Continuous medium area near-surface modeling method, device and equipment and medium

Abstract

The invention discloses a continuous medium area near-surface modeling method, device and equipment and a medium. The method comprises the following steps: determining the wellhead time of a production well according to the depth of the production well and the predetermined thickness and speed of each small layer of a weathered layer; according to the wellhead time of the production well and the obtained apparent reflection time of the weathered layer bottom boundary corresponding to each shot point at the production well, determining the vertical time of each shot point and the common central point of the corresponding first geophone; determining the elevation and speed of the high-speed top interface at the common center point according to a pre-obtained mapping relation between the thickness of the weathered layer and the vertical state and the obtained vertical state at the common center point; performing interpolation processing to obtain a high-speed top interface elevation and a speed of each shot point and a corresponding first detection point; further determining the weathered layer thickness of each shot point and the corresponding first detection point; and establishing a near-surface model according to the coordinates of each shot point and the corresponding first detection point, and the thickness and speed of the weathered layer.

Description

Technical Field

[0001] The invention relates to a method, device, equipment and medium for near-surface modeling of a continuous medium region. Background Art

[0002] In recent years, exploration workers have noticed that obtaining accurate near-surface structures is an important basic work to ensure the quality of seismic imaging. The accuracy of the near-surface model is related to the accuracy of the subsequent first-arrival wave static correction inversion. Only by using a high-precision near-surface model as the initial or constraint condition for refraction or tomography inversion can the accuracy of static correction and near-surface velocity field be guaranteed, and the quality of seismic imaging can be guaranteed. At present, the most commonly used methods for near-surface modeling are: first, surface modeling based on the interpretation results of interpolated micro-logging; second, a modeling method for near-surface layers in transition areas that aims to improve the accuracy of static correction. Summary of the invention

[0003] In order to achieve higher-precision near-surface modeling in a continuous medium near-surface region, embodiments of the present application provide a method, apparatus, device, and medium for near-surface modeling in a continuous medium region.

[0004] In a first aspect, an embodiment of the present application provides a method for near-surface modeling in a continuous medium region, the method comprising:

[0005] For each production well, the wellhead time of the production well is determined according to the depth of the production well and the thickness and velocity of each sublayer of the pre-determined weathering layer;

[0006] According to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well, the vertical time at the common center point of each shot point and the corresponding first detection point is determined;

[0007] According to the mapping relationship between the weathering layer thickness and the vertical time obtained in advance, and the vertical time at the common center point of each shot point and the corresponding first detection point, the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point are determined;

[0008] Interpolation processing is performed based on the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point to obtain the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point;

[0009] Determine the thickness of the weathering layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point;

[0010] A near-surface model is established based on the coordinates of each shot point and the corresponding first detection point of each production well, the thickness and velocity of the weathering layer.

[0011] In an optional implementation of the embodiment of the present application, after obtaining the high-speed top interface height and velocity of each shot point and the corresponding first detection point, the following is further included:

[0012] The high-speed top interface height and velocity of each shot point and the corresponding first detection point are smoothed with a preset radius to obtain the high-speed top interface height and velocity of each shot point and the corresponding first detection point after smoothing.

[0013] In an optional implementation of the embodiment of the present application, determining the wellhead time of the production well according to the depth of the production well and the thickness and velocity of each small layer of the predetermined weathering layer includes:

[0014] According to the depth of the production well and the thickness and velocity of each small layer of the pre-determined weathering layer, the wellhead time of the production well is calculated based on the following formula 1:

[0015] τ=h0 / v0+h1 / v1+…+h n-1 / v n-1 +(wdh-h0-h1-…-h n-1 ) / v n Formula 1;

[0016] Wherein, τ is the wellhead time of the production well; h0 is the thickness of the first sublayer of the weathering layer; h1 is the thickness of the second sublayer of the weathering layer; h n-1 is the thickness of the nth layer of the weathering layer; v0 is the velocity of the first layer of the weathering layer; v1 is the velocity of the second layer of the weathering layer; v n-1 is the velocity of the nth layer of the weathering layer; v n is the velocity of the n+1th layer of the weathering layer; wdh is the depth of the production well; n=0, 1, ... N-1, where N is the total number of layers of the near-surface structure of the weathering layer.

[0017] In an optional implementation of the embodiment of the present application, the verticality at the common center point of each shot point and the corresponding first detection point is determined based on the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well, including:

[0018] According to each single shot record obtained, determine the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point;

[0019] The vertical time at the common center point of each shot point and the corresponding first detection point is determined according to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point.

[0020] In an optional implementation of the embodiment of the present application, determining the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point according to each single shot record obtained includes:

[0021] Performing static correction processing on each single shot record obtained, obtaining each single shot record after static correction and the static correction amount of each shot point and the corresponding first detection point;

[0022] Preprocessing each single shot record or the minimum common offset section obtained after the static correction to obtain each single shot record or the minimum common offset section after preprocessing;

[0023] Obtaining the apparent reflection time of the bottom boundary of the picked weathering layer according to each single shot record or minimum common offset profile after the preprocessing;

[0024] The apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point is determined according to the static correction amount between each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathering layer.

[0025] In an optional implementation of the embodiment of the present application, the determining the apparent reflection time of the bottom boundary of the weathered layer corresponding to each shot point according to the static correction amount of each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathered layer, comprises:

[0026] According to the static correction amount of each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathering layer, the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point is calculated based on the following formula 2:

[0027] t 反 =t′-Sta S -Sta R Formula 2;

[0028] Where, t 反 Sta is the apparent reflection time of the bottom boundary of the weathering layer corresponding to a single shot point; t′ is the apparent reflection time of the bottom boundary of the weathering layer picked up; Sta S Sta is the static correction value of a single shot point; Sta R It is the static correction value of the first detection point corresponding to a single shot point.

[0029] In an optional implementation of the embodiment of the present application, the verticality at the common center point of each shot point and the corresponding first detection point is determined according to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point, including:

[0030] According to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point, the vertical time at the common center point of each shot point and the corresponding first detection point is calculated based on the following formula 3:

[0031] t0≈(τ+t 反 )÷2 Formula 3;

[0032] Where t0 is the vertical time at the common center point of a single shot point and the corresponding first detection point; τ is the wellhead time of the production well; t 反 is the apparent reflection time of the bottom boundary of the weathering layer corresponding to a single shot point.

[0033] In an optional implementation of the embodiment of the present application, the method of determining the elevation and velocity of the high-speed top interface at the common center point of each shot point and the corresponding first detection point based on the pre-obtained mapping relationship between the weathering layer thickness and the vertical time, and the vertical time at the common center point of each shot point and the corresponding first detection point, includes:

[0034] According to the weathering layer thickness and vertical time of each micro-logging well obtained, a mapping relationship between the weathering layer thickness and vertical time of each micro-logging well is established;

[0035] Substitute the vertical time at the common center point of each shot point and the corresponding first detection point into the mapping relationship between the weathering layer thickness and the vertical time of each micro-well logging to determine the weathering layer thickness at the common center point of each shot point and the corresponding first detection point;

[0036] Determine the elevation of the high-speed top interface at the common center point of each shot point and the corresponding first detection point according to the thickness of the weathering layer and the surface elevation at the common center point of each shot point and the corresponding first detection point;

[0037] The weathering layer velocity at the common center point of each shot point and the corresponding first detection point is determined according to the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point and the vertical time.

