A method for reconstructing lithofacies paleogeography of basin marine strata based on tectonic-sedimentary coupling

Abstract

A method for reconstructing the lithofacies paleogeography of basin-based marine strata based on tectonic-sedimentary coupling addresses the difficulty of existing methods in achieving comprehensive, multi-factor quantitative reconstruction of the lithofacies paleogeography of basin-based marine strata. This method, guided by plate tectonics, geotectonic geology, sedimentary petrology, sequence stratigraphy, and geochemistry, fully utilizes basic geological data and employs balanced profiling techniques, macro-microscopic integration, spectral analysis and core retrieval, well-seismic integration, and single-factor analysis and multi-factor comprehensive mapping. This method identifies key unconformities, restores the basin's prototype basement, defines the basin's nature and source-sink system, establishes a stratigraphic division scheme, and constructs a tectonic and sedimentary evolution model for the basin. This method then reconstructs the lithofacies paleogeography of the basin's marine strata within each sequence. This method can determine the tectonic-sedimentary pattern and lithofacies paleogeographic characteristics, and comprehensively reconstructs the lithofacies paleogeography of the basin's marine strata based on multiple factors, providing support for oil and gas reserve enhancement and exploration deployment.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field exploration, and in particular to a method for reconstructing basin marine strata lithofacies paleogeography based on structural-sedimentary coupling. Background Art

[0002] The reconstruction of lithofacies paleogeography is an important research topic in marine strata. It is of great significance to the understanding of the tectonic-sedimentary evolution and sedimentary filling process of the basin, and provides important theoretical support for oil and gas exploration and the prediction of favorable areas. For a long time, the progress of lithofacies paleogeography research in prototype basins has been restricted to a certain extent due to factors such as limited drilling, complex seismic imaging, and low exploration level in the deep strata of the basin. In addition, the differences in the focus of data selection and understanding of paleo-tectonic background among different experts and scholars have also led to significant differences in the understanding of lithofacies paleogeography and tectonic sedimentary patterns. In the current context of oil and gas exploration from shallow to deep layers, deep / ultra-deep marine strata are the key successor areas for future oil and gas exploration. Determining the characteristics of tectonic sedimentary patterns and lithofacies paleogeography is one of the important prerequisites for oil and gas exploration. In recent years, the main methods for reconstructing lithofacies paleogeography include sedimentological methods, sequence stratigraphic analysis, and geophysical methods. These methods have greatly promoted the development and understanding of lithofacies paleogeography in different regions, but they are difficult to meet the comprehensive multi-factor quantitative needs in the process of oil and gas geological exploration. Therefore, how to achieve comprehensive multi-factor quantitative reconstruction of basin marine strata lithofacies paleogeography is a technical problem that urgently needs to be solved in the field of deep / ultra-deep oil and gas exploration. Summary of the Invention

[0003] This invention addresses the difficulty in achieving comprehensive, multi-factor quantitative reconstruction of basin-based marine strata lithofacies paleogeography using existing methods. By providing a method for reconstructing basin-based marine strata lithofacies paleogeography based on tectonic-sedimentary coupling, this method can identify tectonic sedimentary patterns and lithofacies paleogeographic characteristics, comprehensively reconstructing basin-based marine strata lithofacies paleogeography using multiple factors, and providing strong support for oil and gas reserve enhancement and exploration deployment.

[0004] The present invention solves the problem through the following technical solution: a method for reconstructing the lithofacies paleogeography of a basin marine stratum based on tectonic-sedimentary coupling, comprising the following steps:

[0005] S1. Based on the established drilling and 3D seismic work areas, identify and determine the types of different sequence interfaces and restore the prototype basement of the basin;

[0006] S2. Based on the characteristics of the prototype basement of the basin and the outcrop sections of the field, a combination of macroscopic and microscopic techniques is used to clarify the rock types of the basin and establish the rock phase sequence combination of the basin;

[0007] S3. Based on the rock phase sequence combination, electrical logging curves and lithologic interpretation results of the basin, spectrum analysis and core tracing techniques are used to establish a rock-electrical interpretation model to determine the sedimentary process and the nature of seawater changes;

[0008] S4. Based on the 3D seismic area and well logging data, combined with the rock-electrical interpretation model, and using well-seismic combined technology, a well logging-seismic sequence stratigraphic framework section is constructed to determine the sequence stratigraphic division scheme;

