzed. Under their guidance and constraints, well and seismic testing are combined to verify each other and finally determine the favorable planar gas-bearing units.

[0079] This invention addresses the challenges of accurately describing the gas-water distribution in braided river sandstone gas reservoirs, which are characterized by rapid vertical and horizontal variations, complex rock types, strong heterogeneity, discontinuous gas reservoir distribution, and diverse controlling factors. Through comprehensive geological research, combined with well logging interpretation and geophysical prediction results, the invention analyzes the vertical and horizontal distribution of gas and water layers, clarifies the gas reservoir type, and integrates geophysical gas-bearing plane prediction results with well and seismic data for mutual constraint. This ultimately provides a highly operable method for analyzing the gas-water distribution in braided river sandstone gas reservoirs, solving the problem of accurately determining the gas layer distribution in low-permeability tight clastic oil and gas reservoirs during the exploration and development stage. This provides a fundamental decision-making basis for further development and evaluation of the gas field.

[0080] It should be understood that, although Figure 1The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0081] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0082] Example 2

[0083] like Figure 2 A device for analyzing the gas and water distribution in braided river sandstone gas reservoirs is provided, comprising a sequence framework establishment module 210, a profile distribution analysis module 230, a gas reservoir type analysis module 250, and a gas and water distribution determination module 270.

[0084] The sequence framework establishment module 210 is used to establish a high-frequency sequence framework for the target layer based on the lithology of the core sample of the target layer in the braided river sandstone gas reservoir to be analyzed, as well as the corresponding well logging curves of the braided river sandstone gas reservoir. The profile distribution analysis module 230 is used to perform sedimentary facies profile distribution analysis on the target layer. The reservoir type analysis module 250 is used to analyze the gas reservoir type of the braided river sandstone gas reservoir based on the results of the high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer. The gas-water distribution determination module 270 is used to determine the gas-water distribution boundaries and gas layer units according to the gas reservoir type.

[0085] The aforementioned gas-water distribution analysis device for braided river sandstone gas reservoirs, based on high-frequency sequence stratigraphy and sedimentary facies profile analysis, determines the reservoir type and, based on the reservoir type, identifies the gas-water distribution boundaries and gas-bearing units. This device enables the analysis of the gas-water distribution at the horizontal plane in braided river sandstone gas reservoirs, solving the problem of complex gas-water distribution and difficulty in accurately determining its location. It is highly operable, conforms to the principles of sequence stratigraphy and sedimentology, and can effectively describe the gas-water distribution at the horizontal plane in complex braided river water-bearing gas reservoirs, laying a solid foundation for further development and evaluation of clastic rock gas reservoirs.

[0086] Optionally, the above-mentioned braided river sandstone gas reservoir gas-water distribution analysis device also includes a target layer analysis module (not shown in the figure), which is used to determine the lithology and sedimentary facies of the target layer core in the braided river sandstone gas reservoir to be analyzed; if the sedimentary facies is braided river sediment, the sequence grid establishment module performs the corresponding function.

[0087] By determining the sedimentary facies of the target layer and analyzing whether it is braided river deposit, we can ensure the gas-water distribution analysis of low-permeability tight sandstone gas reservoirs in braided river deposits. Specifically, we can observe the core and thin sections of the target layer to determine the main lithology and rock type of the target layer, and analyze the sedimentary environment and sedimentary facies in conjunction with the regional sedimentary background.

[0088] Optionally, the profile distribution analysis module 230 includes identifying and analyzing sedimentary subfacies and microfacies markers, calibrating well logging facies and seismic facies, establishing the relationship between lithofacies, well logging facies and seismic facies, and conducting sedimentary microfacies distribution analysis under the constraints of well logging facies and seismic facies.

[0089] For example, based on the target layer analysis module and the sequence framework establishment module 210, further identification and analysis of sedimentary subfacies and microfacies markers based on core and thin section observations are carried out, well logging facies and seismic facies are calibrated in detail, the relationship between lithofacies, well logging facies and seismic facies is established, and under the constraints of well logging facies and seismic facies, the distribution analysis of sedimentary microfacies is conducted to determine favorable gas reservoir lithological units.