[0038] In an optional implementation of the embodiment of the present application, determining the weathering layer velocity at the common center point of each shot point and the corresponding first detection point according to the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point and the vertical time includes:

[0039] According to the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point and the vertical time, the weathering layer velocity at the common center point of each shot point and the corresponding first detection point is calculated based on the following formula 4:

[0040] v CMP =h CMP / t0 formula 4;

[0041] In the formula, v CMP h is the weathering layer velocity at the common center point of a single shot point and the corresponding first detection point; CMP is the thickness of the weathering layer at the common center point of a single shot point and the corresponding first detection point; t0 is the vertical time at the common center point of a single shot point and the corresponding first detection point.

[0042] In an optional implementation of the embodiment of the present application, before interpolating the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point to obtain the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point, the method further includes:

[0043] According to the obtained east-west coordinates, north-south coordinates and surface elevation of each shot point and the corresponding first detection point, determine the east-west coordinates, north-south coordinates and surface elevation of the common center point of each shot point and the corresponding first detection point;

[0044] The high-speed top interface elevation at the common center point of each shot point and the corresponding first detection point is determined according to the surface elevation and the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point.

[0045] In an optional implementation of the embodiment of the present application, the east-west coordinates, north-south coordinates and surface elevation of the common center point of each shot point and the corresponding first detection point are determined by the following method:

[0046] According to the east-west coordinates of each shot point and the corresponding first detection point, based on the following formula 5, the east-west coordinates of the common center point of each shot point and the corresponding first detection point can be expressed as:

[0047] X CMP =(X S +X R )÷2 Formula 5;

[0048] Where, X CMP X is the east-west coordinate of the common center point between a single shot point and the corresponding first detection point; S is the east-west coordinate of a single shot point; X R The east-west coordinates of the first detection point corresponding to a single shot point;

[0049] According to the north-south coordinates of each shot point and the corresponding first detection point, based on the following formula 6, the north-south coordinates of the common center point of each shot point and the corresponding first detection point can be expressed as:

[0050] Y CMP =(Y S+Y R )÷2 Formula 6;

[0051] Where Y CMP Y is the north-south coordinate of the common center point between a single shot point and the corresponding first detection point; S is the north-south coordinate of a single shot point; Y R The north-south coordinate of the first detection point corresponding to a single shot point;

[0052] According to the surface elevation of each shot point and the corresponding first detection point, based on the following formula 7, the surface elevation at the common center point of each shot point and the corresponding first detection point can be expressed as:

[0053] H CMP =(H S +H R )÷2 Formula 7;

[0054] In the formula, H CMP H is the surface elevation of the common center point between a single shot point and the corresponding first detection point; S is the surface elevation of a single shot point; H R It is the surface elevation of the first detection point corresponding to a single shot point.

[0055] In an optional implementation of the embodiment of the present application, determining the high-speed top interface elevation at the common center point of each shot point and the corresponding first detection point according to the surface elevation and the weathering layer thickness at the common center point of each shot point and the corresponding first detection point includes:

[0056] According to the surface elevation and weathering layer thickness at the common center point of each shot point and the corresponding first detection point, the high-speed top interface elevation at the common center point of each shot point and the corresponding first detection point can be expressed as follows based on the following formula 8:

[0057] E CMP =H CMP -h CMP Formula 8;

[0058] In the formula, Ew CMP H is the elevation of the high-speed top interface at the common center point between a single shot point and the corresponding first detection point; CMP h is the surface elevation at the common center point of a single shot point and the corresponding first detection point; CMP It is the thickness of the weathering layer at the common center point between a single shot point and the corresponding first detection point.

[0059] In an optional implementation of the embodiment of the present application, determining the thickness of the weathered layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point includes:

[0060] The surface elevation of each shot point and the corresponding first detection point is subtracted from the elevation of the high-speed top interface to determine the thickness of the weathered layer of each shot point and the corresponding first detection point.

[0061] In a second aspect, an embodiment of the present application provides a near-surface modeling device for a continuous medium region, the device comprising:

[0062] A first determination module is used to determine the wellhead time of each production well according to the depth of the production well and the thickness and velocity of each sublayer of the pre-determined weathering layer;

[0063] The second determination module is used to determine the vertical time at the common center point of each shot point and the corresponding first detection point according to the wellhead time of the production well and the obtained apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well;

[0064] The third determination module is used to determine the elevation and velocity of the high-speed top interface at the common center point of each shot point and the corresponding first detection point according to the mapping relationship between the weathering layer thickness and the vertical time obtained in advance and the vertical time at the common center point of each shot point and the corresponding first detection point;

[0065] A fourth determination module is used to perform interpolation processing on the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point to obtain the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point;

[0066] A fifth determination module, for determining the thickness of the weathered layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point;

[0067] The model building module is used to build a near-surface model based on the coordinates of each shot point and the corresponding first detection point of each production well, the thickness and velocity of the weathering layer.

[0068] In a third aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for near-surface modeling of a continuous medium region as described above.

[0069] In a fourth aspect, an embodiment of the present application provides a computer device, including 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 near-surface modeling of a continuous medium region as described above is implemented.

[0070] In a fifth aspect, an embodiment of the present application provides a computer program product comprising instructions, which, when executed on a computer device, enables the computer device to execute the method for near-surface modeling of a continuous medium region as described above.

[0071] In a sixth aspect, an embodiment of the present application provides a chip, the chip including a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run a computer program or instruction to implement the near-surface modeling method of a continuous medium region as described above.

[0072] The beneficial effects of the above technical solution provided by the embodiment of the present application include at least:

[0073] The near-surface modeling method of the continuous medium area provided in the embodiment of the present application determines the high-speed top interface elevation and velocity at the common center point of the shot point and the corresponding first detection point based on the mapping relationship between the pre-acquired weathering layer thickness and vertical time, and the accurately acquired vertical time at the common center point of each shot point and the corresponding first detection point, thereby obtaining the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point, and finally establishing a near-surface model. Through the pre-constructed mapping relationship between the weathering layer thickness and vertical time, the scheme can construct a high-precision near-surface model without relying on the method of large-area deep well micro-logging survey, compared with the prior art, without implementing micro-logging, without implementing micro-logging. It greatly reduces production input, saves exploration investment, improves production timeliness, can meet the exploration accuracy requirements, lays the foundation for subsequent static correction accuracy, can provide high-quality basic data for pre-stack depth migration processing, and can effectively improve the imaging effect of seismic profiles. It can be applied to near-surface modeling in research areas of different continuous media such as gravel, rock, Gobi and loess, and is particularly suitable for near-surface modeling in research areas of extremely thick continuous media.

