PS-wave VTI medium dynamic correction method and device based on segmented velocity modeling

Abstract

The present invention discloses a PS-wave VTI medium dynamic correction method and device based on segmented velocity modeling. The method includes: acquiring seismic data of a target transversely isotropic medium to be dynamically corrected, and then organizing to obtain a common conversion point gather and a common midpoint gather; analyzing the common midpoint gather to obtain the P-wave velocity and the P-wave correction velocity; performing velocity analysis iteration on the common conversion point gather, and then realizing segmented velocity analysis modeling through the ratio of offset to depth information, and gradually realizing VTI medium dynamic correction based on the increment of the offset-depth ratio. The embodiments of the present invention can accurately perform PS-wave VTI medium dynamic correction based on segmented velocity modeling, and can be widely applied to the field of data processing technology.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular, to a PS-wave VTI medium dynamic correction method and device based on segmented velocity modeling. Background Art

[0002] With the development of multi-component exploration technology, the application of shear-wave seismic data has become an important means to control the non-uniqueness of the inversion results of reservoir physical property parameters. In the initial stage of the development of multi-component technology, pure-wave seismic exploration was generally adopted in the academic and industrial circles. However, due to the high cost of seismic acquisition excited by shear-wave sources, the conversion (PS)-wave acquisition method of P-wave excitation and S-wave reception was turned to. Different from pure-wave seismic, the ray path of the conversion (PS) wave is asymmetric. Even at the self-excitation and self-reception position, the travel time of the downward P-wave is not equal to the travel time of the upward PS-wave, which results in the non-hyperbolic shape of the reflection wave travel time-distance curve of the same underground cross-section in both the CMP gather and the CCP gather for the conversion (PS) wave data, which brings great difficulties to the conversion (PS) wave dynamic correction. Summary of the Invention

[0003] The present invention aims to solve the problems of related technical limitations at least to a certain extent. For this purpose, the present invention provides a PS-wave VTI medium dynamic correction method and device based on segmented velocity modeling, which can accurately perform PS-wave VTI medium dynamic correction.

[0004] On the one hand, an embodiment of the present invention provides a PS-wave VTI medium dynamic correction method based on segmented velocity modeling, including:

[0005] Obtain seismic data of the target transversely isotropic medium to be dynamically corrected, and then organize a common conversion point gather and a common midpoint gather; take the common conversion point gather as the target gather; the seismic data corresponding to the common conversion point gather is obtained based on the PS wave; the seismic data corresponding to the common midpoint gather is obtained based on the PP wave;

[0006] Analyze the longitudinal wave velocity and the longitudinal wave correction velocity based on the common midpoint gather;

[0007] Perform a first velocity analysis on the target gather to obtain an equivalent velocity;

[0008] Process to obtain the shear wave velocity according to the equivalent velocity and the longitudinal wave velocity;

[0009] Based on the longitudinal wave velocity and the shear wave velocity, use the double square root processing method to obtain the first travel time;

[0010] Perform migration processing on the target gather through the first travel time to obtain a migrated gather, use the migrated gather as the target gather, and then return to execute the step of performing the first velocity analysis on the target gather to obtain the equivalent velocity until the preset number of iterations is reached. Take the latest equivalent velocity as the target equivalent velocity and the latest target gather as the target migrated gather;

[0011] Process the target P-wave velocity ratio based on the target equivalent velocity and the P-wave velocity; obtain the S-wave correction velocity based on the ratio of the P-wave correction velocity to the P-wave to S-wave velocity ratio;

[0012] Based on the first dip ratio corresponding to each seismic data in the target migrated gather, cut the target migrated gather to obtain a preset number of first gather segments; the first gather segments include a first near-offset gather, a first mid-offset gather, and a first far-offset gather; the first dip ratio is based on the ratio of the offset corresponding to the seismic data to the depth information, and the offset represents the distance between the seismic source generating the seismic data and the geophone receiving the seismic data;

[0013] Perform a second velocity analysis on the first gather segments to obtain the first velocity information of the first gather segments;

[0014] Based on the preset first dip ratio threshold, determine the first dip ratio increment corresponding to each seismic data in all the first gather segments;

[0015] Based on the first dip ratio increment, combine the S-wave correction velocity and the preset S-wave anisotropy parameter to obtain the target S-wave velocity corresponding to the seismic data corresponding to the first dip ratio increment; obtain the S-wave anisotropic velocity based on the target S-wave velocities corresponding to all the first gather segments;

[0016] Based on the P-wave velocity and the S-wave anisotropic velocity, use the double square root processing method to obtain the second travel time, and perform dynamic correction on the target transversely isotropic medium according to the second travel time.