[0009] S5. Based on the sequence stratigraphic division scheme, establish the basin sedimentary evolution model and basin sedimentary model, and determine the development characteristics and distribution location of the sedimentary facies;

[0010] S6. Based on the well logging-seismic sequence stratigraphic framework profile, restore the sedimentary micro-geomorphology of different sequences, identify the rock types and sedimentary microfacies within the sequence framework, and count the types and characteristics of rocks and sedimentary facies in different sequences;

[0011] S7. Based on the prototype basement, sedimentary pattern and sedimentary period micro-geomorphology of the basin, and in accordance with the rules of dominant and special phases, the single-factor analysis and multi-factor comprehensive mapping method are used to reconstruct the lithofacies paleogeography of the basin's marine strata in each sequence and determine the paleogeographic pattern of the basin.

[0012] In the entire technical solution:

[0013] Preferably, the drilling work area and the 3D seismic work area process are:

[0014] According to the basin scope, data collection is carried out on geological background, geological maps, structure, well location information, coring data, well logging and seismic data;

[0015] According to the attributes of the collected data, they are sorted and summarized to establish drilling work areas and 3D seismic work areas.

[0016] Preferably, the method for determining the types of different sequence interfaces comprises:

[0017] Based on paleogeological maps and plate tectonic maps, field geological outcrop sections were selected to observe and measure the development characteristics of basin structure and sedimentation, record the structural type and occurrence, and the development characteristics of sedimentary structure and rock type, and determine the type and nature of the structural interface.

[0018] Preferably, the method of restoring the prototype base of the basin in step S1 is:

[0019] Based on the 3D seismic work area, supported by the theories of plate tectonics and geotectonics, and combining previous research results (including geological structure, sedimentary characteristics and evolution, and tectonic characteristics and evolution) with field geological profiles, we identified key unconformities and detailed their properties and characteristics. Furthermore, we analyzed the prototype basement of the study area based on its filling geometry and boundary reconstruction characteristics. Using the balanced profile technique, we restored the prototype basement of the basin, clarifying the properties of the prototype basement and the development characteristics of the source-sink system.

[0020] Preferably, the method for establishing the basin rock phase sequence combination in step S2 is:

[0021] Based on the characteristics of the prototype basement of the basin and the outcrop sections of the field sections, combined with the plane distribution of the well locations and the marine stratigraphic positions, core wells were selected for core observation and photography. Sampling and sectioning, as well as carbon and oxygen isotope and in-situ micro-area element testing, were also carried out according to rock types and sedimentary structures.

[0022] By using a combination of macro- and micro-technical means, we can clarify the rock types and development characteristics of the basin, determine the identification marks of different rock types and stratigraphic sedimentary interfaces, and establish the basin rock phase sequence combination.

[0023] Preferably, the method of establishing a rock-electrical interpretation model based on the rock phase sequence combination of the basin, electrical logging curves and lithologic interpretation results to determine the sedimentation process and the changing properties of seawater in step S3 includes:

[0024] Based on the results of electrical logging curves and lithologic interpretation, combined with the rock types of cores and field geological outcrop profiles, a rock-electrical interpretation model was established using spectrum analysis and core tracing techniques to clarify the sedimentary facies, electrical curve characteristics, and identification marks of different rock types. Based on the longitudinal variation trends of carbon and oxygen isotopes and the results of in-situ micro-area element testing, the relationship between rock phase sequence combinations and sea level changes was analyzed to determine the sedimentary process and the nature of seawater changes.

[0025] Preferably, the method of determining the sequence stratigraphic division scheme in step S4 includes:

[0026] Based on the 3D seismic work area and well logging data, combined with the identification marks of structural and sequence sedimentary interfaces, a well logging-seismic sequence stratigraphic framework profile was constructed using the technical means of well-seismic integration. The sequence strata were identified and tracked, the filling structure and contact relationship of the sequence strata in the horizontal and vertical directions were clarified, and the division scheme of the sequence strata was determined.

[0027] Preferably, the method of constructing the sedimentary model of the basin and determining the development characteristics and distribution positions of the sedimentary facies in step S5 comprises the following steps:

[0028] Based on the sequence stratigraphic division scheme, the marine strata of the basin are divided. Combining the rock phase sequence combination, sea level changes, sedimentary processes and seawater properties, a basin sedimentary evolution model is established, and the main sedimentary characteristics and main controlling factors of different sequences are analyzed.

