Correction method, device and equipment of speed reversal, and medium

Abstract

This application provides a method, apparatus, equipment, and medium for correcting velocity reversal, belonging to the field of petroleum geophysical exploration technology. The method includes: acquiring a hybrid model of the target work area, which describes velocity variations within different layers of the target work area; determining at least one reversal layer based on the inter-layer velocities indicated by the hybrid model; adjusting the velocity sample values ​​corresponding to any reversal layer at least once, and determining a correction gradient value for the reversal layer based on the relationship between the velocity of the upper boundary point corresponding to the reversal layer and the velocity of the lower boundary point after each adjustment; and correcting the intra-layer velocity sample values ​​of the reversal layer based on the correction gradient value to obtain corrected intra-layer velocity sample values. Through this method, velocity reversal problems in the grid model can be corrected, eliminating velocity reversal situations inconsistent with geological laws, and facilitating accurate analysis results in subsequent velocity analysis.

Description

Technical Field

[0001] This application relates to the field of petroleum geophysical exploration technology, and in particular to a method, apparatus, equipment and medium for correcting velocity reversal. Background Technology

[0002] Hybrid models are an important representation of velocity models in deep domain velocity modeling. They employ both layered structural models and mesh models to describe velocities, maintaining consistency between the two during velocity updates. Hybrid models can describe not only velocity boundaries but also intra-layer velocity details, making the velocity field more consistent with geological patterns. However, hybrid models frequently encounter velocity inversion problems during velocity analysis, where the velocity in the upper layer is greater than that in the lower layer at layer boundaries. This inverted velocity field generally does not conform to geological patterns. If this inverted velocity field is used as the initial velocity field for subsequent velocity analyses, accurate results will not be obtained. Summary of the Invention

[0003] This application provides a method, apparatus, device, and medium for correcting velocity reversal, which can correct velocity reversal problems in mesh models, eliminate velocity reversal situations that are inconsistent with geological laws, and facilitate obtaining correct analysis results in subsequent velocity analysis. The technical solution is as follows:

[0004] On the one hand, a method for correcting velocity reversal is provided, the method comprising:

[0005] Obtain a hybrid model of the target work area, the hybrid model being used to describe the velocity variation within different layers of the target work area;

[0006] Based on the interlayer velocity indicated by the hybrid model, at least one reversal layer is determined, the interlayer velocity including the upper boundary point velocity and the lower boundary point velocity at the boundary between two adjacent layers, and the reversal layer is the lower layer among the two adjacent layers where the velocity reversal occurs;

[0007] The velocity sample value corresponding to any inversion layer is adjusted at least once, and the correction gradient value of the inversion layer is determined based on the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment.

[0008] Based on the correction gradient value of the inversion layer, the intra-layer velocity sample value of the inversion layer is corrected to obtain the corrected intra-layer velocity sample value.

[0009] On the other hand, a speed reversal correction device is provided, the device comprising:

[0010] The acquisition module is used to acquire a hybrid model of the target work area, wherein the hybrid model is used to describe the velocity changes in different layers of the target work area.

[0011] The first determining module is used to determine at least one inversion layer based on the interlayer velocity indicated by the hybrid model, wherein the interlayer velocity includes the upper boundary point velocity and the lower boundary point velocity at the boundary between two adjacent layers, and the inversion layer is the lower layer among the two adjacent layers in which the velocity is reversed.

[0012] The second determining module is used to adjust the velocity sample value corresponding to any inversion layer at least once, and determine the correction gradient value of the inversion layer based on the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment.

[0013] The correction module is used to correct the intra-layer velocity sample values ​​of the inversion layer based on the correction gradient value of the inversion layer, so as to obtain the corrected intra-layer velocity sample values.

[0014] In some embodiments, the hybrid model includes a layered structure model and a mesh model. The layered structure model is used to describe the average velocity corresponding to each layer in the target work area, and the mesh model is used to describe the velocity value corresponding to each three-dimensional mesh unit in the target work area.

[0015] The acquisition module is used to acquire an initial layered structure model and a mesh model of the target work area. The initial layered structure model includes multiple layers in the target work area. Based on the layer time or layer depth of the initial layered structure model, the average velocity corresponding to each layer is extracted from the mesh model. The average velocity corresponding to any layer is determined by the velocity values ​​of multiple three-dimensional mesh units corresponding to that layer. The average velocity corresponding to each layer is added to the initial layered structure model to obtain the layered structure model.

[0016] In some embodiments, the first determining module is configured to: determine, for any two adjacent layers in the hybrid model, a layer boundary point on any seismic trace for the two adjacent layers, wherein the layer boundary point is used to distinguish the upper and lower layers in the two adjacent layers; based on the depth value at the layer boundary point, determine the upper boundary point velocity and the lower boundary point velocity through the fitted straight line of the seismic trace corresponding to the two adjacent layers, wherein the fitted straight line of the seismic trace corresponding to any layer is used to indicate the relationship between the velocity value and the depth value on the seismic trace within the layer; and if the upper boundary point velocity is greater than the lower boundary point velocity, determine the lower layer in the two adjacent layers as the inversion layer.

[0017] In some embodiments, the expression for the fitted straight line corresponding to the seismic trace at any layer is:

[0018] V = k * d + b

[0019] Where V represents the velocity at position d, d represents any depth within the layer, k represents the gradient of the fitted line corresponding to the layer, and b represents the intercept of the fitted line corresponding to the layer.

[0020] In some embodiments, the second determining module is configured to, during the i-th adjustment process, determine the velocity sample value after the i-th adjustment, the velocity sample value after the i-th adjustment including the velocity of the lower boundary point after the i-th adjustment, where i is a positive integer not less than 1; if the velocity of the lower boundary point after the i-th adjustment is not less than the velocity of the upper boundary point corresponding to the inversion layer, determine the lower gradient after the i-th adjustment as the correction gradient of the inversion layer; if the velocity of the lower boundary point after the i-th adjustment is less than the velocity of the upper boundary point, perform the (i+1)-th adjustment process until the adjusted velocity of the lower boundary point is not less than the velocity of the upper boundary point.

[0021] In some embodiments, the expression for the velocity of the lower boundary point after the i-th adjustment is:

[0022]

[0023] Among them, V d ' represents the velocity of the lower boundary point after the i-th adjustment, d z d represents the thickness within the lower layer. t k′ represents the time difference within the next lower layer. d This represents the lower-level gradient after the i-th adjustment, which is equal to the product of the lower-level gradient after the (i-1)-th adjustment and the preset gradient adjustment ratio.

[0024] In some embodiments, the formula used in correcting the intralayer velocity sample values ​​of the inversion layer is:

[0025]

[0026] Among them, V i d represents the corrected intra-layer velocity sample value. i Let k′ represent any depth within the inversion layer. d k represents the correction gradient value of the inversion layer. d b represents the gradient of the fitted line corresponding to the inversion layer. d d represents the intercept of the fitted line corresponding to the inversion layer. top d represents the top depth of the inversion layer. btm This indicates the bottom depth of the inversion layer.

[0027] On the other hand, a computer device is provided, the computer device including a processor and a memory, the memory being used to store at least one computer program, the at least one computer program being loaded and executed by the processor to implement the speed reversal correction method in the embodiments of this application.

