Karst ancient landform recovery method and system based on real stratum thickness

Abstract

The invention discloses a karst ancient landform recovery method and system based on the real thickness of a stratum, and belongs to the technical field of rock stratum ancient landform recovery. The real stratum thickness of the first algorithm is calculated through drilling data when the upper interface and the lower interface of the stratum are inclined and not parallel; the real stratum thickness of a second algorithm is obtained through calculation according to the seismic data; counting the thickness difference between the real stratum thickness of the first algorithm and the real stratum thickness of the second algorithm in the research area at the well point, and performing difference gridding interpolation by adopting a cubic spline interpolation method; and merging the difference gridding interpolation data and the stratum real thickness gridding data of the second algorithm to obtain an ancient landform map. According to the method, the drilling data, the seismic data and other data are combined, ancient landform recovery errors caused by the difference between the stratum apparent thickness and the real thickness due to stratum inclination are eliminated by recovering the real thickness of the stratum, and the ancient landform recovery precision and the exploration and development success rate can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of stratum palaeogeomorphology restoration, and particularly relates to a karst palaeogeomorphology restoration method and system based on stratum true thickness. BACKGROUND

[0002] The research method of karst palaeogeomorphology has been one of the hot and difficult problems in the exploration and research of carbonate rock weathering crust karst reservoir. Since the karst palaeogeomorphology of carbonate rock is formed early, and after the formation of the karst palaeogeomorphology, the overlying strata are compacted and reformed by multiple tectonic movements, it is very difficult to accurately restore the karst palaeogeomorphology. In order to solve this problem, scholars have continuously explored and proposed new methods and new ideas for the research of karst palaeogeomorphology. At present, the restoration of carbonate rock palaeogeomorphology mostly adopts methods such as residual thickness method and impression method, and generally calculates the stratum thickness by using drilling data or seismic data. Although the above methods are simple to operate, the calculated result is the apparent thickness of the stratum, not the true thickness of the stratum.

[0003] There are two methods for obtaining the stratum thickness by using drilling data: the first method is well deviation correction method, which is simple to operate and is most widely used at present, but is only suitable for the case that the stratum is horizontal. The second method is correction formula method, which gives the correction formula under different conditions of drilling direction and stratum dip by analyzing the relationship between the well deviation trajectory and the stratum trend. The method has high calculation accuracy, but needs to accurately know various angles between the stratum and the well, and it is difficult to obtain these angles in practical application.

[0004] The common method for obtaining the stratum thickness by using seismic data is to directly subtract the stratum thickness in the time domain obtained by using the seismic horizon data interpreted from the seismic data, or to subtract the stratum thickness in the depth domain obtained by using the time-depth conversion formula. The method actually obtains the apparent thickness of the stratum, not the true thickness of the stratum. The true thickness of the stratum should be equal to the apparent thickness of the stratum multiplied by the cosine of the stratum dip angle at the corresponding position. There are two problems in calculating the stratum dip angle for the seismic profile passing through the well: ① on the seismic profile, the horizontal direction is distance and the vertical direction is time, and the calculated stratum dip angle is different when the seismic profile is displayed in different scales; ② if the seismic profile passing through the well is not perpendicular to the stratum trend, the calculated stratum dip angle is not the true dip angle of the stratum. SUMMARY

[0005] In view of the above problems, in order to further improve the accuracy of palaeogeomorphology restoration, the present application provides a karst palaeogeomorphology restoration method and system based on stratum true thickness. The specific technical scheme is as follows:

[0006] The present application provides a karst palaeogeomorphology restoration method based on stratum true thickness, which comprises the following steps:

[0007] The first algorithm of calculating the real thickness of the stratum when the upper and lower interfaces of the stratum are inclined and not parallel is used to calculate the real thickness of the stratum by using the drilling data;

[0008] The second algorithm of calculating the real thickness of the stratum is calculated by using the seismic data and the curvature body calculation method to determine the real dip angle of the stratum;

[0009] The thickness difference of the real thickness of the stratum calculated by the first algorithm and the real thickness of the stratum calculated by the second algorithm at the well point in the research area is statistically studied, and the difference gridding interpolation is carried out by using the cubic spline interpolation method;

[0010] After the difference gridding interpolation data and the gridding data of the real thickness of the stratum calculated by the second algorithm are combined and processed, the palaeogeomorphology map is obtained.