[0074] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0075] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0077] Figure 1A schematic diagram of the steps of the near-surface modeling method for a continuous medium region provided in an embodiment of the present application;

[0078] Figure 2 A schematic diagram of the micro-well logging interpretation results at a horizontal distance of 16.82 km provided by the embodiment of the present application;

[0079] Figure 3 A schematic diagram of a single shot record after static correction and preprocessing at a horizontal distance of 16.82 km on the survey line provided in an embodiment of the present application;

[0080] Figure 4 A schematic diagram of the minimum common offset profile after preprocessing at a horizontal distance of 16.82 km of the survey line provided in an embodiment of the present application;

[0081] Figure 5 A schematic diagram of the propagation path of the shot point excitation ray at a horizontal distance of 16.82 km on the survey line provided in an embodiment of the present application;

[0082] Figure 6 A graph showing the relationship between the vertical time of each micro-well and the thickness of loess provided in the embodiment of the present application;

[0083] Figure 7 A schematic diagram of a near-surface model established by the height and velocity of the high-speed top interface before smoothing provided in an embodiment of the present application;

[0084] Figure 8 A schematic diagram of a near-surface model established by the height and velocity of the smoothed high-speed top interface provided in an embodiment of the present application;

[0085] Fig. 9 The thickness error calculated by the relationship curve between the vertical time and loess thickness of each micro-well logging provided in the embodiment of the present application is measured by the plate;

[0086] Fig.10 The velocity error calculated by the relationship curve between the vertical time and the loess thickness of each micro-well provided in the embodiment of the present application;

[0087] Fig.11 A schematic diagram of an unconstrained tomographic inversion initial stack section provided in an embodiment of the present application;

[0088] Fig.12 A schematic diagram of the initial stacked section of the model-constrained tomographic inversion after near-surface modeling provided in an embodiment of the present application;

[0089] Fig.13 A schematic diagram of the structure of a near-surface modeling device for a continuous medium region provided in an embodiment of the present application. DETAILED DESCRIPTION

[0090] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0091] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0092] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0093] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0094] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0095] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0096] It should be understood that the size of the serial numbers of the steps in the following embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0097] In order to illustrate the technical solution of the present application, a specific embodiment is provided below for illustration.

[0098] The inventors found that in the prior art, the most common method for carrying out near-surface modeling is to perform surface modeling based on the interpretation results of interpolated micro-logging. Although this method can accurately obtain the near-surface structure at the micro-logging survey location, the near-surface model between different micro-logging cannot guarantee accuracy. Moreover, for extremely thick weathering layers, micro-logging surveys require ultra-deep micro-logging (well depths are basically between 100 and 600m, and most of them exceed 200m). Due to the huge investment in exploration, it is difficult to promote and apply it on a large scale. In addition, the near-surface model can also be inverted by first-arrival wave inversion, but due to the relatively large track spacing, the tomographic inversion is not fine enough to depict the extremely shallow surface model, and the tomographic inversion ultimately needs to interpret the near-surface velocity field. The extracted high-speed top interface has multiple solutions, which makes it difficult to guarantee the accuracy of the near-surface model. Refraction inversion requires known high-precision weathering layer velocity and / or thickness as initial conditions, but in actual exploration, it is difficult to meet such conditions. There is also a modeling method for the near-surface layer in the transition zone, but the main purpose of this method is to improve the accuracy of static correction, which cannot guarantee the accuracy of the near-surface model. In the continuous medium area with a thick weathering layer, there is currently no economical, practical and effective near-surface modeling method. Based on this, the inventors have made the present invention after further research and development, providing a near-surface modeling method, device, equipment and medium in a continuous medium area.

[0099] Embodiment 1

[0100] The present application provides a method for modeling near the surface of a continuous medium region, referring to Figure 1 As shown, the method includes:

[0101] S101: For each production well, determine the wellhead time of the production well according to the depth of the production well and the thickness and velocity of each small layer of the pre-determined weathering layer.

[0102] In the above step S101, the wellhead time of the production well is determined according to the depth of the production well and the thickness and velocity of each small layer of the pre-determined weathering layer, which specifically includes:

[0103] According to the depth of the production well and the thickness and velocity of each small layer of the pre-determined weathering layer, the wellhead time of the production well is calculated based on the following formula 1:

[0104] τ=h0 / v0+h1 / v1+…+hn-1 / v n-1 +(wdh-h0-h1-…-h n-1 ) / v n Formula 1;

[0105] Wherein, τ is the wellhead time of the production well, ms; h0 is the thickness of the first sublayer of the weathering layer, m; h1 is the thickness of the second sublayer of the weathering layer, m; h n-1 is the thickness of the nth layer of the weathering layer, m; v0 is the velocity of the first layer of the weathering layer, m / s; v1 is the velocity of the second layer of the weathering layer, m / s; v n-1 is the velocity of the nth layer of the weathering layer, m / s; v n is the velocity of the n+1th layer of the weathering layer, m / s; wdh is the depth of the production well, m; n=0, 1, ... N-1, where N is the total number of layers of the near-surface structure of the weathering layer, dimensionless.

[0106] In the above step S101, the wellhead time of the production well refers to the vertical propagation time of the seismic wave from the surface of the shot point to the bottom of the exciting production well. According to the conventional micro-well logging survey results with a weathering layer thickness of less than 50m, the extremely shallow structure of the weathering layer at the shot point can be obtained by spatial interpolation to calculate the wellhead time of the production well. Among them, the interpolation method can be an inverse distance weighted method. When calculating the wellhead time of the production well, according to the depth of the production well and the extremely shallow structure of the weathering layer at the shot point, it is determined in which small layer of the weathering layer the bottom position of the production well is located, and based on the above formula 1, the wellhead time of the production well is determined.

[0107] In a specific embodiment, taking the shot point at a horizontal distance of 16.82 km on the survey line as an example, the 210m micro-logging survey results there show that the near-surface structure of the weathering layer there is a 4-layer structure, such as Figure 2 As shown in the figure, the horizontal axis represents the vertical time of the micro-logging well, and the vertical axis represents the depth of the micro-logging well. According to the slope of each section in the curve, the weathering layer velocity of each small layer can be obtained. The specific surface structure parameters are: v0 = 276m / s, h0 = 4.7m; v1 = 647m / s, h1 = 28.2m; v2 = 953m / s, h2 = 47.3m; v3 = 1356m / s, h3 = 111.3m; v4 = 3242m / s. Among them, v0, v1, v2, v3 and v4 are the weathering layer velocities of each small layer of the weathering layer at this location, and h0, h1, h2 and h3 are the weathering layer thicknesses of each small layer of the weathering layer at this location.

[0108] Assuming that in actual production, the depth of the production well is 30.1m, and the sum of the thickness of the first layer of the weathered layer (4.7m) and the thickness of the second layer (28.2m) is 32.9m, it means that the bottom of the production well is in the second layer. Therefore, based on the above formula 1, the depth of the production well, the thickness and velocity of the first layer, and the velocity of the second layer are substituted into formula 1, and the wellhead time of the production well can be obtained as 56.3ms through the following calculation process:

[0109] τ=h0 / v0+(wdh-h0) / v1=[4.7÷276+(30.1-4.7)÷647]×1000=56.3(ms)

[0110] S102: Determine the vertical time at the common center point of each shot point and the corresponding first detection point according to the wellhead time of the production well and the obtained apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well.