[0028] On the other hand, a computer-readable storage medium is provided, wherein at least one computer program is stored in the computer-readable storage medium, the at least one computer program being loaded and executed by a processor to implement the speed reversal correction method in the embodiments of this application.

[0029] On the other hand, a computer program product is provided, including a computer program that is executed by a processor to implement the speed reversal correction method in the embodiments of this application.

[0030] This application provides a method for correcting velocity reversal. First, a hybrid model describing velocity variations within different layers of the target work area is obtained. Then, based on the inter-layer velocities indicated by the hybrid model, at least one reversal layer is identified—that is, the lower of two adjacent layers where velocity reversal occurs. By continuously adjusting the velocity sample values ​​corresponding to any reversal layer, the velocity reversal at the boundary between adjacent layers can be corrected, and the correction gradient value of the reversal layer is determined. Then, based on this correction gradient value, the intra-layer velocity sample values ​​of the reversal layer are corrected, thereby obtaining the corrected intra-layer velocity sample values. This method can correct velocity reversal problems in the grid model, eliminate velocity reversal situations inconsistent with geological laws, and facilitate obtaining accurate analysis results in subsequent velocity analysis. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of an implementation environment provided according to an embodiment of this application;

[0033] Figure 2 This is a flowchart of a speed reversal correction method provided according to an embodiment of this application;

[0034] Figure 3 This is a flowchart of another speed reversal correction method provided according to an embodiment of this application;

[0035] Figure 4 This is a schematic diagram of a hybrid model provided according to an embodiment of this application;

[0036] Figure 5 This is a schematic diagram of a velocity reversal phenomenon provided according to an embodiment of this application;

[0037] Figure 6 This is a schematic diagram of an intralayer velocity curve provided according to an embodiment of this application;

[0038] Figure 7 This is a schematic diagram of model data provided according to an embodiment of this application;

[0039] Figure 8 This is a schematic diagram of actual data provided according to an embodiment of this application;

[0040] Figure 9 This is a schematic diagram of a velocity field offset gather result provided according to an embodiment of this application;

[0041] Figure 10 This is a schematic diagram of a velocity field superposition profile result provided according to an embodiment of this application;

[0042] Figure 11 This is a block diagram of a speed reversal correction device according to an embodiment of this application;

[0043] Figure 12 This is a schematic diagram of the structure of a terminal according to an embodiment of this application;

[0044] Figure 13 This is a schematic diagram of the structure of a server according to an embodiment of this application. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0046] In this application, the terms "first," "second," etc., are used to distinguish identical or similar items with essentially the same function. It should be understood that there is no logical or temporal dependency between "first," "second," and "nth," nor are there any restrictions on quantity or execution order.

[0047] In this application, the term "at least one" means one or more, and "multiple" means two or more.

[0048] The following is a brief introduction to the terminology used in this application.

[0049] Velocity modeling: In petroleum geophysical exploration, pre-stack depth migration is a process that transforms seismic data from the time domain to the depth domain and considers the variation of seismic wave propagation velocity with depth. Velocity modeling is a crucial step in pre-stack depth migration, enabling the accurate interpretation of seismic data by establishing an accurate subsurface velocity model.

[0050] It should be noted that all information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.), and signals involved in this application have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the hybrid model involved in this application was obtained with full authorization.

[0051] Figure 1 This is a schematic diagram of an implementation environment provided according to an embodiment of this application. See also... Figure 1 The implementation environment includes terminal 101 and server 102. Terminal 101 and server 102 can be connected directly or indirectly via wired or wireless communication, which is not limited herein.

[0052] Among them, terminal 101 can be various types of terminals such as mobile phones, desktop computers, laptops, and tablets. Server 102 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers. It can also be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0053] Optionally, the speed reversal correction method provided in this application embodiment can be executed by the terminal 101 alone, by the server 102 alone, or by the terminal 101 and the server 102 interacting.

[0054] In some embodiments, when the terminal 101 executes the method alone, the terminal 101 can obtain the hybrid model of the target work area and correct the velocity of the lower boundary point and the velocity sample point value within the layer corresponding to each inversion layer, thereby obtaining the corrected hybrid model related data.

[0055] In some embodiments, when the server 102 executes the method independently, the server 102 can perform data calculations independently. Data processing is performed based on the hybrid model-related data of the target work area uploaded to the server by other devices, thereby correcting the velocity values ​​of the lower boundary points and intra-layer velocity samples corresponding to the inversion layer. After completing the correction, the server 102 can store the corrected hybrid model-related data in the server, or send the corrected hybrid model-related data to other devices for display to relevant personnel, or continue to perform other data calculations based on the corrected hybrid model-related data; there are no limitations on this.

[0056] In some embodiments, when the terminal 101 and server 102 interactively execute the method, the terminal 101 and server 102 are associated, and the server 102 provides background services to the terminal 101. Optionally, the server 102 undertakes the main computing work, and the terminal 101 undertakes the secondary computing work; or, the server 102 undertakes the secondary computing work, and the terminal 101 undertakes the main computing work; or, the server 102 and the terminal 101 use a distributed computing architecture for collaborative computing.

[0057] That is, some steps in this method are executed by terminal 101, while others are executed by server 102. For example, terminal 101 obtains the hybrid model of the target work area and sends the hybrid model-related data to server 102; server 102 processes the data based on the hybrid model-related data to correct the velocity of the lower boundary points and the velocity sample points within the layer corresponding to the inversion layer, obtaining the corrected hybrid model-related data, and sends the data to terminal 101; terminal 101 receives the data and displays it accordingly.

[0058] It should be noted that in the following embodiments, the speed reversal correction method proposed in this application is described using a terminal alone. That is, the data acquisition and data processing processes in this method are all performed by the terminal.

[0059] Figure 2 This is a flowchart of a speed reversal correction method according to an embodiment of this application. The method is applied to a terminal. (See also...) Figure 2 The method includes the following steps:

[0060] 201. The terminal acquires the hybrid model of the target work area. The hybrid model is used to describe the velocity changes in different layers within the target work area.

[0061] In this embodiment, the hybrid model uses both a layered structure model and a mesh model to describe the velocity, and maintains consistency between the two velocities during velocity updates. The hybrid model can not only describe the average velocity and velocity boundaries of each layer in the target work area, but also the velocity details within each layer, making the velocity field more consistent with geological patterns.

[0062] The layered structure model divides the subsurface medium into a series of horizontal or inclined layers, assuming a uniform velocity distribution within each layer. Layered structure models are used to describe the approximate velocity and stratigraphic information of the subsurface medium. The grid model divides the subsurface medium into a series of grid cells, assuming that the velocity within each grid cell can vary. Grid models can describe the variation of subsurface velocity in greater detail, particularly the velocity details within each layer.

[0063] 202. The terminal determines at least one inversion layer based on the interlayer velocity indicated by the hybrid model. The interlayer velocity includes the upper boundary point velocity and the lower boundary point velocity at the boundary between two adjacent layers. The inversion layer is the lower layer among the two adjacent layers where the velocity inversion occurs.

