Strata erosion amount recovery method and device, equipment and medium

Abstract

The application discloses a stratum denudation amount recovery method and device, equipment and medium, and belongs to the technical field of petroleum geophysical exploration processing. The application corrects the trend surface method by using the acoustic travel time method, obtains the original stratum thickness of a target region, and realizes recovery of the stratum denudation amount. The application also provides a device, computer equipment and computer readable storage medium for realizing the above method. The application can accurately recover the stratum denudation amount and can be applied to petroleum geophysical exploration and oil and gas resource evaluation.

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, in particular 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, and the extent of strata erosion significantly influences the generation, migration, and accumulation of oil and gas within them. The amount of strata erosion is a crucial parameter in basin simulation, and restoring it is a crucial component of studying geological tectonic evolution and a fundamental foundation 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 reflectance 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 measured area. In addition, when the erosion area is large and the stratum thickness varies greatly in the lateral direction, especially when erosion occurs throughout the entire area, the error is large and the stratigraphic correlation method cannot be used at all. Since the erosion rate parameter 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 amounts of erosion. In contrast, the cosmogenic nuclide analysis method is only applicable to areas with extremely small amounts of 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 stages of subsidence and uplift.

[0005] Therefore, a method that can accurately recover the amount of formation erosion is urgently needed to 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 stratum erosion, which can accurately recover 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] In order 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, perform horizon calibration, and determine the unconformity surface range and 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 was selected, and the compaction curves of the rock above and below the unconformity surface were respectively prepared using the collected acoustic time difference data. The paleosurface position was restored using the aforementioned method, and the stratum denudation amount H at the single well was finally calculated. w ;

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

[0019] 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.

[0020] When the thickness of the stratum gradually becomes thinner, first select an arbitrary point B in the target layer that 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, H0' is the apparent thickness at point A,

[0023] Knowing that the intercept slope remains unchanged, 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 thickness H of the eroded stratum 0i ,

[0024] H 0i =H0-K×Li×cosθ.

[0025] The original sedimentary 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 in other words, it can be represented by a vector {Z1(x), Z2(x),…, Z k (x)}. Before observation, it is a vector of K-dimensional regional variables. After observation, it is a spatial point function, that is, {Z1(x), Z2(x),…, Z k (x)} can be considered as a realization of the aforementioned K-dimensional vector. The cokriging algorithm can combine data of varying types and reliability for linear regression. More specifically, it considers geometric features of known samples, such as their shape and size, their spatial distribution relative to the area to be estimated, and the spatial structure of the estimated point. To achieve a linear, unbiased, and minimum-variance estimate, it assigns a weight to each sample value and performs a weighted average.

[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 weight coefficient assigned to the sampling point, and n is the number of samples of the main variable; similarly, is in position The sample value 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, The formation erosion amount H at the single well is calculated using the acoustic time difference method.w , yes The weighting coefficient value of It is the erosion value at a certain point on the erosion plane calculated using the trend surface method, that is, the theoretical formation erosion value H T-ei , yes The weighted coefficient value of the calculation result X * (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 pattern, perform reflection structure analysis, obtain the structural relationship, and complete the layer calibration.

[0035] Furthermore, the determination of the unconformity surface 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 based on 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 unconformity surface range and 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 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 storing a computer program for executing any one 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 formation erosion provided by the present invention solves the problem that the trend surface method can only calculate the relative erosion amount and cannot estimate the erosion caused by the overall uplift of the formation. By using the absolute erosion amount at a single well calculated by the acoustic time difference method to correct the result obtained by the trend surface method, a more accurate formation erosion 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 transit time method and through comprehensive and complementary processing, the paleogeomorphological map obtained is more reasonable and more consistent with the sedimentary rock phase, providing important support for the research on paleogeomorphology and prototype basin restoration 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 will be described in further 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 This is a plan view of the erosion thickness obtained using the trend surface method in Example 1;

[0050] Figure 3 This is a plan view of the ablation thickness obtained using the acoustic transit time method in Example 1;

[0051] Figure 4 This is a plan view of the corrected ablation thickness 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 will be 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 intended 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 generally performed under conventional conditions or the 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. The position of the horizon is determined by combining the synthetic seismic records, wave group characteristics and the contact relationship between the top and bottom of the stratum. The reflection horizon is tracked according to the lateral extension direction of the phase axis in the seismic waveform. Fault interpretation is performed, fault combination and structural pattern are analyzed, reflection structure analysis is performed, complex structural relationships are clarified, and horizon calibration is completed.

