Stratum denudation amount recovery method and device, equipment and medium

Abstract

The invention discloses a stratum denudation amount recovery method and device, equipment and a medium, and belongs to the technical field of petroleum geophysical exploration processing. According to the method, the trend surface method is corrected by using the interval transit time method, the original stratum thickness of the target area is obtained, and the stratum denudation amount is recovered; the invention further provides a device for implementing the method, computer equipment and a computer readable storage medium. The method can accurately recover the stratum denudation amount, and can be applied to geophysical exploration of petroleum and evaluation of oil and gas resources.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum geophysical exploration and processing, and relates to a method for calculating stratum erosion amount, specifically to a method and device, equipment and medium for recovering stratum erosion amount. Background Art

[0002] Stratigraphic erosion is a common phenomenon in sedimentary basins. The amount of strata erosion has an important impact on the generation, migration and accumulation of oil and gas in sedimentary basins. The amount of strata erosion is an important parameter in basin simulation. Restoring the amount of strata erosion is a very important part of the study of geological structural evolution history and an important basic work for quantitative evaluation of oil and gas resources.

[0003] At present, the more mature methods for recovering stratum erosion include stratigraphic correlation method, sedimentation rate method, well logging curve method, fluid inclusion method, vitrinite reflectivity method, cosmogenic nuclide analysis method and apatite fission track analysis method, but all of the above methods have their own limitations.

[0004] The stratigraphic correlation method can only reflect the minimum amount of erosion in the survey area. In addition, when the erosion area is large and the stratum thickness varies greatly in the lateral direction, especially when erosion exists in the entire area, the error is large and the stratigraphic correlation method cannot be used at all. Since the parameter of erosion rate is sometimes difficult to obtain an accurate value, the sedimentation rate method can only be used in areas with in-depth stratigraphic research, and has great limitations. The well logging curve method, fluid inclusion method and vitrinite reflectance method are not suitable for areas with small erosion. On the contrary, the cosmogenic nuclide analysis method is only applicable to areas with extremely small erosion. The apatite fission track analysis method can simultaneously calculate the time and amount of stratum erosion, but this method is not suitable for sedimentary basins with multi-cycle development and evolution of multiple periods of subsidence and uplift.

[0005] Therefore, there is an urgent need for a method that can accurately restore the amount of stratum erosion, which can provide an important reference for basin oil and gas resource evaluation and analysis of favorable oil and gas accumulation zones. Summary of the invention

[0006] In order to solve the above deficiencies in the prior art, one object of the present invention is to provide a method for recovering the amount of stratum erosion, which can accurately recover the amount of stratum erosion; another object of the present invention is to provide an apparatus, computer equipment and computer-readable storage medium for running the above method.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A method for recovering stratum erosion, comprising the following steps performed in sequence:

[0009] S1. Data acquisition

[0010] Convert the seismic interpretation data of the target area into synthetic seismic records, calibrate the horizons, and determine the range of the unconformity surface and the residual stratum thickness Hri;

[0011] S2. Data processing

[0012] 1) Calculate the amount of formation erosion at a single well using the acoustic time difference method

[0013] Under normal compaction conditions, the rock acoustic time difference Δt and the burial depth H are exponentially related, that is,

[0014] Δt=Δt0e -CH

[0015] In the above formula, Δt is the acoustic time difference of rock at depth H (μs / m), Δt0 is the acoustic time difference at the surface of the target area, e is a natural constant, and C is the slope of the normal compaction trend (m -1 ), H is the rock burial depth (m);

[0016] In areas where strata are denuded, the compaction trend line of the rock below the unconformity surface is extended to point A where it intersects with the vertical projection line of Δt0, which is the paleosurface. The distance between the paleosurface and the unconformity surface is the amount of erosion of the stratum.

[0017] Therefore, a single well in the target area is selected, and the compaction curves of the rock above and below the unconformity surface are respectively prepared using the collected acoustic time difference data. The ancient surface position is restored using the above method, and finally the stratum denudation amount H at the single well is calculated. w ;

[0018] 2) Calculate the theoretical stratum erosion amount of the eroded stratum using the trend surface method

[0019] The seismic interpretation data of the target area are selected, and restoration is carried out on the profile along the non-eroded area to the eroded area. The erosion amount of the eroded strata is restored based on the seismic reflection trend of the underlying strata and extended outward.

[0020] When the thickness of the stratum gradually becomes thinner, first select an arbitrary point B in the target stratum where it has not been eroded, then find the starting point A where the stratum is eroded. The horizontal distance between point A and point B is L, and calculate the intercept slope K formed by the eroded stratum and the overlying horizontal stratum.

[0021] K=(H0﹣H0') / L×cosθ

[0022] In the above formula, H0 is the apparent thickness at point B, and H0' is the apparent thickness at point A.