[0064] In this embodiment, velocity reversal refers to an abnormal relationship between the velocity values ​​of two adjacent layers, i.e., the velocity of the upper layer is greater than that of the lower layer. Accordingly, if the velocity of the upper boundary point determined by the fitted line is greater than the velocity of the lower boundary point determined by the fitted line, it can be determined that a velocity reversal problem has occurred between the two adjacent layers, and the lower layer is identified as the reversal layer.

[0065] The upper boundary point velocity refers to the velocity at the layer boundary point determined by the fitted straight line corresponding to the upper layer among two adjacent layers, while the lower boundary point velocity refers to the velocity at the layer boundary point determined by the fitted straight line corresponding to the lower layer among two adjacent layers. Layer boundary points are used to distinguish between upper and lower layers within two adjacent layers. For the same set of adjacent layers, the layer boundary points corresponding to different seismic traces may be the same or different, which can be determined based on the hybrid model. Each layer corresponds to its own fitted straight line. The fitted straight line corresponding to each layer indicates the relationship between the depth and velocity values ​​of that layer.

[0066] It should be noted that the velocities of the upper and lower boundary points determined by the fitted straight line may be the same as or different from the corresponding actual boundary point velocities, depending on the actual situation. In this application, the velocities of both upper and lower boundary points are determined by the fitted straight line, not the actual boundary point velocities, and will not be elaborated further thereafter.

[0067] Velocity reversal typically contradicts geological patterns and can negatively impact the interpretation of seismic data. For instance, using a reversed velocity field as the initial velocity field in iterative velocity analysis rarely yields accurate results. Velocity reversal in depth migration frequently leads to discrepancies between imaging results and actual geological conditions; severe velocity reversal can also cause gather voids and uneven illumination. Therefore, velocity reversal correction is necessary.

[0068] 203. The terminal adjusts the velocity sample value corresponding to any inversion layer at least once, and determines the correction gradient value of the inversion layer based on the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment.

[0069] In this embodiment, the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment refers to the numerical relationship between the two. The gradient value of any layer refers to the slope or rate of change of the velocity within the layer with depth, which can reflect the trend and details of the velocity change within the underground medium.

[0070] The velocity sample values ​​corresponding to the inversion layer are adjusted by adjusting the lower-level gradient. This includes adjusting the velocities of the lower-level boundary points until the adjusted velocities are no longer less than the velocities of the upper-level boundary points. This process requires one or more adjustments to the lower-level gradient to correct the velocity inversion between adjacent layers and ultimately determine the corrected gradient value of the inversion layer. After each adjustment, the relationship between the velocities of the lower and upper-level boundary points is used to determine if the adjustment has met the target: the adjusted lower-level boundary point velocity must no longer be less than the upper-level boundary point velocity. If this target is not met, the next adjustment and judgment is performed; if it is met, the adjusted lower-level gradient is determined as the corrected gradient value of the inversion layer. It should be noted that while adjusting the lower-level gradient, the intra-layer average velocity of the lower layer remains unchanged.

[0071] 204. The terminal corrects the intra-layer velocity sample values ​​of the inversion layer based on the correction gradient value of the inversion layer, and obtains the corrected intra-layer velocity sample values.

[0072] In this embodiment, the intra-layer velocity sample value refers to multiple velocity values ​​corresponding to the seismic trace within the inversion layer. It should be noted that while correcting the intra-layer velocity sample values ​​of the inversion layer, the relative change between them and the original intra-layer velocity sample values ​​is kept basically consistent. This ensures that the morphological trend of the intra-layer velocity curve composed of the corrected intra-layer velocity sample values ​​is the same as that of the original intra-layer velocity curve.

[0073] This application provides a method for correcting velocity reversal. First, a hybrid model describing velocity variations within different layers of the target work area is obtained. Then, based on the inter-layer velocities indicated by the hybrid model, at least one reversal layer is identified—that is, the lower of two adjacent layers where velocity reversal occurs. By continuously adjusting the velocity sample values ​​corresponding to any reversal layer, the velocity reversal at the boundary between adjacent layers can be corrected, and the correction gradient value of the reversal layer is determined. Then, based on this correction gradient value, the intra-layer velocity sample values ​​of the reversal layer are corrected, thereby obtaining the corrected intra-layer velocity sample values. This method can correct velocity reversal problems in the grid model, eliminate velocity reversal situations inconsistent with geological laws, and facilitate obtaining accurate analysis results in subsequent velocity analysis.

[0074] The above Figure 2 A simplified procedure for correcting velocity reversal is introduced below. Figure 3 As shown, the method for correcting speed reversal is described in detail. Figure 3 This is a flowchart of another speed reversal correction method provided according to an embodiment of this application. The method is applied to a terminal and includes the following steps:

[0075] 301. The terminal acquires the hybrid model of the target work area. The hybrid model is used to describe the velocity changes in different layers within the target work area.

[0076] In this embodiment, the hybrid model uses both a layered structure model and a mesh model to describe velocity, maintaining consistency between the two during velocity updates. The hybrid model can describe not only the average velocity and velocity boundaries of each layer in the target work area, but also the velocity details within each layer, making the velocity field more consistent with geological patterns. That is, the hybrid model includes at least a layered structure model and a mesh model; the layered structure model describes the average velocity corresponding to each layer in the target work area, and the mesh model describes the velocity value corresponding to each three-dimensional mesh cell in the target work area.

[0077] More specifically, a layered structure model is a model that divides the subsurface medium into a series of horizontal or inclined layers, assuming a uniform velocity distribution within each layer. Layered structure models are used to describe the approximate velocity and stratigraphic information of the subsurface medium. A mesh model, on the other hand, divides the subsurface medium into a series of three-dimensional mesh cells, assuming that the velocity within each mesh cell can vary. Mesh models can describe the variation of subsurface velocity in greater detail, particularly the velocity details within each layer.

[0078] For easier description of layered structure models, mesh models, and hybrid models, see [link to relevant documentation]. Figure 4 As shown, Figure 4 This is a schematic diagram of a hybrid model provided according to an embodiment of this application. Wherein, Figure 4Figure (a) shows a layered velocity model, with velocities recorded on a block model. Figure 4 Figure (b) shows a mesh model, with velocity recorded on a sample mesh (i.e., three-dimensional mesh cells), such as in Segy format. Figure 4 Figure (c) shows a hybrid model, which uses both a layered result model and a grid model to record velocities.

[0079] In some embodiments, the terminal constructs a layered structure model using the average velocity extracted from the mesh model. Accordingly, the terminal acquires an initial layered structure model and a mesh model of the target work area. The initial layered structure model includes multiple layers within the target work area. Based on the layer time or layer depth of the initial layered structure model, the terminal extracts the average velocity corresponding to each layer from the mesh model. The average velocity corresponding to any layer is determined by the velocity values ​​of multiple three-dimensional mesh elements corresponding to that layer. The terminal adds the average velocity corresponding to each layer to the initial layered structure model to obtain the layered structure model.

[0080] Here, "stratum time" refers to the time required for seismic waves to propagate underground to a certain location or interface. "Stratum depth" refers to the depth value at a certain location or interface. The average velocity is calculated based on the velocity information at the stratum time or stratum depth corresponding to the layered structure model extracted from the mesh model. It should be noted that the initial layered structure model can be directly created by relevant personnel on this terminal based on data from the target work area, or it can be imported from local storage, other terminals, or a backend server; this application does not impose any limitations on this. The mesh model is imported by this terminal from local storage, other terminals, or a backend server.