[0029] Then, based on the filling method and sedimentary process of the sequence, the sedimentary model of the basin is constructed, and the development characteristics and distribution location of the sedimentary facies are determined.

[0030] Preferably, the method of restoring the sedimentary micro-topography of different sequences based on the well logging-seismic sequence stratigraphic framework section and counting the types and characteristics of rocks and sedimentary facies of different sequences in step S6 includes:

[0031] Based on the logging-seismic sequence stratigraphic framework profile, a single sequence is regarded as a sedimentary isochronous geological body. Combined with the basin basement layer, a sequence thickness map is drawn, and the relationship between the internal sedimentary filling mode and the lithofacies combination is analyzed to restore the sedimentary micro-geomorphology of different sequences. Based on the rock-electrical interpretation model, the rock types and sedimentary microfacies within the sequence framework are identified, and the types and characteristics of rocks and sedimentary facies of each sequence are counted according to the data points.

[0032] Preferably, the method for reconstructing the lithofacies paleogeography of the basin-marine strata in step S7 comprises:

[0033] Based on the prototype basement, sedimentary pattern and micro-geomorphology of the basin during the sedimentary period, and using the sedimentary facies types and characteristics of each sequence at each data point, and under the constraint of sequence stratigraphic thickness, according to the dominant and special facies rules, a single-factor analysis and multi-factor comprehensive mapping method was used to reconstruct the lithofacies paleogeography of the basin's marine strata in each sequence, and thus determine the paleogeographic pattern of the basin.

[0034] The present invention is based on a method for reconstructing the lithofacies paleogeography of basin marine strata by tectonic-sedimentary coupling. Guided by the theories of plate tectonics, geotectonic geology, sedimentary petrology, sequence stratigraphy, and geochemistry, the present invention fully utilizes basic geological data and adopts balanced profile technology, macro-micro integration, spectrum analysis and core placement, well-seismic integration, single-factor analysis, and multi-factor comprehensive mapping to determine key unconformity interfaces, restore the prototype basement of the basin, define the basin properties and source-sink system, establish a stratigraphic division scheme, construct a basin tectonic evolution model and a sedimentary evolution model, and then reconstruct the lithofacies paleogeography of the basin marine strata in each sequence, thus achieving multi-factor comprehensive quantitative lithofacies paleogeography restoration and laying a data foundation for oil and gas exploration in deep / ultra-deep marine strata. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a flow chart of the present invention;

[0036] Figure 2 A plate tectonic diagram of an embodiment of the present invention;

[0037] Figure 3 The basin structure evolution model of the embodiment of the present invention;

[0038] Figure 4 This is the basin deposition model of an embodiment of the present invention;

[0039] Figure 5 This is a basin lithofacies paleogeography map according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0041] The process of establishing the drilling area and the 3D seismic area includes:

[0042] According to the basin scope, data collection is carried out on geological background, geological maps, structure, well location information, coring data, well logging and seismic data;

[0043] According to the attributes of the collected data, they are sorted and summarized to establish drilling work areas and 3D seismic work areas.

[0044] The method for determining the types of different sequence interfaces comprises:

[0045] Based on paleogeological maps and plate tectonic maps, field geological outcrop sections were selected to observe and measure the developmental characteristics of basin structures and sediments, record the structural types and occurrences, and the developmental characteristics of sedimentary structures and rock types, and determine the types and properties of structural interfaces.

[0046] By analyzing the development characteristics and genetic mechanism of stratigraphic sequences, we determine the identification marks of different sequence interfaces, explore their contact relationship with tectonic interfaces, and then collect samples and make thin sections based on sequence types and rock structures.

[0047] Methods for restoring the basin's prototype basement include:

[0048] Based on the 3D seismic work area, supported by the theories of plate tectonics and geotectonics, and combining previous research results (including geological structure, sedimentary characteristics and evolution, and tectonic characteristics and evolution) with field geological profiles, we identified key unconformities and detailed their properties and characteristics. Furthermore, we analyzed the prototype basement of the study area based on its filling geometry and boundary reconstruction characteristics, and used the balanced profile technique to restore the prototype basement of the basin.

[0049] Based on the restoration of the prototype basement of the basin, the properties of the prototype basement of the basin and the development characteristics of the source-sink system are clarified, and a basin tectonic evolution model is established.

