A method, system, device and storage medium for restoring a buried hill type karst paleogeomorphology

Abstract

The application discloses a buried hill type karst palaeogeomorphology recovery method, system, device and storage medium, and comprises the following processes: S1, selecting a sedimentary limestone as a datum plane, and taking a sedimentary limestone pinch-out line as a 0-line plane standard; S2, respectively acquiring palaeogeomorphology thicknesses above and below the 0-line plane; S3, fitting a trend surface equation to a buried hill top structural plane to acquire a trend surface value; and subtracting the trend surface value from present carbonate rock top structural data to acquire a residual error; and S4, splicing the palaeogeomorphology thicknesses above and below the 0-line plane, and then subtracting the residual error to perform correction, so that an accurate buried hill type karst palaeogeomorphology recovery thickness can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas development and relates to a method, system, equipment and storage medium for the restoration of buried hill type karst paleomorphology. Background Technology

[0002] Karst paleogeography not only controls the development and distribution of karst reservoirs, but also reflects the evolution of paleogeography and paleoriver systems, which is of great significance for studying the spatial distribution of reservoirs and the laws of hydrocarbon accumulation. However, due to multiple tectonic activities, carbonate buried hills have experienced different erosion intensities in different areas, resulting in different subsequent sedimentary patterns and reservoir distribution characteristics. Therefore, current technologies cannot accurately reconstruct buried hill-type karst paleogeography. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, system, equipment and storage medium for the restoration of buried hill type karst paleomorphology, which can accurately restore buried hill type karst paleomorphology.

[0004] To achieve the above objectives, the present invention employs the following technical solution: A method for restoring buried hill-type karst paleogeography includes the following processes: S1, sedimentary limestone is selected as the reference surface, and the pinch-out line of sedimentary limestone is taken as the standard of the 0 line surface; S2, obtain the paleogeographic thickness above and below the 0 line surface respectively; S3. The trend surface value is obtained by fitting the trend surface equation to the top structure of the buried mountain; the residual is obtained by subtracting the trend surface value from the current structural data of the top of the carbonate rock. S4 splices the paleogeographic thickness above and below the 0 line surface, and then corrects it by subtracting it from the residual to obtain the restored thickness of the buried hill type karst paleogeographic feature.

[0005] Preferably, in S1, the rock segment closest to the weathering crust interface and with marine sedimentation and strong wave impedance interface is used as the reference surface.

[0006] Preferably, the paleogeographic thickness below the 0 line surface is obtained by using the impression thickness method.

[0007] Furthermore, by establishing and fitting a relationship function between stratigraphic density and stratigraphic thickness, a relationship function is obtained. This relationship function is then used to obtain a function showing the variation of stratigraphic porosity with stratigraphic thickness, thereby enabling compaction correction of the paleogeographic thickness below the 0-line plane.

[0008] Furthermore, based on the obtained data from multiple sedimentary paleothickness points, the compaction ratio of the paleokarst strata was obtained. The compaction ratio of the paleokarst strata was corrected using a mudstone compaction restoration experiment, thereby correcting the paleogeographic thickness below the 0-line plane.

[0009] Furthermore, the mudstone compaction recovery experiment process was as follows: mudstone samples were collected from the main area of ​​the study area for bulk density testing to obtain the bulk density range of different samples; then the samples were ground into powder, and the powder was poured into a consolidation apparatus to simulate karst water erosion and other scenarios. The samples were then allowed to air dry naturally for a set time without applying external pressure, until the water in the pores was basically drained. The bulk density at this point was calculated, and the experimental compaction ratio was obtained.

[0010] Preferably, in S5, the top surface of the Ordovician system is used as the trend surface.

