Geologic process-based ancient landform recovery method and related equipment

Abstract

The invention discloses an ancient landform restoration method based on a geological process and related equipment. The method is specifically implemented by the following key steps. Comprising the steps of recognizing a current stratum interface through seismic interpretation, analyzing and correcting the stratum denudation amount through seismic structure analysis, calculating the original deposition thickness through well-seismic combination, distinguishing rock correction difference compaction, removing the influence of a newly-added containable space through containable space analysis and correcting the surface influence through a sedimentary analogy terrain trend, and finally obtaining the comparable deposition thickness. According to the method, the original landform before sediment deposition is obtained through mirroring, the original landform morphology is obtained through recovery of all geological elements in the geological formation process on the basis of the geological evolution process, and all the elements influencing the landform are stripped and recovered from the final sediment to be corrected step by step. According to the method, all factors influencing the ancient landform restoration are comprehensively considered, and the accuracy of the ancient landform restoration result is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of paleo-geomorphology restoration, and specifically relates to a paleo-geomorphology restoration method based on geological processes and related equipment. Background Art

[0002] Paleomorphology is the surface morphology of the earth when sediments were deposited. It determines the distribution and relationship of sediment erosion, transportation channels and depositional areas, and thus affects the distribution of sediments. As the core issue of source-sink system research, it is one of the keys to sedimentological research. Generally, it can be restored by methods such as mudstone compaction rate, acoustic time difference (stratum velocity), organic matter maturity and sediment thickness mirroring (such as the Chinese invention patent with application number 201510713107.5).

[0003] However, the compaction rate of mudstone and the acoustic time difference method can only reflect the discontinuity of deposition, and cannot form a quantitative continuous landform. The study of organic matter maturity can only obtain large-scale landforms. The mirror method is the most commonly used paleo-geomorphological restoration method. Its principle is to obtain paleo-geomorphology by mirroring the existing sediments. The principle is that the sediments after deposition can fill the original surface to a horizontal state, so its thickness mirror is the landform before deposition. Considering that there may be water bodies on the surface of sediments after deposition, different types of sediments will have different degrees of volume shrinkage (compaction) under the pressure of overlying rocks during the burial process after deposition. The existing correction methods are mostly water depth and compaction correction, but this method does not give a method to obtain the existing sediment thickness, does not consider the difference in compaction correction and has no operation method, simplifies the surface after deposition to horizontal, and in the deposition process, there are new spaces in different regions to accumulate more sediments or the sediments may be eroded and less than the original sediments, so that the method has large errors or even errors due to the overly simple model. Summary of the invention

[0004] The present invention provides a paleo-geomorphology restoration method based on geological processes and related equipment, which solves the problem of large errors in existing paleo-geomorphology restoration.

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

[0006] A method for paleo-geomorphological restoration based on geological processes, comprising:

[0007] Acquisition of seismic and well logging data;

[0008] Obtain the time stratigraphic thickness distribution map of each stratum today and the time erosion thickness distribution map of the erosion zone based on seismic data;

[0009] The stratigraphic thickness distribution map of each stratum after restoration and denudation is obtained based on well logging data, seismic data, the time stratigraphic thickness distribution map of each stratum today and the time denudation thickness distribution map of the denuded area;

[0010] Based on the well logging data and the stratum thickness distribution map of each stratum after restoration and denudation, the total sediment thickness distribution map is obtained;

[0011] The thickness distribution map of balanced subsidence strata is obtained according to the original sediment thickness distribution map of each stratum and the total sediment thickness distribution map;

[0012] The terrain elevation correction distribution map is obtained based on the seismic data and well logging data. Based on the terrain elevation correction distribution map and the balanced settlement stratum thickness distribution map, the comparable original sediment thickness distribution map is obtained.

[0013] The comparable original sediment thickness distribution map is mirrored to obtain the original landform distribution map before sediment deposition.

[0014] Preferably, the time-stratum thickness distribution map of each stratum obtained based on seismic data is specifically as follows:

[0015] Slice tracking is performed in the 3D seismic data text to identify the reflection event axis of the sedimentary interface in the slice and obtain the initial stratigraphic interface in the slice;

[0016] According to the initial stratigraphic interface, the discontinuous layer is identified, and then the discontinuous layer is flattened to obtain the current stratigraphic interface of the slice;

[0017] After slicing and interpreting the present stratigraphic interface, we get several slices of the present stratigraphic interface, and then through interpolation, we get the distribution map of the present stratigraphic interface, and then get the time stratigraphic thickness distribution map of each stratum in the study area.

[0018] Preferably, the time erosion thickness distribution map of the erosion zone obtained according to the seismic data is specifically:

[0019] The integrity of the reflection events of the strata in the study area is analyzed based on seismic data. The reflection events are analyzed from the tracking level. For the locations where the events are missing or incomplete, the reasons for the missing or incomplete events are analyzed based on the overall geological structure characteristics. If the missing or incomplete events are caused by later erosion, they are classified as erosion areas. In the erosion areas, the extension of the complete reflection events and the erosion trend are used to obtain the time erosion thickness distribution map of the erosion area.

