Qualitative characterization methods, devices, media and equipment for river channel sandbody connectivity

Abstract

The present invention relates to a method, device, medium and equipment for qualitative characterization of river channel sandbody connectivity. The method comprises the following steps: using three-dimensional seismic data and combining well and seismic data to track and interpret the top and bottom interfaces of a meandering river composite sandbody; based on the top and bottom interfaces of the meandering river composite sandbody and the three-dimensional seismic data, obtaining relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sandbody; based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sandbody and the three-dimensional seismic data, obtaining sensitive seismic attributes of longitudinal inter-period intervals and interlayers within the meandering river composite sandbody; based on the top and bottom interfaces of the meandering river composite sandbody and the three-dimensional seismic data, obtaining the change rate of sensitive seismic attributes of longitudinal reservoirs of each period within the meandering river composite sandbody; and based on the sensitive seismic attributes of longitudinal inter-period intervals and interlayers within the meandering river composite sandbody and the three-dimensional seismic data, qualitatively characterizing the connectivity of the meandering river channel sandbody.

Description

Technical Field

[0001] The invention relates to a method, device, medium and equipment for qualitatively characterizing the connectivity of a river channel sand body, and belongs to the technical field of geological research on offshore oilfield development. Background Art

[0002] Reservoir sandbody connectivity generally refers to the manner and degree of vertical and lateral contact and connection between genetically derived sand bodies. It is a crucial factor influencing oil and gas field development, directly influencing the deployment of injection and production well patterns, the selection of development methods, and the potential for residual oil in later stages. However, due to the high heterogeneity of underground reservoir sand bodies, especially fluvial sand bodies, frequent changes in river channels lead to the intersecting and overlapping of sand bodies from different phases, resulting in a very complex connectivity between sand bodies in different river channels, making sandbody connectivity prediction often difficult.

[0003] Current sandbody connectivity analysis methods primarily rely on a comprehensive analysis of sandbody depositional type, development level and scale, and phase transition contact relationships. These methods, combined with geological modeling and the relationship between injection and production volumes in development wells, determine the connectivity between various sandbodies. However, these methods are often labor-intensive and time-consuming. Furthermore, existing techniques primarily rely on data from dense underground well networks, and the abundance of these underlying data also influences the results of sandbody connectivity analysis. However, for offshore oil and gas fields with sparse well networks (well spacing typically exceeding 1000 m in the early stages, reaching 200–500 m in some areas during the mid- to late-stage), existing reservoir sandbody connectivity analysis techniques lack the accuracy required for offshore development. Therefore, a qualitative characterization method for channel sandbody connectivity constrained by relatively isochronous sedimentary interfaces is needed. Summary of the Invention

[0004] In response to the above technical problems, the present invention provides a method, device, medium and equipment for qualitative characterization of river channel sandbody connectivity. This method makes full use of three-dimensional seismic data and drilled well data to carry out qualitative characterization of meandering river channel sandbody connectivity, making up for the shortcomings of reservoir connectivity analysis methods based mainly on well information under sparse offshore well network conditions, effectively reducing the uncertainty of reservoir connectivity prediction, and at the same time improving the prediction efficiency of reservoir connectivity.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for qualitatively characterizing river channel sandbody connectivity comprises the following steps:

[0007] Using 3D seismic data, combined with geological and well logging data, we can trace and interpret the top and bottom interfaces of the meandering river composite sand body.

[0008] Based on the top and bottom interfaces of the meandering river composite sand body and 3D seismic data, the relative isochronous sedimentary interfaces between longitudinal stages within the meandering river composite sand body are obtained;

[0009] Based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and 3D seismic data, the sensitive seismic attributes of the longitudinal inter-period intercalation layers within the meandering river composite sand body are obtained.