[0011] A method for restoring buried hill-type karst paleogeography includes the following processes: The reference surface selection module is used to select sedimentary limestone as the reference surface, with the pinch-out line of the sedimentary limestone as the 0-line surface standard; The paleogeographic thickness calculation module is used to obtain the paleogeographic thickness above and below the 0 line surface. The residual calculation module is used to fit the buried hilltop structural surface to the trend surface equation to obtain the trend surface value; and to obtain the residual by subtracting the trend surface value from the current structural data of the top of the carbonate rock. The correction module is used to stitch together the paleogeographic thickness above and below the 0 line surface, and then correct it by subtracting it from the residual to obtain the restored thickness of the buried hill type karst paleogeographic feature.

[0012] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for restoring the buried hill type karst paleogeography.

[0013] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method for restoring buried hill type karst paleogeography.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes different methods to obtain the paleogeographic thickness above and below the 0-line plane. A compaction correction method using well-controlled multiple iterations and modern mudstone compaction restoration experiments or paleostratigraphic compaction ratios is applied to correct the paleogeographic thickness below the 0-line plane. After stitching together the paleogeographic thicknesses above and below the 0-line plane, correction is performed using trend surface residual data (tectonic trend surface and paleoburied hill top surface). Residual correction, while ensuring precise relative elevation differences, highlights the characteristics of micro-amplitude tectonic changes, representing the undulation characteristics of micro-geomorphology, thus ensuring that the positive and negative relative elevation differences of micro-geomorphology remain unchanged. This yields a high-precision restored thickness of paleoburied hill-type karst paleogeographic features. Attached Figure Description

[0015] Figure 1 This is a flowchart of the method for restoring buried hill type karst paleolandforms according to the present invention; Figure 2 This is a schematic diagram showing the selection of the reference surface and paleomorphological restoration method of the present invention; Figure 3 This is a schematic flowchart of the residual superposition method for mold decompaction correction trend surface in this invention; Figure 4 This is a plan view after the relative residual thickness trend surface is superimposed with residual + mold decompaction correction trend surface superimposed with residual and recovered. Figure 5 This is a planar view after restoration using the existing molding method combined with the relative residual thickness method. Detailed Implementation

[0016] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terms “installation,” “connection,” and “linkage” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; a mechanical connection, an electrical connection, or a connection that allows communication; a direct connection or an indirect connection via an intermediate medium; or a connection within two elements or an interaction between two elements. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0019] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0020] like Figure 1 As shown, this embodiment illustrates the restoration method for buried hill-type karst paleomorphology. It comprehensively restores the karst paleomorphology using both the "relative residual thickness trend surface superimposed residual" and "imprint decompaction correction trend surface superimposed residual" methods. The process is as follows: Step 1: Select sedimentary limestone as the reference surface. The selection of the reference surface should follow these points: First, it should be able to represent the paleosea level during the deposition period and be an isochronous interface for the entire region. Second, it should have obvious seismic characteristics, be a strong wave impedance interface, and be traceable throughout the region. Finally, the closer it is to the weathering crust interface, the smaller the later tectonic activity and the relative undulation of the strata, and the more accurate the reconstruction accuracy.

[0021] Step 2: Selection of Paleomorphological Restoration Method: Considering that the stable sedimentary limestone section at the top of the buried hill is eroded and cannot be selected, this patent uses the pinch-out line of the sedimentary limestone as the "0" line standard to obtain the relative thickness of the paleokarst surface relative to the "0" line, which is used to restore the buried hill-type karst paleomorphological features. Below the "0" line, there is a sedimentary limestone distribution area, and above the "0" line, there is no sedimentary limestone distribution area. Therefore, two methods are adopted to restore the pre-Carboniferous karst paleomorphological features: below the "0" line, the impression compaction correction method is used, and above the "0" line, the relative residual thickness method is used.

[0022] Step 3: Different types of sediments exhibit varying degrees of compaction under the same external conditions during the compaction process at different burial depths. Therefore, differential compaction structures often form in laterally heterogeneous strata, with strata of different thicknesses showing significant differences in compaction amounts. The paleostrata thickness is determined using a well-controlled multiple iteration method, establishing the density ρ(Z) and porosity... (Z) is fitted to the relationship function between the two layers. Based on the obtained paleothickness data of multiple sedimentary layers, the paleogeographic thickness below the 0 line surface is then compacted and corrected.