[0017] Optionally, analyzing the common midpoint gather to obtain the P-wave velocity and the P-wave correction velocity includes the following steps:

[0018] Perform a third velocity analysis on the common midpoint gather to obtain an initial velocity model in the time domain; convert the velocity and time information in the initial velocity model to obtain the first depth information corresponding to each seismic data in the common midpoint gather;

[0019] Based on the ratio of the offset corresponding to the seismic data in the common midpoint gather to the depth information, obtain the second dip ratio of each seismic data;

[0020] Based on the second dip ratio, cut the common midpoint gather to obtain a preset number of second gather segments; the second gather segments include a second near-offset gather, a second mid-offset gather, and a second far-offset gather;

[0021] Perform the fourth velocity analysis on the second trace gather segments to obtain the second velocity information corresponding to each seismic data in the second trace gather segments;

[0022] Preset the P-wave correction velocity based on the second velocity information of the second trace gather segments; the P-wave correction velocity includes the P-wave near-offset velocity, the P-wave mid-offset velocity, and the P-wave far-offset velocity;

[0023] Determine the second depth-offset ratio increment corresponding to each seismic data in all the second trace gather segments based on the preset third depth-offset ratio threshold value;

[0024] Based on the second depth-offset ratio increment and in combination with the preset P-wave anisotropic parameters, obtain the P-wave anisotropic velocity at the offset corresponding to the seismic data corresponding to the second depth-offset ratio increment, and use the P-wave anisotropic velocity as the P-wave velocity.

[0025] Optionally, the first trace gather segments include the first near-offset trace gather, the first mid-offset trace gather, and the first far-offset trace gather; cutting the target offset trace gather based on the first depth-offset ratio corresponding to each seismic data in the target offset trace gather to obtain a preset number of first trace gather segments, including the following steps:

[0026] Divide the seismic data in the target offset trace gather with the first depth-offset ratio less than or equal to the first depth-offset ratio threshold value into the first near-offset trace gather;

[0027] Divide the seismic data in the target offset trace gather with the first depth-offset ratio greater than the first depth-offset ratio threshold value and less than or equal to the second depth-offset ratio threshold value into the first mid-offset trace gather;

[0028] Divide the seismic data in the target offset trace gather with the first depth-offset ratio greater than the second depth-offset ratio threshold value into the first far-offset trace gather.

[0029] Optionally, processing to obtain the S-wave velocity based on the equivalent velocity and the P-wave velocity, including the following steps:

[0030] Invert the P-wave to S-wave velocity ratio according to the equivalent velocity and the P-wave velocity through the equivalent velocity formula;

[0031] Among them, the expression of the equivalent velocity formula is:

[0032] v c(x) =v p(x) ·2 / 1+gama;

[0033] In the formula, v c(x) represents the equivalent velocity, v p(x) represents the P-wave velocity, and gama represents the P-wave to S-wave velocity ratio;

[0034] Obtain the S-wave velocity based on the ratio of the equivalent velocity to the P-wave to S-wave velocity ratio.

[0035] Optionally, determining the first depth ratio increment corresponding to each seismic data in all first trace gather segments based on a preset first depth ratio threshold value includes the following steps:

[0036] Determining the first depth ratio increment corresponding to each seismic data according to the difference between the first depth ratio of each seismic data in the first middle-offset trace gather and the first far-offset trace gather and the first depth ratio threshold value;

[0037] Among them, the first depth ratio increment corresponding to each seismic data in the first near-offset trace gather is determined to be 0.