[0010] Based on the top and bottom interfaces of the meandering river composite sand body and 3D seismic data, the change rate of the sensitive seismic attributes of the reservoir in each period in the vertical direction of the meandering river composite sand body is obtained;

[0011] The connectivity of meandering river channel sandbodies was qualitatively characterized based on the sensitive seismic attributes of longitudinal interval interlayers within the meandering river composite sandbodies and the change rate of sensitive seismic attributes of longitudinal reservoirs within the meandering river composite sandbodies.

[0012] The method for qualitatively characterizing the connectivity of river channel sand bodies preferably obtains the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body based on the top and bottom interfaces of the meandering river composite sand body and three-dimensional seismic data, and specifically comprises the following steps:

[0013] Step A1: Select a typical well, perform wavelet transform on the GR curve, perform single well and well sequence analysis based on the curve characteristics, and obtain the relative isochronous sedimentary interface on the initial well.

[0014] Step A2: Using the top and bottom interfaces of the meandering river composite sand body interpreted by tracing as constraints, a scaled stratigraphic slice is produced based on the 3D seismic data;

[0015] Step A3: Based on the sedimentary geological characteristics and combined with the initial well-surface relative isochronous sedimentary interface, the slice deduction analysis technology is used to merge the equal-scale slices of the formation to obtain the initial relative isochronous sedimentary interface;

[0016] Step A4: Based on the 3D seismic data, with the initial relative isochronous sedimentary interface as a constraint, the well-seismic interaction is used to optimize the relative isochronous sedimentary interface to obtain the final relative isochronous sedimentary interface between longitudinal stages within the meandering river composite sand body.

[0017] The method for qualitatively characterizing the connectivity of channel sand bodies preferably obtains sensitive seismic attributes of intercalated layers in the longitudinal intervals within the meandering river composite sand body based on the relatively isochronous sedimentary interfaces between longitudinal intervals within the meandering river composite sand body and three-dimensional seismic data, and specifically comprises the following steps:

[0018] Step B1: extracting seismic attributes representing interlayers based on the 3D seismic data according to the relatively isochronous sedimentary interfaces between longitudinal phases within the meandering river composite sand body obtained in step A4;

[0019] Step B2: Based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and the top and bottom interfaces of the composite sand body interpreted by tracing, well-seismic interaction is performed to calculate the actual drilling interlayer thickness;

[0020] Step B3: Perform correlation analysis on seismic attributes and interlayer thickness, select interlayer-sensitive seismic attributes, and calibrate and classify the attributes based on the actual drilling interlayer thickness.

[0021] The method for qualitatively characterizing the connectivity of river channel sand bodies preferably obtains the change rate of the sensitive seismic attributes of the reservoirs in each longitudinal period within the meandering river composite sand body based on the top and bottom interfaces of the meandering river composite sand body and three-dimensional seismic data, and specifically comprises the following steps:

[0022] Step C1: Using the top and bottom interfaces of the composite sand body interpreted by tracking and the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body as time windows, extract the seismic attributes of each longitudinal period within the meandering river composite sand body respectively;

[0023] Step C2: Using the top interface of the composite sand body interpreted by tracking and the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body as constraints, the actual drilling sand body thickness of each longitudinal period within the meandering river composite sand body is calculated;

[0024] Step C3: performing correlation analysis on the seismic attributes of each longitudinal period within the meandering river composite sand body and the actual drilling sand body thickness, and selecting the sensitive seismic attributes of the reservoir at each longitudinal period within the meandering river composite sand body;

[0025] Step C4: Calculate the maximum curvature of the sensitive seismic attributes of each reservoir layer in the vertical direction of the meandering river composite sand body to obtain the change rate of the sensitive seismic attributes of each reservoir layer in the vertical direction of the meandering river composite sand body.