[0020] Preferably, the stratigraphic thickness distribution map of each stratum after restoration and denudation is obtained based on the well logging data, seismic data, the time stratigraphic thickness distribution map of each stratum today, and the time denudation thickness distribution map of the denuded area, as follows:

[0021] According to the logging data and seismic data, the current time stratigraphic thickness distribution map of each stratum is converted into the current stratigraphic thickness distribution map of each stratum, and the time erosion thickness distribution map of the erosion zone is converted into the erosion thickness distribution map of the erosion zone. Based on the current stratigraphic thickness distribution map of each stratum and the erosion thickness distribution map of the erosion zone, the stratigraphic thickness distribution map of each stratum after restoration of erosion is obtained.

[0022] Preferably, the total sediment thickness distribution map is obtained based on the well logging data and the stratum thickness distribution map of each stratum after restoration and denudation, specifically:

[0023] The lithofacies distribution map and VSP velocity distribution map of each stratum are obtained according to the logging data. The original sedimentary thickness distribution map of each stratum is obtained according to the lithofacies distribution map, VSP velocity distribution map and the stratum thickness distribution map of each stratum after restoration and denudation. The total sedimentary thickness distribution map is obtained according to the original sedimentary thickness distribution map of each stratum.

[0024] Preferably, obtaining the balanced settlement stratum thickness distribution map according to the original sedimentation thickness distribution map and the total sedimentation thickness distribution map of each stratum specifically comprises obtaining a settlement amount distribution map according to the original sedimentation thickness distribution map of each stratum, obtaining an average settlement amount according to the settlement amount distribution map, obtaining a differential settlement amount distribution map according to the settlement amount distribution map and the average settlement amount, and obtaining a balanced settlement stratum thickness distribution map according to the differential settlement amount distribution map and the total sedimentation thickness distribution map;

[0025] According to the settlement distribution diagram and the average settlement, the differential settlement distribution diagram is obtained as follows:

[0026] The average settlement is subtracted from the settlement at each location in the settlement distribution diagram to obtain the differential settlement at each location, and then the differential settlement distribution diagram is obtained.

[0027] Preferably, the comparable original deposition thickness distribution map is obtained by:

[0028] The sedimentary facies distribution map is obtained based on the seismic data and well logging data, the terrain elevation correction distribution map is obtained based on the sedimentary facies distribution map, and the comparable original sedimentary thickness distribution map is obtained based on the terrain elevation correction distribution map and the balanced settlement stratum thickness distribution map;

[0029] The terrain elevation correction distribution map obtained according to the sedimentary phase distribution map is as follows:

[0030] According to the sedimentary phase distribution map and the preset slopes of each sedimentary phase, a terrain elevation correction distribution map is obtained;

[0031] The method for obtaining the preset slopes of each sedimentary phase is: obtaining the surface topography under different modern sedimentary environments, statistically summarizing the slope coefficients, and obtaining the preset slopes of each sedimentary phase.

[0032] A paleo-geomorphology restoration system based on geological processes, comprising:

[0033] Data acquisition module: used to obtain seismic data and well logging data;

[0034] The first distribution map acquisition module is used to obtain the time stratigraphic thickness distribution map of each stratum and the time erosion thickness distribution map of the erosion zone according to the seismic data;

[0035] The second distribution map acquisition module is used to obtain the stratum thickness distribution map of each stratum after restoration and denudation based on the well logging data, seismic data, the time stratum thickness distribution map of each stratum today and the time denudation thickness distribution map of the denudation area;

[0036] The third distribution map acquisition module is used to obtain the total sediment thickness distribution map based on the well logging data and the stratum thickness distribution map of each stratum after restoration and denudation;

[0037] The fourth distribution map acquisition module is used to obtain a balanced sedimentation stratum thickness distribution map according to the original sedimentation thickness distribution map of each stratum and the total sedimentation thickness distribution map;

[0038] The fifth distribution map acquisition module is used to obtain a terrain elevation correction distribution map based on seismic data and well logging data, and obtain a comparable original sediment thickness distribution map based on the terrain elevation correction distribution map and the balanced settlement stratum thickness distribution map;

[0039] Restoration module: Mirror the comparable original sediment thickness distribution map to obtain the original landform distribution map before sediment deposition.

[0040] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of a paleo-geomorphology restoration method based on geological processes when executing the computer program.

[0041] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a paleo-geomorphology restoration method based on geological processes.

[0042] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a paleo-geomorphology restoration method based on geological processes, which is based on the geological evolution process and obtains the original geomorphology by restoring various geological elements in the geological formation process. The various elements that affect the landform are stripped and restored from the final sediments and corrected in steps, and the original paleo-geomorphology characteristics are finally obtained through process restoration. The specific implementation is mainly divided into the following key steps, namely, seismic interpretation to identify the current stratigraphic interface, seismic structure analysis to correct the amount of stratigraphic erosion, well-seismic combination to calculate the original sedimentary thickness, rock differentiation to correct differential compaction, accommodative space analysis to remove the impact of newly added accommodative space, and sedimentary analog terrain trend to correct the surface impact, and finally obtain the comparable sedimentary thickness, and obtain the original landform before the sediment deposition, that is, the paleo-geomorphology, through mirroring. This method comprehensively considers all factors that affect the restoration of paleo-geomorphology and improves the accuracy of the paleo-geomorphology restoration results. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic flow chart of an embodiment of a paleo-geomorphology restoration method based on geological processes provided by the present invention.