[0111] In the above step S102, the process of determining the verticality of each shot point and the common center point of the corresponding first detection point according to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well specifically includes:

[0112] According to each single shot record obtained, determine the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point;

[0113] The vertical time at the common center point of each shot point and the corresponding first detection point is determined according to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point.

[0114] In a specific embodiment, determining the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point according to each single shot record obtained may specifically include:

[0115] Performing static correction processing on each single shot record obtained, obtaining each single shot record after static correction and the static correction amount of each shot point and the corresponding first detection point;

[0116] Preprocessing each single shot record or the minimum common offset section obtained after the static correction to obtain each single shot record or the minimum common offset section after preprocessing;

[0117] Obtaining the apparent reflection time of the bottom boundary of the picked weathering layer according to each single shot record or minimum common offset profile after the preprocessing;

[0118] The apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point is determined according to the static correction amount between each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathering layer.

[0119] In the embodiment of the present application, after each single shot record obtained has been subjected to static correction processing, it is necessary to preprocess each single shot record after static correction or the obtained minimum common offset profile, wherein the preprocessing method includes linear denoising, surface wave removal and removal of strong energy interference.

[0120] In a specific embodiment, the above-mentioned determination of the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point according to the static correction amount of each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathering layer, may specifically include:

[0121] According to the static correction amount of each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathering layer, the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point is calculated based on the following formula 2:

[0122] t 反 =t′-Sta S -Sta R Formula 2;

[0123] Where, t 反 is the apparent reflection time of the bottom boundary of the weathering layer corresponding to a single shot point, ms; t′ is the apparent reflection time of the bottom boundary of the weathering layer picked up, ms; Sta S Static correction value for a single shot point, ms; Sta R It is the static correction value of the first detection point corresponding to a single shot point, ms.

[0124] In a specific embodiment, taking a single shot point at a horizontal distance of 16.82 km on the survey line as an example, Figure 3 As shown in, this is the single shot record after static correction and preprocessing of the shot point; Figure 4 As shown in the figure, it is the minimum common offset section after preprocessing. The apparent reflection time t' that can be picked up in the single shot record or the minimum common offset section is 410.0ms. The static correction value of this shot point obtained by tomographic static correction is 50.0ms. The static correction value of the first detection point corresponding to this shot point is 0.2ms. Substituting it into the above formula 2, the apparent reflection time of the bottom boundary of the weathering layer corresponding to this shot point can be obtained by the following calculation process as 359.8ms:

[0125] t 反 =t′-Sta S -Sta R =410.0-50.0-0.2=359.8(ms)

[0126] In a specific embodiment, the above-mentioned determination of the perpendicularity between each shot point and the common center point of the corresponding first detection point based on the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point may specifically include:

[0127] According to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point, the vertical time at the common center point of each shot point and the corresponding first detection point is calculated based on the following formula 3:

[0128] t0≈(τ+t 反 )÷2 Formula 3;

[0129] Where t0 is the vertical time between a single shot point and the corresponding first detection point at the common center, ms; τ is the wellhead time of the production well, ms; t 反 is the apparent reflection time of the bottom boundary of the weathering layer corresponding to a single shot point, ms.

[0130] In a specific embodiment, a single shot point at a horizontal distance of 16.82 km on the survey line is taken as an example. Figure 5 As shown in the figure, it is the propagation path of the shot point excitation ray, which is transmitted from the shot point S to the common center point CMP, and then to the detection point R. The apparent reflection time of the bottom boundary of the weathering layer corresponding to the shot point is 359.8ms, and the wellhead time of the production well is 56.3ms. Substituting into the above formula 3, the vertical time at the common center point of the shot point and the corresponding first detection point can be obtained through the following calculation process as 208.05ms:

[0131] t0≈(τ+t 反 )÷2=(56.3+359.8)÷2=208.05(ms)

[0132] S103: Determine the elevation and velocity of the high-speed top interface at the common center point of each shot point and the corresponding first detection point based on the pre-obtained mapping relationship between the weathering layer thickness and the vertical time, and the vertical time at the common center point of each shot point and the corresponding first detection point.

[0133] In the above step S103, the method of determining the elevation and velocity of the high-speed top interface at the common center point of each shot point and the corresponding first detection point according to the pre-obtained mapping relationship between the weathering layer thickness and the vertical time and the vertical time at the common center point of each shot point and the corresponding first detection point comprises:

[0134] According to the weathering layer thickness and vertical time of each micro-logging well obtained, a mapping relationship between the weathering layer thickness and vertical time of each micro-logging well is established;

[0135] Substitute the vertical time at the common center point of each shot point and the corresponding first detection point into the mapping relationship between the weathering layer thickness and the vertical time of each micro-well logging to determine the weathering layer thickness at the common center point of each shot point and the corresponding first detection point;

[0136] Determine the elevation of the high-speed top interface at the common center point of each shot point and the corresponding first detection point according to the thickness of the weathering layer and the surface elevation at the common center point of each shot point and the corresponding first detection point;

[0137] The weathering layer velocity at the common center point of each shot point and the corresponding first detection point is determined according to the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point and the vertical time.

[0138] In the embodiment of the present application, when it is necessary to obtain the thickness and verticality of the weathered layer of each micro-logging well in advance, before or during the execution of this solution, the near-surface structure of the weathered layer at multiple different micro-logging wells and the surface structure parameters at different depths can be obtained by conducting a real-time micro-logging survey in the study area or directly obtaining the historical micro-logging survey result data, including the total number of layers of the near-surface structure of the weathered layer of the micro-logging well, the thickness and layer velocity of the weathered layer of each small layer, and then according to the surface structure parameters at different depths of the micro-logging well, based on the following formula 9, the thickness of the weathered layer of each micro-logging well is determined respectively:

[0139]

[0140] In the formula, h 总 is the thickness of the weathering layer of the micro-well logging, m; N is the total number of layers of the near-surface structure of the micro-well weathering layer, dimensionless; i = 0, 1, ..., N-1; h i is the thickness of the weathering layer of the i+1th layer at the micro-logging location, m.

[0141] In addition, according to the surface structure parameters of the micro-well at different depths, the vertical time of each micro-well can be determined based on the following formula 10:

[0142]

[0143] Where t is the vertical time of the micro-well logging, s; N is the total number of layers of the near-surface structure of the micro-well logging weathering layer, dimensionless; i = 0, 1, ..., N-1; h i is the thickness of the weathering layer in the i+1th layer of the micro-well logging, m; v i is the weathering layer velocity of the i+1th layer in micro-well logging, m / s.