[0026] The method for qualitatively characterizing the connectivity of the channel sand bodies is preferably based on the sensitive seismic attributes of the longitudinal interval interlayers within the meandering river composite sand body and the change rate of the sensitive seismic attributes of the longitudinal reservoirs of each period within the meandering river composite sand body to qualitatively characterize the connectivity of the channel sand bodies of the meandering river, and specifically includes the following steps:

[0027] Step D1: Based on the actual drilling interlayer thickness obtained in step B2 and the interlayer sensitive seismic attributes selected in step B3, the connectivity between the channel sand bodies at each stage in the longitudinal direction of the first-level meandering river composite sand body is classified to obtain the connectivity boundaries of the channel sand bodies at different levels;

[0028] Step D2: linearly characterize the change rate of the vertical sensitive seismic attributes of the reservoir at each stage inside the meandering river composite sand body obtained in step C4 to obtain the initial reservoir architecture boundary;

[0029] Step D3: Based on the initial reservoir architecture boundary obtained in step D2 and combined with the superposition pattern of the channel sand bodies, different types of architecture boundaries within each longitudinal period of the meandering river composite sand body are obtained;

[0030] Step D4: Combined with production dynamic characteristics, the connectivity of the boundaries of different types of structures was qualitatively analyzed to obtain the qualitative characterization results of the connectivity of the internal channel sand bodies of the late composite channel SQ2.

[0031] In the method for qualitatively characterizing the connectivity of channel sand bodies, preferably, the three-dimensional seismic data includes: post-stack seismic data and seismic velocity volumes.

[0032] In the method for qualitatively characterizing the connectivity of river channel sand bodies, preferably, the geological data include: drilling data, logging data, core data, geological stratification; and the logging data include: logging curves and logging interpretation results.

[0033] A second aspect of the present invention provides a device for qualitatively characterizing the connectivity of river sand bodies, comprising:

[0034] The first processing unit is used to use 3D seismic data in combination with geological data and well logging data to track and interpret the top and bottom interfaces of the meandering river composite sand body;

[0035] The second processing unit is used to obtain the relative isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body based on the top and bottom interfaces of the meandering river composite sand body and the three-dimensional seismic data;

[0036] The third processing unit is used to obtain the sensitive seismic attributes of the longitudinal inter-period interval interlayers within the meandering river composite sand body based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and the three-dimensional seismic data;

[0037] The fourth processing unit is used to obtain the change rate of the sensitive seismic attributes of the reservoirs in each longitudinal period inside the meandering river composite sand body based on the top and bottom interfaces of the meandering river composite sand body and the three-dimensional seismic data;

[0038] The fifth processing unit is used to qualitatively characterize the connectivity of the meandering river channel sand body based on the sensitive seismic attributes of the longitudinal interval interlayers within the meandering river composite sand body and the change rate of the sensitive seismic attributes of the longitudinal reservoirs of each period within the meandering river composite sand body.

[0039] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned method for qualitative characterization of channel sandbody connectivity.

[0040] A fourth aspect of the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for qualitatively characterizing the connectivity of river sand bodies when executing the computer program.

[0041] The present invention has the following advantages due to the adoption of the above technical solution:

[0042] 1. This invention employs a hierarchical analysis approach. First, by identifying relatively isochronous sedimentary interfaces and determining the planar distribution of interlayers, this method completes the first-level reservoir connectivity analysis. This is then combined with information such as the amplitude change rate of reservoir seismic sensitivity attributes and the structure of the drilled reservoir to complete the second-level reservoir connectivity analysis. This method not only adapts to the complex internal structural hierarchy of fluvial reservoirs but also improves the accuracy of qualitative characterization of reservoir connectivity.

[0043] 2. The present invention adopts a combined well-seismic analysis method, making full use of rich three-dimensional seismic information to constrain the qualitative characterization of reservoir connectivity, making up for the shortcomings of reservoir connectivity analysis methods based mainly on well information under sparse offshore well network conditions, effectively reducing the uncertainty of reservoir connectivity prediction, and at the same time improving the prediction efficiency of reservoir connectivity.