[0044] Figure 2 for Figure 1 Schematic diagram of the process of step S2 in .

[0045] Figure 3 This is the seismic profile after the E layer is flattened.

[0046] Figure 4 This is the seismic profile after the K1bx layer is flattened.

[0047] Figure 5 This is the seismic profile after the J layer is flattened.

[0048] Figure 6 for Figure 5 Schematic diagram of the partially denuded area identified in the seismic profile.

[0049] Figure 7 This is the plan distribution map of the erosion amount of a certain layer in the study area.

[0050] Figure 8 for Figure 1 Schematic diagram of the process of step S5 in .

[0051] Fig. 9 This is a sandstone percentage distribution diagram in one embodiment of the present invention.

[0052] Fig.10 This is a cross-sectional diagram of a seismic section after compaction and restoration.

[0053] Fig.11 This is the distribution map of total sediment thickness in the study area.

[0054] Fig.12 Schematic diagram of the zero line of differential settlement and the maximum differential settlement line.

[0055] Fig.13 Schematic diagram of surface topography under different sedimentary environments.

[0056] Fig.14 This is the comparable original deposition thickness distribution map finally obtained.

[0057] Fig.15 Based on Fig.14 Schematic diagram of ancient sedimentary landforms obtained by mirroring.

[0058] Fig.16 This is a flow chart of a paleo-geomorphology restoration method based on geological processes according to the present invention.

[0059] Fig.17 This is a block diagram of a paleo-geomorphology restoration system based on geological processes according to the present invention. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0061] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0063] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0064] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0065] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0067] The paleo-geomorphology restoration method based on geological processes provided by the present invention is an improvement based on the mirror image method. Therefore, the assumptions and premises of the mirror image method are first explained.

[0068] The assumptions of the mirror method include:

[0069] (1) The landform was horizontal at the end of deposition;

[0070] (2) The original landform is completely filled with sediments or water. When there is water, the ancient water depth is used to correct the landform after deposition;

[0071] (3) No differential sedimentation or erosion occurs during the deposition process;

[0072] Under the above assumptions, the total thickness of the sediment or the sum of the total thickness of the sediment and the depth of the water body represents the elevation difference between the landform before deposition and the horizontal plane after deposition. Its mirror image is the original landform. The greater the thickness of the sediment, the lower the original landform. This is the basic basis and idea of ​​​​recovering ancient landforms using the mirror image method.

[0073] However, considering the differential compaction in the strata, that is, different types of sediments have different volume changes during diagenesis, it is necessary to correct the sediment thickness caused by compaction. It is generally believed that different types of sediments have different compaction rates, and differential compaction correction is performed according to the sand-to-land ratio or the composition of different lithologies. The correction amount is equal to the stratum thickness multiplied by the compaction coefficient, and the original sedimentary thickness is equal to the current sedimentary thickness divided by the compaction rate.

[0074] Considering the differential settlement in different parts, it is necessary to correct the differential settlement, that is, to superimpose the differential settlement curve on the obtained geomorphic map, and subtract the newly added accommodation space due to differential settlement from the sediment thickness to obtain the original accommodation space. The differential settlement can be positive or negative, representing settlement or erosion respectively.

[0075] In fact, the terrain after deposition is not horizontal. At this time, the landform after deposition should also be considered or given, and the landform after deposition should be used to correct the original landform. The correction method is to analyze the landform trend, superimpose the landform trend on the formed landform map, and form a real landform map.

[0076] Based on the above theoretical basis, please refer to Figure 1 The present invention provides a method for restoring ancient landforms based on geological processes, comprising:

[0077] S1. Obtain seismic data and well logging data in the study area;

[0078] S2. Obtain the time-stratigraphic thickness distribution map of each stratum in the study area based on seismic data;

[0079] Please refer to Figure 2 , step S2 specifically includes:

[0080] S21, performing slice tracking in the 3D seismic data text, identifying the reflection event axis of the sedimentary interface in the slice, and obtaining the initial stratigraphic interface in the slice;

[0081] S22. According to the initial stratigraphic interface, the discontinuous layer is identified, and then the discontinuous layer is flattened to obtain the current stratigraphic interface of the slice. When flattening, attention should be paid to maintaining the coordination of the stratigraphic layers above and below the comparison layer, ensuring that the thickness changes of the layers above and below the layer do not show consistent elevation deviations, and at the same time ensuring that the tracking layer does not penetrate the layer;

[0082] In this embodiment, Figure 3-Figure 5 , first flatten the E layer ( Figure 3 ), and then flatten the K1bx layer ( Figure 4 ), and finally flatten the J layer ( Figure 5 ), all discontinuous layers can be leveled.

[0083] S23. After interpreting slices at a certain density, the present stratigraphic interfaces of several slices are obtained. Then, through interpolation, the distribution map of the present stratigraphic interfaces is obtained, and then the temporal stratigraphic thickness distribution map of the present strata in the study area is obtained.