[0011] Further, the first algorithm of calculating the real thickness of the stratum when the upper and lower interfaces of the stratum are inclined and not parallel includes the following steps:

[0012] A geological model of the upper and lower interfaces of the stratum being inclined and not parallel is established;

[0013] The apparent dip angle of the upper interface of the stratum, the apparent dip angle of the lower interface of the stratum and the inclination angle of the well are determined in the geological model;

[0014] The real dip angle of the upper interface of the stratum and the real dip angle of the lower interface of the stratum are calculated according to the angle between the stratum tendency and the drilling direction, the apparent dip angle of the upper interface of the stratum and the apparent dip angle of the lower interface of the stratum;

[0015] The real thickness of the stratum calculated by the first algorithm is calculated according to the real dip angle of the upper interface of the stratum, the real dip angle of the lower interface of the stratum, the inclination angle of the well, the angle between the stratum tendency and the drilling direction and the thickness of the stratum drilled.

[0016] Further, the calculation formula of the real dip angle of the upper interface of the stratum and the real dip angle of the lower interface of the stratum according to the angle between the stratum tendency and the drilling direction and the apparent dip angle of the upper interface of the stratum and the apparent dip angle of the lower interface of the stratum respectively is as follows:

[0017] θ1=arctan(tanλ1*COSα)

[0018] θ2=arctan(tanλ2*COSα)

[0019] Wherein, θ1 and θ2 are the apparent dip angle of the upper interface of the stratum and the apparent dip angle of the lower interface of the stratum respectively, λ1 and λ2 are the real dip angle of the upper interface of the stratum and the real dip angle of the lower interface of the stratum respectively, and α is the angle between the stratum tendency and the drilling direction.

[0020] Further, the calculation formula of the real thickness of the stratum calculated by the first algorithm according to the real dip angle of the upper interface of the stratum, the real dip angle of the lower interface of the stratum, the inclination angle of the well, the angle between the stratum tendency and the drilling direction and the thickness of the stratum drilled and the real thickness of the stratum is as follows:

[0021] OC = [ON * COS(arctan(tan λ2 * COS α)) * COS ψ] / COS [arctan(tan λ2 * COS α) - arctan(tan λ1 * COS α)]

[0022] OC = [ON * COS(arctan(tan λ2 * COS α)) * COS ψ] / COS [arctan(tan λ2 * COS α) - arctan(tan λ1 * COS α)]

[0023] Wherein, OC is the real thickness of the stratum; ON is the thickness of the drilling stratum, λ1 and λ2 are the true dip angles of the upper and lower interfaces of the stratum respectively, α is the included angle between the stratum dip and the drilling azimuth, and ψ is the inclination angle.

[0024] Further, the real thickness of the stratum determined by the second algorithm based on the real dip angle of the stratum calculated by the curvature volume calculation method comprises the following steps:

[0025] The seismic data is subjected to structural smoothing processing by using the median filter algorithm;

[0026] The seismic data subjected to the structural smoothing processing is subjected to parameter experiment, and the variance volume is calculated, and the curvature volume is calculated by constructing the surface fitting equation;

[0027] The real dip angle of the stratum at the calculation position is calculated by using the difference method;

[0028] The real thickness of the stratum at the corresponding position according to the second algorithm is calculated according to the real dip angle of the stratum and the apparent thickness of the stratum.

[0029] Further, the calculation formula of the real dip angle of the stratum is as follows:

[0030]

[0031] Wherein, θ is the real dip angle of the stratum; d and e are constants obtained by the derivative formula of the discrete data by the difference method.