[0144] In a specific embodiment, a micro-logging well at 210 m at a horizontal distance of about 16.82 km on the survey line can be taken as an example. The micro-logging survey results show that the near-surface structure of the weathered layer at this location is a 4-layer structure, and the specific surface structure parameters are: v0 = 276 m / s, h0 = 4.7 m; v1 = 647 m / s, h1 = 28.2 m; v2 = 953 m / s, h2 = 47.3 m; v3 = 1356 m / s, h3 = 111.3 m; v4 = 3242 m / s. Substituting the surface structure parameters into the above formula 9, the thickness of the weathered layer at the micro-logging well can be obtained as 191.5 m through the following calculation process:

[0145] h=h0+h1+h2+h3=4.7+28.2+47.3+111.3=191.5(m)

[0146] Substituting the surface structure parameters into the above formula 10, the vertical time of the micro-logging at this location can be obtained as 192.3ms through the following calculation process:

[0147] t=h0 / v0+h1 / v1+h2 / v2+h3 / v3

[0148] =(4.7÷276+28.2÷647+47.3÷953+111.3÷1356)×1000=192.3(ms)

[0149] In the embodiment of the present application, the weathering layer thickness and vertical time of each micro-logging well can be obtained based on the above method, so as to establish a mapping relationship between the weathering layer thickness and vertical time of the micro-logging well, and the mapping relationship can be a relationship curve between the weathering layer and vertical time. In the embodiment of the present application, the real-time micro-logging survey or direct acquisition of historical micro-logging survey result data in the research area used to establish the mapping relationship between the weathering layer thickness and vertical time of the micro-logging well can come from micro-logging wells of different depths, including ultra-deep micro-logging wells, deep well micro-logging wells and conventional micro-logging wells, wherein the ultra-deep micro-logging wells can be, for example, micro-logging wells with a depth greater than 100m, the deep well micro-logging wells can be, for example, micro-logging wells with a depth of 50 to 100m, and the conventional micro-logging wells can be micro-logging wells with a depth of less than 50m.

[0150] In a specific embodiment, taking a thick loess continuous medium region as an example, Figure 6 As shown in the figure, by obtaining the loess thickness and vertical time of each micro-logging well, the vertical time can be used as the horizontal coordinate and the loess thickness as the vertical coordinate. In the same rectangular coordinate system, the binomial function fitting method is used to establish the relationship curve between the vertical time and loess thickness of the micro-logging well in this area. 2 =0.9866 is the fitting value of the fitting function. The closer the value is to "1", the more accurate the fitting is. The curve formula in the figure is as follows:

[0151] h=0.0022t2 +0.528t+0.1322 Formula 11;

[0152] Where: h is the loess thickness of the micro-well, m; t is the vertical time of the micro-well, ms.

[0153] After obtaining the mapping relationship between the weathering layer thickness and vertical time of each micro-well according to the above method, substituting the vertical time at the common center point of a single shot point and the corresponding first detection point, the weathering layer thickness at the corresponding common center point can be obtained.

[0154] In a specific embodiment, taking a single shot point at a horizontal distance of 16.82 km on the survey line as an example, the vertical time at the common center point between the shot point and the first detection point has been obtained to be 208.05 ms. Substituting it into the above formula 11, the loess thickness at the common center point between the shot point and the first detection point can be obtained through the following calculation process to be 205.2 m:

[0155] h=0.0022t 2 +0.528t+0.1322

[0156] =0.0022×208.052+0.528×208.05+0.1322=205.2(m)

[0157] In a specific embodiment, the method of determining the weathering layer velocity at the common center point of each shot point and the corresponding first detection point according to the weathering layer thickness and vertical time at the common center point of each shot point and the corresponding first detection point specifically includes:

[0158] According to the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point and the vertical time, the weathering layer velocity at the common center point of each shot point and the corresponding first detection point is calculated based on the following formula 4:

[0159] v CMP =h CMP / t0 formula 4;

[0160] In the formula, v CMP h is the weathering layer velocity at the common center point of a single shot point and the corresponding first detection point; CMP is the thickness of the weathering layer at the common center point of a single shot point and the corresponding first detection point; t0 is the vertical time at the common center point of a single shot point and the corresponding first detection point.

[0161] In a specific embodiment, a single shot point at a horizontal distance of 16.82 km on the survey line is taken as an example. The vertical time at the common center point between the shot point and the first detection point is 208.05 ms, and the loess thickness at the common center point between the shot point and the first detection point is 205.2 m. Substituting into the above formula 4, the loess velocity at the common center point between the shot point and the first detection point can be obtained through the following calculation process:

[0162] v CMP =h CMP / t0=205.2÷208.05×1000=986.3(m / s)

[0163] S104: performing interpolation processing on the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point to obtain the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point.

[0164] In the embodiment of the present application, before executing the above S104, the following steps are also included:

[0165] According to the obtained east-west coordinates, north-south coordinates and surface elevation of each shot point and the corresponding first detection point, determine the east-west coordinates, north-south coordinates and surface elevation of the common center point of each shot point and the corresponding first detection point;

[0166] The high-speed top interface elevation at the common center point of each shot point and the corresponding first detection point is determined according to the surface elevation and the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point.

[0167] The east-west coordinates and north-south coordinates of the shot points, detection points, and common center points described in the embodiments of the present application may be longitude and latitude coordinates in the geodetic coordinate system, respectively.

[0168] In the embodiment of the present application, the east-west coordinates, north-south coordinates and surface elevation of the common center point of each shot point and the corresponding first detection point are determined in the following manner:

[0169] According to the east-west coordinates of each shot point and the corresponding first detection point, based on the following formula 5, the east-west coordinates of the common center point of each shot point and the corresponding first detection point can be expressed as:

[0170] X CMP =(X S +X R )÷2 Formula 5;

[0171] Where, X CMP X is the east-west coordinate of the common center point between a single shot point and the corresponding first detection point; SThe east-west coordinates of a single shot point; X R The east-west coordinates of the first detection point corresponding to a single shot point;

[0172] According to the north-south coordinates of each shot point and the corresponding first detection point, based on the following formula 6, the north-south coordinates of the common center point of each shot point and the corresponding first detection point can be expressed as:

[0173] Y CMP =(Y S +Y R )÷2 Formula 6;

[0174] Where Y CMP Y is the north-south coordinate of the common center point between a single shot point and the corresponding first detection point; S is the north-south coordinate of a single shot point; Y R The north-south coordinate of the first detection point corresponding to a single shot point;

[0175] According to the surface elevation of each shot point and the corresponding first detection point, based on the following formula 7, the surface elevation at the common center point of each shot point and the corresponding first detection point can be expressed as:

[0176] H CMP =(H S +H R )÷2 Formula 7;

[0177] In the formula, H CMP H is the surface elevation of the common center point between a single shot point and the corresponding first detection point; S is the surface elevation of a single shot point; H R It is the surface elevation of the first detection point corresponding to a single shot point.

[0178] In a specific embodiment, taking a single shot point and the corresponding first detection point at a horizontal distance of 16.82 km on the survey line as an example, through actual measurement, it can be obtained that the east-west coordinate of the shot point is 711945.8, the north-south coordinate is 138982.5 and the surface elevation is 2300.7; the east-west coordinate of the first detection point corresponding to the shot point is 711931.5, the north-south coordinate is 138974.5 and the surface elevation is 2302.0.