[0050] Based on the characteristics of the prototype basement of the basin and the outcrop sections of the field sections, combined with the plane distribution of the well locations and the marine stratigraphic positions, core wells were selected for core observation and photography. Sampling and sectioning, as well as carbon and oxygen isotope and in-situ micro-area element testing, were also carried out according to rock types and sedimentary structures.

[0051] By using a combination of macro- and micro-technical means, we can clarify the rock types and development characteristics of the basin, determine the identification marks of different rocks and stratigraphic sedimentary interfaces, and establish the basin rock phase sequence combination.

[0052] Based on the results of electrical logging curves and lithologic interpretation, combined with the rock types of cores and field geological outcrop profiles, a rock-electrical interpretation model was established using spectrum analysis and core tracing techniques to clarify the sedimentary facies, electrical curve development characteristics, and identification marks of different rock types. Based on the longitudinal variation trends of carbon and oxygen isotopes and the results of in-situ micro-area element testing, the relationship between rock phase sequence combinations and sea level changes was analyzed to determine the sedimentary process and the nature of seawater changes.

[0053] Based on the 3D seismic work area and logging and well data, combined with the identification marks of the interface between structure and sequence deposition, the well logging-seismic stratigraphic framework section was constructed using the technical means of combining well and seismic data to identify and track the sequence strata, clarify the filling structure and contact relationship of the sequence strata in the horizontal and vertical directions, and determine the division scheme of the sequence strata.

[0054] Based on the sequence stratigraphic division scheme, the marine strata of the basin are divided. Combining the rock phase sequence combination, sea level changes, sedimentary processes and seawater properties, a basin sedimentary evolution model is established, and the main sedimentary characteristics and main controlling factors of different sequences are analyzed.

[0055] Then, based on the filling method and sedimentary process of the sequence, the sedimentary model of the basin is constructed, and the development characteristics and distribution location of the sedimentary facies are determined.

[0056] Based on the logging-seismic sequence stratigraphic framework profile, a single sequence is regarded as a sedimentary isochronous geological body. Combined with the basin basement layer, a sequence thickness map is drawn, and the relationship between the internal sedimentary filling mode and the lithofacies combination is analyzed to restore the sedimentary micro-geomorphology of different sequences. Based on the rock-electrical interpretation model, the rock types and sedimentary microfacies within the sequence framework are identified, and the types and characteristics of rocks and sedimentary facies of each sequence are counted according to the data points.

[0057] Based on the prototype basement, sedimentary pattern and micro-geomorphology of the basin during the sedimentary period, and using the sedimentary facies types and characteristics of each sequence at each data point, and under the constraint of sequence stratigraphic thickness, according to the dominant and special facies rules, a single-factor analysis and multi-factor comprehensive mapping method was used to reconstruct the lithofacies paleogeography of the basin's marine strata in each sequence, and thus determine the paleogeographic pattern of the basin. Example

[0058] The following describes the implementation process of the method of the present invention by taking the tectonic-sedimentary coupled Ordovician marine strata in the Sichuan Basin as an example.

[0059] The present invention provides a flow chart of a method for reconstructing the lithofacies paleogeography of a basin-marine stratum based on tectonic-sedimentary coupling, comprising the following steps:

[0060] Step 1: Establish drilling area and 3D seismic area;

[0061] Based on the scope of the basin, data on geological background, geological maps, structure, well location information, coring data, well logging, and seismic data are collected and summarized according to data attributes, and drilling work areas and 3D seismic work areas are established.

[0062] Step 2: Observe the geological outcrop sections in the field to determine the types of different sequence interfaces;

[0063] Based on paleogeological maps and plate tectonic maps (e.g. Figure 2 (as shown), field geological outcrop sections were selected, and with structural geology and sedimentary petrology as theoretical guidance, the development characteristics of basin structure and sedimentation were observed and measured, and the structural types and occurrences, as well as the development characteristics of sedimentary structures and rock types were recorded respectively. The analysis confirmed that the Upper Yangtze Platform in the Sichuan Basin was formed in the forebulge position of the arc-back foreland basin under the background of Gondwana convergence; by analyzing the development characteristics and genetic mechanism of stratigraphic sequences, with the ancient weathering crust, karst interface, unconformity interface and lithology-lithofacies transition surface as the main identification marks of sequence interfaces, their contact relationship with structural interfaces was explored, and then samples were collected and thin sections were made according to the sequence type and rock fabric.

