A multi-factor coupling oil and gas field high-quality reserve selection method and system

Abstract

The application discloses a multi-factor coupling oil and gas field high-quality reserve selection method and system, and qualitatively / quantitatively characterizes a composite channel sand body top surface microstructure, a sand body oil-water boundary, sand body thickness, sand body connectivity and the like by fully mining seismic information, so that a composite channel sand body high-quality reserve distribution area under a marine sparse well pattern condition is quickly screened out, potential analysis of an oil and gas field, well pattern deployment and optimization are guided, and important technical support is provided for efficient development and scheme adjustment of an underground oil and gas reservoir.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of multi-factor coupling oil and gas field high-quality reserves selection method and system, belong to offshore oilfield development geological research technical field. BACKGROUND

[0002] With the deepening of oil and gas field development, high-quality reserves area is decreasing, reservoir quality gradually reduces, development object is increasingly complex, how to quickly lock the remaining high-quality reserves is the severe challenge that oil and gas field stable production and recovery ratio improvement face.At present, the main method of reserve classification mainly relies on the classification and evaluation of reserve abundance, which can show the reserve scale and plane distribution of each zone in oil and gas field, and plays a certain role in the early stage of exploration and development evaluation, but cannot reflect the complex geological information such as composite sand body connectivity, composite sand body internal barrier and microstructure, resulting in low correlation between geological static and production dynamic, which is difficult to meet the needs of middle and late development, directly affecting the deployment of injection-production well pattern, the selection of development mode and the tapping of remaining oil in the development process of oil and gas field.

[0003] In addition, the existing technology mainly carries out related analysis based on underground dense well pattern data, and the richness of basic data also affects the analysis results of remaining high-quality reserves to some extent.However, under the condition of sparse well pattern (early well spacing is generally greater than 1000m, and locally 200-500m in middle and late period) of offshore oil and gas field, it is difficult to quickly lock the remaining high-quality reserves of offshore oil and gas field by using the existing high-quality reserve analysis method, and further fine evaluation and research are carried out. SUMMARY

[0004] The purpose of the present application is to provide an oil and gas field high-quality reserve selection method and system, which realizes the selection of oil and gas field high-quality reserves by coupling multiple factors such as microstructure, sand body thickness, barrier, sand body connectivity and fluid properties by using three-dimensional seismic data and drilled well data.

[0005] To achieve the above purpose, the present application provides the following technical scheme:

[0006] In the first aspect, the present application provides a high-quality reserve selection method for oil and gas field, comprising the following steps:

[0007] S1, the top and bottom interfaces of composite sand body are obtained by using three-dimensional seismic data, well-to-seismic combination and tracking interpretation;

[0008] S2, the top microstructure of the composite sand body is obtained based on the time-depth relationship of well-to-seismic calibration according to the top and bottom interfaces of the composite sand body;

[0009] S3, the oil-water boundary of the composite sand body is obtained based on the oil-water interface data of the drilled well according to the top and bottom interfaces of the composite sand body;

[0010] S4. According to the top and bottom interfaces of the composite sand body, based on the 3D seismic data, a relatively isochronous depositional interface inside the composite sand body is obtained;

[0011] S5. Calculating the thickness of each phase of the composite sand body based on the top and bottom interfaces of the composite sand body and the relatively isochronous depositional interface and the three-dimensional seismic data;

[0012] S6. Obtaining, according to the relatively isochronous depositional interface and based on the 3D seismic data, boundaries representing connectivity between the composite sand bodies at various stages;

[0013] S7. Based on the top surface microstructure of the composite sand body, the oil-water boundary, the sand body thickness, and the sand body connectivity characterization boundary, a multi-factor coupling method is used to determine the distribution area of ​​high-quality reserves in the oil and gas field.

[0014] In step S1, the composite sand body is a meandering river composite sand body.

[0015] In step S2, obtaining the top surface microstructure of the composite sand body includes the following steps:

[0016] Step S21: Based on the well seismic calibration, the time-depth relationship of each well is obtained, a multi-well time-depth relationship cross-plot is prepared, and a time-depth relationship fitting formula is obtained;

[0017] Step S22: using the top and bottom interfaces of the composite sand body as constraints and according to the time-depth relationship fitting formula, obtaining top and bottom structural data of the composite sand body in depth domain;

[0018] Step S23: Acquire the top surface microstructure based on the top and bottom structural data of the composite sand body in the depth domain.