[0090] Optionally, gas reservoir types include tectonic gas reservoirs, lithologic gas reservoirs, and tectonic-lithologic gas reservoirs.

[0091] The gas reservoir type analysis module 250 can utilize reservoir fluid logging interpretation results, and place the logging fluid interpretation results in single-well high-frequency sequence, sedimentary microfacies division and well-to-well sedimentary microfacies comparison. Based on the high-frequency sequence framework and sedimentary facies profile distribution of the target layer, well-seismic combination is used to draw gas reservoir profiles and summarize all gas reservoir types in the study area.

[0092] Optionally, the gas-water distribution determination module 270 is used to determine the gas-water distribution interface for different gas reservoir types; and to determine different interconnected gas layer units based on the gas-water distribution boundary.

[0093] Specifically, based on the geophysical gas-bearing prediction results, and according to the different gas reservoir types determined by the gas reservoir type analysis module 250, the gas and water distribution control factors of different gas reservoir types are analyzed. Under their guidance and constraints, well and seismic testing are combined and mutually verified to finally determine the favorable planar gas-bearing units.

[0094] Specific limitations regarding the braided river sandstone gas reservoir gas distribution analysis device can be found in the above-described limitations of the braided river sandstone gas reservoir gas distribution analysis method, and will not be repeated here. Each module in the aforementioned braided river sandstone gas reservoir gas distribution analysis device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module. It should be noted that the module division in this embodiment is illustrative and only represents a logical functional division; other division methods may be used in actual implementation.

[0095] Example 3

[0096] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0097] Step 1: Based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves of the braided river sandstone gas reservoir, establish a high-frequency sequence grid for the target layer.

[0098] Step 2: Perform sedimentary facies profile distribution analysis on the target layer.

[0099] Step 3: Based on the results of the high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer, analyze the gas reservoir type of braided river sandstone gas reservoir.

[0100] Step 4: Determine the gas-water distribution boundary and gas layer unit based on the gas reservoir type.

[0101] The aforementioned computer equipment can realize the gas-water distribution analysis method for braided river sandstone gas reservoirs, determine the gas reservoir type based on high-frequency sequence framework and sedimentary facies profile distribution analysis, and determine the gas-water distribution boundary and gas layer unit based on the gas reservoir type. It can realize the analysis of the gas level distribution of braided river sandstone gas reservoirs, and solve the problem of complex gas-water distribution and difficulty in accurately determining the gas-water distribution of braided river sandstone gas reservoirs.

[0102] Optionally, when the processor executes the computer program, it also performs the following steps before step one: determining the lithology and sedimentary facies of the target layer core in the braided river sandstone gas reservoir to be analyzed; if the sedimentary facies is braided river sediment, then step one is executed.

[0103] By determining the sedimentary facies of the target layer and analyzing whether it is braided river deposit, we can ensure the gas-water distribution analysis of low-permeability tight sandstone gas reservoirs in braided river deposits. Specifically, we can observe the core and thin sections of the target layer to determine the main lithology and rock type of the target layer, and analyze the sedimentary environment and sedimentary facies in conjunction with the regional sedimentary background.

[0104] Optionally, step two includes: identifying and analyzing sedimentary subfacies and microfacies markers, calibrating well logging facies and seismic facies, establishing the relationship between lithofacies, well logging facies and seismic facies, and conducting distribution analysis of sedimentary microfacies under the constraints of well logging facies and seismic facies.

[0105] For example, based on the analysis steps and step one, further identification and analysis of sedimentary subfacies and microfacies markers based on core and thin section observations are carried out, well logging facies and seismic facies are calibrated in detail, the relationship between lithofacies, well logging facies and seismic facies is established, and under the constraints of well logging facies and seismic facies, the distribution of sedimentary microfacies is analyzed to determine favorable gas reservoir lithological units.