[0032] Further, the real thickness of the stratum at the corresponding position according to the second algorithm is calculated according to the real dip angle of the stratum and the apparent thickness of the stratum.

[0033] Further, the difference grid interpolation data and the real thickness grid data of the stratum according to the second algorithm calculated by using the seismic data are merged, so as to obtain the paleogeomorphology map, which comprises the following steps:

[0034] The real thickness data of the stratum according to the second algorithm is subjected to grid interpolation by using the weighted least square method, so as to obtain the real thickness grid data of the stratum according to the second algorithm;

[0035] The second algorithm real thickness grid data and the difference grid interpolation data are combined to generate a new real thickness contour map of strata;

[0036] A palaeogeomorphology map is generated according to the new real thickness contour map of strata.

[0037] In a second aspect, the present application provides a karst palaeogeomorphology recovery system based on real thickness of strata, comprising:

[0038] A first algorithm real thickness calculation unit is configured to calculate the first algorithm real thickness of strata when the upper and lower interfaces of strata are inclined and not parallel by using drilling data;

[0039] A second algorithm real thickness calculation unit is configured to calculate the second algorithm real thickness of strata by using seismic data and a curvature body calculation method to determine the real dip angle of strata;

[0040] A thickness interpolation unit is configured to calculate the thickness difference of the first algorithm real thickness of strata and the second algorithm real thickness of strata at well points in a study area and perform difference grid interpolation by using a cubic spline interpolation method;

[0041] A recovery unit is configured to combine the difference grid interpolation data with the second algorithm real thickness grid data of strata to obtain a palaeogeomorphology map.

[0042] In a third aspect, the present application provides an electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory complete mutual communication through the communication bus;

[0043] The memory stores a computer program;

[0044] The processor is configured to execute the program stored in the memory to implement the karst palaeogeomorphology recovery method based on real thickness of strata.

[0045] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed to implement the karst palaeogeomorphology recovery method based on real thickness of strata.

[0046] The present application has the following beneficial effects:

[0047] The present application combines various data such as drilling data and seismic data, eliminates the palaeogeomorphology recovery error caused by the difference between apparent thickness and real thickness of strata due to strata inclination by recovering real thickness of strata, effectively improves the palaeogeomorphology recovery precision and improves the exploration and development success rate.

[0048] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 A flowchart of the carbonate rock karst paleogeographic restoration method based on the actual thickness of strata proposed in an embodiment of the present invention is shown;

[0051] Figure 2 This diagram illustrates the solution of the true thickness of strata in a geological model where the upper and lower interfaces of the strata are inclined and non-parallel, according to an embodiment of the present invention.

[0052] Figure 3 This invention presents a paleogeographic map of the Permian Maokou Formation in the MX region obtained solely from drilling data in an embodiment of the invention.

[0053] Figure 4 This invention presents a paleogeographic map of the Permian Maokou Formation in the MX region obtained solely from seismic data in an embodiment of the invention.

[0054] Figure 5 This invention illustrates a paleogeographic map of the Permian Maokou Formation in the MX region obtained by fusing drilling and seismic data in an embodiment of the invention.

[0055] Figure 6 A schematic diagram of an electronic device proposed in an embodiment of the present invention is shown. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] This invention proposes a method for reconstructing paleogeographic features of carbonate karst based on the actual thickness of strata, such as... Figure 1 As shown, it includes the following steps:

[0058] S1: calculating the real thickness of the formation by using drilling data according to the first algorithm;

[0059] The process of calculating the real thickness of the formation by using drilling data according to the first algorithm in the embodiment is as follows:

[0060] The real thickness of the inclined well is solved by establishing a geological model in which the upper and lower boundaries of the formation are inclined and not parallel, and the specific model is as shown in FIG. 1, wherein W is the trajectory of the wellbore, AB and EF are the upper boundary of the formation and the lower boundary of the formation respectively, θ1 and θ2 are the apparent dip angles of the upper boundary of the formation and the lower boundary of the formation respectively, ψ is the inclination angle, and the dashed lines OG, OC and OD are the vertical reference line, the vertical reference line of the upper boundary of the formation and the vertical reference line of the lower boundary of the formation respectively. Figure 2

[0061] According to the trigonometric relationship, the following can be obtained:

[0062] OD = OC * COS (θ2-θ1) (1)

[0063] OD = OG * COSθ2 (2)

[0064] OG = ON * COSψ (3)

[0065] According to the formulas (1)-(3), the following can be obtained:

[0066] OC = (ON * COSθ2 * COSψ) / COS (θ2-θ1) (4)

[0067] Since θ1 and θ2 are the apparent dip angles of the upper boundary of the formation and the lower boundary of the formation respectively, they must be converted into the true dip angles. The relationship between the true dip angle of the formation and the apparent dip angle of the formation is as follows:

[0068] According to tanθ1 = tanλ1 * COSα, θ1 is converted into arctan (tanλ1 * COSα) (5)

[0069] According to tanθ2 = tanλ2 * COSα, θ2 is converted into arctan (tanλ2 * COSα) (6)

[0070] In the formulas (5) and (6), λ1 and λ2 are the true dip angles of the upper boundary of the formation and the lower boundary of the formation respectively; and α is the included angle between the dip direction of the formation and the drilling direction.

[0071] The formulas (5) and (6) are substituted into the formula (4), and the real thickness of the formation can be obtained, that is,

[0072] OC = [ON * COS (arctan (tanλ2 * COSα)) * COSψ] / COS [arctan (tanλ2 * COSα)] (7) ​

[0073] α)-arctan(tanλ1*COSα)](7)

[0074] In formula (7), OC is the actual formation thickness; ON is the drilling formation thickness, wherein the drilling formation thickness ON and the well inclination angle ψ are obtained from the drilling data; α is obtained from both the drilling data and the logging data, and λ1 and λ2 are obtained from the logging data.

[0075] Based on the information obtained from well logging and drilling data, the true thickness of the formation when the upper and lower interfaces are inclined and not parallel can be calculated using Formula 7.

[0076] In one embodiment of the present invention, a cubic spline interpolation method can be used to perform gridded interpolation on the actual formation thickness data obtained from the first algorithm using drilling data, thereby obtaining a paleogeographic map, such as... Figure 3 As shown. It should be noted that cubic spline interpolation is the process of constructing a smooth curve through a series of shape points, ensuring the smoothness of the entire curve; grid interpolation refers to generating a continuous grid or surface in a two-dimensional or higher-dimensional space using a given set of discrete data points.

[0077] S2: The true thickness of the formation using the second algorithm is calculated based on the true dip angle of the formation determined by seismic data and the curvature body calculation method; specifically, it includes the following steps:

[0078] Seismic data preprocessing; structural smoothing of the seismic data volume; specifically, median filtering algorithm can be used to effectively reduce noise interference and enhance the continuity of seismic reflection axes;

[0079] Curvature volume calculation: Experiments are conducted on preprocessed seismic data using different algorithms (additive and multiplicative modes), different trace numbers, and different time windows. Based on the optimized parameters, the variance volume is calculated. The calculated variance volume is then fitted with a surface equation to realize the curvature volume calculation. The optimized parameters must adhere to the following principles:

[0080] The algorithm selection principle is based on a comprehensive consideration of the fault direction and computation time.

[0081] The principle for selecting the number of channels is: the higher the required calculation precision, the more channels should be selected;

[0082] The principle for selecting a time window is that the greater the dip angle of the formation, the larger the selected time window should be.