[0019] In step S3, the acquisition of the oil-water boundary includes the following steps:

[0020] Step S31, using the oil-water interface data of the actual drilling as a constraint, obtaining the oil-water interface value of the composite sand body;

[0021] Step S32: Obtain the oil-water boundary of the composite sand body according to the oil-water interface value of the composite sand body and based on the top and bottom structural data of the composite sand body in the depth domain in step S22.

[0022] In step S4, the acquisition of the relatively isochronous deposition interface includes the following steps:

[0023] Step S41: using the top and bottom interfaces of the composite sand body as constraints and based on the three-dimensional seismic data, making a stratigraphic slice of equal proportions;

[0024] Step S42: combining the equal-scale stratigraphic slices using a slice deduction analysis technique in combination with sedimentary geological characteristics;

[0025] Step S43: obtaining the initial relatively isochronous depositional interfaces between longitudinal phases within the composite sand body according to the merging result in step S42;

[0026] Step S44: Based on the initial relatively isochronous depositional interface and the three-dimensional seismic data, the interaction is sliced ​​and leveled to obtain a final relatively isochronous depositional interface.

[0027] In step S5, obtaining the sand body thickness includes the following steps:

[0028] Step S51: extracting the reservoir sensitive seismic attributes of each longitudinal period inside the composite sand body based on the top and bottom interfaces of the composite sand body and the relatively isochronous deposition interface;

[0029] Step S52: performing intersection analysis on the reservoir sensitive seismic attributes and the sand body thickness of the actual drilling well to obtain a fitting formula for the quantitative relationship between the sand body thickness and the reservoir sensitive seismic attributes;

[0030] Step S53: Obtain the sand body thickness of each period in the longitudinal direction inside the composite sand body according to the quantitative relationship fitting formula.

[0031] In step S6, obtaining the sand body connectivity characterization boundary includes the following steps:

[0032] Step S61: extracting sensitive seismic attributes of the interlayers within the composite sand body based on the three-dimensional seismic data according to the relatively isochronous depositional interface;

[0033] Step S62: performing intersection analysis on the interlayer sensitive seismic attribute and the interlayer thickness of the actual well, and obtaining a fitting formula for the quantitative relationship between the interlayer thickness and the interlayer sensitive seismic attribute;

[0034] Step S63: obtaining the thickness of the interlayer in the composite sand body according to a fitting formula of the quantitative relationship between the thickness of the interlayer and the sensitive seismic attribute of the interlayer, and classifying the thickness of the interlayer;

[0035] Step S64: Based on the classification result, the connectivity between the channel sand bodies in each longitudinal period within the composite sand body is graded to obtain the characterization boundaries of the channel sand body connectivity of different levels.

[0036] In step S7, obtaining the distribution area of ​​high-quality reserves of the oil and gas field includes the following steps:

[0037] Step S71: obtaining relative structural highs within the oil-bearing range of the composite sand body according to the top surface structure of the composite sand body, based on the top surface microstructure and the oil-water boundary;

[0038] Step S72: Obtaining an initial high-quality reserve range based on the relative structural high point and the sand body connectivity characterization boundary;

[0039] Step S73: Obtain a final high-quality reserve range based on the initial high-quality reserve range and the sand body thickness.

[0040] In a second aspect, the present invention further provides a system for selecting high-quality reserves in oil and gas fields, comprising the following processing units:

[0041] The first processing unit is used to use 3D seismic data, well-seismic combination, tracking interpretation to obtain the top and bottom interfaces of the composite sand body;

[0042] The second processing unit is used to obtain the top surface microstructure of the composite sand body according to the top and bottom interfaces of the composite sand body and based on the well-seismic calibration time-depth relationship;

[0043] A third processing unit is configured to obtain the oil-water boundary of the composite sand body according to the top and bottom interfaces of the composite sand body and based on the oil-water interface data of actual drilling;

[0044] a fourth processing unit, configured to obtain a relative isochronous depositional interface within the composite sand body according to the top and bottom interfaces of the composite sand body and based on the three-dimensional seismic data;

[0045] a fifth processing unit, configured to obtain the thickness of the composite sand body at each stage based on the top and bottom interfaces of the composite sand body and the relatively isochronous depositional interface and the three-dimensional seismic data;

[0046] a sixth processing unit, configured to obtain, according to the relatively isochronous depositional interface and based on the three-dimensional seismic data, a sand body connectivity characterization boundary between each phase of the composite sand body;

[0047] The seventh processing unit is used to characterize the boundary of the composite sand body according to the top surface microstructure, the oil-water boundary, the sand body thickness, and the sand body connectivity, and to obtain the distribution area of ​​the high-quality reserves of the oil and gas field by coupling multiple factors.