[0179] Substituting the east-west coordinates of the shot point 711945.8 and the east-west coordinates of the corresponding first detection point 711931.5 into the above formula 5, the east-west coordinates of the common center point between the shot point and the first detection point can be obtained as 711938.7 through the following calculation process:

[0180] X CMP =(X S +XR )÷2=(711945.8+711931.5)÷2=711938.7

[0181] Substituting the north-south coordinates of the shot point 138982.5 and the corresponding north-south coordinates of the first detection point 138974.5 into the above formula 6, the east-west coordinates of the common center point between the shot point and the first detection point can be obtained as 138978.5 through the following calculation process:

[0182] Y CMP =(Y S +Y R )÷2=(138982.5+138974.5)÷2=138978.5

[0183] Substituting the surface elevation of the shot point 2300.7 and the surface elevation of the corresponding first detection point 2302.0 into the above formula 7, the surface elevation of the common center point between the shot point and the first detection point can be obtained as 2301.35 through the following calculation process:

[0184] H CMP =(H S +H R )÷2=(2300.7+2302.0)÷2=2301.35

[0185] After the surface elevation at the common center point between each shot point and the first detection point is obtained in the above manner, the high-speed top interface elevation at the common center point between each shot point and the corresponding first detection point is determined according to the surface elevation at the common center point between each shot point and the corresponding first detection point and the thickness of the weathered layer, specifically including:

[0186] According to the surface elevation and weathering layer thickness at the common center point of each shot point and the corresponding first detection point, the high-speed top interface elevation at the common center point of each shot point and the corresponding first detection point can be expressed as follows based on the following formula 8:

[0187] E CMP =H CMP -h CMP Formula 8;

[0188] In the formula, Ew CMP H is the elevation of the high-speed top interface at the common center point between a single shot point and the corresponding first detection point, m; CMP h is the surface elevation at the common center point of a single shot point and the corresponding first detection point; CMP is the thickness of the weathering layer at the common center point between a single shot point and the corresponding first detection point, m.

[0189] In a specific embodiment, taking a single shot point and the corresponding first detection point at a horizontal distance of 16.82 km on the survey line as an example, the surface elevation 2301.35 and the loess thickness 205.2 m at the common center point of the shot point and the corresponding first detection point are substituted into the above formula 8, and the high-speed top interface elevation at the common center point between the shot point and the first detection point can be obtained as 2096.15 through the following calculation process:

[0190] E CMP =H CMP -h CMP =2301.35-205.2=2096.15

[0191] In the above step S104, after obtaining the high-speed top interface elevation and velocity at the common center point of multiple shot points at different positions and the corresponding first detection point, interpolation processing needs to be performed. Inverse distance weighted method, Kriging method and triangulation method can be used for spatial interpolation. The high-speed top interface elevation and velocity of each shot point and the corresponding first detection point are obtained through interpolation processing. The specific implementation method of difference processing can refer to the detailed description in the prior art, which will not be repeated here.

[0192] S105: Determine the thickness of the weathered layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point.

[0193] In the above step S105, the step of determining the thickness of the weathered layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point comprises:

[0194] The surface elevation of each shot point and the corresponding first detection point is subtracted from the elevation of the high-speed top interface to determine the thickness of the weathered layer of each shot point and the corresponding first detection point.

[0195] In the embodiment of the present application, the near-surface model finally established requires the thickness and velocity of the weathering layer of each shot point and the corresponding first detection point. Therefore, in the above step S105, the high-speed top interface elevation of each shot point and the corresponding first detection point needs to be processed again, and the high-speed top interface elevation of each shot point and the corresponding first detection point is obtained by subtracting it from the surface elevation. Among them, the high-speed top interface elevation of each shot point and the corresponding first detection point is the high-speed top interface elevation after being smoothed by a preset radius.

[0196] S106: Establish a near-surface model based on the coordinates of each shot point of each production well and the corresponding first detection point, the thickness and velocity of the weathering layer.

[0197] In the above step S106, steps S101 to S105 need to be executed for each shot point and the corresponding first detection point of each production well to obtain the coordinates, weathering layer thickness and velocity of each shot point and the corresponding first detection point of each production well, and establish a near-surface model of the study area.

[0198] In a specific embodiment, in order to make the final near-surface model of the study area smoother, after executing step S104 to obtain the high-speed top interface height and velocity of each shot point and the corresponding first detection point, the method may further include:

[0199] The high-speed top interface height and velocity of each shot point and the corresponding first detection point are smoothed with a preset radius to obtain the high-speed top interface height and velocity of each shot point and the corresponding first detection point after smoothing.

[0200] After obtaining the high-speed top interface height and velocity of each smoothed shot point and the corresponding first detection point, the above steps S105 and S106 are performed using the high-speed top interface height and velocity of each smoothed shot point and the corresponding first detection point. The thickness of the weathered layer of each shot point and the corresponding first detection point is determined based on the high-speed top interface elevation of each smoothed shot point and the corresponding first detection point. In addition, a near-surface model is established based on the coordinates, weathered layer thickness and velocity of each shot point and the corresponding first detection point of each production well.

[0201] The preset radius is set according to the actual accuracy requirement, for example, it can be set to a radius of 150 to 1500 m.

[0202] In a specific embodiment, Figure 7 As shown in the figure, it is a near-surface model established without smoothing the height and velocity of the high-speed top interface of the shot point and the corresponding first detection point in the study area. It can be seen that the edge of the near-surface model in the figure is not smooth and has many jagged edges; Figure 8 As shown in the figure, the near-surface model is established based on the smoothed high-speed top interface height and velocity of each shot point and the corresponding first detection point in the study area. It can be seen that the edge of the near-surface model in the figure is smoother and less jagged than the near-surface model obtained before smoothing.

[0203] In a specific embodiment, the application of a two-dimensional seismic exploration and acquisition project is taken as an example, taking the study area as the thick loess continuous medium area in the southwest of the Tarim Basin. The northern part of the surface of the area is Gobi, the middle part is gully, and the rest is all covered by thick loess, and the thickness of the loess can even reach 500m. If a micro-logging survey is conducted in this area with a density of 1 point / 2km, at least 8 deep well micro-loggings are required, with an average well depth of 295m, and the total drilling footage will reach 2360m. However, even with such a large effort to conduct surface surveys, the model accuracy between micro-loggings cannot be guaranteed. In this embodiment, the near-surface structure of the loess, that is, the near-surface structure of the weathering layer, can be obtained by conducting a real-time micro-logging survey in the area or directly obtaining the historical micro-logging survey result data to establish a near-surface model. After the near-surface modeling method of the continuous medium area provided in the embodiment of the present application is used to perform near-surface modeling in the study area, the weathering layer thickness and velocity error are calculated based on the mapping relationship between the weathering layer thickness and the vertical time established according to the micro-logging survey results and verified by actual data. Fig. 9 As shown in the figure, it is the loess velocity error value and percentage. Fig.10 As shown in the figure, it is the error value and percentage of loess thickness. Fig. 9 and Fig.10 It can be seen that the errors of loess thickness and velocity are within ±5%, which is a small error.