[0084] S3. Analyze the integrity of the reflection phase axis of the strata in the study area based on seismic data, identify the erosion area, and obtain the time erosion thickness distribution map of the erosion area according to the extension of the complete reflection phase axis and the erosion trend in the erosion area;

[0085] Among them, the integrity of the reflection event axes of the strata in the study area is analyzed based on seismic data to identify the erosion zone. Specifically, the reflection event axes are analyzed from the tracking level. For the locations where the event axes are missing or incomplete, the reasons for the missing or incomplete event axes are analyzed based on the overall geological structure characteristics. If the missing or incomplete event axes are caused by later erosion, they will be classified as erosion zones.

[0086] In this embodiment, Figure 6 As shown in the figure, by tracing the reflection phase axis on the seismic profile, it can be observed that the phase axis is missing or incomplete in some locations. According to the characteristics of geological structure, it can be concluded that these missing or incomplete phase axes are caused by later erosion, and they are classified as erosion areas. For each erosion area, according to the direction of the stratigraphic interface above and below the missing phase axis, the temporal erosion thickness distribution of the erosion area can be obtained. After analyzing multiple seismic profiles, the results are projected onto the plane map of the study area, and then the plane distribution map of the erosion amount of a certain layer in the study area is obtained by interpolation (such as Figure 7 ).

[0087] It should be noted that for areas with large-scale denudation, restoring the amount of denudation is a very critical and difficult task. There are two reasons for local denudation. One is that the local uplift landform is flattened due to the occurrence of local uplift. At this time, the restoration is mainly to restore the amount of uplift caused by the landform and the degree of integrity of the original stratum. The amount of denudation is evaluated by the structural trend and the integrity of the stratum. The second is local erosion caused by local downcutting. At this time, there is no deformation of the stratum, only the incompleteness of the lower stratum, and the amount of denudation can be estimated by the integrity of the stratum. The third is regional unbalanced denudation. At this time, there is no structural deformation, and the landform is basically uplifted and eroded. At this time, the denudation package may be relatively consistent, but the landforms after uplift in different regions are different, resulting in different denudation restoration amounts. Another type is regional consistent uplift, that is, there is a difference in uplift, but this difference is regional, with consistent regional change characteristics, and the difference in uplift can be obtained through regional estimation to obtain the size of the denudation.

[0088] Regional erosion restoration requires an understanding of regional structural deformation, based on which the overall erosion trend can be inferred. On the basis of the overall trend, the eroded stratigraphic structure is analyzed and the amount of stratigraphic erosion is restored according to the preserved stratigraphic structure.

[0089] S4. Calibrate the seismic data by using the well logging data, convert the time stratigraphic thickness distribution map of each stratum into the current stratigraphic thickness distribution map of each stratum, convert the time erosion thickness distribution map of the erosion area into the erosion thickness distribution map of the erosion area, and obtain the stratigraphic thickness distribution map of each stratum after restoration and erosion by using the current stratigraphic thickness distribution map of each stratum and the erosion thickness distribution map of the erosion area;

[0090] Among them, the seismic data are calibrated by well logging data, and the time stratigraphic thickness distribution map of each stratum today is converted into the stratigraphic thickness distribution map of each stratum today, and the time erosion thickness distribution map of the erosion zone is converted into the erosion thickness distribution map of the erosion zone. Specifically, the seismic data and the well logging data are calibrated with VSP to obtain the relationship between the time domain thickness and the depth domain thickness of the seismic reflection. According to the relationship between the time domain thickness and the depth domain thickness of the seismic reflection, the time stratigraphic thickness distribution map of each stratum today is converted into the stratigraphic thickness distribution map of each stratum today, and the time erosion thickness distribution map of the erosion zone is converted into the erosion thickness distribution map of the erosion zone.

[0091] Among them, the stratigraphic thickness distribution map of each stratum after restoration and denudation is obtained through the current stratigraphic thickness distribution map of each stratum and the erosion thickness distribution map of the eroded area. Specifically, the current stratigraphic thickness distribution map of each stratum and the erosion thickness distribution map of the eroded area are superimposed, and the stratigraphic thickness at each position is added to the erosion thickness to obtain the stratigraphic thickness distribution map of each stratum after restoration and denudation.

[0092] S5. Obtain the lithofacies distribution map of each stratum in the study area and the VSP velocity distribution map of each stratum in the study area based on the well logging data. Obtain the compaction rate of different lithofacies at different depths based on the lithofacies distribution map of each stratum and the VSP velocity distribution map of each stratum in the study area by regression. Obtain the original sedimentary thickness distribution map of each stratum in the study area based on the compaction rate of different lithofacies at different depths, the lithofacies distribution map of each stratum and the stratum thickness distribution map of each stratum after restoration and denudation. Obtain the total sedimentary thickness distribution map of the study area based on the original sedimentary thickness distribution map of each stratum in the study area.