[0081] Through the above process, it is ensured that the time and average velocity of the velocity medium are the same at the same layer position in both the layered structure model and the grid model, thus establishing a hybrid model that includes both the layered structure model and the grid model, providing a data foundation for subsequent steps.

[0082] 302. For any two adjacent layers in the hybrid model, the terminal determines the layer boundary point of the two adjacent layers on any seismic trace.

[0083] In this embodiment, the hybrid model can describe the average velocity of multiple layers in the target work area, and also the specific velocity of multiple seismic traces at different depths in the target work area. The terminal performs velocity reversal correction on each seismic trace at each group of adjacent layers, mainly to determine whether there is velocity reversal at the inter-layer position of each seismic trace in each group of adjacent layers, and performs velocity reversal correction if velocity reversal exists. Here, each group of adjacent layers refers to two adjacent upper and lower layers, and velocity reversal means that the velocity of the upper layer is greater than the velocity of the lower layer in the two adjacent upper and lower layers.

[0084] The horizon boundary point is used to distinguish the upper and lower layers in two adjacent layers. For the same set of adjacent layers, the horizon boundary points corresponding to different seismic traces may be the same or different, which can be determined according to the hybrid model. For ease of description, the upper layer in two adjacent layers is referred to as H. u The lower of two adjacent layers is called H. d The boundary point between two adjacent layers is called point A.

[0085] 303. Based on the depth value at the layer boundary point, the terminal determines the upper boundary point velocity and the lower boundary point velocity by using the fitted straight line corresponding to the two adjacent layers of the seismic trace.

[0086] In this embodiment, the fitted straight line corresponding to the seismic trace at any layer is used to indicate the relationship between the velocity and depth values ​​of the seismic trace within that layer. This is obtained by fitting the velocity values ​​of the seismic trace within that layer. The upper boundary point velocity refers to the velocity of the upper layer at the layer boundary point, and the lower boundary point velocity refers to the velocity of the lower layer at the layer boundary point. Accordingly, based on the depth value at the layer boundary point, the upper boundary point velocity is determined using the expression of the fitted straight line corresponding to the seismic trace at the upper layer; similarly, based on the depth value at the layer boundary point, the lower boundary point velocity is determined using the expression of the fitted straight line corresponding to the seismic trace at the lower layer.

[0087] The expression for the fitted straight line corresponding to a seismic trace in any layer is shown in Formula 1 below.

[0088] Formula 1:

[0089] V = k * d + b

[0090] Where V represents the velocity at position d within the layer, d represents any depth within the layer, k represents the gradient of the fitted line corresponding to the layer, and b represents the intercept of the fitted line corresponding to the layer.

[0091] For ease of description, the velocity of the upper boundary point is denoted as V. u The velocity at the lower boundary point is denoted as V. d The upper-level gradient is the gradient of the corresponding fitted line in the upper layer, denoted as k. u The lower-level gradient is the gradient of the corresponding fitted line in the lower layer, denoted as k. d .

[0092] 304. When the terminal's velocity at the upper boundary point is greater than the velocity at the lower boundary point, the lower of the two adjacent layers is determined to be the inversion layer.

[0093] In this embodiment, velocity reversal refers to an abnormal relationship between the velocity values ​​of two adjacent layers, i.e., the velocity of the upper layer is greater than that of the lower layer. Accordingly, when the velocity at the upper layer boundary point is greater than that at the lower layer boundary point, it can be determined that a velocity reversal problem has occurred between the two adjacent layers, and the lower layer is identified as the reversal layer.

[0094] For a clearer description of this velocity reversal phenomenon, see [link to relevant documentation]. Figure 5 As shown, Figure 5 This is a schematic diagram illustrating a velocity reversal phenomenon according to an embodiment of this application. The horizontal axis represents velocity, and the vertical axis represents depth. Layer 1, layer 2, and layer 3 represent three layers, with depth values ​​gradually increasing from layer 1 to layer 2 to layer 3. For adjacent layers 2 and 3, layer 2 is the upper layer, and layer 3 is the lower layer. V2(d) and V3(d) are the intra-layer velocity curves for layers 2 and 3, respectively. The intra-layer velocity curve describes the change in intra-layer velocity with depth. The boundary point between layers 2 and 3 on a certain seismic trace is denoted as point A, and the depth at this boundary point is denoted as d. A As shown in the figure, V2(d) A )>V3(d A This means that the velocity of the upper boundary point is greater than that of the lower boundary point, so there is a velocity reversal between layer 2 and layer 3.

[0095] It should be noted that steps 302 to 304 above are an exemplary way for the terminal to determine at least one inversion layer based on the interlayer velocity indicated by the hybrid model.

[0096] 305. The terminal adjusts the velocity sample value corresponding to any inversion layer at least once, and determines the correction gradient value of the inversion layer based on the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment.

[0097] In this embodiment, the velocity sample values ​​corresponding to the inversion layer are adjusted by adjusting the lower-layer gradient. This includes adjusting the velocity of the lower-layer boundary points until the adjusted lower-layer boundary point velocity is no longer less than the upper-layer boundary point velocity. This process requires adjusting the lower-layer gradient one or more times to correct the velocity reversal between adjacent layers and ultimately determine the corrected gradient value of the inversion layer. After each adjustment of the lower-layer gradient, the adjusted velocity sample values ​​are fitted to determine the lower-layer boundary point velocity based on the fitted line. The relationship between the lower-layer boundary point velocity and the upper-layer boundary point velocity is used to determine whether the adjustment has met the adjustment target, i.e., the adjusted lower-layer boundary point velocity is no longer less than the upper-layer boundary point velocity. If the adjustment target is not met, the next adjustment and judgment are performed; if the adjustment target is met, the adjusted lower-layer gradient is determined as the corrected gradient value of the inversion layer.

[0098] Accordingly, during any adjustment process, the terminal determines the velocity sample value after the adjustment; if the velocity of the lower boundary point after the adjustment is not less than the velocity of the upper boundary point corresponding to the inversion layer, the terminal determines the lower gradient after the adjustment as the correction gradient of the inversion layer; if the velocity of the lower boundary point after the adjustment is less than the velocity of the upper boundary point, the next adjustment process is carried out until the velocity of the lower boundary point after the adjustment is not less than the velocity of the upper boundary point.

[0099] In this process, after each adjustment of the lower-level gradient, the velocity of the lower-level boundary points changes with the gradient. The formula used in any adjustment is shown in Equation 2 below. It should be noted that Equation 2 reflects the relationship between the velocity of the lower-level boundary points and the lower-level gradient. Equation 2 allows for the adjustment of the lower-level gradient and the velocity of the lower-level boundary points while keeping the average velocity within the lower layer constant.

[0100] Formula 2:

[0101]

[0102] Among them, V d ' represents the velocity of the lower boundary point after the current adjustment, d z d represents the thickness within the lower layer. t k′ represents the time difference within the next lower layer. d This represents the lower-level gradient after the current adjustment. The lower-level gradient after the current adjustment is equal to the product of the lower-level gradient after the previous adjustment and the preset gradient adjustment ratio.