[0023] Knowing that the interception slope is constant, by changing the horizontal distance L between any point B selected in the uneroded area and the eroded point in the target area i, calculate the original sedimentary stratum thickness H of the denuded stratum 0i ,

[0024] H 0i =H0-K×Li×cosθ.

[0025] The original sedimentary stratum thickness H of the eroded stratum is calculated. 0i Subtract the residual formation thickness H in step S1 ri , calculate the theoretical stratum erosion amount H T-ei ;

[0026] S3. Correction

[0027] The co-kriging algorithm is used for correction. The co-regionalized variables can be represented by a set of K related regionalized variables {Z1(x), Z2(x), …, Z k (x)}, or it can be represented by a vector {Z1(x), Z2(x), …, Z k Before observation, it is a vector of K-dimensional regionalized variables. After observation, it is a spatial point function, that is, {Z1(x), Z2(x), …, Z k (x)} is regarded as a realization of the above K-dimensional vector. The co-kriging algorithm can combine various types of data with different reliability levels for linear regression. More specifically, it is an estimation method that gives a certain weight coefficient to each sample value and finally performs weighted average estimation after considering the geometric characteristics of the known samples such as shape, size, and spatial distribution position between the area to be estimated, as well as the spatial structure information at the point to be estimated, in order to achieve linear, unbiased and minimum estimation variance.

[0028] The formula for the co-kriging algorithm is as follows:

[0029]

[0030] Among them, X * (u0) is the estimated value of the position of u0; is in position The sampling value of the main variable on is the value of the weighting coefficient assigned to the sampling point, and n is the number of samples of the main variable; similarly, is in position The sampled values ​​of the upper secondary variable, is the value of the weighting coefficient assigned to the sampling point, and m is the number of samples of the secondary variable.

[0031] In this method, is the formation erosion volume H at the single well calculated using the acoustic time difference methodw , yes The weighting coefficient value of is the erosion value at a certain point on the erosion plane calculated using the trend surface method, that is, the theoretical stratum erosion value H T-ei , yes The weighted coefficient value of * (u0) is the optimized stratum erosion amount H f ;

[0032] S4. Restoration of stratum erosion

[0033] The residual formation thickness H ri Adding the optimized formation erosion amount Hf, the original formation thickness of the target area is obtained, thereby realizing the recovery of the formation erosion amount.

[0034] Furthermore, the layer calibration is to use synthetic seismic records, wave group characteristics and the contact relationship between the top and bottom of the formation to comprehensively determine the layer position, track the reflection layer according to the lateral extension direction of the phase axis in the seismic waveform, perform fault interpretation, analyze the fault combination and structural mode, perform reflection structure analysis, obtain the structural relationship, and complete the layer calibration.

[0035] Furthermore, the determination of the unconformity range and the residual stratum thickness H ri The truncation characteristics of the upper and lower strata of the unconformity surface, the contact relationship between the unconformity surface and the upper and lower strata, and the distribution range of the unconformity surface are determined according to the calibrated horizon. The residual stratum thickness H of the denuded stratum is calculated by subtracting the unconformity surface and the underlying horizon. ri .

[0036] The present invention also provides a stratum erosion recovery device, comprising:

[0037] Data acquisition unit module: used to convert the seismic interpretation data of the target area into synthetic seismic records, perform horizon calibration, and determine the range of the unconformity surface and the residual stratum thickness Hri;

[0038] Data processing unit module: used to obtain the amount of erosion of each stratum using the acoustic time difference method and the trend surface method;

[0039] Correction unit module: used to correct the trend surface method using the acoustic time difference method;

[0040] Formation erosion recovery unit module: used to obtain the original formation thickness of the target area and realize the recovery of formation erosion.

[0041] The present invention also provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any of the above-mentioned methods for recovering stratum erosion when executing the computer program.

[0042] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program for executing any of the above-mentioned methods for recovering stratum erosion.

[0043] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0044] (1) The method for recovering stratum denudation provided by the present invention solves the problem that the trend surface method can only obtain the relative denudation amount and cannot estimate the denudation caused by the overall uplift of the stratum. The absolute denudation amount at a single well obtained by the acoustic time difference method is used to correct the result obtained by the trend surface method, so that a more accurate stratum denudation thickness can be obtained.

[0045] (2) The method for recovering stratum denudation provided by the present invention can be applied to the Sichuan Basin. By utilizing the respective advantages of the trend surface method and the acoustic time difference method and through comprehensive complementary processing, the paleo-geomorphological map obtained is more reasonable and more consistent with the sedimentary rock phase, providing important support for the research on paleo-geomorphology and prototype basin recovery in the Sichuan Basin.