[0093] Among them, Figure 8 According to the lithofacies distribution map of each stratum in the study area and the VSP velocity distribution map, the compaction rates of different lithofacies at different depths are obtained by regression, including:

[0094] S511. Obtain the percentage of different lithofacies at each point in the study area according to the lithofacies distribution map of each stratum in the study area. In this embodiment, the lithofacies include sandstone and mudstone, and the distinction between sandstone and mudstone can be achieved through the interpretation of well logging data. Fig. 9 Shown is a graph showing the sandstone percentage distribution in one embodiment.

[0095] S512, obtaining the VSP velocity at each point according to the VSP velocity distribution diagram;

[0096] S513. According to the percentage of different lithofacies at each point and the VSP velocity at each point, the compaction rate of different lithofacies at different depths is obtained by regression.

[0097] Among them, according to the compaction rate of different lithofacies at different depths, the lithofacies distribution map of each stratum and the stratum thickness distribution map of each stratum after restoration and denudation, the original sedimentary thickness distribution map of each stratum in the study area is obtained, specifically:

[0098] The stratum thickness at each position in the stratum thickness distribution map of each stratum after restoration and denudation is divided by the compaction rate of the corresponding lithofacies at that position to obtain the original sedimentary thickness at each position, thereby obtaining the original sedimentary thickness distribution map of each stratum in the study area. In this embodiment, Fig.10 This is a cross-sectional diagram of a seismic section after compaction and restoration.

[0099] Among them, according to the original sediment thickness distribution map of each stratum in the study area, the total sediment thickness distribution map of the study area is obtained, specifically: the original sediment thickness of each stratum at each position in the study area is added to obtain the total sediment thickness at each position, and then the total sediment thickness distribution map of the study area is obtained. In this embodiment, the total sediment thickness distribution map of the study area is as follows Fig.11 shown.

[0100] S6. According to the original sediment thickness distribution map of each stratum in the study area, the tectonic evolution analysis of the study area is carried out to obtain the settlement distribution map of the study area. According to the settlement distribution map of the study area, the average settlement of the study area is obtained. According to the settlement distribution map and the average settlement of the study area, the differential settlement distribution map of the study area is obtained. According to the differential settlement distribution map and the total sediment thickness distribution map of the study area, the balanced settlement stratum thickness distribution map of the study area is obtained.

[0101] Among them, according to the settlement distribution map and the average settlement of the study area, the differential settlement distribution map of the study area is obtained. Specifically, the settlement of each location in the settlement distribution map of the study area is subtracted from the average settlement to obtain the differential settlement of each location, and then the differential settlement distribution map of the study area is obtained.

[0102] In this embodiment, structural evolution analysis is performed on different sedimentary areas to determine the settlement conditions of different areas and clarify the settlement differences. According to the settlement amounts of different areas, the average settlement amount of the area is obtained. Areas with settlement amounts greater than or less than the average settlement amount are taken as differential settlement areas, and the differential settlement zero line and the maximum differential settlement line (such as Fig.12), the differential settlement curve of the differential settlement area is obtained by interpolation. The space with positive differential settlement can be regarded as the newly added accommodative space. By removing this value from the corrected sedimentary thickness, the influence of the newly added accommodative space can be removed and the equilibrium settlement stratum thickness value can be obtained.

[0103] S7. Obtain a sedimentary facies distribution map of the study area based on seismic data and well logging data, obtain a terrain elevation correction distribution map of the study area based on the sedimentary facies distribution map and the preset slopes of each sedimentary facies, and obtain a comparable original sedimentary thickness distribution map based on the terrain elevation correction distribution map of the study area and the balanced settlement stratum thickness distribution map of the study area;

[0104] The method for obtaining the preset slopes of each sedimentary phase is as follows: obtaining the surface topography under different modern sedimentary environments, statistically summarizing the slope coefficients, and obtaining the preset slopes of each sedimentary phase.

[0105] According to the characteristics of modern sedimentary topography, the surface was not horizontal after deposition, but had a certain slope. Through modern sedimentary investigations, the surface topography under different sedimentary environments (such as Fig.13 As shown in the figure, the slope coefficient is statistically summarized, and the elevation increment is interpolated according to the slope in the sedimentary facies belt according to the compiled sedimentary facies belt boundary to perform elevation correction. The method is to set the correction amount of the lowest part to zero, and perform terrain correction of the first layer from this part outward. According to the average slope, the sedimentary facies belt line from the center point to the outer edge is uniformly interpolated to obtain the correction amount on different interpolation lines, and the terrain elevation correction is performed on the corresponding points. Then, the contour line is interpolated from the boundary of the previous sedimentary facies belt to the sedimentary facies belt outside, and the points on the contour line are corrected to obtain the elevation correction amount until all points are corrected.

[0106] In this embodiment, the terrain slopes of different regions measured in modern sedimentation are used for analogy. For example, different terrain slopes can be used as references for analogy in floodplains, delta plains, lake areas, and foreset areas. The restoration of sedimentary landforms should take into account the impact of different sedimentation processes. For the valley slope area in front of the mountain, the difference in landform calculation may be too large due to the syngenetic faults, and the difference in landform morphology after deposition may not be considered, resulting in an overestimation of the landform difference. For the parts with ancient protrusions, the original landform difference cannot be estimated due to the lack of sediment thickness.