[0048] In a third aspect, the present invention further provides a computer storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for selecting high-quality reserves of oil and gas fields.

[0049] In a fourth aspect, the present invention further 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 method for selecting high-quality reserves of oil and gas fields when executing the computer program.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The present invention discloses a method for selecting high-quality reserves in oil and gas fields using multi-factor coupling. The method uses three-dimensional seismic data and a well-seismic combined analysis method to track and interpret the top and bottom interfaces of meandering river composite sand bodies. By adopting a stratigraphic proportional slicing deduction method, the well-seismic interaction obtains the relatively isochronous sedimentary interfaces between longitudinal periods within the meandering river composite sand bodies, thereby achieving qualitative / quantitative characterization of information such as sand body microstructure, sand body oil-water boundary, sand body thickness, and reservoir connectivity. The multi-factor coupling method is then used to screen the distribution areas of high-quality reserves in oil and gas fields, thereby making up for the shortcomings of related analysis methods based mainly on well information under sparse offshore well network conditions, effectively reducing the uncertainty in the prediction of sand body microstructure, sand body thickness, reservoir connectivity, etc., and improving the prediction efficiency of the potential distribution of high-quality reserves in oil and gas fields.

[0052] The method for selecting high-quality reserves in oil and gas fields provided by the present invention guides oil and gas field potential analysis and development well pattern deployment and optimization, providing important technical support for the efficient development of underground oil and gas reservoirs and program adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A flowchart of a method for selecting high-quality reserves in oil and gas fields using multi-factor coupling provided in an embodiment of the present invention.

[0054] Figure 2 A schematic diagram of tracking and interpreting the top and bottom interfaces of a composite sand body based on three-dimensional seismic data provided by an embodiment of the present invention.

[0055] Figure 3 Schematic diagram of the top surface structure and microstructure of the composite sand body provided in an embodiment of the present invention; the left figure is the top surface structure, and the right figure is the microstructure.

[0056] Figure 4 Schematic diagram of the internal longitudinal relative isochronous sedimentary interface of a composite sand body obtained through well-seismic interaction according to an embodiment of the present invention; the upper figure is a seismic slice profile, and the lower figure is a river channel stage division profile.

[0057] Figure 5 Schematic diagram of the thickness of the composite sand body provided in an embodiment of the present invention; the left figure is a schematic diagram of the thickness of the SQ1 sand body, and the right figure is a schematic diagram of the thickness of the SQ2 sand body.

[0058] Figure 6Schematic diagram of the internal interlayer distribution of the composite sand body provided by an embodiment of the present invention; the left figure is a plan view of the sensitive properties of the internal interlayer of the composite sand body, and the right figure is a plan view of the classification of the sensitive properties of the interlayer.

[0059] Figure 7 Schematic diagram of the classification of the connectivity of the composite sand bodies between different periods in the longitudinal direction provided by the embodiment of the present invention; the left figure is a plan view of the classification of the sensitive attributes of the interlayer, the upper right figure is the seismic profile of Section 1, and the lower right figure is the seismic profile of Section 2.

[0060] Figure 8 Schematic diagram of the high-quality reserve distribution area of ​​the composite sand body provided in an embodiment of the present invention; the left figure is the initial high-quality reserve distribution area, and the right figure is the final high-quality reserve distribution area. DETAILED DESCRIPTION

[0061] The present invention will be further described below with reference to specific examples, but the present invention is not limited to the following examples.