[0106] Optionally, gas reservoir types include tectonic gas reservoirs, lithologic gas reservoirs, and tectonic-lithologic gas reservoirs.

[0107] Step three can be to utilize the reservoir fluid logging interpretation results, and place the logging fluid interpretation results in the single-well high-frequency sequence stratigraphy, sedimentary microfacies division and well-to-well sedimentary microfacies comparison. Based on the high-frequency sequence stratigraphy framework and sedimentary facies profile distribution of the target layer, well-seismic combination can be used to draw gas reservoir profiles and summarize all gas reservoir types in the study area.

[0108] Optionally, step four includes: determining the gas-water distribution interface for different gas reservoir types; and determining different interconnected gas layer units based on the gas-water distribution boundary.

[0109] Specifically, based on the geophysical gas-bearing prediction results, and according to the different gas reservoir types determined in step three, the gas-water distribution control factors of different gas reservoir types are analyzed. Under their guidance and constraints, well and seismic testing are combined to verify each other and finally determine the favorable planar gas-bearing units.

[0110] Example 4

[0111] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0112] Step 1: Based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves of the braided river sandstone gas reservoir, establish a high-frequency sequence grid for the target layer.

[0113] Step 2: Perform sedimentary facies profile distribution analysis on the target layer.

[0114] Step 3: Based on the results of the high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer, analyze the gas reservoir type of braided river sandstone gas reservoir.

[0115] Step 4: Determine the gas-water distribution boundary and gas layer unit based on the gas reservoir type.

[0116] The aforementioned computer-readable storage medium can realize the aforementioned method for analyzing the gas-water distribution of braided river sandstone gas reservoirs. Based on high-frequency sequence lattice and sedimentary facies profile distribution analysis, it can determine the gas reservoir type, and based on the gas reservoir type, it can determine the gas-water distribution boundary and gas layer unit. It can realize the analysis of the gas level distribution of braided river sandstone gas reservoirs, and solve the problem of complex gas-water distribution and difficulty in accurately determining the gas-water distribution of braided river sandstone gas reservoirs.

[0117] Optionally, when the processor executes the computer program, it also performs the following steps before step one: determining the lithology and sedimentary facies of the target layer core in the braided river sandstone gas reservoir to be analyzed; if the sedimentary facies is braided river sediment, then step one is executed.

[0118] By determining the sedimentary facies of the target layer and analyzing whether it is braided river deposit, we can ensure the gas-water distribution analysis of low-permeability tight sandstone gas reservoirs in braided river deposits. Specifically, we can observe the core and thin sections of the target layer to determine the main lithology and rock type of the target layer, and analyze the sedimentary environment and sedimentary facies in conjunction with the regional sedimentary background.

[0119] Optionally, step two includes: identifying and analyzing sedimentary subfacies and microfacies markers, calibrating well logging facies and seismic facies, establishing the relationship between lithofacies, well logging facies and seismic facies, and conducting distribution analysis of sedimentary microfacies under the constraints of well logging facies and seismic facies.

[0120] For example, based on the analysis steps and step one, further identification and analysis of sedimentary subfacies and microfacies markers based on core and thin section observations are carried out, well logging facies and seismic facies are calibrated in detail, the relationship between lithofacies, well logging facies and seismic facies is established, and under the constraints of well logging facies and seismic facies, the distribution of sedimentary microfacies is analyzed to determine favorable gas reservoir lithological units.

[0121] Optionally, gas reservoir types include tectonic gas reservoirs, lithologic gas reservoirs, and tectonic-lithologic gas reservoirs.

[0122] Step three can be to utilize the reservoir fluid logging interpretation results, and place the logging fluid interpretation results in the single-well high-frequency sequence stratigraphy, sedimentary microfacies division and well-to-well sedimentary microfacies comparison. Based on the high-frequency sequence stratigraphy framework and sedimentary facies profile distribution of the target layer, well-seismic combination can be used to draw gas reservoir profiles and summarize all gas reservoir types in the study area.