[0044] 3. The method disclosed in this paper qualitatively characterizes the connectivity of meandering river sand bodies. Using 90° 3D seismic data, the method combines well and seismic data to track and interpret the top and bottom interfaces of meandering river composite sand bodies. Using a stratigraphic slice deduction method, the method uses well and seismic data to interactively determine the relative isochronous sedimentary interfaces between longitudinal stages within the meandering river composite sand bodies. This method, combined with the sensitive seismic attributes of interlayers, the amplitude change rate of reservoir seismic attributes, and the architecture of drilled reservoirs, allows for a qualitative characterization of meandering river channel sand body connectivity. This in turn guides reservoir sand body connectivity analysis and optimizes development well patterns, providing important technical support for the efficient development and plan adjustment of underground oil and gas reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a flow chart of a method for qualitatively characterizing the connectivity of river channel sand bodies provided by one embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of the top and bottom interfaces of a composite sand body tracked and interpreted based on three-dimensional seismic data provided by this embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of obtaining the longitudinal relative isochronous sedimentary interface inside a composite sand body through well-seismic interaction provided in this embodiment of the present invention;

[0048] Figure 4 a is a schematic diagram of obtaining sensitive seismic attributes of interlayers based on 3D seismic data using longitudinal relative isochronous sedimentary interface constraints within the composite sand body provided by this embodiment of the present invention. Figure 4 b is a schematic diagram of classification of sensitive seismic attributes of interlayer;

[0049] Figure 5 a is a schematic diagram of the late sensitive properties of the composite sand body obtained by constraining the top interface of the sublacustrine fan composite sand body and the relative isochronous deposition interface provided by this embodiment of the present invention, Figure 5 b is a schematic diagram of the earthquake attribute change rate;

[0050] Figure 6 a is a schematic diagram of seismic reflection characteristics of the interlayer sensitive seismic attribute classification provided by this embodiment of the present invention, Figure 6 b is Figure 6 a is a partially enlarged schematic diagram;

[0051] Figure 7 A schematic diagram of the initial reservoir configuration boundary of the late-stage channel of a composite sand body provided in an embodiment of the present invention;

[0052] Figure 8 Schematic diagram of boundary classification of late-stage composite sand body reservoir architecture of meandering rivers provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by ordinary persons in this field based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0054] The present invention aims to address the existing sand body connectivity analysis methods, which are mainly based on a comprehensive analysis of sand body deposition type, development degree and scale, and phase change contact relationship, combined with geological modeling, development well injection and production volume relationships, etc. to judge the connectivity status between various sand bodies. However, these methods often have the problems of large workload and long time consumption. A qualitative characterization method for river channel sand body connectivity is proposed. This method adopts a combined well-seismic analysis method, fully utilizing rich three-dimensional seismic information to constrain the qualitative characterization of reservoir connectivity, making up for the shortcomings of reservoir connectivity analysis methods based mainly on well information under sparse offshore well network conditions, effectively reducing the uncertainty of reservoir connectivity prediction, and at the same time improving the prediction efficiency of reservoir connectivity.

[0055] like Figure 1 As shown, the method for qualitatively characterizing the connectivity of river channel sand bodies involved in the present invention comprises the following steps:

[0056] Step A: Using 3D seismic data, combined with geological data and well logging data, the top and bottom interfaces of the meandering river composite sand body are explained by interactive tracking. Figure 2 It can be seen that based on the 3D seismic data, the top and bottom interfaces of the target sedimentary sand body can be tracked and interpreted.