[0083] True dip angle calculation: To calculate the dip angle attribute of a point on the calculation plane, a local quadratic surface is fitted using the least squares method with the values ​​of the surrounding grid points. The first derivative of the quadratic surface equation is then obtained using the finite difference method, which yields the true dip angle. The formula for calculating the true dip angle is as follows:

[0084]

[0085] Where θ is the true dip angle of the formation; d and e are constants that can be obtained from the derivative formula of the discrete data using the finite difference method.

[0086] For example, if a 3×3 grid unit is used for approximation, d and e can be obtained from the derivative formula of the discretized data using the finite difference method.

[0087] d=dz / dx=(z3+z6+z9-z1-z4-z7) / 6Δx 2 ,

[0088] e=dz / dy=(z1+z2+z3-z7-z8-z9) / 6Δy 2 ,

[0089] Where z1, z2, z3, ..., z9 are the values ​​of the layer mesh nodes 1, 2, 3, ..., 9, respectively, and Δx 2 Δy 2 These represent the distances between grid nodes.

[0090] The true thickness of the strata at the corresponding location is calculated using the second algorithm based on the true dip angle and apparent thickness of the strata; where the corresponding location refers to the same location calculated by the first algorithm.

[0091] The weighted squares method is used to perform gridded interpolation on the actual stratigraphic thickness data obtained from the second algorithm using seismic data, resulting in gridded data of the actual stratigraphic thickness of the second algorithm. This data is then used to further obtain paleogeographic maps, such as... Figure 4 As shown.

[0092] The true formation thickness can be calculated using both drilling and seismic data. However, due to the difficulty in accurately determining seismic wave velocity, the true formation thickness obtained from drilling data often differs from that obtained from well-side seismic data. To overcome this deficiency, this invention combines the accuracy of the first algorithm for calculating the true formation thickness at the well point using drilling data with the rationality of the lateral distribution trend of the second algorithm using seismic data to calculate the true formation thickness.

[0093] Based on the actual stratigraphic thickness obtained in steps S1 and S2, the paleomorphology is reconstructed by calculating the actual stratigraphic thickness using well-seismic fusion, which includes two steps:

[0094] S3: The difference between the actual formation thickness of the first algorithm and the actual formation thickness of the second algorithm at the well point in the statistical study area, and the grid interpolation method is used for interpolation.

[0095] S4: Merge the interpolated data using the interpolation and the stratigraphic thickness gridded data obtained using the second algorithm to generate a new stratigraphic thickness contour map, thus obtaining a paleomorphological map, such as... Figure 5 As shown. Specifically, the true thickness contour map data of the strata can be imported into GIS (Geographic Information System) software, and the necessary format conversion and coordinate system adjustment can be performed. Then, the spatial analysis function of the GIS software can be used to further analyze the true thickness data of the strata, and the boundaries and characteristics of geomorphic units (such as highlands, lowlands, basins, etc.) can be identified. Then, based on the geological tectonic background, the true thickness data of the strata can be structurally restored to eliminate the influence of tectonic deformation on paleogeography. Finally, based on the true thickness data of the strata and the spatial analysis results, paleogeographic maps can be drawn in the GIS software, which usually involves coloring, labeling and symbolizing geomorphic units to visually display the paleogeographic features.

[0096] Using the above method, the Permian Maokou Formation karst paleogeography was restored in the MX area of ​​the SC Basin. The accuracy of the actual formation thickness calculated from drilling data at the well points and the rationality of the actual formation thickness calculated from seismic data in the lateral distribution trend were fully utilized. The actual formation thickness was calculated by organically integrating the two, and the paleogeography was quantitatively restored. Based on the restoration results, three wells (moxi145, moxi147, and moxi149) were deployed, and all of them encountered high-quality reservoirs.

[0097] Based on the same inventive concept, one embodiment of the present invention proposes a karst paleogeographic reconstruction system based on the actual thickness of strata, such as... Figure 5 As shown, it includes:

[0098] The first algorithm's formation true thickness calculation unit is used to calculate the formation true thickness of the first algorithm when the upper and lower interfaces of the formation are inclined and non-parallel using drilling data.