[0123] Optionally, step four includes: determining the gas-water distribution interface for different gas reservoir types; and determining different interconnected gas layer units based on the gas-water distribution boundary.

[0124] Specifically, based on the geophysical gas-bearing prediction results, and according to the different gas reservoir types determined in step three, the gas-water distribution control factors of different gas reservoir types are analyzed. Under their guidance and constraints, well and seismic testing are combined to verify each other and finally determine the favorable planar gas-bearing units.

[0125] Example 5

[0126] The invention will be further described in detail below with reference to specific application examples:

[0127] like Figure 3 As shown, this embodiment of the invention provides a comprehensive sedimentary facies analysis based on high-frequency sequence constraints, combined with reservoir fluid logging interpretation and reservoir gas-bearing prediction results, integrating well and seismic data to ultimately provide a highly operable method for analyzing the gas-water distribution in braided river sandstone gas reservoirs. The method includes the following steps:

[0128] (1) Detailed observation of the target layer cores and thin sections was conducted to determine the main lithology and rock types of the target layer. Combined with the regional sedimentary background, the sedimentary environment and sedimentary facies were analyzed. For example, the target layer of the clastic gas reservoir in the study area is about 60m thick. Detailed observation of the cores and thin sections of the cored section was conducted to determine the lithology and rock types. The core sampling of well J3 in the target layer was relatively continuous. Based on detailed core observation and microscopic identification of thin sections, the overall core observation showed that it was mainly composed of gravelly coarse sandstone, coarse sandstone, and medium sandstone, with diverse bedding types, including trough cross-bedding, platy cross-bedding, scour surface structures, and other typical lithofacies of high-energy channels. The channel type of the main target layer, He 1 section, is mainly characterized by upward-shallowing meter-level sedimentary cycles, exhibiting an atypical binary structure. The lower riverbed sedimentary thickness is much greater than that of the upper embankment and overlying sediments, reflecting the characteristics of wide and shallow river bodies, rapid water flow, and unfixed and easily migrating channels. Comprehensive analysis suggests that it is a typical braided river deposit.

[0129] (2) Using core-logging cross-calibration, sensitive curves reflecting lithology were selected. Utilizing the logging response characteristics of high-frequency sequence boundaries, and combining well-seismic analysis, high-frequency sequence boundaries were identified and compared across the entire well section under the constraint of seismic interfaces, establishing a high-frequency sequence framework for the target layer. Based on the high-frequency sequence division and sub-layer comparison method, resistivity sensitive curves reflecting lithology were selected using core-logging cross-calibration. The three-porosity curves calculated for the tight layer section were overlapped, and the interfaces of second- and third-order low-frequency sequences and fourth-order high-frequency sequences were identified and compared. Then, the lithological interfaces of the high-frequency sequence boundaries were further calibrated in detail using well-logging and seismic interfaces, with a full combination of well-seismic analysis. Finally, a fourth-order high-frequency sequence framework was established, and the results are as follows: Figure 4 .

[0130] (3) Based on steps (1) and (2), further identify and analyze sedimentary subfacies and microfacies markers based on core and thin section observations, finely calibrate well logging facies and seismic facies, establish the connection and comprehensive response model between lithofacies, well logging facies and seismic facies, and under the constraints of well logging facies and seismic facies, analyze the distribution of sedimentary microfacies to determine favorable gas reservoir lithological units.

[0131] Through lithofacies analysis of the main target layers in the study area in step (1), it is clear that the study area is dominated by braided river deposits. By calibrating well logging curves in detail through lithofacies analysis and combining core and well logging closely, vertical sequence analysis of braided river well logging facies was carried out. Overall, the vertical sequence is composed of sedimentary assemblages with increasingly finer grain size, which is consistent with the type of high-frequency sequence. It mainly includes the following two subfacies and three microfacies:

[0132] Floodplain subfacies: mainly developed in the upper part of the vertical facies sequence, with mudstone as the main lithology, interbedded with siltstone, and occasionally mudstone deformation bedding. The logging curves are low-amplitude, flat, and toothed, with low curve anomaly amplitude.