[0057] Step B: Using 3D seismic data and the top and bottom interfaces of the meandering river composite sand body, obtain the relatively isochronous sedimentary interfaces between longitudinal stages within the meandering river composite sand body. The specific steps are as follows:

[0058] Step B1: Select a typical well, perform wavelet transform on the GR (gamma) curve, perform single well and well-connected sequence analysis based on the curve characteristics, and obtain the relative isochronous sedimentary interface on the initial well;

[0059] Step B2: Using the top and bottom interfaces of the meandering river composite sand body interpreted by tracing as constraints, make stratigraphic slices based on the 3D seismic data;

[0060] Step B3: Based on the initial wellbore relative isochronous sedimentary interface and sedimentary geological characteristics, slice deduction analysis technology (existing technology) is used to merge the equal-proportion slices of the formation to obtain the initial relative isochronous sedimentary interface;

[0061] Step B4: Using the initial relative isochronous sedimentary interface as a constraint, based on 3D seismic data and well-seismic interaction (comprehensive analysis of seismic profiles of typical wells and through-wells), the initial relative isochronous sedimentary interface is optimized to obtain the final relative isochronous sedimentary interface between longitudinal stages within the meandering river composite sandbody.

[0062] Depend on Figure 3 It can be seen that the target sedimentary body is divided into two composite river channels of early and late stages, SQ1 and SQ2, based on the relative isochronous depositional interface.

[0063] Step C: Based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and 3D seismic data, the sensitive seismic attributes of the longitudinal inter-period intercalation layers within the meandering river composite sand body are obtained. The specific steps are as follows:

[0064] Step C1: Using the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body obtained in Step B4 as constraints, appropriate upper and lower time windows are selected, and seismic attributes characterizing the intercalation layer are extracted based on the 3D seismic data (seismic attributes include root mean square, maximum amplitude, total positive amplitude, and arc length);

[0065] Step C2: Using the top and bottom interfaces of the composite sand body and the relative isochronous sedimentary interface interpreted by tracking as constraints, calculate the actual drilling interlayer thickness;

[0066] Step C3: Perform correlation analysis on the seismic attributes extracted by SQ2 and the thickness of interlayers, optimize the reservoir-sensitive seismic attributes, and calibrate and classify the attributes based on the actual interlayer thickness;

[0067] Depend on Figure 4 From a, we can see that the SQ2 interlayers are mainly distributed on the east and west sides, and the interlayers in the middle are less developed. Figure 4 b It can be seen that the sensitive properties of interlayers can be divided into three categories: I, II, and III. Among them, the thickness of type I interlayer is greater than 6m; the thickness of type II interlayer is 0-6m; and the thickness of type III interlayer is 0m.

[0068] Step D: Based on the top and bottom interfaces of the meandering river composite sand body and 3D seismic data, obtain the change rate of the sensitive seismic attributes of the reservoir at each stage in the vertical direction of the meandering river composite sand body. The specific steps are as follows:

[0069] Step D1: Extract seismic attributes using the top and bottom interfaces of the composite sand body and the relative isochronous sedimentary interface interpreted by the late composite channel SQ2 tracking as the time window;

[0070] Step D2: Using the top interface of the composite sand body and the relative isochronous sedimentary interface interpreted by the late composite channel SQ2 tracking as constraints, the actual drilling sand body thickness is calculated;

[0071] Step D3: Correlation analysis is performed on the seismic attributes extracted from the late composite channel SQ2 and the sand body thickness to optimize the reservoir sensitive seismic attributes;

[0072] Step D4: Obtain the maximum curvature of the reservoir-sensitive seismic attribute of the late-stage composite channel SQ2 to obtain the reservoir-sensitive seismic attribute change rate. The seismic attribute change rate can be obtained by obtaining the maximum curvature attribute from the seismic amplitude.

[0073] Depend on Figure 5 a and Figure 5 As can be seen from Figure b, the late composite channel SQ2 reservoir is distributed in a north-south direction, and its interior is characterized by the superposition of multiple channels.

[0074] Step E: Qualitative characterization of meandering river channel sandbody connectivity includes the following steps:

[0075] Step E1: The first level involves qualitatively characterizing the connectivity between the longitudinal channels and sand bodies within the meandering river composite sand body. Based on the thickness of interlayers and their sensitive seismic attributes from actual drilling, the connectivity between the longitudinal channels and sand bodies within the meandering river composite sand body is classified to determine the connectivity boundaries of the channels and sand bodies at different levels.