[0103] For ease of description, the unadjusted lower-level gradient, which is also the gradient of the corresponding fitted line in the lower level, is denoted as k. d Let the preset gradient adjustment ratio be denoted as r, then the gradient after the initial gradient adjustment is k. d *r, denoted as k′ d If, after each adjustment, the velocity of the lower boundary point is still less than the velocity of the upper boundary point, that is, in V... d ′ is still less than V u In the case of k′, determine d =k′ d *r, and recalculate V according to Formula 2. d ′, until V d ′ greater than V u Thus, the corrected gradient value k′ of the inversion layer is obtained. d .

[0104] 306. The terminal corrects the intra-layer velocity sample values ​​of the inversion layer based on the correction gradient value of the inversion layer, and obtains the corrected intra-layer velocity sample values.

[0105] In this embodiment, the intra-layer velocity sample value refers to multiple velocity values ​​corresponding to the seismic trace within the inversion layer. The formula used in correcting the intra-layer velocity sample values ​​of the inversion layer is shown in Formula 3 below. It should be noted that Formula 3 reflects the relationship between the intra-layer velocity sample values ​​and depth. Formula 3 ensures that while correcting the intra-layer velocity sample values ​​of the inversion layer, the relative change between them and the original intra-layer velocity sample values ​​remains essentially consistent. This results in the corrected intra-layer velocity curve, composed of the intra-layer velocity sample values, exhibiting the same morphological trend as the original intra-layer velocity curve.

[0106] Formula 3:

[0107]

[0108] Among them, V i d represents the corrected intra-layer velocity sample value. i k′ represents any depth within the inversion layer. d k represents the correction gradient value of the inversion layer. d This represents the gradient of the fitted line corresponding to the inversion layer, which is also the unadjusted gradient of the lower layer. b d d represents the intercept of the fitted line corresponding to the inversion layer. top d represents the depth of the top of the inversion layer. btm This indicates the depth of the bottom layer of the inversion layer.

[0109] For a clearer description of intra-layer velocity profiles that retain interlayer detail after correction, see [link to relevant documentation]. Figure 6 As shown, Figure 6 This is a schematic diagram of an intralayer velocity curve according to an embodiment of this application. The horizontal axis represents velocity, and the vertical axis represents depth. Layer 1 and Layer 2 represent two layers. V(d) represents the intralayer velocity curve before gradient modification. V′(d) identifies the intralayer velocity curve after gradient modification. As can be seen from the diagram, although the gradients are different, the relative morphological trend remains unchanged; that is, the curves still maintain a relative detail trend.

[0110] It should be noted that the embodiments of this application do not limit the specific data processing order during the speed reversal correction process.

[0111] Optionally, the terminal performs velocity reversal correction on multiple groups of adjacent layers sequentially according to the layer order indicated by the depth values ​​from smallest to largest. During the velocity reversal correction of each group of adjacent layers, each seismic trace is processed separately. That is, after constructing the hybrid model of the target work area through step 301 above, a velocity reversal correction of adjacent layers is achieved through steps 302 to 306 above. This velocity reversal correction of adjacent layers includes separate correction processing for the velocities of multiple seismic traces. By repeating steps 302 to 306 for each group of adjacent layers, the velocity reversal correction can be achieved.

[0112] Alternatively, the terminal performs velocity reversal correction on multiple seismic traces sequentially according to a preset processing order. During the velocity reversal correction of each seismic trace, each group of adjacent layers is processed separately. This embodiment will not be elaborated further. That is, after constructing the hybrid model of the target work area through step 301, velocity reversal correction of one seismic trace is achieved through steps 302 to 306. The velocity reversal correction of this seismic trace includes correcting multiple groups of adjacent layers separately. Repeating steps 302 to 306 for each seismic trace achieves the velocity reversal correction.

[0113] It should be noted that, since the layered structure model in the hybrid model is used to describe the average velocity corresponding to each layer, and this scheme can ensure that the average velocity corresponding to each layer does not change after the velocity reversal correction, this scheme does not actually correct the layered structure model in the hybrid model, but instead achieves the velocity reversal correction of the grid velocity field indicated by the grid model in the hybrid model.

[0114] This application provides a method for correcting velocity inversion. Specifically, it provides a method for correcting velocity inversion in a mesh model using intra-layer gradients. This method is mainly used to correct the inter-layer velocity inversion problem that occurs in hybrid models during velocity analysis. In correcting velocity inversion in a mesh model, this method can correct inter-layer velocity inversion by gradually modifying the gradient of the lower layer while keeping the average velocity between upper and lower layers constant and the relative detail of the inter-layer velocity curve unchanged, until the velocity inversion no longer exists.

[0115] This method has at least the following effects: First, it can correct the velocity inversion problem in the grid model, eliminating velocity inversion that is inconsistent with geological laws; second, it maintains the average velocity within the layer during the correction process, thus ensuring that the position of the phase axis of the migration profile remains unchanged and does not significantly alter the migration results; third, it maintains the relative detail of the velocity curves between layers; fourth, the grid model after correcting velocity inversion is more consistent with reality, making velocity analysis on this basis easier to converge and obtain more accurate velocities. Correspondingly, the corrected velocity field has at least the following characteristics: First, the velocity curves between layers no longer exhibit velocity inversion at the interface, eliminating inter-layer velocity inversion; second, the average velocity within the layer remains unchanged after correction; and third, it maintains the relative detail of the velocity curves within the layer. Here, the migration profile refers to the seismic profile image after migration processing. The migration profile can more accurately reflect the structural and lithological characteristics of the subsurface medium. The phase axis refers to the curve composed of seismic waves with the same phase (i.e., wave crests or troughs). The phase axis can reflect the stratigraphic and structural information of the subsurface medium.

[0116] The velocity field corrected by this method has a certain geological rationality and conforms to geological laws. Using it as the initial velocity field for subsequent velocity analysis will yield accurate velocities more quickly. It should be noted that this invention only applies to cases where the average velocities between upper and lower layers have not reversed. If the average velocities between upper and lower layers reverse, it is impossible to substantially correct the reversed velocity.

[0117] To facilitate the description of the overall process of this method, Figure 7 Let's take an example to illustrate. Figure 7 This is a schematic diagram of model data provided according to an embodiment of this application. The method includes four steps (1)-(4) as described below.

[0118] (1) Establish a hybrid model, which includes a layered structure model and a mesh model, as shown in step 301 above.

[0119] (2) Determine the reversal layer where velocity reversal occurs by calculating the interlayer velocity, as shown in steps 302 to 304 above. More specifically, see... Figure 7 As shown in (a), layer 1 and layer 2 are used as examples for illustration. Fitting lines are obtained for each seismic trace based on its velocity value at layer 1 and layer 2. Assume the gradient of the fitting line for layer 1 is k. up The intercept is b up The depth at stratigraphic boundary point A is d. up Using Formula 1, the velocity at layer 1 at layer boundary point A (i.e., the velocity at the upper boundary point) is: V A_up =k up *d up +b up Assume the gradient of the fitted line corresponding to layer 2 is k.dn The intercept is b dn The depth at stratigraphic boundary point A is d. dn Using Formula 1, the velocity at layer 2 at layer boundary point A (i.e., the velocity at the lower layer boundary point) is: V A_dn =k dn *d dn +b dn By comparison, we can obtain V. A_up >V A_dn If there is a velocity reversal between layer 1 and layer 2 at layer boundary point A, then layer 2 is determined to be the reversal layer.