[0099] The second algorithm's true formation thickness calculation unit is used to calculate the true formation thickness of the second algorithm by using seismic data and the true dip angle of the formation determined by the curvature body calculation method.

[0100] The thickness interpolation unit is used to statistically measure the difference between the actual formation thickness of the first algorithm and the actual formation thickness of the second algorithm at the well point in the study area, and to perform gridded interpolation of the difference using the cubic spline interpolation method.

[0101] The recovery unit is used to merge the interpolated data of the difference gridding with the gridded data of the actual thickness of the strata from the second algorithm to obtain the paleogeographic map.

[0102] The execution steps of each unit in the formation true thickness calculation unit of the first algorithm, the formation true thickness calculation unit of the second algorithm, the thickness interpolation unit, and the recovery unit are similar to those described above, and will not be explained in detail here.

[0103] Another exemplary embodiment of the present invention provides an electronic device. For example... Figure 6 As shown, the electronic device includes at least one processor 601, at least one communication interface 602, at least one memory 603, and at least one communication bus 604; wherein the processor 601, communication interface 602, and memory 603 communicate with each other through the communication bus 604.

[0104] Memory 603 stores computer programs;

[0105] The processor 601, when executing the program stored in the memory 603, implements the karst paleogeographic restoration method based on the actual thickness of the strata.

[0106] Optionally, the communication interface can be an interface of a communication module, such as the interface of a GSM module; the processor may be a CPU, an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The memory may include high-speed RAM and may also include non-volatile memory, such as at least one disk storage device. The memory stores a program, and the processor calls the program stored in the memory to execute some or all of the above-described method embodiments.

[0107] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when executed, implements some or all of the above-described method embodiments. Optionally, the storage medium may be a non-transitory computer-readable storage medium, such as a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0108] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A karst paleogeomorphology restoration method based on true thickness of strata, characterized in that, The method comprises the following steps: calculating the real thickness of the stratum by a first algorithm when the upper and lower interfaces of the stratum are inclined and not parallel by using drilling data; calculating the real thickness of the stratum by a second algorithm by using the real dip angle of the stratum determined by using seismic data and a curvature body calculation method; statistically studying the thickness difference of the real thickness of the stratum by the first algorithm and the real thickness of the stratum by the second algorithm at the well point, and performing difference gridding interpolation by using a cubic spline interpolation method; obtaining a palaeogeomorphology map by merging and processing the difference gridding interpolation data and the real thickness of the stratum by the second algorithm.

2. The karst palaeogeomorphology restoration method based on true thickness of strata according to claim 1, characterized in that, The method for calculating the real thickness of the stratum by the first algorithm when the upper and lower interfaces of the stratum are inclined and not parallel by using drilling data comprises the following steps: establishing a geological model in which the upper and lower interfaces of the stratum are inclined and not parallel; determining the apparent dip angle of the upper interface of the stratum, the apparent dip angle of the lower interface of the stratum and the inclination angle of the well in the geological model; calculating the real dip angle of the upper interface of the stratum and the real dip angle of the lower interface of the stratum according to the angle between the stratum tendency and the drilling direction, the apparent dip angle of the upper interface of the stratum and the apparent dip angle of the lower interface of the stratum; calculating the real thickness of the stratum by the first algorithm according to the real dip angle of the upper interface of the stratum, the real dip angle of the lower interface of the stratum, the inclination angle of the well, the angle between the stratum tendency and the drilling direction and the stratum thickness of the well.

3. The karst palaeogeomorphology restoration method based on true thickness of strata according to claim 2, characterized in that, The calculation formulae of the real dip angle of the upper interface of the stratum and the real dip angle of the lower interface of the stratum are as follows: θ1=arctan(tanλ1*COSα) θ2=arctan(tanλ2*COSα) wherein θ1 and θ2 are the apparent dip angle of the upper interface of the stratum and the apparent dip angle of the lower interface of the stratum respectively, λ1 and λ2 are the real dip angle of the upper interface of the stratum and the real dip angle of the lower interface of the stratum respectively, and α is the angle between the stratum tendency and the drilling direction.