[0076] Depend on Figure 6 It can be seen from a that the first level, that is, the connectivity between the longitudinal channel sand bodies of each period within the meandering river composite sand body, can be initially divided into three categories. Among them, Category I is that the thickness of the interlayer is greater than 6 m, which has the strongest sealing effect on the sand body, and the longitudinal channel sand bodies are not connected; Category II is that the thickness of the interlayer is relatively small, between 0 and 6 m, the interlayer has a certain sealing effect on the sand body, and the longitudinal channel sand body connectivity is poor; Category III is that the interlayer is not developed, and the longitudinal channel sand body connectivity is good.

[0077] Step E2: The second level, i.e., qualitative characterization of the connectivity of the channel sand bodies within the late composite channel SQ2. Linear characterization of the change rate of the reservoir sensitive seismic attributes is performed to obtain the initial reservoir architecture boundary;

[0078] Depend on Figure 7It can be seen that the initial reservoir architecture boundaries of the late composite channel SQ2 are distributed in nearly north-south, east-west and northwest-southeast directions.

[0079] Step E3: Classify the initial reservoir architecture boundaries according to the channel sand body contact relationship to obtain different types of architecture boundaries.

[0080] Step E4: Combined with production dynamic characteristics (specifically, the injection profile of the water injection well and the liquid and oil production profiles of the oil production well are used to analyze the injection-production effect, and then qualitatively analyze the connectivity between the injection and production wells), a qualitative analysis of the connectivity of the boundaries of different types of structures is conducted to obtain the qualitative characterization results of the internal channel sandbody connectivity of the late-stage composite channel SQ2.

[0081] Depend on Figure 8 It can be seen that the connectivity of the channel sand bodies in the late composite channel SQ2 can be divided into three categories, namely, category I - good connectivity (the sand bodies are cut and overlapped), category II - relatively good connectivity (the sand bodies are side-overlapped), and category III - poor connectivity (the sand bodies are isolated).

[0082] A second aspect of the present invention provides a device for qualitatively characterizing the connectivity of river sand bodies, comprising:

[0083] The first processing unit is used to use 3D seismic data in combination with geological data and well logging data to track and interpret the top and bottom interfaces of the meandering river composite sand body;

[0084] The second processing unit is used to obtain the relative isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body based on the top and bottom interfaces of the meandering river composite sand body and the three-dimensional seismic data;

[0085] The third processing unit is used to obtain the sensitive seismic attributes of the longitudinal inter-period interval interlayers within the meandering river composite sand body based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and the three-dimensional seismic data;

[0086] The fourth processing unit is used to obtain the change rate of the sensitive seismic attributes of the reservoirs in each longitudinal period inside the meandering river composite sand body based on the top and bottom interfaces of the meandering river composite sand body and the three-dimensional seismic data;

[0087] The fifth processing unit is used to qualitatively characterize the connectivity of the meandering river channel sand body based on the sensitive seismic attributes of the longitudinal interval interlayers within the meandering river composite sand body and the change rate of the sensitive seismic attributes of the longitudinal reservoirs of each period within the meandering river composite sand body.

[0088] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned method for qualitative characterization of channel sandbody connectivity.

[0089] A fourth aspect of the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for qualitatively characterizing the connectivity of river sand bodies when executing the computer program.