[0120] (3) Adjust the gradient at layer 2 to correct the velocity reversal between layer 1 and layer 2, as shown in step 305 above. More specifically, determine the gradient at layer 2 (i.e., the lower layer gradient) as k. dn If the preset gradient adjustment ratio is r, then the gradient of layer 2 after one adjustment is k. dn *r, denoted as k′ dn Assume the thickness of the lower layer is d. z The time difference within the lower layer is d. t Then, keeping the average velocity within the layer constant, the velocity at layer boundary point A of layer 2 after adjustment, according to Formula 2, is: If V d ′ n Still less than V A_up Let k′ dn =k′ dn *r, recalculate V d ′ n until V d ′ n No longer less than V A_up Thus, the corrected gradient value for layer 2 is obtained as k′. dn .

[0121] (4) Correct the intralayer velocity of layer 2 based on the correction gradient value of layer 2, as shown in step 306 above. More specifically, based on the correction gradient value k′ of layer 2... dn The intralayer velocity sample values ​​of layer 2 are corrected. Assume the depth of the top of layer 2 is d. top The bottom depth of layer 2 is d. btm The velocity sampling point depth in layer 2 is d i_dn Therefore, according to Formula 3, the corrected intra-layer velocity sample values ​​for layer 2 are: As shown in Formula 3, while correcting the velocity sample values ​​within the corrected layer, the relative changes between the original velocity sample values ​​within the corrected layer are maintained, ensuring that the updated velocity curve remains unchanged in shape from the original velocity curve. (See also...) Figure 7As shown in (b), the velocity reversal at the boundary between layer 1 and layer 2 is eliminated.

[0122] For a clearer description of the effectiveness of this method, please refer to [link / reference]. Figure 7 As shown, Figure 7 This is a schematic diagram of model data provided according to an embodiment of this application. The horizontal axis represents the seismic trace number, and the vertical axis represents depth. The bottom color scheme is used to represent velocity. Figure 7 Figure (a) shows the initial mesh model with interlayer velocity reversal. According to velocity curves C1 and C2, the velocity is reversed at the layer interface between layer 1 and layer 2, and at the layer interface between layer 2 and layer 3. Figure 7 Figure (b) shows the mesh model after correction using this method. Based on the corrected velocity curves C1 and C2, it can be seen that the velocity at the interface between layer 1 and layer 2, and at the interface between layer 2 and layer 3, no longer reverses. See also... Figure 8 As shown, Figure 8 This is a schematic diagram of actual data provided according to an embodiment of this application. The horizontal axis represents the seismic trace number, and the vertical axis represents depth. The bottom color chart is used to represent velocity. Figure 8 Figure (a) shows the initial mesh model with interlayer velocity reversal. The velocity curve indicates the presence of velocity reversal. Figure 8 Figure (b) shows the mesh model after correction using this method. The velocity curve shows that the velocity no longer reverses, which is more consistent with geological patterns. It should be noted that the shallow layers have a fixed embedded velocity and do not require reversal correction. That is, this method allows users to set the range or depth of the layers where velocity reversal needs to be detected and corrected, and to perform processing within that range or depth using steps 302 to 306.

[0123] For a clearer description of the effectiveness of this method, please refer to [link / reference]. Figure 9 As shown, Figure 9 This is a schematic diagram of a velocity field migration gather result provided according to an embodiment of this application. The horizontal axis represents the migration distance, and the circled position is the location of the inversion layer. Figure 9 Figure (a) shows the offset gather before velocity correction. Figure 9 Figure (b) shows the velocity-corrected migration gather. It can be seen that because this method maintains the average velocity within the layer constant, it does not cause large changes in the phase axis at the layer level. The corrected velocity field eliminates velocity reversal, making it more reasonable and more consistent with geological laws. See also Figure 10 As shown, Figure 10 This is a schematic diagram of a velocity field superposition profile result provided according to an embodiment of this application. The horizontal axis represents the seismic trace number, the vertical axis represents the depth, and the arrow indicates the location of the velocity inversion layer. Figure 10Figure (a) shows the offset profile before velocity correction. Figure 10 Figure (b) shows the offset profile after velocity correction. Since this method keeps the average velocity within the layer constant, it will not cause large changes in the phase axis at the layer level on the profile. The corrected velocity field eliminates velocity reversal, which is more reasonable and more in line with geological laws.

[0124] Figure 11 This is a block diagram of a speed reversal correction device according to an embodiment of this application. The device is used to perform the steps of the speed reversal correction method described above, see [link to relevant documentation]. Figure 11 The speed reversal correction device includes: an acquisition module 1101, a first determination module 1102, a second determination module 1103, and a correction module 1104.

[0125] The acquisition module 1101 is used to acquire the hybrid model of the target work area. The hybrid model is used to describe the velocity changes in different layers of the target work area.

[0126] The first determining module 1102 is used to determine at least one inversion layer based on the interlayer velocity indicated by the hybrid model. The interlayer velocity includes the upper boundary point velocity and the lower boundary point velocity at the boundary between two adjacent layers. The inversion layer is the lower layer among the two adjacent layers where the velocity is reversed.

[0127] The second determining module 1103 is used to adjust the velocity sample value corresponding to any inversion layer at least once, and determine the correction gradient value of the inversion layer based on the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment.

[0128] The correction module 1104 is used to correct the intra-layer velocity sample values ​​of the inversion layer based on the correction gradient value of the inversion layer, so as to obtain the corrected intra-layer velocity sample values.

[0129] In some embodiments, the hybrid model includes a layered structure model and a mesh model. The layered structure model is used to describe the average velocity corresponding to each layer in the target work area, and the mesh model is used to describe the velocity value corresponding to each three-dimensional mesh unit in the target work area.

[0130] The acquisition module 1101 is used to acquire the initial layered structure model and mesh model of the target work area. The initial layered structure model includes multiple layers in the target work area. Based on the layer time or layer depth of the initial layered structure model, the average velocity corresponding to each layer is extracted from the mesh model. The average velocity corresponding to any layer is determined by the velocity values ​​of multiple three-dimensional mesh elements corresponding to the layer. The average velocity corresponding to each layer is added to the initial layered structure model to obtain the layered structure model.

[0131] In some embodiments, the first determining module 1102 is used to determine, for any two adjacent layers in the hybrid model, the layer boundary point on any seismic trace of the two adjacent layers, the layer boundary point is used to distinguish the upper layer and the lower layer in the two adjacent layers; based on the depth value at the layer boundary point, the upper boundary point velocity and the lower boundary point velocity are determined by the fitted straight line corresponding to the seismic trace in the two adjacent layers, the fitted straight line corresponding to the seismic trace in any layer is used to indicate the relationship between the velocity value and the depth value on the seismic trace in the layer; if the upper boundary point velocity is greater than the lower boundary point velocity, the lower layer in the two adjacent layers is determined to be the inversion layer.

[0132] In some embodiments, the expression for the fitted straight line corresponding to the seismic trace at any layer is:

[0133] V = k * d + b

[0134] Where V represents the velocity at position d, d represents any depth within the layer, k represents the gradient of the fitted line corresponding to the layer, and b represents the intercept of the fitted line corresponding to the layer.