[0062] Example 1: Multi-factor coupling method for selecting high-quality reserves in oil and gas fields

[0063] Taking the meandering river composite sand body of a certain oil and gas field as an example, the selection method of its high-quality reserves is as follows: Figure 1 As shown, the following steps are included:

[0064] Step A: Using 3D seismic data, well-seismic integration, and cross-section interaction, the top and bottom interfaces of the composite sand body are tracked and interpreted. The tracking and interpretation results of the top and bottom interfaces of the target sedimentary sand body are as follows: Figure 2 As shown;

[0065] Step B: Use the well-seismic calibration time-depth relationship to obtain the microstructure of the sand body top surface. The specific steps are as follows:

[0066] Step B1: obtaining the time-depth relationship of each well based on well seismic calibration, creating a multi-well time-depth relationship crossplot, fitting the crossplot data, and obtaining a time-depth relationship fitting formula;

[0067] Step B2: Based on the top and bottom surfaces of the composite sand body in the time domain obtained by tracking interpretation, the time-depth relationship fitting formula obtained in step B1 is used to obtain the top and bottom structural surface data of the composite sand body in the depth domain;

[0068] Step B3: Smoothing the top surface structural data of the composite sand body in the depth domain obtained in step B2 to obtain a structural trend surface of the top surface of the composite sand body;

[0069] Step B4: Based on the depth domain composite sand body top surface structural data obtained in step B2 and the composite sand body top surface structural trend surface obtained in step B3, subtract the two to obtain the composite sand body top surface microstructure;

[0070] Depend on Figure 3It can be seen that the overall structure of the composite sand body is high in the east and low in the west; the relatively high points of the microstructure are mainly located in the middle and east of the main area;

[0071] Step C: Obtain the oil-water boundary of the composite sand body based on the actual drilling well data, and the specific steps are as follows:

[0072] Step C1: Constrain the oil-water interface data of the actual drilling well to obtain the numerical value of the oil-water interface of the composite sand body;

[0073] Step C2: Based on the oil-water interface value obtained in step C1, obtain the depth domain composite sand body top and bottom structure data based on step B2, extract the corresponding structure contour, and obtain the oil-water boundary in the composite sand body.

[0074] Step D: Use three-dimensional seismic data to obtain the relative isochronous sedimentary interface between the vertical stages in the meandering river composite sand body, and the specific steps are as follows:

[0075] Step D1: Select a typical well, perform wavelet transform on the GR curve, and perform single-well and multi-well sequence analysis based on the curve characteristics to obtain the initial relative isochronous sedimentary interface on the well;

[0076] Step D2: Constrain the top and bottom interfaces of the composite sand body interpreted by tracking, and make a stratigraphic isometric slice based on three-dimensional seismic data;

[0077] Step D3: Combine the initial relative isochronous sedimentary interface, based on the sedimentary geological characteristics, and use slice deduction to merge the stratigraphic isometric slice to obtain the initial relative isochronous sedimentary interface;

[0078] Step D4: Constrain the initial relative isochronous sedimentary interface, and based on three-dimensional seismic data, optimize the relative isochronous sedimentary interface through "well-seismic interaction" to obtain the final relative isochronous sedimentary interface between the vertical stages in the meandering river composite sand body.

[0079] From Figure 4 It can be seen that the relative isochronous sedimentary interface divides the target sedimentary body into SQ1 (early stage) and SQ2 (late stage) two-stage composite channels.

[0080] Step E: Obtain the thickness of each vertical stage sand body in the composite sand body based on three-dimensional seismic data, and the specific steps are as follows:

[0081] Step E1: Based on the top and bottom interfaces of the composite sand body interpreted by tracking and the relative isochronous sedimentary interface, extract the reservoir sensitive seismic attributes of each vertical stage in the composite sand body;

[0082] Step E2: Make a crossplot of the reservoir sensitive seismic attributes obtained in step E1 and the actual drilling well sand body thickness;

[0083] Step E3: Based on the analysis results of step E2, the crossplot data is fitted to obtain a fitting formula for the relationship between sand body thickness and sensitive seismic attributes;

[0084] Step E4: Based on the analysis results of step E3, the thickness of the sand bodies in each period in the longitudinal direction of the composite sand body is calculated.

[0085] Depend on Figure 5 It can be seen that the thickness of the early composite channel sand body SQ1 within the composite sand body ranges from 0 to 12 m, and is generally thick in the south and thin in the north; the thickness of the late composite channel sand body SQ2 ranges from 0 to 14 m, and is generally thick in the east and thin in the west.

[0086] Step F, qualitatively characterizing the connectivity of the composite sand body based on 3D seismic data, comprises the following specific steps:

[0087] Step F1: extracting sensitive seismic attributes of 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 D4;

[0088] Step F2: performing an intersection analysis on the sensitive seismic attributes of the interlayer and the thickness of the interlayer actually drilled, and obtaining a fitting formula for the quantitative relationship between the thickness of the interlayer and the sensitive seismic attributes;

[0089] Step F3: Based on the analysis results of step F2, the thickness of the interlayer inside the composite sand body is obtained, and the thickness of the interlayer is calibrated and classified in combination with the sealing capability of the interlayer in actual drilling;

[0090] Step F4: Based on the analysis results of step F3, the connectivity between the longitudinal channel sand bodies of each period within the meandering river composite sand body is classified to obtain the characterization boundary of the connectivity between the longitudinal channels of the composite river channel.