[0107] For the old mountainous areas, the main approach is to identify the ancient canyons and then determine the source-channel relationship of the provenance system through the differences in ancient landforms. The source area morphology is obtained by describing the current landforms of the bedrock, and the outlet of the channel can be obtained by restoring the sediment thickness.

[0108] For a complete sedimentary area, the analysis of its geomorphology needs to distinguish the denuded underlying strata area, the area denuded by later strata, the progradational geomorphic conversion area, and the thickness change area caused by the development of the river channel. Among them, the thickness change area formed by the river channel development needs to find out the difference between the river channel belt and the floodplain outside the river channel. In fact, when the river channel was developed, its original landform was low, and its post-deposition landform was higher than the surrounding area, so the calculation of its geomorphic difference would be too large. However, it should be noted how wide the river channel or river channel belt is, whether it can be reflected in the earthquake or in the drilling. Because its geomorphic difference is small, it may generally be smaller than the error caused by seismic tracking, so it may be difficult to find the difference of this type of landform in the study. Detailed tracking may provide some clues. The thickness of the floodplain of a river channel can range from ten meters to zero meters from the bank to the floodplain, and in the channel, there may be downcutting that causes its elevation to be more than ten meters below the bank, but when tracing, the geomorphic changes of the river channel are generally not traced or are not particularly prominent, and there may be depressions that can reflect its geomorphology. The identification of downcut channels may be an important aspect of determining ancient canyons or river channels, and we cannot rely on the geomorphic map obtained by thickness to distinguish the river channel in the plain area.

[0109] S8. Mirror the comparable original sediment thickness distribution map to obtain the original geomorphic distribution map before sediment deposition in the study area;

[0110] After achieving layer tracking, erosion correction, compaction correction, additional accommodation space correction and relative terrain correction, the final comparable original sediment thickness distribution map can be obtained (such as Fig.14 ), by mirroring the original sediment thickness distribution map, the accurate sedimentary landform can be obtained (such as Fig.15 ).

[0111] The above is a general implementation scheme of the present invention. However, in actual application, some special situations may be encountered, which need to be dealt with specifically, including:

[0112] (1) For flat plain areas, river valleys generally appear in low-lying areas before deposition, and high landforms will be formed after deposition. At this time, the final prominent landform caused by the thickness of the river valley should be considered, which will lead to deviations in the estimation of the original landform and underestimate the landform estimate;

[0113] (2) If there is a downcutting effect of the river channel, the thickness of the sediment is equal to the sum of the newly added accommodation space and the original accommodation space due to the addition of accommodation space, resulting in an underestimate of the landform estimate;

[0114] (3) If there is an ancient canyon with no differential sedimentation, its sediment thickness can be used to invert the geomorphology of the ancient canyon, but this geomorphology needs to be corrected with the geomorphology after deposition;

[0115] (4) The difference in terrain slope in the lakeshore area or the front area is inconsistent with the terrain slope of the landforms on both sides, resulting in different elevation differences between the sediment surface and the horizontal plane, and the terrain slope needs to be corrected. At this time, the underwater area can be corrected by the ancient water depth or the lake bottom topography, but the above-water area can only be corrected by the topography. Therefore, when restoring the ancient landform, we still need an imaginary post-deposition landform as a substitute for the horizontal plane;

[0116] (5) The paleo-geomorphological restoration method is mainly applicable to areas with obvious landform fluctuations, especially strata with bedrock areas, where the developed filling effect can better reflect its original landform characteristics. However, this method is not very applicable to continuous sedimentary strata, including floodplains, lake areas, riverbanks or lakeshores;

[0117] (6) For continuous sedimentary strata, identifying the erosion and filling structures in the sediments is a way to identify the main sedimentary channels. However, based on the changes in stratum thickness, it may be difficult to identify the development location of the channels;

[0118] (7) The determination of the post-deposition landforms in a region is mainly based on the analysis of the sedimentary background. The terrain slope is determined by zoning. The ups and downs of the landforms in different parts are analyzed based on the terrain slope. Superimposing it on the thick landform can give the corresponding correction amount. Among them, there are two important rapid change zones, namely the piedmont transition zone and the underwater transition zone. These two locations are places of progradation and have large changes in sedimentary slope. They are also the locations that indicate the transition of different sedimentary phases. They should be mainly based on progradational structure identification.

[0119] (8) Geomorphic filling after the completion of deposition should be distinguished as full or partial filling of the basin. After full filling, the original bottom shape of the basin after foreset will no longer exist, and a unified basin bottom shape will be formed. At this time, the basin filling may have two parts, namely the foreset filling area and the alletl filling area. The former has a foreset structure, and the latter may have a bidirectional overlap structure or a top overlap structure. If it is partially filled, the incompletely filled basin part will develop, and its terrain slope will be different from that of other areas. At this time, the basin may have obvious characteristics of decreasing sediment thickness, and there may also be differences between the structure inside the basin and the foreset structure. Observing this accumulation conversion and difference is of great significance for identifying different geomorphic zones.