4. The karst palaeogeomorphology restoration method based on true thickness of strata according to claim 3, characterized in that, The calculation formula of the real thickness of the stratum by the first algorithm is as follows: OC=[ON*COS(arctan(tanλ2*COSα)*COSψ] / COS[arctan(tanλ2*COSα)-arctan(tanλ1*COSα)] wherein OC is the real thickness of the stratum; ON is the stratum thickness of the well, λ1 and λ2 are the real dip angle of the upper interface of the stratum and the real dip angle of the lower interface of the stratum respectively, α is the angle between the stratum tendency and the drilling direction, and ψ is the inclination angle of the well. The method for calculating the real thickness of the stratum by the second algorithm by using the real dip angle of the stratum determined by using seismic data and a curvature body calculation method comprises the following steps:

5. The karst palaeogeomorphology restoration method based on true thickness of strata according to claim 1, characterized in that, performing structural smoothing processing on the seismic data by using a median filter algorithm; performing parameter experiments on the seismic data after the structural smoothing processing, and calculating a variance body, and calculating the curvature body by constructing a surface fitting equation; calculating the real dip angle of the stratum at the calculation position by using a difference method; calculating the real thickness of the stratum at the corresponding position by the second algorithm according to the real dip angle of the stratum and the apparent thickness of the stratum. The calculation formula of the real dip angle of the stratum is as follows:

6. The karst palaeogeomorphology restoration method based on true thickness of strata according to claim 5, characterized in that, wherein θ is the real dip angle of the stratum; d and e are constants obtained by a derivation formula of discrete data by using the difference method. The real thickness of the stratum at the corresponding position by the second algorithm is calculated by multiplying the apparent thickness of the stratum by the cosine of the real dip angle of the stratum at the corresponding position.

7. The karst palaeogeomorphology restoration method based on true thickness of strata according to claim 5, characterized in that, ​ 8. The karst palaeogeomorphology restoration method based on true thickness of strata according to claim 1, characterized in that, The difference grid interpolation data is combined with second algorithm stratum true thickness grid data calculated by seismic data, so as to obtain the palaeogeomorphology map, including the following steps: The second algorithm stratum true thickness data is grid interpolated by using the weighted least square method, so as to obtain the second algorithm stratum true thickness grid data; The second algorithm stratum true thickness grid data and the difference grid interpolation data are combined to generate a new stratum true thickness contour map; The palaeogeomorphology map is generated according to the new stratum true thickness contour map.

9. A karst paleogeomorphology restoration system based on real thickness of strata, characterized in that, It comprises: A first algorithm stratum true thickness calculation unit for calculating the first algorithm stratum true thickness by using drilling data when the stratum upper and lower interfaces are inclined and not parallel; A second algorithm stratum true thickness calculation unit for calculating the second algorithm stratum true thickness by using seismic data and adopting a curvature body calculation method to determine the stratum true dip angle; A thickness interpolation unit for calculating the thickness difference of the first algorithm stratum true thickness and the second algorithm stratum true thickness at the well point in the research area and adopting a cubic spline interpolation method to perform difference grid interpolation; A recovery unit for combining the difference grid interpolation data with the second algorithm stratum true thickness grid data to obtain the palaeogeomorphology map.

10. An electronic device, comprising: It comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory complete communication with each other through the communication bus; The memory stores a computer program; The processor is used to execute the program stored in the memory, so as to realize the karst palaeogeomorphology recovery method based on stratum true thickness according to any one of claims 1-8.

11. A computer-readable storage medium storing a computer program, characterized in that, The computer program is executed to perform the karst palaeogeomorphology recovery method based on stratum true thickness according to any one of claims 1-8.

Images