[0064] Step 3: Based on the established drilling and 3D seismic work areas, identify and determine the types of different sequence interfaces and restore the prototype basement of the basin;

[0065] Based on the 3D seismic work area, supported by the theories of plate tectonics and geotectonics, and combining previous research results (including geological structure, sedimentary characteristics and evolution, and tectonic characteristics and evolution) with field geological profiles, we determined the third-order sequence interfaces, and detailed their properties and characteristics. Furthermore, we analyzed the prototype basement of the study area based on its filling geometry and boundary reconstruction characteristics, and used the balanced profile technique to restore the prototype basement of the basin.

[0066] Based on the restoration of the prototype basement of the basin, the properties of the prototype basement of the basin and the development characteristics of the source-sink system were clarified. The Yangtze Platform (South China Plate) where the basin is located was mainly subjected to plate subduction and compression in the Late Cambrian and Ordovician (Yunnan Movement). Multiple structural-sedimentary cycles developed inside, forming the structural characteristics of the Nanhua Rift and the Xuefeng Uplift, and thus establishing the basin's tectonic evolution model. (See Figure 3 ).

[0067] Step 4: Based on the prototype basement characteristics of the basin and the outcrop sections of the field section, use a combination of macroscopic and microscopic techniques to clarify the basin rock types and establish the basin rock phase sequence combination;

[0068] Based on the prototype basement characteristics of the basin and the outcrop profiles of the field sections, combined with the plane distribution of the well locations and the marine stratigraphic positions, core wells were selected for core observation and photography, and sampling and sectioning, carbon and oxygen isotope and in-situ micro-area element testing were carried out according to the rock types and sedimentary structures. Using a combination of macroscopic and microscopic technical means, the main rock types developed in the basin were determined to be mudstone, marlstone, micritic limestone, bioclastic micritic limestone, micritic bioclastic limestone, dolomite, argillaceous siltstone, and shale. The identification marks of the sedimentary interfaces of different rocks and sequences were determined, and the rock phase sequence combination of the basin was established, such as shale-micritic limestone-bioclastic micritic limestone-micritic bioclastic limestone, mudstone-micritic limestone-bioclastic micritic limestone-micritic bioclastic limestone.

[0069] Step 5: Based on the rock phase sequence combination, electrical logging curves and lithologic interpretation results of the basin, spectrum analysis and core tracing techniques are used to establish a rock-electrical interpretation model to determine the sedimentary process and the nature of seawater changes;

[0070] Based on the results of electrical logging curves and lithologic interpretation, combined with the rock types of cores and field geological outcrop profiles, a rock-electrical interpretation model was established using spectrum analysis and core tracing techniques. The sedimentary facies, electrical curve development characteristics, and identification marks corresponding to mudstone, marlstone, micritic limestone, bioclastic micritic limestone, micritic bioclastic limestone, dolomite, argillaceous siltstone, and shale were clearly identified. Based on the longitudinal variation trend of carbon and oxygen isotopes and the results of in situ micro-area element testing, the relationship between rock phase sequence and sea level changes was analyzed. The sea level mainly experienced three sedimentary processes: lowstand system tract, transgressive system tract, and highstand system tract. The energy of the water body transitioned from low energy to high energy in the vertical direction, and the sedimentary environment changed from open to semi-confined environment.

[0071] Step 6: Based on the 3D seismic area and well logging data, combined with the rock electrical interpretation model, and using well-seismic combined technology, a well logging-seismic sequence stratigraphic framework section is constructed to determine the sequence stratigraphic division scheme;

[0072] Based on the 3D seismic work area and logging and well data, combined with the identification marks of the interface between structure and sequence deposition, the well logging-seismic sequence stratigraphic framework section was constructed using the technical means of combining well and seismic. The sequence strata were identified and tracked, and the filling structure and contact relationship (conformity contact, parallel unconformity, angular unconformity) of the sequence strata in the horizontal and vertical directions were clarified. The strata were determined to be divided into five third-level sequences.

[0073] Step 7: Based on the division scheme of the five third-order sequence stratigraphic layers, establish the basin sedimentary evolution model and basin sedimentary model (such as Figure 4(as shown), determine the development characteristics and distribution location of sedimentary facies;

[0074] Based on the sequence stratigraphic division scheme, the basin's marine strata were divided. Combined with the rock phase sequence combination, sea level changes, sedimentary processes and seawater properties, a basin sedimentary evolution model was established, and the main sedimentary characteristics and main controlling factors of different sequences were analyzed. Then, based on the filling method and sedimentary process of the sequence, the basin's sedimentary model was constructed, and the sedimentary facies development characteristics and distribution locations of restricted lagoons, deltas, tidal margin beaches, tidal flats, platform flats, semi-restricted seas, intra-platform beaches, Xuefeng Mountain underwater uplift, and shelf-slopes were determined.