[0090] The present invention is described in terms of flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to specific embodiments. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as a combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0091] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for qualitative characterization of river channel sandbody connectivity, characterized in that: The steps include: Using 3D seismic data, combined with geological and well logging data, we can trace and interpret the top and bottom interfaces of the meandering river composite sand body. Based on the top and bottom interfaces of the meandering river composite sand body and 3D seismic data, the relative isochronous sedimentary interfaces between longitudinal stages within the meandering river composite sand body are obtained; Based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and 3D seismic data, the sensitive seismic attributes of the longitudinal inter-period intercalation layers within the meandering river composite sand body are obtained. Based on the top and bottom interfaces of the meandering river composite sand body and 3D seismic data, the change rates of the sensitive seismic attributes of the reservoirs in each vertical period within the meandering river composite sand body are obtained. The specific steps include: Step C1: Using the top and bottom interfaces of the composite sand body interpreted by tracking and the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body as time windows, extract the seismic attributes of each longitudinal period within the meandering river composite sand body respectively; Step C2: Using the top interface of the composite sand body interpreted by tracking and the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body as constraints, the actual drilling sand body thickness of each longitudinal period within the meandering river composite sand body is calculated; Step C3: performing correlation analysis on the seismic attributes of each longitudinal period within the meandering river composite sand body and the actual drilling sand body thickness, and selecting the sensitive seismic attributes of the reservoir at each longitudinal period within the meandering river composite sand body; Step C4: Calculate the maximum curvature of the sensitive seismic attributes of each reservoir layer in the vertical direction of the meandering river composite sand body, obtain the change rate of the sensitive seismic attributes of each reservoir layer in the vertical direction of the meandering river composite sand body, and qualitatively characterize the connectivity of the meandering river channel sand body. Specifically, the steps include: Step D1: Based on the thickness of interlayers obtained from actual drilling and the sensitive seismic attributes of interlayers, the connectivity between the channel sand bodies of each period in the first layer of meandering river composite sand bodies is classified to obtain the connectivity boundaries of the channel sand bodies of different levels; Step D2: linearly characterize the change rate of the vertical sensitive seismic attributes of the reservoir at each stage inside the meandering river composite sand body obtained in step C4 to obtain the initial reservoir architecture boundary; Step D3: Based on the initial reservoir architecture boundary obtained in step D2 and combined with the superposition pattern of the channel sand bodies, different types of architecture boundaries within each longitudinal period of the meandering river composite sand body are obtained; Step D4: Combined with production dynamic characteristics, qualitative analysis of the connectivity of different types of structural boundaries was performed to obtain qualitative characterization results of the connectivity of the internal channel sand bodies of the late composite channel SQ2; The connectivity of meandering river channel sandbodies was qualitatively characterized based on the sensitive seismic attributes of longitudinal interval interlayers within the meandering river composite sandbodies and the change rate of sensitive seismic attributes of longitudinal reservoirs within the meandering river composite sandbodies.

2. The method for qualitative characterization of river channel sandbody connectivity according to claim 1, characterized in that: Based on the top and bottom interfaces of the meandering river composite sand body and 3D seismic data, the relative isochronous sedimentary interfaces between longitudinal stages within the meandering river composite sand body are obtained, which specifically includes the following steps: Step A1: Select a typical well, perform wavelet transform on the GR curve, perform single well and well sequence analysis based on the curve characteristics, and obtain the relative isochronous sedimentary interface on the initial well. Step A2: Using the top and bottom interfaces of the meandering river composite sand body interpreted by tracing as constraints, a scaled stratigraphic slice is produced based on the 3D seismic data; Step A3: Based on the sedimentary geological characteristics and combined with the initial well-surface relative isochronous sedimentary interface, the slice deduction analysis technology is used to merge the equal-scale slices of the formation to obtain the initial relative isochronous sedimentary interface; Step A4: Based on the 3D seismic data, with the initial relative isochronous sedimentary interface as a constraint, the well-seismic interaction is used to optimize the relative isochronous sedimentary interface to obtain the final relative isochronous sedimentary interface between longitudinal stages within the meandering river composite sand body.