[0046] (3) The device, computer equipment and computer-readable storage medium provided by the present invention can quickly and effectively restore the amount of stratum erosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Figure 1 A schematic flow chart of a method for recovering stratum erosion provided in Example 1;

[0049] Figure 2 is a plane diagram of the erosion thickness obtained by the trend surface method in Example 1;

[0050] Figure 3 The plane diagram of the ablation thickness obtained by using the acoustic time difference method in Example 1;

[0051] Figure 4 is a plane diagram of the thickness of the ablation amount after correction in Example 1;

[0052] Figure 5 A flow chart of a stratum erosion recovery device provided in Example 2;

[0053] Figure 6A flow chart of a medium for a formation erosion recovery method provided in Example 4. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below through specific embodiments. It should be understood that the preferred embodiments described herein are only used to illustrate and understand the present invention, and are not used to limit the present invention.

[0055] Unless otherwise specified, the materials and reagents used in the examples of the present invention can be obtained from commercial sources. Experimental methods without specific conditions in the examples are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0056] Example 1 A method for recovering stratum erosion

[0057] This embodiment is a method for recovering stratum erosion, and its flow chart is as follows: Figure 1 As shown, the process includes:

[0058] S1. Data acquisition

[0059] Convert the seismic interpretation data of the target area into synthetic seismic records, determine the position of the layer through synthetic seismic records, wave group characteristics and the contact relationship between the top and bottom of the formation, track the reflection layer according to the lateral extension direction of the phase axis in the seismic waveform, interpret the fault, analyze the fault combination and structural mode, conduct reflection structure analysis, clarify the complex structural relationship, and complete the layer calibration;

[0060] On the basis of horizon calibration, the distribution range of the unconformity surface is determined according to the cut-off characteristics of the strata above and below the unconformity surface and the contact relationship between the unconformity surface and the underlying strata. The residual stratum thickness H can be calculated by subtracting the seismic horizons of the unconformity surface and the underlying target layer. ri ;

[0061] S2. Data processing

[0062] Select a single well in the target area and use the acoustic time difference method to calculate the formation erosion volume H at the single well. w ;

[0063] Calculation of the original sedimentary stratum thickness H of the denuded stratum using the trend surface method 0i , using the original sedimentary formation thickness H 0i Subtract the residual formation thickness H ri , calculate the theoretical stratum erosion amount H T-ei ;

[0064] S3. Correction

[0065] The trend surface method is corrected by using the acoustic time difference method. The correction method uses the collaborative kriging algorithm. The correction calculation formula is as follows:

[0066]

[0067] in, is the formation erosion volume H at the single well calculated using the acoustic time difference method w , yes The weighting coefficient value of is the erosion value at a certain point on the erosion plane calculated using the trend surface method, that is, the theoretical stratum erosion value H T-ei , yes The weighted coefficient value of * (u0) is the optimized stratum erosion amount H f ;

[0068] S4. Restoration of stratum erosion

[0069] The residual formation thickness H ri Add the optimized stratum erosion amount H f , that is, to obtain the original formation thickness of the target area and realize the recovery of the formation erosion amount.

[0070] Verification experiment

[0071] This verification experiment compares the erosion thickness plane diagrams obtained by using the trend surface method, the acoustic wave time difference method and the correction method of the present invention for the same target area in Example 1.

[0072] Comparative Example 1 is a plan view of the erosion thickness obtained using the trend surface method, such as Figure 2 As shown;

[0073] Comparative Example 2 is a plan view of the erosion thickness obtained by using the acoustic time difference method, as shown in FIG. Figure 3 As shown;

[0074] This embodiment is a corrected ablation thickness plane diagram, such as Figure 4 As shown;

[0075] Since the simple trend surface method can only observe the macroscopic trend of the eroded formation, but has no well constraints, the overall erosion volume is not accurately recovered. Figure 2 As shown in the figure, while the acoustic time difference method can accurately measure the erosion at the well point, it cannot control the erosion trend in areas outside the well point, such as Figure 3 Therefore, the overall erosion recovery is also inaccurate. Therefore, the method of the present invention calculates the erosion amount at the well point through comprehensive complementary processing, and the erosion amount is accurate, such as Figure 4 As shown in the figure, the area outside the well point is relatively more accurate and has smaller errors because it is controlled by the trend surface. It is more in line with the macroscopic geological laws and provides important support for the research on basin paleo-geomorphology and prototype basin restoration.