[0120] (9) Paleogeomorphological restoration mainly involves two aspects: the change in slope or the transition zone of sedimentation, and the change in channel or the change zone of sediment channel. The former solves the problem of sediment accumulation area, by finding the slope break zone to determine the priority sediment accumulation area, and analyzing the type of sediment and the dominant sedimentary phase zone. The latter solves the problem of sediment transportation direction. By finding the transition zone through geomorphological restoration, the development of sedimentary bodies can be analyzed, and by channel tracking, the transportation channel can be found to determine the development of potential sedimentary areas, and the combined relationship between source, channel and sink can be established to conduct quantitative sedimentary system analysis.

[0121] In summary, the technical solution provided by the present invention is based on the geological evolution process, and restores the original landform of each geological element in the geological formation process. The various elements that affect the landform are stripped and restored from the final sediments and corrected in steps, and the original paleo-geomorphic features are finally obtained through process restoration. The specific implementation is mainly divided into the following key steps, namely, seismic interpretation to identify the current stratigraphic interface (S2), seismic structure analysis to correct the amount of stratigraphic erosion (S3), well-seismic combination to calculate the original sedimentary thickness (S4), distinguishing rocks to correct differential compaction (S5), accommodative space analysis to remove the impact of newly added accommodative space (S6), sedimentary analog terrain trend correction surface impact (S7), and finally obtain comparable sedimentary thickness, and obtain the original landform before sediment deposition through mirroring (S8), that is, paleo-geomorphology. This method comprehensively considers all factors that affect the restoration of paleo-geomorphology and improves the accuracy of the paleo-geomorphology restoration results.

[0122] like Fig.17 The present invention also provides a paleo-geomorphology restoration system based on geological processes, comprising:

[0123] Data acquisition module: used to obtain seismic data and well logging data;

[0124] The first distribution map acquisition module is used to obtain the time stratigraphic thickness distribution map of each stratum and the time erosion thickness distribution map of the erosion zone according to the seismic data;

[0125] The second distribution map acquisition module is used to obtain the stratum thickness distribution map of each stratum after restoration and denudation based on the well logging data, seismic data, the time stratum thickness distribution map of each stratum today and the time denudation thickness distribution map of the denudation area;

[0126] The third distribution map acquisition module is used to obtain the total sediment thickness distribution map based on the well logging data and the stratum thickness distribution map of each stratum after restoration and denudation;

[0127] The fourth distribution map acquisition module is used to obtain a balanced sedimentation stratum thickness distribution map according to the original sedimentation thickness distribution map of each stratum and the total sedimentation thickness distribution map;

[0128] The fifth distribution map acquisition module is used to obtain a terrain elevation correction distribution map based on seismic data and well logging data, and obtain a comparable original sediment thickness distribution map based on the terrain elevation correction distribution map and the balanced settlement stratum thickness distribution map;

[0129] Restoration module: Mirror the comparable original sediment thickness distribution map to obtain the original landform distribution map before sediment deposition.

[0130] A terminal device is provided in one embodiment of the present invention. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0131] The computer program may be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to accomplish the present invention.

[0132] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0133] The processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0134] The memory may be used to store the computer program and / or module, and the processor implements various functions of the terminal device by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0135] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0136] Although the embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields, and the above-mentioned specific embodiments are only illustrative and instructive, rather than restrictive. Under the guidance of the specification, a person skilled in the art can also make many forms without departing from the scope of protection of the claims of the present invention, all of which belong to the scope of protection of the present invention.

Claims

1. A method for restoring ancient landforms based on geological processes, characterized in that: include: Acquisition of seismic and well logging data; Obtain the time stratigraphic thickness distribution map of each stratum today and the time erosion thickness distribution map of the erosion zone based on seismic data; The stratigraphic thickness distribution map of each stratum after restoration and denudation is obtained based on well logging data, seismic data, the time stratigraphic thickness distribution map of each stratum today and the time denudation thickness distribution map of the denuded area; Based on the well logging data and the stratum thickness distribution map of each stratum after restoration and denudation, the total sediment thickness distribution map is obtained; The thickness distribution map of balanced subsidence strata is obtained according to the original sediment thickness distribution map of each stratum and the total sediment thickness distribution map; The terrain elevation correction distribution map is obtained based on the seismic data and well logging data. Based on the terrain elevation correction distribution map and the balanced settlement stratum thickness distribution map, the comparable original sediment thickness distribution map is obtained. The comparable original sediment thickness distribution map is mirrored to obtain the original landform distribution map before sediment deposition.

2. A method for restoring ancient landforms based on geological processes according to claim 1, characterized in that: The time-stratum thickness distribution map of each stratum obtained based on seismic data is as follows: Slice tracking is performed in the 3D seismic data text to identify the reflection event axis of the sedimentary interface in the slice and obtain the initial stratigraphic interface in the slice; According to the initial stratigraphic interface, the discontinuous layer is identified, and then the discontinuous layer is flattened to obtain the current stratigraphic interface of the slice; After slicing and interpreting the present stratigraphic interface, we get several slices of the present stratigraphic interface, and then through interpolation, we get the distribution map of the present stratigraphic interface, and then get the time stratigraphic thickness distribution map of each stratum in the study area.