[0091] Depend on Figure 6 From the middle left figure, it can be seen that the interlayers in the composite sand body are mainly distributed on the east and west sides, and the interlayers in the middle are less developed. Figure 6 As can be seen from the middle right figure, the sensitive properties of interlayers can be divided into three categories: I, II, and III. Among them, the thickness of Class I interlayer is greater than 6m; the thickness of Class II interlayer is between 0 and 6m; and the thickness of Class III interlayer is 0m.

[0092] Depend on Figure 7 The connectivity between the sand bodies of the vertical channels within the composite sand bodies can be preliminarily divided into three categories: Type I, where the interlayer thickness is greater than 6 m, has the strongest sealing effect on the sand body, and the vertical channel sand bodies are not connected; Type II, where the interlayer thickness is relatively small, between 0 and 6 m, has some sealing effect on the sand body, and the vertical channel sand body connectivity is poor; and Type III, where the interlayer is not well developed, has good vertical channel sand body connectivity. The well-developed interlayers in Types I and II, with poor vertical connectivity, can effectively slow the rate of bottom water rise and help improve oilfield recovery.

[0093] Step G: Based on the coupling of multiple factors such as sand body top microstructure, oil-water boundary, sand body thickness, and connectivity, the distribution area of ​​high-quality reserves in the late SQ2 sand body of the oil and gas field composite sand body is obtained. The specific steps are as follows:

[0094] Step G1: Obtain the relative structural high points within the oil-bearing range based on the sand body top surface structure, sand body top surface microstructure, and oil-water boundary;

[0095] Step G2: Based on the relative structural highs obtained in step G1, the initial high-quality reserve range is obtained based on the connectivity characterization boundary of the sand bodies between the longitudinal channels of the composite channel;

[0096] Step G3: Based on the initial high-quality reserve range obtained in step G2 and the thickness of the SQ2 late sand body, the final high-quality reserve range is obtained.

[0097] Depend on Figure 8 From the middle left figure, we can see that 7 initial high-quality reserve distribution areas of composite sand bodies were screened out; Figure 8 As can be seen from the middle right figure, seven high-quality reserve distribution areas of the composite sand body were screened out. These areas are located in relatively high structural positions within the oil-bearing area of ​​the composite sand body, and have well-developed reservoirs and interlayers.

[0098] Example 2

[0099] The above-mentioned embodiment 1 provides a method for selecting high-quality reserves of oil and gas fields by coupling multiple factors. Correspondingly, this embodiment provides a system for selecting high-quality reserves of oil and gas fields by coupling multiple factors.

[0100] The multi-factor coupling oil and gas field high-quality reserves selection system provided in this embodiment can implement the multi-factor coupling oil and gas field high-quality reserves selection method described in the above embodiment 1. The system can be implemented through software, hardware, or a combination of software and hardware.

[0101] For example, the system may include integrated or separate functional modules or functional units to execute the corresponding steps in each method of Example 1. Since the multi-factor coupled oil and gas field high-quality reserve selection system of this embodiment is substantially similar to the method embodiment, the description of the process in this embodiment is relatively simple. For relevant details, please refer to the partial description of Example 1. The multi-factor coupled oil and gas field high-quality reserve selection system of this embodiment is merely illustrative.

[0102] The embodiment of the present invention provides a multi-factor coupled oil and gas field high-quality reserve selection system, comprising:

[0103] Includes the following processing units:

[0104] The first processing unit is used to use 3D seismic data, well-seismic combination, tracking interpretation to obtain the top and bottom interfaces of the composite sand body;

[0105] The second processing unit is used to obtain the top surface microstructure of the composite sand body according to the top and bottom interfaces of the composite sand body and based on the well-seismic calibration time-depth relationship;

[0106] A third processing unit is configured to obtain the oil-water boundary of the composite sand body according to the top and bottom interfaces of the composite sand body and based on the oil-water interface data of actual drilling;