3. The method for qualitative characterization of river channel sandbody connectivity according to claim 2, wherein: Based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and 3D seismic data, the sensitive seismic attributes of the longitudinal inter-period intercalations within the meandering river composite sand body are obtained, which specifically includes the following steps: Step B1: extracting seismic attributes representing interlayers based on the 3D seismic data according to the relatively isochronous sedimentary interfaces between longitudinal phases within the meandering river composite sand body obtained in step A4; Step B2: Based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and the top and bottom interfaces of the composite sand body interpreted by tracing, well-seismic interaction is performed to calculate the actual drilling interlayer thickness; Step B3: Perform correlation analysis on seismic attributes and interlayer thickness, select interlayer-sensitive seismic attributes, and calibrate and classify the attributes based on the actual drilling interlayer thickness.

4. The method for qualitative characterization of river channel sandbody connectivity according to claim 1, wherein: 3D seismic data include: post-stack seismic data and seismic velocity volume.

5. A device for qualitative characterization of river channel sandbody connectivity, characterized in that: include: The first processing unit is used to use 3D seismic data in combination with geological data and well logging data to track and interpret the top and bottom interfaces of the meandering river composite sand body; The second processing unit is used to obtain the relative isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body based on the top and bottom interfaces of the meandering river composite sand body and the three-dimensional seismic data; The third processing unit is used to obtain the sensitive seismic attributes of the longitudinal inter-period interval interlayers within the meandering river composite sand body based on the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body and the three-dimensional seismic data; The fourth processing unit is used to obtain the change rate of the sensitive seismic attributes of the reservoirs in each period in the vertical direction of the meandering river composite sand body based on the top and bottom interfaces of the meandering river composite sand body and the three-dimensional seismic data, and specifically includes the following steps: Step C1: Using the top and bottom interfaces of the composite sand body interpreted by tracking and the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body as time windows, extract the seismic attributes of each longitudinal period within the meandering river composite sand body respectively; Step C2: Using the top interface of the composite sand body interpreted by tracking and the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand body as constraints, the actual drilling sand body thickness of each longitudinal period within the meandering river composite sand body is calculated; Step C3: performing correlation analysis on the seismic attributes of each longitudinal period within the meandering river composite sand body and the actual drilling sand body thickness, and selecting the sensitive seismic attributes of the reservoir at each longitudinal period within the meandering river composite sand body; Step C4: Calculate the maximum curvature of the sensitive seismic attributes of each reservoir layer in the vertical direction of the meandering river composite sand body, obtain the change rate of the sensitive seismic attributes of each reservoir layer in the vertical direction of the meandering river composite sand body, and qualitatively characterize the connectivity of the meandering river channel sand body. Specifically, the steps include: Step D1: Based on the thickness of interlayers obtained from actual drilling and the sensitive seismic attributes of interlayers, the connectivity between the channel sand bodies of each period in the first layer of meandering river composite sand bodies is classified to obtain the connectivity boundaries of the channel sand bodies of different levels; Step D2: linearly characterize the change rate of the vertical sensitive seismic attributes of the reservoir at each stage inside the meandering river composite sand body obtained in step C4 to obtain the initial reservoir architecture boundary; Step D3: Based on the initial reservoir architecture boundary obtained in step D2 and combined with the superposition pattern of the channel sand bodies, different types of architecture boundaries within each longitudinal period of the meandering river composite sand body are obtained; Step D4: Combined with production dynamic characteristics, qualitative analysis of the connectivity of different types of structural boundaries was performed to obtain qualitative characterization results of the connectivity of the internal channel sand bodies of the late composite channel SQ2; The fifth processing unit is used to qualitatively characterize the connectivity of the meandering river channel sand body based on the sensitive seismic attributes of the longitudinal interval interlayers within the meandering river composite sand body and the change rate of the sensitive seismic attributes of the longitudinal reservoirs of each period within the meandering river composite sand body.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for qualitatively characterizing the connectivity of river channel sand bodies according to any one of claims 1 to 4 are implemented.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method for qualitatively characterizing the connectivity of river sand bodies according to any one of claims 1 to 4 are implemented.

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