[0133] Channel subfacies: mainly developed in the middle and lower parts of the vertical facies sequence, with typical scour surfaces and various types of cross-bedding (gravelly) coarse sandstone facies, etc. The logging curves are high-amplitude serrated box-shaped with a small number of bell-shaped curves, including mid-bar and channel-filling microfacies deposits.

[0134] Based on the analysis of petrology, sedimentary structures, and corresponding well logging responses of drill cores, as well as the seismic response characteristics calibrated by synthetic seismic records, well logging and seismic facies models of the main sedimentary microfacies of the Lower Shihezi Formation in the Shilijiahan area were established. Figure 5Based on the above analysis results, guided by the upward finer sedimentary variation trend within the fourth-order high-frequency sequence, and based on the main sedimentary microfacies types observed in cores and thin sections, and under the constraints of sedimentary facies sequence regularity and well logging facies, single-well braided channel sedimentary subfacies and core bar, channel filling, and floodplain microfacies were delineated in the target interval based on the high-frequency sequence. Furthermore, the high-frequency sequence framework established in step (2) and the seismic facies response characteristics in step (3) were used as constraints for the lateral correlation of sedimentary microfacies. Figure 4 , Figure 5 ), to complete the correlation of sedimentary micro-connected wells in the target layer ( Figure 6 ).

[0135] Based on single-well facies, interconnected-well facies, and facies sequence analysis, the seismic interpretation attribute of the maximum wave trough amplitude is selected as the constraint for sedimentary microfacies boundaries. Well-seismic analysis is combined and cross-calibrated. Guided by the sedimentary system and facies sequence rules, a planar microfacies diagram is compiled. Figure 7 Taking the planar sedimentary microfacies of Box 1 section as an example, the Jin 72 well area in the Shilijiahan area can be roughly divided into multiple composite channel zones from west to east.

[0136] (4) Using the reservoir fluid logging interpretation results, the logging fluid interpretation results are listed in the single-well high-frequency sequence, sedimentary microfacies division and well-to-well sedimentary microfacies comparison. Based on the high-frequency sequence framework in step (2) and the sedimentary facies profile distribution in step (3), the gas reservoir profile is drawn by combining well and seismic analysis, and all gas reservoir types in the study area are summarized.

[0137] Using reservoir fluid logging interpretation results, these results are integrated into single-well high-frequency sequence stratigraphy, sedimentary microfacies classification, and well-to-well sedimentary microfacies comparison. Under the constraints of high-frequency sequence stratigraphy and fine correlation of facies and sand bodies in well-to-well profiles, a study on the lateral distribution of gas and water within the study area is conducted to further summarize gas reservoir types. For example, through analysis of single-well fluid interpretation results and fluid geophysical prediction results, the He1 member is a region with concentrated water layer development in the north and west of the study area, a region with concentrated gas layer and gas-water co-existence in the south, and a region with gas-bearing water layer and gas-water co-existence in the central part. For example, the lateral distribution of gas and water in wells Jin116-J72P2-Jin9 in the Jin72 well area, a region with overall water layer development, is shown below. Figure 8 Vertically, gas and water co-occur in the same layer, and gas-bearing layers are usually developed in the upper part of relatively continuous sand bodies. Laterally, they are usually developed in the higher structural parts of relatively continuous sand bodies, exhibiting the characteristics of gas above and water below, making them typical structural-lithological gas reservoirs. Looking at the lateral distribution of gas layers in the southern part of the Jin 72 well area... Figure 9 In the first part, the gas reservoirs are mostly laterally pinch-out type, the main target layers are basically water-free, and the distribution of gas reservoirs is not completely controlled by the structural highs. Therefore, they are mainly characterized by lithologic gas reservoirs. In the middle part, they are mainly transitional types from structural-lithologic gas reservoirs to pure lithologic gas reservoirs, that is, water-bearing lithologic gas reservoirs affected by microstructures.