[0204] Furthermore, the inventors have found through comparative experiments that the near-surface model obtained by the near-surface modeling method of the continuous medium region provided by the present application can be processed by pre-stack depth migration, which can effectively improve the imaging effect of the seismic profile: Fig.11 As shown in Figure 1, it is the initial stacked section of the study area obtained by unconstrained tomographic inversion. Fig.12 As shown, the near-surface model obtained by the near-surface modeling method of the continuous medium area provided by the present application is compared with the initial stacked profile of the study area obtained by constrained tomography inversion. Fig.11 and Fig.12 It can be seen that the initial stacked profile imaging of the study area obtained by the near-surface model constrained tomographic inversion obtained after near-surface modeling using the near-surface modeling method for the continuous medium area provided in this application has more details and displays more effective information, which effectively improves the imaging effect of the profile.

[0205] The near-surface modeling method of the continuous medium area provided in the embodiment of the present application determines the high-speed top interface elevation and velocity at the common center point of the shot point and the corresponding first detection point based on the mapping relationship between the pre-acquired weathering layer thickness and vertical time, and the accurately acquired vertical time at the common center point of each shot point and the corresponding first detection point, thereby obtaining the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point, and finally establishing a near-surface model. Through the pre-constructed mapping relationship between the weathering layer thickness and vertical time, the scheme can construct a high-precision near-surface model without relying on the method of large-area deep well micro-logging survey, compared with the prior art, without implementing micro-logging, without implementing micro-logging. It greatly reduces production input, saves exploration investment, improves production timeliness, can meet the exploration accuracy requirements, lays the foundation for subsequent static correction accuracy, can provide high-quality basic data for pre-stack depth migration processing, and can effectively improve the imaging effect of seismic profiles. It can be applied to near-surface modeling in research areas of different continuous media such as gravel, rock, Gobi and loess, and is particularly suitable for near-surface modeling in research areas of extremely thick continuous media.

[0206] Embodiment 2

[0207] Based on the same inventive concept, the present application also provides a near-surface modeling device for a continuous medium region, referring to Fig.13 As shown, the device comprises:

[0208] The first determination module 101 is used to determine the wellhead time of each production well according to the depth of the production well and the thickness and velocity of each sublayer of the pre-determined weathering layer;

[0209] The second determination module 102 is used to determine the vertical time at the common center point of each shot point and the corresponding first detection point according to the wellhead time of the production well and the obtained apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well;

[0210] The third determination module 103 is used to determine the elevation and velocity of the high-speed top interface at the common center point of each shot point and the corresponding first detection point according to the pre-acquired mapping relationship between the weathering layer thickness and the vertical time and the vertical time at the common center point of each shot point and the corresponding first detection point;

[0211] The fourth determination module 104 is used to perform interpolation processing on the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point to obtain the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point;

[0212] A fifth determination module 105, for determining the thickness of the weathered layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point;

[0213] The model building module 106 is used to build a near-surface model based on the coordinates of each shot point and the corresponding first detection point of each production well, the thickness and velocity of the weathering layer.

[0214] Embodiment 3

[0215] Based on the same inventive concept, an embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method for near-surface modeling of a continuous medium region as described in the above-mentioned embodiment 1 is implemented.

[0216] Embodiment 4

[0217] Based on the same inventive concept, an embodiment of the present application also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the near-surface modeling method of the continuous medium region as described in the above-mentioned embodiment 1 is implemented.

[0218] Embodiment 5

[0219] Based on the same inventive concept, an embodiment of the present application also provides a computer program product containing instructions. When the computer program product is run on a computer device, the computer device executes the near-surface modeling method of a continuous medium region as described in the above-mentioned embodiment 1.

[0220] Embodiment 6

[0221] Based on the same inventive concept, an embodiment of the present application also provides a chip, the chip includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run a computer program or instruction to implement the near-surface modeling method of the continuous medium area as described in the above-mentioned embodiment one.

[0222] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0223] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0224] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0225] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0226] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for near-surface modeling in a continuous medium region, characterized in that: include: For each production well, the wellhead time of the production well is determined according to the depth of the production well and the thickness and velocity of each sublayer of the pre-determined weathering layer; According to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well, the vertical time at the common center point of each shot point and the corresponding first detection point is determined; According to the mapping relationship between the weathering layer thickness and the vertical time obtained in advance, and the vertical time at the common center point of each shot point and the corresponding first detection point, the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point are determined; Interpolation processing is performed based on the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point to obtain the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point; Determine the thickness of the weathering layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point; A near-surface model is established based on the coordinates of each shot point and the corresponding first detection point of each production well, the thickness and velocity of the weathering layer.

2. The method according to claim 1, characterized in that After obtaining the high-speed top interface height and velocity of each shot point and the corresponding first detection point, it also includes: The high-speed top interface height and velocity of each shot point and the corresponding first detection point are smoothed with a preset radius to obtain the high-speed top interface height and velocity of each shot point and the corresponding first detection point after smoothing.

3. The method according to claim 1, characterized in that The method of determining the wellhead time of the production well according to the depth of the production well and the thickness and velocity of each small layer of the pre-determined weathering layer comprises: According to the depth of the production well and the thickness and velocity of each small layer of the pre-determined weathering layer, the wellhead time of the production well is calculated based on the following formula 1: τ=h0 / v0+h1 / v1+…+h n-1 / v n-1 +(wdh-h0-h1-…-h n-1 ) / v n Formula 1; Wherein, τ is the wellhead time of the production well; h0 is the thickness of the first sublayer of the weathering layer; h1 is the thickness of the second sublayer of the weathering layer; h n-1 is the thickness of the nth layer of the weathering layer; v0 is the velocity of the first layer of the weathering layer; v1 is the velocity of the second layer of the weathering layer; v n-1 is the velocity of the nth layer of the weathering layer; v n is the velocity of the n+1th layer of the weathering layer; wdh is the depth of the production well; n=0, 1, ... N-1, where N is the total number of layers of the near-surface structure of the weathering layer.

4. The method according to claim 1, characterized in that The method of determining the verticality of each shot point and the common center point of the corresponding first detection point according to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well comprises: According to each single shot record obtained, determine the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point; The vertical time at the common center point of each shot point and the corresponding first detection point is determined according to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point.

5. The method according to claim 4, characterized in that Determining the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point according to each single shot record obtained includes: Performing static correction processing on each single shot record obtained, obtaining each single shot record after static correction and the static correction amount of each shot point and the corresponding first detection point; Preprocessing each single shot record or the minimum common offset section obtained after the static correction to obtain each single shot record or the minimum common offset section after preprocessing; Obtaining the apparent reflection time of the bottom boundary of the picked weathering layer according to each single shot record or minimum common offset profile after the preprocessing; The apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point is determined according to the static correction amount between each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathering layer.

6. The method according to claim 5, characterized in that Determining the apparent reflection time of the bottom boundary of the weathered layer corresponding to each shot point according to the static correction amount of each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathered layer, comprises: According to the static correction amount of each shot point and the corresponding first detection point, and the picked apparent reflection time of the bottom boundary of the weathering layer, the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point is calculated based on the following formula 2: t 反 =t′-Sta S -Sta R Formula 2; Where, t 反 is the apparent reflection time of the bottom boundary of the weathering layer corresponding to a single shot point; t′ is the apparent reflection time of the bottom boundary of the weathering layer picked up; Sta S Sta is the static correction value of a single shot point; Sta R It is the static correction value of the first detection point corresponding to a single shot point.