[0023] Step 4: Mudstone Compaction Restoration Experiment Corrects and Restores Paleothickness: Mudstone samples were collected from the main area of ​​the study area to calculate the compaction ratio. The compaction ratio of the paleokarst strata was corrected to eliminate interference from logging anomalies and local lithological changes, thus obtaining the compaction ratio of modern karst sediments. An accurate compaction correction coefficient was obtained, and the compaction ratio of paleokarst was corrected using the compaction ratio of modern karst sediments to obtain the compaction ratio of paleokarst strata that conforms to the study area.

[0024] Step 5: By fitting the trend surface equation to obtain the trend of the buried hilltop structural surface, the paleogeography is corrected by trend surface correction to compensate for the accuracy problem caused by the elevation difference. Then, the residual between the impression thickness and the current structural thickness can be calculated. The residual (relative elevation difference of paleoweathered crust topography) serves as the undulation feature of micro-geography, which not only ensures the accuracy of the relative elevation difference of micro-geography, but also highlights the undulation of the landform.

[0025] The process involves subtracting the obtained trend surface values ​​from the structural data of the ancient buried hill summit to obtain residual data. This residual data, while ensuring precise relative elevation differences, highlights the characteristics of micro-amplitude tectonic changes, serving as the undulation features of micro-topography and ensuring that the positive and negative relative elevation differences of micro-topography remain unchanged. This yields a high-precision restored thickness of the ancient buried hill-type karst paleogeography.

[0026] The above steps are described in detail below: Step 1: The selection of the reference surface should follow these key points: First, it should represent the paleosea level during the depositional period and be an isochronous interface for the entire region; second, it should exhibit clear seismic characteristics, be a strong impedance interface, and be traceable throughout the region; finally, the closer it is to the weathering crust interface, the smaller the subsequent tectonic activity and relative undulations of the strata, and the more accurate the reconstruction. Taking the paleogeographic reconstruction of the Lunnan ancient buried hill in the Tarim Oilfield as an example: Based on the sedimentary distribution pattern of the overlying strata and the seismic reflection characteristics, the Shuangfeng limestone section is the reference surface that is closest to the weathering crust interface and has the characteristics of marine deposition and a strong impedance interface.

[0027] Step 2: Selection of Paleomorphological Restoration Method: Considering that the stable sedimentary limestone section (bimodal limestone) at the top of the ancient buried hill cannot be selected due to erosion, such as... Figure 2As shown, this patent uses the pinch-out line of bimodal limestone as the "0" line standard to establish the relative thickness of the paleokarst surface relative to the "0" line, in order to restore the paleomorphology of buried hill type karst. Below the "0" line, there is a bimodal limestone distribution area, while above the "0" line, there is no bimodal limestone distribution area. Therefore, two methods are adopted to restore the pre-Carboniferous karst paleomorphology: below the "0" line, compaction and correction are performed using an impression mold (steps 3-7); above the "0" line, the relative residual thickness method is used (step 8).

[0028] Step 3: For areas with bimodal limestone distribution below the "0" line, such as... Figure 3 As shown, the "imprint decompaction correction" method is employed. Baseline stratigraphic data and buried hill erosion surface stratigraphic data are obtained using seismic interpretation results. The imprint thickness method is used to reconstruct the karst paleomorphology, obtaining imprint thickness data, i.e., the paleomorphological thickness below the "0" line. Figure 3 As shown in a.

[0029] Step 4: For the restoration of buried hill-type karst paleomorphology, simple paleomorphological restoration is not effective. Different types of sediments, under the same external conditions, exhibit varying degrees of compaction during the burial and compaction process. Therefore, differential compaction structures often form in laterally heterogeneous strata, with strata of different thicknesses showing significant differences in compaction amounts. This patent, guided by the restoration of modern karst landforms in southern China, considers that surface weathering crust sediments undergo significant karst water release and reduced porosity during deposition and diagenesis, resulting in stratigraphic compaction. Therefore, considering the compaction amount correction scale in karst paleomorphological restoration is essential.