[0076] Example 2 A device for recovering stratum erosion

[0077] Figure 5 A flow chart of a formation erosion recovery device according to an embodiment of the present invention is shown, comprising:

[0078] Data acquisition unit module 201: used to convert the seismic interpretation data of the target area into synthetic seismic records, perform layer calibration, and determine the residual stratum thickness;

[0079] Data processing unit module 202: used to obtain the erosion amount of each stratum using the acoustic time difference method and the trend surface method;

[0080] Correction unit module 203: used to correct the trend surface method using the acoustic time difference method;

[0081] The formation erosion recovery unit module 204 is used to obtain the original formation thickness of the target area and realize the recovery of the formation erosion.

[0082] Embodiment 3 A computer device

[0083] This embodiment provides a computer device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, so as to implement the above-mentioned formation denudation recovery method.

[0084] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0085] The processor may be a central processing unit (CPU) or other forms of processing units with data processing capability and / or instruction execution capability, and may control other components in the electronic device to perform desired functions. The processor is used to run the computer-readable instructions stored in the memory.

[0086] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present disclosure.

[0087] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0088] Embodiment 4 A computer readable storage medium

[0089] This embodiment provides a computer-readable storage medium. The storage 302 in the computer device 300 stores a computer program. When the computer program is executed by the processor 301, the method for recovering the amount of stratum denudation is implemented. Figure 6 A flow chart showing a method for recovering stratum erosion according to an embodiment of the present invention includes:

[0090] Data acquisition unit: used to convert the seismic interpretation data of the target area into synthetic seismic records, perform horizon calibration, and determine the residual stratum thickness;

[0091] Data processing unit: used to obtain the amount of erosion of each stratum using the acoustic time difference method and the trend surface method;

[0092] Correction unit: used to correct the trend surface method using the acoustic time difference method;

[0093] Formation erosion recovery unit: used to obtain the original formation thickness of the target area and realize the recovery of formation erosion.

[0094] The computer-readable storage medium stores non-transitory computer-readable instructions. When the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the above-mentioned methods of various embodiments are executed.

[0095] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or mobile hard disk), media with built-in rewritable non-volatile memory (e.g., memory card) and media with built-in ROM (e.g., ROM box).

[0096] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for recovering stratum erosion, characterized in that: The process includes the following steps: S1. Data acquisition Convert the seismic interpretation data of the target area into synthetic seismic records, perform layer calibration, and determine the residual stratum thickness H ri ; S2. Data processing Select a single well in the target area and use the acoustic time difference method to calculate the formation erosion volume H at the single well. w ; Calculation of the original sedimentary stratum thickness H of the denuded stratum using the trend surface method 0i , using the original sedimentary stratum thickness H 0i Subtract the residual formation thickness H ri , calculate the theoretical stratum erosion amount H T-ei ; S3. Correction The trend surface method is corrected by using the acoustic time difference method. The correction method uses the collaborative kriging algorithm. The correction calculation formula is as follows: in, is the formation erosion volume H at the single well calculated using the acoustic time difference method w , yes The weighting coefficient value of is the erosion value at a certain point on the erosion plane calculated using the trend surface method, that is, the theoretical stratum erosion value H T-ei , yes The weighted coefficient value of * (u0) is the optimized stratum erosion amount H f ; S4. Restoration of stratum erosion The residual formation thickness H ri Add the optimized stratum erosion amount H f , that is, to obtain the original formation thickness of the target area and realize the recovery of the formation erosion amount.

2. The method for recovering stratum erosion according to claim 1, characterized in that: The layer calibration is to determine the layer position by using synthetic seismic records, wave group characteristics and the contact relationship between the top and bottom of the formation, track the reflection layer according to the lateral extension direction of the phase axis in the seismic waveform, perform fault interpretation, analyze the fault combination and structural mode, perform reflection structure analysis, obtain the structural relationship, and complete the layer calibration.

3. The method for recovering stratum erosion according to claim 2, characterized in that: Determine the unconformity range and residual stratum thickness H ri The truncation characteristics of the upper and lower strata of the unconformity surface, the contact relationship between the unconformity surface and the upper and lower strata, and the distribution range of the unconformity surface are determined according to the calibrated horizon. The residual stratum thickness H of the denuded stratum is calculated by subtracting the unconformity surface and the underlying horizon. ri .

4. A stratum erosion recovery device according to any one of claims 1 to 3, characterized in that: include: Data acquisition unit module: used to convert the seismic interpretation data of the target area into synthetic seismic records, perform layer calibration, and determine the residual stratum thickness; Data processing unit module: used to obtain the amount of erosion of each stratum using the acoustic time difference method and the trend surface method; Correction unit module: used to correct the trend surface method using the acoustic time difference method; Formation erosion recovery unit module: used to obtain the original formation thickness of the target area and realize the recovery of formation erosion.

5. 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 method for recovering the amount of stratum erosion according to any one of claims 1 to 3 is implemented.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for executing the method for recovering the amount of stratum erosion according to any one of claims 1 to 3.

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