[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] Calculate the original sedimentary thickness H of the eroded stratum using the trend surface method 0i , using the original sedimentary layer 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 using the acoustic time difference method. The correction method uses the collaborative kriging algorithm. The correction calculation formula is as follows:

[0066]

[0067] in, The formation erosion amount H at the single well is calculated using the acoustic time difference method. w , yes The weighting coefficient value of It is the erosion value at a certain point on the erosion plane calculated using the trend surface method, that is, the theoretical formation erosion value H T-ei , yes The weighted coefficient value of the calculation result X * (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 calculated using the trend surface method, the acoustic transit time 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, as shown in Figure 2 As shown;

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

[0074] This embodiment is a corrected ablation thickness plane diagram, as shown in 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 amount is not accurately recovered. Figure 2 As shown in the figure, the acoustic time difference method can accurately measure the erosion amount at the well point, but it cannot control the erosion amount change trend in areas outside the well point. 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, as shown in the figure. 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 consistent with the macro-geological laws and provides important support for the research on basin paleogeomorphology and prototype basin restoration.

[0076] Example 2: A device for recovering stratum erosion

[0077] Figure 5 A flow chart of a device for recovering stratum erosion 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 horizon calibration, and determine the residual stratum thickness;

[0079] Data processing unit module 202: used to obtain the amount of erosion 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 amount.

[0082] Example 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 erosion recovery method.

[0084] The memory is used to store non-transitory 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 include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), a hard disk, flash memory, etc.

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

[0086] Those skilled in the art should understand that in order to solve the technical problem of how to obtain a good user experience, this 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 scope of protection of this disclosure.

[0087] For detailed description of this embodiment, please refer to the corresponding description in the aforementioned embodiments, which will not be repeated here.

[0088] Example 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 formation erosion is implemented. Figure 6 A flow chart showing a method for recovering formation 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 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, which, when executed by a processor, execute all or part of the steps of the aforementioned methods.

[0095] The above-mentioned computer-readable storage media include, but are not limited to, optical storage media (e.g., CD-ROMs and DVDs), magneto-optical storage media (e.g., MOs), magnetic storage media (e.g., magnetic tapes or mobile hard disks), media with built-in rewritable non-volatile memory (e.g., memory cards), and media with built-in ROM (e.g., ROM cartridges).

[0096] It should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art may still modify the technical solutions described in the above embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection 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 layer 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 ; Calculate the original sedimentary thickness H of the eroded stratum using the trend surface method 0i , using the original sedimentary layer 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 using the acoustic time difference method. The correction method uses the collaborative kriging algorithm. The correction calculation formula is as follows: in, The formation erosion amount H at the single well is calculated using the acoustic time difference method. w , yes The weighting coefficient value of It is the erosion value at a certain point on the erosion plane calculated using the trend surface method, that is, the theoretical formation erosion value H T-ei , yes The weighted coefficient value of the calculation result X * (u0) is the optimized stratum erosion amount H f , n is the sampling number of the primary variable, m is the sampling number of the secondary variable; 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, wherein: 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 pattern, perform reflection structure analysis, obtain the structural relationship, and complete the layer calibration.

3. The method for recovering stratum erosion according to claim 2, wherein: Determine the extent of the unconformity surface and the thickness of the residual strata 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 based on 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 device for realizing the method for recovering stratum erosion 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 horizon 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 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, wherein: When the processor executes the computer program, the method for recovering the amount of formation 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 stratum erosion amount according to any one of claims 1 to 3.

Images