[0075] Step 8: Based on the well logging-seismic sequence stratigraphic framework profile, restore the sedimentary micro-geomorphology of different sequences, identify the rock types and sedimentary microfacies within the sequence framework, and count the types and characteristics of rocks and sedimentary facies in different sequences;

[0076] Based on the logging-seismic sequence stratigraphic framework profile, a single sequence is regarded as a sedimentary isochronous geological body. Combined with the basin basement layer, a sequence thickness map is drawn, and the relationship between the internal sedimentary filling mode and the lithofacies combination is analyzed to restore the sedimentary micro-geomorphology of different sequences. Based on the rock-electrical interpretation model, the rock types and sedimentary microfacies within the sequence framework are identified, and the types and characteristics of rocks and sedimentary facies of each sequence are counted according to the data points.

[0077] Step 9: Based on the basin prototype basement, sedimentary pattern, and sedimentary period micro-geomorphology, and in accordance with the dominant and special phases rules, a single-factor analysis and multi-factor comprehensive mapping method is used to reconstruct the lithofacies paleogeography of the basin marine strata of each sequence and determine the paleogeographic pattern of the basin;

[0078] Based on the prototype basement, sedimentary model and sedimentary micro-geomorphology of the basin, the sedimentary facies type and characteristics of each sequence at each data point, under the constraint of sequence stratigraphic thickness, and according to the dominant and special facies rules, the lithofacies paleogeography of the basin marine strata of each sequence was reconstructed using the single factor analysis and multi-factor comprehensive mapping method (see Figure 5 ), and then determined that the basin generally presents a paleogeographic pattern of high in the west and low in the east.

Claims

1. A method for reconstructing the lithofacies paleogeography of a basin-based marine strata based on tectonic-sedimentary coupling, characterized by: The following steps are involved: S1. Based on the established drilling and 3D seismic work areas, identify and determine the types of different sequence interfaces and restore the prototype basement of the basin; S2. Based on the characteristics of the prototype basement of the basin and the outcrop sections of the field section, a macroscopic and microscopic method is used to clarify the rock types of the basin and establish the rock phase sequence combination of the basin; S3. Based on the rock phase sequence combination, electrical logging curves and lithologic interpretation results of the basin, spectrum analysis and core tracing methods are used to establish a rock electrical interpretation model to determine the sedimentary process and the nature of seawater changes; S4. Based on the 3D seismic area and well logging data, combined with the rock-electrical interpretation model, a well-logging-seismic method is used to construct a well logging-seismic sequence stratigraphic framework section and determine the sequence stratigraphic division scheme; S5. Based on the sequence stratigraphic division scheme, establish the basin sedimentary evolution model and basin sedimentary model, and determine the development characteristics and distribution location of the sedimentary facies; S6. Based on the well logging-seismic sequence stratigraphic framework profile, restore the sedimentary micro-geomorphology of different sequences, identify the rock types and sedimentary microfacies within the sequence framework, and count the types and characteristics of rocks and sedimentary facies in different sequences; S7. Based on the prototype basement, sedimentary pattern and sedimentary period micro-geomorphology of the basin, and in accordance with the rules of dominant and special phases, the single-factor analysis and multi-factor comprehensive mapping method are used to reconstruct the lithofacies paleogeography of the basin's marine strata in each sequence and determine the paleogeographic pattern of the basin.

2. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 1, characterized in that: The method for establishing drilling work area and 3D seismic work area is: According to the basin scope, data collection is carried out on geological background, geological maps, structure, well location information, coring data, well logging and seismic data; According to the attributes of the collected data, they are sorted and summarized to establish drilling work areas and 3D seismic work areas.

3. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 2, characterized in that: Methods for determining the types of different sequence interfaces include: Based on paleogeological maps and plate tectonic maps, field geological outcrop sections were selected to observe and measure the development characteristics of basin structure and sedimentation, record the structural types and occurrences, and the development characteristics of sedimentary structures and rock types, and determine the types and properties of different structural interfaces.

4. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 3, characterized in that: The method for S1 to restore the prototype basement of the basin is: Based on the 3D seismic work area, supported by the theories of plate tectonics and geotectonics, and combining existing research results with field geological profiles, we identified key unconformities and detailed their properties and characteristics. Furthermore, we analyzed the prototype basement of the study area based on its filling geometry and boundary reconstruction characteristics. Using the balanced profile technique, we restored the prototype basement of the basin, clarifying its properties and the development characteristics of the source-sink system. The existing research results include geological structure, sedimentary characteristics and evolution, and structural characteristics and evolution results.

5. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 4, characterized in that: S2. The specific method for establishing the basin rock phase sequence combination includes the following steps: Based on the characteristics of the prototype basement of the basin and the outcrop sections of the field sections, combined with the plane distribution of the well locations and the marine stratigraphic positions, core wells were selected for core observation and photography. Sampling and sectioning, as well as carbon and oxygen isotope and in-situ micro-area element testing, were also carried out according to rock types and sedimentary structures. A combination of macro and micro methods is used to clarify the rock types and development characteristics of the basin, determine the identification marks of different rock types and stratigraphic sedimentary interfaces, and establish the basin rock phase sequence combination.

6. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 5, characterized in that: Based on the basin rock phase sequence combination, electrical logging curves and lithologic interpretation results, spectrum analysis and core tracing methods are used to establish a rock electrical interpretation model to determine the sedimentary process and seawater change properties. The specific methods include: Based on the results of electrical logging curves and lithologic interpretation, combined with the rock types of cores and field geological outcrop profiles, a rock-electrical interpretation model was established using spectrum analysis and core tracing methods to clarify the sedimentary facies, electrical curve characteristics, and identification marks of different rock types. Based on the longitudinal variation trends of carbon and oxygen isotopes and the results of in-situ micro-area element testing, the relationship between rock phase sequence combinations and sea level changes was analyzed to determine the sedimentary process and the nature of seawater changes.

7. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 6, characterized in that: S4. A method for determining a sequence stratigraphic division scheme, comprising: Based on the 3D seismic work area and well logging data, combined with the identification marks of structural and sequence sedimentary interfaces, a well logging-seismic sequence stratigraphic framework section was constructed using a well-seismic method to identify and track the sequence strata, clarify the filling structure and contact relationship of the sequence strata in the horizontal and vertical directions, and determine the division scheme of the sequence strata.

8. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 7, characterized in that: S5: The method for determining the development characteristics and distribution location of sedimentary facies includes the following steps: Based on the sequence stratigraphic division scheme, the marine strata of the basin are divided. Combining the rock phase sequence combination, sea level changes, sedimentary processes and seawater properties, a basin sedimentary evolution model is established, and the main sedimentary characteristics and main controlling factors of different sequences are analyzed. Then, based on the filling method and sedimentary process of the sequence, the sedimentary model of the basin is constructed, and the development characteristics and distribution location of the sedimentary facies are determined.

9. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 8, characterized in that: S6 is based on the well logging-seismic sequence stratigraphic framework section to restore the sedimentary micro-geomorphology of different sequences, identify the rock types and sedimentary microfacies within the sequence framework, and count the types and characteristics of rocks and sedimentary facies in different sequences. The specific methods include: Based on the logging-seismic sequence stratigraphic framework profile, a single sequence is regarded as a sedimentary isochronous geological body. Combined with the basin basement layer, a sequence thickness map is drawn, and the relationship between the internal sedimentary filling mode and the lithofacies combination is analyzed to restore the sedimentary micro-geomorphology of different sequences. Based on the rock-electrical interpretation model, the rock types and sedimentary microfacies within the sequence framework are identified, and the types and characteristics of rocks and sedimentary facies of each sequence are counted according to the data points.

10. The method for basin marine stratigraphic lithofacies paleogeography reconstruction based on tectonic-sedimentary coupling according to claim 9, characterized in that: S7 Methods for reconstructing the lithofacies paleogeography of basin-marine strata in each sequence include: Based on the prototype basement, sedimentary pattern and micro-geomorphology of the basin during the sedimentary period, and using the sedimentary facies types and characteristics of each sequence at each data point, and under the constraint of sequence stratigraphic thickness, according to the dominant and special facies rules, a single-factor analysis and multi-factor comprehensive mapping method was used to reconstruct the lithofacies paleogeography of the basin's marine strata in each sequence, and thus determine the paleogeographic pattern of the basin.

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