[0038] Optionally, the shear wave anisotropy parameters include shear wave middle-offset parameters and shear wave far-offset parameters, and the shear wave correction velocities include shear wave near-offset velocity, shear wave middle-offset velocity, and shear wave far-offset velocity; obtaining the target shear wave velocity corresponding to the seismic data corresponding to the first depth ratio increment based on the first depth ratio increment in combination with the shear wave correction velocity and the preset shear wave anisotropy parameters includes the following steps:

[0039] Based on the shear wave correction velocity, setting the shear wave anisotropy parameters in combination with the range interval values of the first depth ratios corresponding to the first middle-offset trace gather and the first far-offset trace gather;

[0040] Among them, the expression of the shear wave middle-offset parameter is:

[0041]

[0042] In the formula, g s_mid represents the shear wave middle-offset parameter; v s_mid represents the shear wave middle-offset velocity; v s_near represents the shear wave near-offset velocity; rod mid represents the range interval value of the first depth ratio corresponding to the first middle-offset trace gather;

[0043] The expression of the shear wave far-offset parameter is:

[0044]

[0045] In the formula, g s_far represents the shear wave far-offset parameter; v s_far represents the shear wave far-offset velocity; rod far represents the range interval value of the first depth ratio corresponding to the first far-offset trace gather;

[0046] When the seismic data corresponding to the first depth ratio increment belongs to the first middle-offset trace gather, making a first increment adjustment to the shear wave near-offset velocity based on the product of the first middle-offset parameter and the first depth ratio increment to obtain the target shear wave velocity at the offset corresponding to the seismic data;

[0047] When the seismic data corresponding to the first offset-depth ratio increment belongs to the first far-offset gather, the shear-wave near-offset velocity is secondarily incrementally adjusted based on the product of the shear-wave far-offset parameter and the first offset-depth ratio increment to obtain the target shear-wave velocity at the offset corresponding to the seismic data.

[0048] Optionally, based on the P-wave velocity and the shear-wave anisotropic velocity, the second traveltime is obtained by using the double-square root processing method, including the following steps:

[0049] Obtain the reflection time of the target reflection interface in the target transversely isotropic medium at zero offset;

[0050] Based on the P-wave velocity and the target P-to-S wave velocity ratio, the back-calculated equivalent velocity is processed, and based on the product of the back-calculated equivalent velocity and half of the reflection time, the equivalent depth of the target reflection interface is obtained;

[0051] Obtain the offset parameter corresponding to each seismic data; the offset parameter includes the projection position of the shot point to the imaging point at the offset and the distance from the geophone point to the imaging point at the offset;

[0052] Based on the equivalent depth, the P-wave velocity, and the shear-wave anisotropic velocity, and combined with the offset parameter, the second traveltime is obtained through the double-square root processing method;

[0053] The expression of the double-square root processing method is:

[0054]

[0055] In the formula, t(x) represents the second traveltime, x sou represents the projection position of the shot point to the imaging point at the offset, z eff represents the equivalent depth, V p(x) represents the P-wave velocity, x rec represents the distance from the geophone point to the imaging point at the offset, V s(x) represents the shear-wave anisotropic velocity.

[0056] On the other hand, an embodiment of the present invention provides a PS-wave VTI medium dynamic correction device based on segmented velocity modeling, including:

[0057] The first module is configured to obtain the seismic data of the target transversely isotropic medium to be dynamically corrected, and then organize and obtain a common conversion point gather and a common midpoint gather; use the common conversion point gather as the target gather; the seismic data corresponding to the common conversion point gather is obtained based on the PS wave; the seismic data corresponding to the common midpoint gather is obtained based on the PP wave;

[0058] The second module is configured to analyze and obtain the P-wave velocity and the P-wave correction velocity based on the common midpoint gather;

[0059] A third module, configured to perform a first velocity analysis on a target gather to obtain an equivalent velocity;

[0060] A fourth module, configured to process and obtain a shear wave velocity based on the equivalent velocity and the P-wave velocity;

[0061] A fifth module, configured to obtain a first travel time by using a double square root processing method based on the P-wave velocity and the shear wave velocity;

[0062] A sixth module, configured to perform migration processing on the target gather through the first travel time to obtain a migrated gather, use the migrated gather as the target gather, and then return to execute the third module until a preset number of iterations is reached. The latest equivalent velocity is used as the target equivalent velocity, and the latest target gather is used as the target migrated gather;