[0135] In some embodiments, the second determining module 1103 is used to determine the velocity sample value after the i-th adjustment during the i-th adjustment process. The velocity sample value after the i-th adjustment includes the velocity of the lower boundary point after the i-th adjustment, where i is a positive integer not less than 1. If the velocity of the lower boundary point after the i-th adjustment is not less than the velocity of the upper boundary point corresponding to the inversion layer, the lower gradient after the i-th adjustment is determined as the correction gradient of the inversion layer. If the velocity of the lower boundary point after the i-th adjustment is less than the velocity of the upper boundary point, the process of the (i+1)-th adjustment is performed until the velocity of the lower boundary point after the adjustment is not less than the velocity of the upper boundary point.

[0136] In some embodiments, the expression for the velocity of the lower boundary point after the i-th adjustment is:

[0137]

[0138] Among them, V d ' represents the velocity of the lower boundary point after the i-th adjustment, d z d represents the thickness within the lower layer. t k′ represents the time difference within the next lower layer. d This represents the lower-level gradient after the i-th adjustment. The lower-level gradient after the i-th adjustment is equal to the product of the lower-level gradient after the (i-1)-th adjustment and the preset gradient adjustment ratio.

[0139] In some embodiments, the formula used in correcting the intralayer velocity sample values ​​of the inversion layer is:

[0140]

[0141] Among them, V i d represents the corrected intra-layer velocity sample value. i Let j′ represent any depth within the inversion layer. d j represents the correction gradient value of the inversion layer. d b represents the gradient of the fitted line corresponding to the inversion layer. d d represents the intercept of the fitted line corresponding to the inversion layer. top d represents the depth of the top of the inversion layer. btm This indicates the depth of the bottom layer of the inversion layer.

[0142] This application provides a velocity reversal correction device. First, a hybrid model describing velocity variations within different layers of the target work area is acquired. Then, based on the inter-layer velocities indicated by the hybrid model, at least one reversal layer is identified—that is, the lower of two adjacent layers where velocity reversal occurs. By continuously adjusting the velocity sample values ​​corresponding to any reversal layer, the velocity reversal at the boundary between adjacent layers can be corrected, and the correction gradient value of the reversal layer is determined. Then, based on this correction gradient value, the intra-layer velocity sample values ​​of the reversal layer are corrected, thereby obtaining the corrected intra-layer velocity sample values. This device can correct velocity reversal problems in the grid model, eliminate velocity reversal situations inconsistent with geological laws, and facilitate obtaining accurate analysis results in subsequent velocity analysis.

[0143] It should be noted that the speed reversal correction device provided in the above embodiments is only illustrated by the division of the above functional modules when running the application. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the terminal can be divided into different functional modules to complete all or part of the functions described above. In addition, the speed reversal correction device and the speed reversal correction method embodiments provided in the above embodiments belong to the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0144] Figure 12 This is a schematic diagram of a terminal according to an embodiment of this application. The terminal 1200 can be a portable mobile terminal, such as a smartphone, tablet computer, laptop computer, or desktop computer. The terminal 1200 may also be referred to as user equipment, portable terminal, laptop terminal, desktop terminal, or other names.

[0145] Typically, terminal 1200 includes a processor 1201 and a memory 1202.

[0146] Processor 1201 may include one or more processing cores, such as a quad-core processor or a twelfth-core processor. Processor 1201 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). Processor 1201 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 1201 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, processor 1201 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0147] The memory 1202 may include one or more computer-readable storage media, which may be non-transitory. The memory 1202 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory 1202 are used to store at least one computer program, which is executed by the processor 1201 to implement the speed reversal correction method provided in the method embodiments of this application.

[0148] In some embodiments, the terminal 1200 may also optionally include a peripheral device interface 1203 and at least one peripheral device. The processor 1201, memory 1202, and peripheral device interface 1203 can be connected via a bus or signal line. Each peripheral device can be connected to the peripheral device interface 1203 via a bus, signal line, or circuit board. Specifically, the peripheral device includes at least one of the following: radio frequency circuitry 1204, display screen 1205, camera assembly 1206, audio circuitry 1207, and power supply 1208.

[0149] Peripheral device interface 1203 can be used to connect at least one I / O (Input / Output) related peripheral device to processor 1201 and memory 1202. In some embodiments, processor 1201, memory 1202 and peripheral device interface 1203 are integrated on the same chip or circuit board; in some other embodiments, any one or two of processor 1201, memory 1202 and peripheral device interface 1203 can be implemented on separate chips or circuit boards, which is not limited in this embodiment.

[0150] The radio frequency (RF) circuit 1204 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The RF circuit 1204 communicates with communication networks and other communication devices via electromagnetic signals. The RF circuit 1204 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals back into electrical signals. In some embodiments, the RF circuit 1204 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a user identity module card, etc. The RF circuit 1204 can communicate with other terminals via at least one wireless communication protocol. This wireless communication protocol includes, but is not limited to: the World Wide Web, metropolitan area networks, intranets, various generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks, and / or WiFi (Wireless Fidelity) networks. In some embodiments, the RF circuit 1204 may also include circuitry related to NFC (Near Field Communication), which is not limited in this application.

[0151] Display screen 1205 is used to display a UI (User Interface). This UI may include graphics, text, icons, videos, and any combination thereof. When display screen 1205 is a touch display screen, it also has the ability to collect touch signals on or above its surface. These touch signals can be input as control signals to processor 1201 for processing. In this case, display screen 1205 can also be used to provide virtual buttons and / or a virtual keyboard, also known as soft buttons and / or a soft keyboard. In some embodiments, there may be one display screen 1205, disposed on the front panel of terminal 1200; in other embodiments, there may be at least two display screens, disposed on different surfaces of terminal 1200 or in a folded design; in still other embodiments, display screen 1205 may be a flexible display screen, disposed on a curved or folded surface of terminal 1200. Furthermore, display screen 1205 may also be configured as a non-rectangular, irregular shape, i.e., a non-rectangular screen. The display screen 1205 can be made of materials such as LCD (Liquid Crystal Display) and OLED (Organic Light-Emitting Diode).

[0152] The camera assembly 1206 is used to acquire images or videos. In some embodiments, the camera assembly 1206 includes a front-facing camera and a rear-facing camera. Typically, the front-facing camera is located on the front panel of the terminal, and the rear-facing camera is located on the back of the terminal. In some embodiments, there are at least two rear-facing cameras, which are any one of a main camera, a depth-sensing camera, a wide-angle camera, and a telephoto camera, to achieve background blurring by fusion of the main camera and the depth-sensing camera, panoramic shooting by fusion of the main camera and the wide-angle camera, VR (Virtual Reality) shooting, or other fusion shooting functions. In some embodiments, the camera assembly 1206 may also include a flash. The flash can be a single-color temperature flash or a dual-color temperature flash. A dual-color temperature flash is a combination of a warm-light flash and a cool-light flash, which can be used for light compensation at different color temperatures.