7. The method according to claim 6, characterized in that Determining the perpendicularity between each shot point and the common center point of the corresponding first detection point according to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point includes: According to the wellhead time of the production well and the apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point, the vertical time at the common center point of each shot point and the corresponding first detection point is calculated based on the following formula 3: t0≈(τ+t 反 )÷2Formula 3; Where t0 is the vertical time at the common center point of a single shot point and the corresponding first detection point; τ is the wellhead time of the production well; t 反 is the apparent reflection time of the bottom boundary of the weathering layer corresponding to a single shot point.

8. The method according to claim 1, characterized in that The method of determining the elevation and velocity of the high-speed top interface at the common center point of each shot point and the corresponding first detection point based on the pre-obtained mapping relationship between the weathering layer thickness and the vertical time and the vertical time at the common center point of each shot point and the corresponding first detection point comprises: According to the weathering layer thickness and vertical time of each micro-logging well obtained, a mapping relationship between the weathering layer thickness and vertical time of each micro-logging well is established; Substitute the vertical time at the common center point of each shot point and the corresponding first detection point into the mapping relationship between the weathering layer thickness and the vertical time of each micro-well logging to determine the weathering layer thickness at the common center point of each shot point and the corresponding first detection point; Determine the elevation of the high-speed top interface at the common center point of each shot point and the corresponding first detection point according to the thickness of the weathering layer and the surface elevation at the common center point of each shot point and the corresponding first detection point; The weathering layer velocity at the common center point of each shot point and the corresponding first detection point is determined according to the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point and the vertical time.

9. The method according to claim 8, characterized in that Determining the weathering layer velocity at the common center point of each shot point and the corresponding first detection point according to the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point and the vertical time, comprises: According to the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point and the vertical time, the weathering layer velocity at the common center point of each shot point and the corresponding first detection point is calculated based on the following formula 4: v CMP =h CMP / t0 formula 4; In the formula, v CMP h is the weathering layer velocity at the common center point between a single shot point and the corresponding first detection point; CMP is the thickness of the weathering layer at the common center point of a single shot point and the corresponding first detection point; t0 is the vertical time at the common center point of a single shot point and the corresponding first detection point.

10. The method according to claim 1, characterized in that Before interpolating the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point to obtain the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point, the method further includes: According to the obtained east-west coordinates, north-south coordinates and surface elevation of each shot point and the corresponding first detection point, determine the east-west coordinates, north-south coordinates and surface elevation of the common center point of each shot point and the corresponding first detection point; The high-speed top interface elevation at the common center point of each shot point and the corresponding first detection point is determined according to the surface elevation and the thickness of the weathering layer at the common center point of each shot point and the corresponding first detection point.

11. The method according to claim 10, characterized in that The east-west coordinates, north-south coordinates and surface elevation of the common center point of each shot point and the corresponding first detection point are determined by the following method: According to the east-west coordinates of each shot point and the corresponding first detection point, based on the following formula 5, the east-west coordinates of the common center point of each shot point and the corresponding first detection point can be expressed as: X CMP =(X S +X R )÷2 Formula 5; Where, X CMP X is the east-west coordinate of the common center point between a single shot point and the corresponding first detection point; S is the east-west coordinate of a single shot point; X R The east-west coordinates of the first detection point corresponding to a single shot point; According to the north-south coordinates of each shot point and the corresponding first detection point, based on the following formula 6, the north-south coordinates of the common center point of each shot point and the corresponding first detection point can be expressed as: Y CMP =(Y S +Y R )÷2 Formula 6; Where Y CMP Y is the north-south coordinate of the common center point between a single shot point and the corresponding first detection point; S is the north-south coordinate of a single shot point; Y R The north-south coordinate of the first detection point corresponding to a single shot point; According to the surface elevation of each shot point and the corresponding first detection point, based on the following formula 7, the surface elevation at the common center point of each shot point and the corresponding first detection point can be expressed as: H CMP =(H S +H R )÷2 Formula 7; In the formula, H CMP H is the surface elevation of the common center point between a single shot point and the corresponding first detection point; S is the surface elevation of a single shot point; H R It is the surface elevation of the first detection point corresponding to a single shot point.

12. The method according to claim 10, characterized in that Determining the high-speed top interface elevation at the common center point of each shot point and the corresponding first detection point according to the surface elevation and the weathering layer thickness at the common center point of each shot point and the corresponding first detection point includes: According to the surface elevation and weathering layer thickness at the common center point of each shot point and the corresponding first detection point, the high-speed top interface elevation at the common center point of each shot point and the corresponding first detection point can be expressed as follows based on the following formula 8: Ew CMP = H CMP -h CMP Formula 8: In the formula, Ew CMP H is the elevation of the high-speed top interface at the common center point between a single shot point and the corresponding first detection point; CMP h is the surface elevation at the common center point of a single shot point and the corresponding first detection point; CMP It is the thickness of the weathering layer at the common center point between a single shot point and the corresponding first detection point.

13. The method according to claim 1, characterized in that Determining the thickness of the weathered layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point includes: The surface elevation of each shot point and the corresponding first detection point is subtracted from the elevation of the high-speed top interface to determine the thickness of the weathered layer of each shot point and the corresponding first detection point.

14. A near-surface modeling device for a continuous medium region, characterized in that: include: The first determination module is used to determine the wellhead time of each production well according to the depth of the production well and the thickness and velocity of each sublayer of the pre-determined weathering layer; The second determination module is used to determine the vertical time at the common center point of each shot point and the corresponding first detection point according to the wellhead time of the production well and the obtained apparent reflection time of the bottom boundary of the weathering layer corresponding to each shot point at the production well; The third determination module is used to determine the elevation and velocity of the high-speed top interface at the common center point of each shot point and the corresponding first detection point according to the mapping relationship between the weathering layer thickness and the vertical time obtained in advance and the vertical time at the common center point of each shot point and the corresponding first detection point; A fourth determination module is used to perform interpolation processing on the high-speed top interface elevation and velocity at the common center point of each shot point and the corresponding first detection point to obtain the high-speed top interface elevation and velocity of each shot point and the corresponding first detection point; A fifth determination module, for determining the thickness of the weathered layer at each shot point and the corresponding first detection point according to the high-speed top interface elevation of each shot point and the corresponding first detection point; The model building module is used to build a near-surface model based on the coordinates of each shot point and the corresponding first detection point of each production well, the thickness and velocity of the weathering layer.

15. A computer-readable storage medium storing instructions, which, when executed on a terminal, enable the terminal to execute the method for near-surface modeling of a continuous medium region as claimed in any one of claims 1 to 13.

16. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the near-surface modeling method of a continuous medium region as claimed in any one of claims 1 to 13 when executing the computer program.

17. A computer program product comprising instructions, which, when executed on a computer device, enables the computer device to execute the method for near-surface modeling of a continuous medium region as claimed in any one of claims 1 to 13.

18. A chip, comprising a processor and a communication interface, wherein the communication interface and the processor are coupled, and the processor is used to run a computer program or instruction to implement the near-surface modeling method of a continuous medium region as described in any one of claims 1 to 13.

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