[0063] A seventh module, configured to process and obtain a target P-S wave velocity ratio based on the target equivalent velocity and the P-wave velocity; obtain a shear wave correction velocity based on the ratio of the P-wave correction velocity to the P-S wave velocity ratio;

[0064] An eighth module, configured to cut the target migrated gather based on a first depth-offset ratio corresponding to each seismic data in the target migrated gather to obtain a preset number of first gather segments; the first gather segments include a first near-offset migrated gather, a first mid-offset migrated gather, and a first far-offset migrated gather; the first depth-offset ratio is based on the ratio of the offset corresponding to the seismic data to the depth information, and the offset represents the distance between the seismic source generating the seismic data and the geophone receiving the seismic data;

[0065] A ninth module, configured to perform a second velocity analysis on the first gather segments to obtain first velocity information of the first gather segments;

[0066] A tenth module, configured to determine a first depth-offset ratio increment corresponding to each seismic data in all the first gather segments based on a preset first depth-offset ratio threshold;

[0067] An eleventh module, configured to obtain a target shear wave velocity corresponding to the seismic data corresponding to the first depth-offset ratio increment based on the first depth-offset ratio increment, the shear wave correction velocity, and a preset shear wave anisotropy parameter; obtain a shear wave anisotropic velocity based on the target shear wave velocities corresponding to all the first gather segments;

[0068] A twelfth module, configured to obtain a second travel time by using a double square root processing method based on the P-wave velocity and the shear wave anisotropic velocity, and perform NMO correction on the target transversely isotropic medium according to the second travel time.

[0069] On the other hand, an embodiment of the present invention provides an electronic device, including: a processor and a memory; the memory is used for storing a program; the processor executes the program to implement the above-mentioned NMO correction method for a PS wave VTI medium based on segmented velocity modeling.

[0070] On the other hand, an embodiment of the present invention provides a computer storage medium storing a program executable by a processor. When the program executable by the processor is executed by the processor, it is used to implement the above-mentioned PS-wave VTI medium NMO method based on segmented velocity modeling.

[0071] In the embodiment of the present invention, seismic data of a target transversely isotropic medium to be NMO corrected is obtained, and then a common conversion point gather and a common midpoint gather are sorted out; the common conversion point gather is used as the target gather; the seismic data corresponding to the common conversion point gather is obtained based on the PS wave; the seismic data corresponding to the common midpoint gather is obtained based on the PP wave; the P-wave velocity and the P-wave correction velocity are analyzed based on the common midpoint gather; a first velocity analysis is performed on the target gather to obtain an equivalent velocity; the S-wave velocity is obtained by processing according to the equivalent velocity and the P-wave velocity; based on the P-wave velocity and the S-wave velocity, the first travel time is obtained by using the double square root processing method; the target gather is migrated by the first travel time to obtain a migrated gather, and the migrated gather is used as the target gather, and then the step of performing a first velocity analysis on the target gather to obtain an equivalent velocity is returned and executed until a preset number of iterations is reached, the latest equivalent velocity is used as the target equivalent velocity, and the latest target gather is used as the target migrated gather; the target P-S wave velocity ratio is obtained by processing according to the target equivalent velocity and the P-wave velocity; the S-wave correction velocity is obtained based on the ratio of the P-wave correction velocity to the P-S wave velocity ratio; the target migrated gather is cut based on the first depth-offset ratio corresponding to each seismic data in the target migrated gather to obtain a preset number of first gather segments; the first gather segments include a first near-offset gather, a first mid-offset gather, and a first far-offset gather; the first depth-offset ratio is based on the ratio of the offset corresponding to the seismic data to the depth information, and the offset represents the distance between the seismic source generating the seismic data and the geophone receiving the seismic data; a second velocity analysis is performed on the first gather segments to obtain the first velocity information of the first gather segments; the first depth-offset ratio increment corresponding to each seismic data in all the first gather segments is determined based on a preset first depth-offset ratio threshold; based on the first depth-offset ratio increment, the S-wave anisotropic parameter, and the preset S-wave anisotropic parameter, the target S-wave velocity corresponding to the seismic data corresponding to the first depth-offset ratio increment is obtained; the S-wave anisotropic velocity is obtained according to the target S-wave velocities corresponding to all the first gather segments; based on the P-wave velocity and the S-wave anisotropic velocity, the second travel time is obtained by using the double square root processing method, and the target transversely isotropic medium is NMO corrected according to the second travel time. In the embodiment of the present invention, first, an optimal target migrated gather and a target P-S wave velocity ratio are obtained through iterative velocity analysis, and then, by using the ratio of the offset to the depth information, segmented velocity analysis modeling is realized through the depth-offset ratio, and then, NMO correction of the VTI medium is gradually realized based on the first depth-offset ratio increment. The embodiment of the present invention can accurately perform PS-wave VTI medium NMO correction based on segmented velocity modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The accompanying drawings are used to provide a further understanding of the technical solution 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 technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention.