[0153] The audio circuit 1207 may include a microphone and a speaker. The microphone is used to collect sound waves from the user and the environment, converting the sound waves into electrical signals that are input to the processor 1201 for processing, or input to the radio frequency circuit 1204 for voice communication. For stereo sound acquisition or noise reduction purposes, multiple microphones may be used, each positioned at a different location on the terminal 1200. The microphone may also be an array microphone or an omnidirectional microphone. The speaker is used to convert electrical signals from the processor 1201 or the radio frequency circuit 1204 into sound waves. The speaker may be a conventional diaphragm speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can convert electrical signals not only into audible sound waves but also into inaudible sound waves for purposes such as distance measurement. In some embodiments, the audio circuit 1207 may also include a headphone jack.

[0154] Power supply 1208 is used to power the various components in terminal 1200. Power supply 1208 can be AC ​​power, DC power, a disposable battery, or a rechargeable battery. When power supply 1208 includes a rechargeable battery, the rechargeable battery can support wired charging or wireless charging. The rechargeable battery can also be used to support fast charging technology.

[0155] Those skilled in the art will understand that Figure 12 The structure shown does not constitute a limitation on terminal 1200 and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0156] Figure 13 This is a schematic diagram of a server structure according to an embodiment of this application. The server 1300 can vary considerably due to different configurations or performance. It may include one or more Central Processing Units (CPUs) 1301 and one or more memories 1302. The memory 1302 stores at least one computer program, which is loaded and executed by the processor 1301 to implement the speed reversal correction method provided in the above-described method embodiments. Of course, the server may also have wired or wireless network interfaces, a keyboard, and input / output interfaces for input and output. The server may also include other components for implementing device functions, which will not be elaborated here.

[0157] This application also provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to implement the speed reversal correction method described above. For example, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, floppy disk, or optical data storage device, etc.

[0158] This application also provides a computer program product, including a computer program that is executed by a processor to implement the speed reversal correction method of this application.

[0159] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0160] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for correcting speed reversal, characterized in that, The method includes: Obtain a hybrid model of the target work area, the hybrid model being used to describe the velocity variation within different layers of the target work area; Based on the interlayer velocity indicated by the hybrid model, at least one reversal layer is determined, the interlayer velocity including the upper boundary point velocity and the lower boundary point velocity at the boundary between two adjacent layers, and the reversal layer is the lower layer among the two adjacent layers where the velocity reversal occurs; The velocity sample value corresponding to any inversion layer is adjusted at least once, and the correction gradient value of the inversion layer is determined based on the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment. Based on the correction gradient value of the inversion layer, the intra-layer velocity sample value of the inversion layer is corrected to obtain the corrected intra-layer velocity sample value.

2. The speed reversal correction method according to claim 1, characterized in that, The hybrid model includes a layered structure model and a mesh model. The layered structure model is used to describe the average velocity corresponding to each layer in the target work area, and the mesh model is used to describe the velocity value corresponding to each three-dimensional mesh unit in the target work area. The process of obtaining the hybrid model of the target work area includes: Obtain the initial layered structure model and the mesh model of the target work area, wherein the initial layered structure model includes multiple layers in the target work area; Based on the layer time or layer depth of the initial layered structure model, the average velocity corresponding to each layer is extracted from the mesh model. The average velocity corresponding to any layer is determined by the velocity values ​​of multiple three-dimensional mesh elements corresponding to that layer. The average velocity corresponding to each layer is added to the initial layered structure model to obtain the layered structure model.

3. The speed reversal correction method according to claim 1, characterized in that, Determining at least one inversion layer based on the interlayer velocity indicated by the hybrid model includes: For any two adjacent layers in the hybrid model, determine the layer boundary point of the two adjacent layers on any seismic trace. The layer boundary point is used to distinguish the upper and lower layers in the two adjacent layers. Based on the depth value at the layer boundary point, the velocity of the upper boundary point and the velocity of the lower boundary point are determined by the fitted straight line of the seismic trace in the two adjacent layers. The fitted straight line of the seismic trace in any layer is used to indicate the relationship between the velocity value and the depth value on the seismic trace within the layer. If the velocity of the upper boundary point is greater than the velocity of the lower boundary point, the lower of the two adjacent layers is determined to be the inversion layer.

4. The speed reversal correction method according to claim 3, characterized in that, The expression for the fitted straight line corresponding to the seismic trace at any layer is: V = k * d + b Where V represents the velocity at position d, d represents any depth within the layer, k represents the gradient of the fitted line corresponding to the layer, and b represents the intercept of the fitted line corresponding to the layer.

5. The speed reversal correction method according to claim 1, characterized in that, The step of adjusting the velocity sample value corresponding to any inversion layer at least once, and determining the correction gradient value of the inversion layer based on the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment, includes: During the i-th adjustment, the velocity sample value after the i-th adjustment is determined. The velocity sample value after the i-th adjustment includes the velocity of the lower boundary point after the i-th adjustment, where i is a positive integer not less than 1. If the velocity of the lower boundary point after the i-th adjustment is not less than the velocity of the upper boundary point corresponding to the inversion layer, the lower gradient after the i-th adjustment is determined as the correction gradient of the inversion layer. If the speed of the lower boundary point after the i-th adjustment is less than the speed of the upper boundary point, the process of the (i+1)-th adjustment is performed until the speed of the lower boundary point after the adjustment is not less than the speed of the upper boundary point.

6. The speed reversal correction method according to claim 5, characterized in that, The expression for the velocity of the lower boundary point after the i-th adjustment is: Among them, V d ′ d represents the velocity of the lower boundary point after the i-th adjustment. z d represents the thickness within the lower layer. t k represents the time difference within the next lower layer. ′ d This represents the lower-level gradient after the i-th adjustment, which is equal to the product of the lower-level gradient after the (i-1)-th adjustment and the preset gradient adjustment ratio.

7. The speed reversal correction method according to claim 1, characterized in that, The formula used in correcting the intralayer velocity sample values ​​of the inversion layer is as follows: Among them, V i d represents the corrected intra-layer velocity sample value. i k represents any depth within the inversion layer. ′ d k represents the correction gradient value of the inversion layer. d b represents the gradient of the fitted line corresponding to the inversion layer. d d represents the intercept of the fitted line corresponding to the inversion layer. top d represents the top depth of the inversion layer. btm This indicates the bottom depth of the inversion layer.

8. A speed reversal correction device, characterized in that, The device includes: The acquisition module is used to acquire a hybrid model of the target work area, wherein the hybrid model is used to describe the velocity changes in different layers of the target work area. The first determining module is used to determine at least one inversion layer based on the interlayer velocity indicated by the hybrid model, wherein the interlayer velocity includes the upper boundary point velocity and the lower boundary point velocity at the boundary between two adjacent layers, and the inversion layer is the lower layer among the two adjacent layers in which the velocity is reversed. The second determining module is used to adjust the velocity sample value corresponding to any inversion layer at least once, and determine the correction gradient value of the inversion layer based on the relationship between the velocity of the upper boundary point corresponding to the inversion layer and the velocity of the lower boundary point after each adjustment. The correction module is used to correct the intra-layer velocity sample values ​​of the inversion layer based on the correction gradient value of the inversion layer, so as to obtain the corrected intra-layer velocity sample values.

9. A computer device, characterized in that, The computer device includes a processor and a memory, the memory being used to store at least one computer program, the at least one computer program being loaded by the processor and executed as the speed reversal correction method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store at least one computer program for performing the speed reversal correction method according to any one of claims 1 to 7.

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