[0138] (5) Based on the geophysical gas-bearing prediction results, according to the different gas reservoir types determined in step (4), analyze the gas and water distribution control factors of different gas reservoir types, and under their guidance and constraints, combine well and seismic data to verify each other, and finally determine the favorable planar gas-bearing units.

[0139] Based on the longitudinal and lateral distribution of gas and water layers in single wells and interconnected wells, guided by the gas-water distribution controlled by different gas reservoir types, and taking structural interpretation, geophysical reservoir, and fluid prediction results as important references, this study combines the results of planar sedimentary microfacies and lithological unit division to determine the gas-water distribution boundaries of different gas-bearing units for different gas reservoir types. Specifically, for the structural-lithological gas reservoirs in the northern part of the study area, the gas-water boundaries of interconnected gas reservoir units are primarily determined by the structural depth line corresponding to the gas and water layer boundaries in a single well. Under the constraints of reservoir geophysical prediction, the lithological boundaries of interconnected sand bodies at structurally low positions are mainly (gas-bearing) water layer boundaries, while at structurally high positions, lithological boundaries are used to determine the gas layer boundaries. Figure 10 For determining the gas-water boundary of the water-bearing lithologic gas reservoir in the central part of the study area, the boundaries of interconnected lithologic bodies should be identified, and the influence of microstructures and reservoir properties on water layer distribution should be appropriately considered within them. Figure 11 For the water-free, pure lithologic gas reservoirs in the southern part of the study area, the reservoir boundaries are mainly determined based on lithologic boundaries. Figure 12 Using the methods described above, a detailed analysis of the air-level distribution of the main target layers was conducted, ultimately identifying the different interconnected air-layer units. Figure 13 ).

[0140] The above technical solution is merely one embodiment of the present invention. For those skilled in the art, based on the application methods and principles disclosed in this invention, various types of modifications can be easily made, not limited to the geophysical properties such as maximum wave trough amplitude selected in the specific embodiments described above. Different seismic properties can be selected according to actual conditions. Therefore, the maximum wave trough amplitude and other properties selected above are the results of optimization based on local conditions and well comparisons, and are not restrictive.

[0141] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0142] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for analyzing the gas-water distribution in braided river sandstone gas reservoirs, characterized in that, include: Based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves of the braided river sandstone gas reservoir, a high-frequency sequence stratigraphy framework for the target layer is established. Specifically, by mutual calibration of the core and well logging curves, a resistivity-sensitive curve reflecting the lithology is selected, and the three porosity curves calculated for the tight sections are overlapped. Second-order, third-order low-frequency sequence stratigraphy, and fourth-order high-frequency sequence stratigraphy interfaces are identified and compared. Then, the lithological interfaces of the high-frequency sequence stratigraphy interfaces are further calibrated in detail using well logging and seismic interfaces, with a thorough integration of well and seismic data, ultimately establishing a fourth-order high-frequency sequence stratigraphy framework. The braided river sandstone gas reservoir to be analyzed is a low-permeability, tight braided river sandstone water-bearing gas reservoir. The sedimentary facies profile distribution analysis of the target layer is performed. This analysis includes: based on the establishment of a high-frequency sequence stratigraphic framework for the target layer, identifying and analyzing sedimentary subfacies and microfacies markers, calibrating well-logging and seismic facies, establishing the relationship between lithofacies, well-logging, and seismic facies, and performing sedimentary microfacies distribution analysis under the constraints of well-logging and seismic facies; wherein the well-logging facies includes the calculated three-porosity curve. Based on the results of the high-frequency sequence stratigraphic framework and sedimentary facies profile distribution analysis of the target layer, the gas reservoir type of the braided river sandstone gas reservoir is analyzed; the gas reservoir type includes tectonic gas reservoir, lithologic gas reservoir, and tectonic-lithologic gas reservoir. The gas-water distribution boundaries and gas layer units are determined based on the gas reservoir type. The gas and water layers are based on the longitudinal and lateral distribution of gas layers and water layers in single wells and interconnected wells. The gas and water distribution controlled by different gas reservoir types is used as a guide. The results of structural interpretation, geophysical reservoir and fluid prediction are used as important references. Combined with the results of plane sedimentary microfacies lithology unit division, the gas and water distribution boundaries of different gas-bearing units are determined according to different gas reservoir types.