3. The method for restoring ancient landforms based on geological processes according to claim 1, characterized in that: The time erosion thickness distribution map of the erosion zone obtained based on seismic data is as follows: The integrity of the reflection events of the strata in the study area is analyzed based on seismic data. The reflection events are analyzed from the tracking level. For the locations where the events are missing or incomplete, the reasons for the missing or incomplete events are analyzed based on the overall geological structure characteristics. If the missing or incomplete events are caused by later erosion, they are classified as erosion areas. In the erosion areas, the extension of the complete reflection events and the erosion trend are used to obtain the time erosion thickness distribution map of the erosion area.

4. The method for restoring ancient landforms based on geological processes according to claim 1, characterized in that: The stratigraphic thickness distribution map of each stratum after restoration and denudation is obtained based on the well logging data, seismic data, the time stratigraphic thickness distribution map of each stratum today, and the time denudation thickness distribution map of the denuded area. Specifically, the stratigraphic thickness distribution map of each stratum after restoration and denudation is as follows: According to the logging data and seismic data, the current time stratigraphic thickness distribution map of each stratum is converted into the current stratigraphic thickness distribution map of each stratum, and the time erosion thickness distribution map of the erosion zone is converted into the erosion thickness distribution map of the erosion zone. Based on the current stratigraphic thickness distribution map of each stratum and the erosion thickness distribution map of the erosion zone, the stratigraphic thickness distribution map of each stratum after restoration of erosion is obtained.

5. The method for restoring ancient landforms based on geological processes according to claim 1, characterized in that: According to the logging data and the stratum thickness distribution map of each stratum after restoration and denudation, the total sediment thickness distribution map is obtained, which is as follows: The lithofacies distribution map and VSP velocity distribution map of each stratum are obtained according to the logging data. The original sedimentary thickness distribution map of each stratum is obtained according to the lithofacies distribution map, VSP velocity distribution map and the stratum thickness distribution map of each stratum after restoration and denudation. The total sedimentary thickness distribution map is obtained according to the original sedimentary thickness distribution map of each stratum.

6. The method for restoring ancient landforms based on geological processes according to claim 1, characterized in that: The balanced settlement stratum thickness distribution map is obtained according to the original sedimentation thickness distribution map of each stratum and the total sedimentation thickness distribution map. Specifically, the settlement distribution map is obtained according to the original sedimentation thickness distribution map of each stratum, the average settlement is obtained according to the settlement distribution map, the differential settlement distribution map is obtained according to the settlement distribution map and the average settlement, and the balanced settlement stratum thickness distribution map is obtained according to the differential settlement distribution map and the total sedimentation thickness distribution map; According to the settlement distribution diagram and the average settlement, the differential settlement distribution diagram is obtained as follows: The average settlement is subtracted from the settlement at each location in the settlement distribution diagram to obtain the differential settlement at each location, and then the differential settlement distribution diagram is obtained.

7. The method for restoring ancient landforms based on geological processes according to claim 1, characterized in that: The acquisition of comparable original sediment thickness distribution map is as follows: The sedimentary facies distribution map is obtained based on the seismic data and well logging data, the terrain elevation correction distribution map is obtained based on the sedimentary facies distribution map, and the comparable original sedimentary thickness distribution map is obtained based on the terrain elevation correction distribution map and the balanced settlement stratum thickness distribution map; The terrain elevation correction distribution map obtained according to the sedimentary phase distribution map is as follows: According to the sedimentary phase distribution map and the preset slopes of each sedimentary phase, a terrain elevation correction distribution map is obtained; The method for obtaining the preset slopes of each sedimentary phase is: obtaining the surface topography under different modern sedimentary environments, statistically summarizing the slope coefficients, and obtaining the preset slopes of each sedimentary phase.

8. A paleo-geomorphology restoration system based on geological processes, characterized in that: include: Data acquisition module: used to obtain seismic data and well logging data; The first distribution map acquisition module is used to obtain the time stratigraphic thickness distribution map of each stratum and the time erosion thickness distribution map of the erosion zone according to the seismic data; The second distribution map acquisition module is used to obtain the stratum thickness distribution map of each stratum after restoration and denudation based on the well logging data, seismic data, the time stratum thickness distribution map of each stratum today and the time erosion thickness distribution map of the denudation area; The third distribution map acquisition module is used to obtain the total sediment thickness distribution map based on the well logging data and the stratum thickness distribution map of each stratum after restoration and denudation; The fourth distribution map acquisition module is used to obtain a balanced sedimentation stratum thickness distribution map according to the original sedimentation thickness distribution map of each stratum and the total sedimentation thickness distribution map; The fifth distribution map acquisition module is used to obtain a terrain elevation correction distribution map based on seismic data and well logging data, and obtain a comparable original sediment thickness distribution map based on the terrain elevation correction distribution map and the balanced settlement stratum thickness distribution map; Restoration module: Mirror the comparable original sediment thickness distribution map to obtain the original landform distribution map before sediment deposition.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the paleo-geomorphology restoration method based on geological processes as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of a paleo-geomorphology restoration method based on geological processes as described in any one of claims 1 to 7 are implemented.

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