[0107] A fourth processing unit is configured to obtain a relative isochronous depositional interface within the composite sand body based on the top and bottom interfaces of the composite sand body and the three-dimensional seismic data;

[0108] a fifth processing unit, configured to obtain the thickness of the composite sand body at each stage based on the top and bottom interfaces of the composite sand body and the relatively isochronous depositional interface and the three-dimensional seismic data;

[0109] a sixth processing unit, configured to obtain, according to the relatively isochronous depositional interface and based on the three-dimensional seismic data, a sand body connectivity characterization boundary between each phase of the composite sand body;

[0110] The seventh processing unit is used to characterize the boundary of the composite sand body according to the top surface microstructure, the oil-water boundary, the sand body thickness, and the sand body connectivity, and to obtain the distribution area of ​​the high-quality reserves of the oil and gas field by coupling multiple factors.

[0111] Example 3

[0112] An embodiment of the present invention provides a processing device for implementing the multi-factor coupling oil and gas field high-quality reserve selection method provided in Example 1. The processing device can be a processing device for a client, such as a mobile phone, laptop computer, tablet computer, desktop computer, etc., to execute the method of Example 1.

[0113] The processing device includes a processor, a memory, a communication interface, and a bus. The processor, memory, and communication interface are connected via the bus to facilitate communication between them. The memory stores a computer program executable by the processor. When the processor executes the computer program, it executes the multi-factor coupled oil and gas field high-quality reserve selection method provided in Example 1.

[0114] Preferably, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0115] Preferably, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or other general-purpose processors of various types, which are not limited here.

[0116] Example 4

[0117] The multi-factor coupling method for selecting high-quality reserves of oil and gas fields provided in Example 1 of the present invention can be specifically implemented as a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for executing the multi-factor coupling method for selecting high-quality reserves of oil and gas fields provided in Example 1 of the present invention.

[0118] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.

[0119] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A method for selecting high-quality reserves in oil and gas fields, comprising the following steps: S1. Using 3D seismic data, well-seismic integration, and tracking interpretation to obtain the top and bottom interfaces of the composite sand body; S2. Obtaining the top surface microstructure of the composite sand body according to the top and bottom interfaces of the composite sand body and based on the well-seismic calibration time-depth relationship; S3. Obtaining the oil-water boundary of the composite sand body according to the top and bottom interfaces of the composite sand body and based on the oil-water interface data of actual drilling; S4. According to the top and bottom interfaces of the composite sand body, based on the 3D seismic data, a relatively isochronous depositional interface inside the composite sand body is obtained; S5. Calculating the thickness of each phase of the composite sand body based on the top and bottom interfaces of the composite sand body and the relatively isochronous depositional interface and the three-dimensional seismic data; S6. Obtaining, according to the relatively isochronous depositional interface and based on the 3D seismic data, boundaries representing connectivity between the composite sand bodies at various stages; S7. Based on the top surface microstructure of the composite sand body, the oil-water boundary, the sand body thickness, and the sand body connectivity characterization boundary, a multi-factor coupling method is used to determine the distribution area of ​​high-quality reserves in the oil and gas field.

2. The method for selecting high-quality oil and gas field reserves according to claim 1, characterized in that: In step S2, obtaining the top surface microstructure includes the following steps: Step S21: Based on the well seismic calibration, the time-depth relationship of each well is obtained, a multi-well time-depth relationship cross-plot is prepared, and a time-depth relationship fitting formula is obtained; Step S22: using the top and bottom interfaces of the composite sand body as constraints and according to the time-depth relationship fitting formula, obtaining top and bottom structural data of the composite sand body in depth domain; Step S23: Acquire the top surface microstructure based on the top and bottom structural data of the composite sand body in the depth domain.

3. The method for selecting high-quality oil and gas field reserves according to claim 2, characterized in that: In step S3, the acquisition of the oil-water boundary includes the following steps: Step S31, using the oil-water interface data of the actual drilling as a constraint, obtaining the oil-water interface value of the composite sand body; Step S32: Obtain the oil-water boundary of the composite sand body according to the oil-water interface value of the composite sand body and based on the top and bottom structural data of the composite sand body in the depth domain in step S22.