[0030] Step 5: Fully utilize the abundant well logging data in the study area, and use the well-controlled multiple iteration method to solve for the paleostrata thickness. This is achieved by establishing the density ρ(Z) and porosity... The relationship between Z and formation thickness is fitted using a function. Taking the density function ρ(Z) as an example: Construct a system of relational equations: (1)

[0031]

[0032] Matrix standardization yields: (2) In the formula, y is the burial depth and stratum thickness, x is the current weighted average density, ρ is the density polynomial fitting function, and Z is the stratum depth.

[0033] By orthogonalizing it using formula (2), the function ρ(Z) of density variation with thickness is obtained.

[0034] Step 6: Use formulas (1) and (2) to obtain the porosity variation function with thickness. (Z), based on the fitting parameters obtained in step 5, assuming that the stratigraphic skeleton volume and skeleton mass remain unchanged, the paleogeographic thickness is obtained by referring to formula (3). Finally, based on the obtained paleogeographic thickness data of multiple points, the compaction ratio of the paleokarst strata that conforms to the study area is obtained, and then the paleogeographic thickness below the 0 line surface is compacted and corrected, such as... Figure 3 As shown in b.

[0035] (3) In the formula, Z is the current burial depth of the top plate of the strata (m), h is the current stratum thickness (m), and S is the paleothickness of the sedimentary layer (m). (Z) is the porosity-depth relationship function, and ρ(Z) is the density-depth relationship function.

[0036] Step 7: Mudstone compaction restoration experiment to correct paleogeographic thickness: Collect mudstone samples from the main area of ​​the study area for bulk density testing to obtain the bulk density range γ1 of different samples; then grind the samples into powder, simulate karst water erosion and other scenarios, pour them into the ring cutter of the consolidation apparatus (filled with permeable stones), let them stand for one month without applying external pressure, and air dry them under natural conditions. The water in the pores is basically drained, and the bulk density γ0 is calculated at this time. Under the condition of constant mass, volume is inversely proportional to bulk density. The experimental compaction ratio is calculated by formula (4), and the compaction ratio of the paleokarst strata obtained in step (6) is corrected to eliminate the interference caused by well logging anomalies and local lithological changes, and obtain an accurate compaction correction coefficient, thereby correcting the paleogeographic thickness.

[0037] (4) Where: V0—volume before compaction; V1—volume after compaction; γ0—bulk density before compaction; γ1—bulk density after compaction.

[0038] Step 8: For the area above the "0" line where there is no bimodal limestone distribution, the relative residual thickness method is used. Using seismic interpretation results, the elevation plane of the bimodal limestone pinch-out line and the stratigraphic position of the buried hill erosion surface are obtained. Since the area above the "0" line is composed of rigid carbonate strata, the relative elevation difference between the positive and negative topography will not change significantly due to compaction. The residual paleogeographic thickness of the area without bimodal limestone distribution, i.e., the paleogeographic thickness above the "0" line, is obtained by directly subtracting the two data points.

[0039] Step 9: As Figure 3As shown in b, after restoring the paleostratum thickness in steps (7) and (8), it was found that due to the influence of paleotopography, the amount of compaction correction restoration in different parts was different (the amount of restoration in positive topography parts was small, and the amount of restoration in negative topography parts was large), which caused changes in the relative elevation difference between positive and negative topography. Therefore, it is necessary to perform trend surface correction on the paleotopography to make up for the accuracy problem caused by the elevation difference. Then, it is possible to calculate the residual between the impression thickness and the current structural thickness. The residual (relative elevation difference of paleoweathered crust topography) serves as the undulation feature of microtopography, which not only ensures the accuracy of the relative elevation difference of microtopography, but also highlights the undulation of the topography. The specific process is steps 10-11.