2. The method according to claim 1, characterized in that, Before establishing the high-frequency sequence framework of the target layer based on the lithology of the core of the target layer in the braided river sandstone gas reservoir to be analyzed and the corresponding well logging curves of the braided river sandstone gas reservoir, the process also includes: Determine the lithology and sedimentary facies of the target layer core in the braided river sandstone gas reservoir to be analyzed; If the sedimentary facies is braided river sedimentary, then the step of establishing a high-frequency sequence framework for the target layer based on the lithology of the target layer core in the braided river sandstone gas reservoir to be analyzed and the corresponding well logging curves of the braided river sandstone gas reservoir is performed.

3. The method according to claim 1, characterized in that, The step of determining the gas-water distribution boundary and gas layer unit based on the gas reservoir type includes: For different types of gas reservoirs, the gas-water distribution interface must be determined; Based on the gas-water distribution boundary, different interconnected gas layer units are determined.

4. A device for analyzing the gas-water distribution in braided river sandstone gas reservoirs, characterized in that, include: The sequence framework establishment module is used to establish a high-frequency sequence framework for the target layer based on the lithology of the core sample of the target layer in the braided river sandstone gas reservoir to be analyzed, and the corresponding well logging curves of the braided river sandstone gas reservoir. Specifically, by using core-well logging curve mutual calibration, a resistivity-sensitive curve reflecting lithology is selected, and the three-porosity curves calculated for the tight layer are overlapped. Second-order, third-order low-frequency sequence, and fourth-order high-frequency sequence interfaces are identified and compared. Then, the lithological interfaces of the high-frequency sequence interfaces are further calibrated in detail using well logging and seismic interfaces, with a full integration of well and seismic data, ultimately establishing a fourth-order high-frequency sequence framework. The braided river sandstone gas reservoir to be analyzed is a low-permeability, tight braided river sandstone water-bearing gas reservoir. The profile distribution analysis module is used to perform sedimentary facies profile distribution analysis on the target layer. Based on the established high-frequency sequence framework of the target layer, this module identifies and analyzes sedimentary subfacies and microfacies markers, calibrates well-logging and seismic facies, establishes the relationship between lithofacies, well-logging, and seismic facies, and performs sedimentary microfacies distribution analysis under the constraints of well-logging and seismic facies; wherein the well-logging facies includes the calculated three-porosity curve. The gas reservoir type analysis module is used to analyze the gas reservoir type of the braided river sandstone gas reservoir based on the results of the high-frequency sequence framework and sedimentary facies profile distribution analysis of the target layer; the gas reservoir type includes structural gas reservoir, lithological gas reservoir, and structural-lithological gas reservoir; The gas-water distribution determination module is used to determine the gas-water distribution boundaries and gas layer units according to the gas reservoir type. It is based on the longitudinal and lateral distribution of gas and water layers in single wells and interconnected wells, guided by the gas-water distribution controlled by different gas reservoir types, and takes structural interpretation, geophysical reservoir and fluid prediction results as important references. Combined with the results of plane sedimentary microfacies lithology unit division, the gas-water distribution boundaries of different gas-bearing units are determined according to different gas reservoir types.

5. The apparatus according to claim 4, characterized in that, It also includes a target layer analysis module, used to determine the lithology and sedimentary facies of the target layer core in the braided river sandstone gas reservoir to be analyzed; if the sedimentary facies is braided river sediment, the sequence framework establishment module performs the corresponding function.

6. The apparatus according to claim 4, characterized in that, The gas-water distribution determination module is used to determine the gas-water distribution interface for different gas reservoir types; and based on the gas-water distribution boundary, to determine different interconnected gas layer units.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

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