[0073] Figure 1 It is a schematic diagram of an implementation environment for performing PS-wave VTI medium dynamic correction based on segmented velocity modeling provided by an embodiment of the present invention;

[0074] Figure 2 It is a schematic flow diagram of a method for PS-wave VTI medium dynamic correction based on segmented velocity modeling provided by an embodiment of the present invention;

[0075] Figure 3 It is a schematic flow diagram of the analysis process for the common midpoint gather provided by an embodiment of the present invention;

[0076] Figure 4 It is a schematic diagram of a PS-wave example provided by an embodiment of the present invention;

[0077] Figure 5 It is a schematic overall flow diagram of a method for PS-wave VTI medium dynamic correction based on segmented velocity modeling provided by an embodiment of the present invention;

[0078] Figure 6 It is a schematic diagram of the splitting effect of the gather provided by an embodiment of the present invention;

[0079] Figure 7 It is a schematic diagram of the medium offset velocity analysis effect provided by an embodiment of the present invention;

[0080] Figure 8 It is a schematic diagram of the PS-wave dynamic correction effect of the VTI medium provided by an embodiment of the present invention;

[0081] Figure 9 It is a schematic structural diagram of a device for predicting the bottom boundary of the hydrate stability zone provided by an embodiment of the present invention;

[0082] Figure 10 It is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0083] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0084] It should be noted that although the functional modules are divided in the system schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different module division in the system or a different order in the flowchart. The terms "first / S100", "second / S200", etc. in the specification, claims and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence.

[0085] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present invention. The phrase appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0086] It can be understood that the PS-wave VTI medium dynamic correction method based on piecewise velocity modeling provided by the embodiments of the present invention can be applied to any computer device with data processing and computing capabilities, and this computer device can be various types of terminals or servers. When the computer device in the embodiment is a server, the server is an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms. Optionally, the terminal is a smart phone, a tablet computer, a laptop computer, a desktop computer, etc., but is not limited thereto.

[0087] For the convenience of understanding the technical solutions of the present invention, first, the technical feature proper nouns that may appear in the embodiments of the present invention are explained:

[0088] The reception record of a single geophone is called a seismic trace. A set of multiple seismic traces is simply called a trace gather.

[0089] VTI medium is the abbreviation of transverse isotropy with a vertical axis of symmetry (i.e., VTI) medium.

[0090] As Figure 1 shown, it is a schematic diagram of an implementation environment provided by an embodiment of the invention. Referring to Figure 1, the implementation environment includes at least one terminal 102 and a server 101. The terminal 102 and the server 101 can be connected through a network in a wireless or wired manner to complete data transmission and exchange.

[0091] The server 101 can be an independent physical server, a server cluster or a distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0092] In addition, the server 101 can also be a node server in a blockchain network. Among them, the blockchain is a new application mode of computer technologies such as distributed data storage, peer-to-peer transmission, consensus mechanism, and encryption algorithms.

[0093] The terminal 102 can be a smart phone, a tablet computer, a notebook computer, a desktop computer, a smart speaker, a smart watch, etc., but is not limited thereto. The terminal 102 and the server 101 can be directly or indirectly connected through wired or wireless communication methods, and the embodiments of the present invention do not limit this here.