[0040] Step 10: As Figure 3 As shown in c, the selection approach for the trend surface is as follows: Taking the Lunnan ancient buried hill as an example, the later-stage tectonic activity of the weathering crust mainly involves uplift and bulging. The relative elevation difference between the positive and negative topographic features of the Ordovician top surface will not change significantly. Therefore, the trend surface analysis is based on the Ordovician top surface tectonic surface as a reference. The trend surface is obtained by fitting the trend surface equation (Formula 5) to the tectonic surface of the buried hilltop.

[0041] Step 11: As Figure 3 As shown in d, the residual data is obtained by subtracting the trend surface value obtained in step 10 from the structural data of the ancient buried hill top. This data, while ensuring the accuracy of the relative elevation difference, highlights the characteristics of micro-amplitude structural changes, serving as the undulation characteristics of the micro-landform and ensuring that the positive and negative relative elevation differences of the micro-landform do not change. The imprinted paleo-landform thickness obtained in step 7 and the residual paleo-landform thickness obtained in step 8 are spliced ​​together, and then subtracted from the trend surface-residual data obtained in step 11 to obtain the high-precision restored thickness of the ancient buried hill type karst paleo-landform (see attached). Figure 4 Compared with the simple impression-residual thickness combination method (see appendix) Figure 5 The karst gullies and water systems are more clearly visible, accurately restoring the original karst landform. Both the micro-landform depiction and the accuracy of the data have been greatly improved.

[0042] The following are embodiments of the apparatus of the present invention, which can be used to execute embodiments of the method of the present invention. For details not omitted in the apparatus embodiments, please refer to the embodiments of the method of the present invention.

[0043] In another embodiment of the present invention, a restoration system for buried hill type karst paleolandforms is provided. This system can be used to implement the above-mentioned restoration method for buried hill type karst paleolandforms. Specifically, the system includes a reference surface selection module, a paleolandform thickness calculation module, a residual calculation module, and a correction module.

[0044] The reference surface selection module is used to select sedimentary limestone as the reference surface, with the pinch-out line of the sedimentary limestone as the 0-line surface standard.

[0045] The paleogeographic thickness calculation module is used to obtain the paleogeographic thickness above and below the 0 line surface.

[0046] The residual calculation module is used to fit the buried hilltop structural surface by fitting the trend surface equation to obtain the trend surface value; the residual is obtained by subtracting the trend surface value from the current structural data of the top of the carbonate rock.

[0047] The correction module is used to stitch together the paleogeographic thickness above and below the 0 line surface, and then correct it by subtracting it from the residual to obtain the restored thickness of the buried hill type karst paleogeographic feature.

[0048] In another embodiment of the present invention, a terminal device is provided, comprising a processor and a memory. The memory stores a computer program, the computer program including program instructions, and the processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), or field-programmable gate arrays (FPGAs). Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., are the computing core and control core of the terminal. They are suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to realize the corresponding method flow or corresponding function. The processor described in this embodiment of the invention can be used for the operation of the restoration method of buried hill type karst paleogeography, including: S1, selecting sedimentary limestone as the reference surface, and taking the pinch-out line of sedimentary limestone as the 0-line surface standard; S2, obtaining the paleogeographic thickness above and below the 0-line surface respectively; S3, fitting the buried hill top structural surface by fitting the trend surface equation to obtain the trend surface value; subtracting the trend surface value from the current carbonate rock top structural data to obtain the residual; S4, splicing the paleogeographic thickness above and below the 0-line surface, and then subtracting it from the residual for correction to obtain the restored thickness of buried hill type karst paleogeography.

[0049] In another embodiment, the present invention also provides a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It is understood that the computer-readable storage medium here may include both the built-in storage medium in the terminal device and extended storage media supported by the terminal device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor, which may be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here may be high-speed RAM or non-volatile memory, such as at least one disk storage device.