4. The method for selecting high-quality reserves of oil and gas fields according to any one of claims 1 to 3, characterized in that: In step S4, the acquisition of the relatively isochronous deposition interface includes the following steps: Step S41: using the top and bottom interfaces of the composite sand body as constraints and based on the three-dimensional seismic data, making a stratigraphic slice of equal proportions; Step S42: combining the equal-scale stratigraphic slices using a slice deduction analysis technique in combination with sedimentary geological characteristics; Step S43: obtaining the initial relatively isochronous depositional interfaces between longitudinal phases within the composite sand body according to the merging result in step S42; Step S44: Based on the initial relatively isochronous depositional interface and the three-dimensional seismic data, the interaction is sliced ​​and leveled to obtain a final relatively isochronous depositional interface.

5. The method for selecting high-quality reserves of oil and gas fields according to any one of claims 1 to 3, characterized in that: In step S5, obtaining the sand body thickness includes the following steps: Step S51: extracting the reservoir sensitive seismic attributes of each longitudinal period inside the composite sand body based on the top and bottom interfaces of the composite sand body and the relatively isochronous deposition interface; Step S52: performing intersection analysis on the reservoir sensitive seismic attributes and the sand body thickness of the actual drilling well to obtain a fitting formula for the quantitative relationship between the sand body thickness and the reservoir sensitive seismic attributes; Step S53: Obtain the sand body thickness of each period in the longitudinal direction inside the composite sand body according to the quantitative relationship fitting formula.

6. The method for selecting high-quality reserves of oil and gas fields according to any one of claims 1 to 3, characterized in that: In step S6, obtaining the sand body connectivity characterization boundary includes the following steps: Step S61: extracting sensitive seismic attributes of the interlayers within the composite sand body based on the three-dimensional seismic data according to the relatively isochronous depositional interface; Step S62: performing intersection analysis on the interlayer sensitive seismic attribute and the interlayer thickness of the actual well, and obtaining a fitting formula for the quantitative relationship between the interlayer thickness and the interlayer sensitive seismic attribute; Step S63: obtaining the thickness of the interlayer in the composite sand body according to a fitting formula of the quantitative relationship between the thickness of the interlayer and the sensitive seismic attribute of the interlayer, and classifying the thickness of the interlayer; Step S64: Based on the classification result, the connectivity between the channel sand bodies in each longitudinal period within the composite sand body is graded to obtain the characterization boundaries of the channel sand body connectivity of different levels.

7. The method for selecting high-quality reserves of oil and gas fields according to any one of claims 1 to 3, characterized in that: In step S7, obtaining the distribution area of ​​high-quality reserves of the oil and gas field includes the following steps: Step S71: according to the top surface structure of the composite sand body, based on the top surface microstructure and the oil-water boundary, obtaining relative structural high points within the oil-bearing range of the composite sand body; Step S72: Obtaining an initial high-quality reserve range based on the relative structural high point and the sand body connectivity characterization boundary; Step S73: Obtain a final high-quality reserve range based on the initial high-quality reserve range and the sand body thickness.

8. A system for selecting high-quality reserves in oil and gas fields, characterized by: The following processing units are included: The first processing unit is used to use 3D seismic data, well-seismic combination, tracking interpretation to obtain the top and bottom interfaces of the composite sand body; The second processing unit is configured to obtain the top surface microstructure of the composite sand body according to the top and bottom interfaces of the composite sand body and based on the well-seismic calibration time-depth relationship; A third processing unit is configured to obtain the oil-water boundary of the composite sand body according to the top and bottom interfaces of the composite sand body and based on the oil-water interface data of actual drilling; a fourth processing unit, configured to obtain a relative isochronous depositional interface within the composite sand body according to the top and bottom interfaces of the composite sand body and based on the three-dimensional seismic data; a fifth processing unit, configured to obtain the thickness of the composite sand body at each stage based on the top and bottom interfaces of the composite sand body and the relatively isochronous depositional interface and the three-dimensional seismic data; a sixth processing unit, configured to obtain, according to the relatively isochronous depositional interface and based on the three-dimensional seismic data, a sand body connectivity characterization boundary between each phase of the composite sand body; The seventh processing unit is used to characterize the boundary of the composite sand body according to the top surface microstructure, the oil-water boundary, the sand body thickness, and the sand body connectivity, and to obtain the distribution area of ​​the high-quality reserves of the oil and gas field by coupling multiple factors.

9. A computer 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 selecting high-quality reserves of oil and gas fields as described in any one of claims 1 to 7 are implemented.

10. 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 selecting high-quality reserves of oil and gas fields as described in any one of claims 1 to 7 are implemented.

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