[0050] One or more instructions stored in a computer-readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the restoration method for buried hill-type karst paleogeography in the above embodiments; one or more instructions in the computer-readable storage medium are loaded and executed by the processor in the following steps: S1, select sedimentary limestone as the reference surface, and take the pinch-out line of sedimentary limestone as the 0-line surface standard; S2, obtain the paleogeographic thickness above and below the 0-line surface respectively; S3, fit the buried hill top structural surface by fitting the trend surface equation to obtain the trend surface value; subtract the trend surface value from the current carbonate rock top structural data to obtain the residual; S4, splice the paleogeographic thickness above and below the 0-line surface, and then subtract it from the residual for correction to obtain the restored thickness of buried hill-type karst paleogeography.

[0051] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0052] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0053] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0054] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0055] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0056] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0057] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0058] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0059] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

[0060] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this patent should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

Claims

1. A method for restoring buried hill-type karst paleolandforms, characterized in that, The process includes the following: S1, sedimentary limestone is selected as the reference surface, and the pinch-out line of sedimentary limestone is taken as the standard of the 0 line surface; S2, obtain the paleogeographic thickness above and below the 0 line surface respectively; S3. The trend surface value is obtained by fitting the trend surface equation to the top structure of the buried mountain; the residual is obtained by subtracting the trend surface value from the current structural data of the top of the carbonate rock. S4 splices the paleogeographic thickness above and below the 0 line surface, and then corrects it by subtracting it from the residual to obtain the restored thickness of the buried hill type karst paleogeographic feature.

2. The method for restoring buried hill type karst paleolandforms according to claim 1, characterized in that, In S1, the rock segment closest to the weathering crust interface and containing marine sediments and a strong wave impedance interface is used as the reference surface.

3. The method for restoring buried hill type karst paleolandforms according to claim 1, characterized in that, In S2, the paleogeographic thickness below the 0 line surface is obtained using the impression thickness method.

4. The method for restoring buried hill type karst paleolandforms according to claim 3, characterized in that, By establishing a relationship function between stratigraphic density and stratigraphic thickness and fitting it, a relationship function is obtained. Using the relationship function, the variation function of stratigraphic porosity with stratigraphic thickness is obtained, and then the thickness of paleogeography below the 0 line plane is compacted and corrected.

5. The method for restoring buried hill type karst paleolandforms according to claim 4, characterized in that, Based on the obtained data of multiple paleogeographic thickness points, the compaction ratio of the paleokarst strata was obtained. The compaction ratio of the paleokarst strata was corrected by mudstone compaction restoration experiments, and then the paleogeographic thickness below the 0 line surface was corrected.

6. The method for restoring buried hill type karst paleolandforms according to claim 5, characterized in that, The mudstone compaction recovery experiment process is as follows: mudstone samples from the main area of ​​the study area are collected for bulk density testing to obtain the bulk density range of different samples; then the samples are ground into powder, and the powder is poured into a consolidation apparatus to simulate karst water erosion and other scenarios. The powder is left to stand for a set time without external pressure and air-dried naturally until the water in the pores is basically drained. The bulk density at this time is calculated, and the experimental compaction ratio is obtained.

7. The method for restoring buried hill type karst paleolandforms according to claim 1, characterized in that, In S3, the top surface of the Ordovician system is used as the trend surface.

8. A method for restoring buried hill type karst paleolandforms, characterized in that, The process includes the following: The reference surface selection module is used to select sedimentary limestone as the reference surface, with the pinch-out line of the sedimentary limestone as the 0-line surface standard; The paleogeographic thickness calculation module is used to obtain the paleogeographic thickness above and below the 0 line surface. The residual calculation module is used to fit the buried hilltop structural surface to the trend surface equation to obtain the trend surface value; and to obtain the residual by subtracting the trend surface value from the current structural data of the top of the carbonate rock. The correction module is used to stitch together the paleogeographic thickness above and below the 0 line surface, and then correct it by subtracting it from the residual to obtain the restored thickness of the buried hill type karst paleogeographic feature.

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, it implements the steps of the method for restoring buried hill type karst paleolandforms as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for restoring buried hill type karst paleolandforms as described in any one of claims 1 to 7.

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