[0094] Exemplarily based on Figure 1 the shown implementation environment, the embodiments of the present invention provide a PS-wave VTI medium dynamic correction method based on segmented velocity modeling. Taking the application of the PS-wave VTI medium dynamic correction method based on segmented velocity modeling to the server 101 as an example for description, it can be understood that the PS-wave VTI medium dynamic correction method based on segmented velocity modeling can also be applied to the terminal 102.

[0095] Referring to Figure 2 , Figure 2 is a flowchart of the PS-wave VTI medium dynamic correction method based on segmented velocity modeling applied to a server provided by the embodiments of the present invention. The execution subject of the PS-wave VTI medium dynamic correction method based on segmented velocity modeling can be any of the foregoing computer devices (including a server or a terminal). Referring to Figure 2 , the method includes the following steps:

[0096] S100. Obtain seismic data of the target transversely isotropic medium to be dynamically corrected, and then organize it to obtain a common conversion point gather and a common midpoint gather; use the common conversion point gather as the target gather;

[0097] Among them, the seismic data corresponding to the common conversion point gather is obtained based on the PS wave; the seismic data corresponding to the common midpoint gather is obtained based on the PP wave;

[0098] S200. Obtain the P-wave velocity and the P-wave correction velocity based on the common midpoint gather analysis;

[0099] It should be noted that in some embodiments, such as Figure 3 shown, step S200 may include the following steps: S201. Perform a third velocity analysis on the common midpoint gather to obtain an initial velocity model in the time domain; S202. Based on the velocity and time information in the initial velocity model, convert to obtain the first depth information corresponding to each seismic data in the common midpoint gather; S203. Based on the ratio of the offset to the depth information corresponding to the seismic data in the common midpoint gather, obtain the second depth-offset ratio for each seismic data; S204. Cut the common midpoint gather based on the second depth-offset ratio to obtain a preset number of second gather segments; The second gather segments include a second near-offset gather, a second mid-offset gather, and a second far-offset gather; S205. Perform a fourth velocity analysis on the second gather segments to obtain the second velocity information corresponding to each seismic data in the second gather segments; S206. Preset the P-wave correction velocity based on the second velocity information of the second gather segments; The P-wave correction velocity includes the P-wave near-offset velocity, the P-wave mid-offset velocity, and the P-wave far-offset velocity; S207. Determine the second depth-offset ratio increment corresponding to each seismic data in all the second gather segments based on a preset third depth-offset ratio threshold value; S208. Based on the second depth-offset ratio increment and combined with the preset P-wave anisotropic parameter, obtain the P-wave anisotropic velocity at the offset corresponding to the seismic data corresponding to the second depth-offset ratio increment, and use the P-wave anisotropic velocity as the P-wave velocity.

[0100] Among them, it should be noted that the first velocity analysis, the second velocity analysis, the third velocity analysis, and the fourth velocity analysis can all adopt the conventional velocity analysis methods for seismic wave data, which do not fall within the scope defined by the embodiments of the present invention and will not be elaborated here. Specifically, through the conventional velocity analysis, a preliminary seismic wave propagation velocity model can be obtained, and this velocity model is in the time domain, and then it can be converted to depth through velocity and time.

[0101] Among them, in some embodiments, cutting the common midpoint gather based on the second depth-offset ratio to obtain a preset number of second gather segments may include the following steps: Divide the seismic data in the common midpoint gather with a depth-offset ratio less than or equal to the third depth-offset ratio threshold value into the second near-offset gather; Divide the seismic data in the common midpoint gather with a depth-offset ratio greater than the third depth-offset ratio threshold value and less than or equal to the fourth depth-offset ratio threshold value into the second mid-offset gather; Divide the seismic data in the common midpoint gather with a depth-offset ratio greater than the fourth depth-offset ratio threshold value into the second far-offset gather.

[0102] Exemplarily, in some specific embodiments, for example, a depth-offset ratio less than 0.5 is defined as near-offset, a depth-offset ratio between 0.5 - 1.0 is defined as mid-offset, and a depth-offset ratio greater than 1.0 is defined as far-offset.

[0103] Exemplarily, in some specific embodiments, velocity analysis can be separately performed on the split gathers, and three velocity models can be obtained, namely the near-offset velocity, the mid-offset velocity, and the far-offset velocity. The differences among these three velocity models characterize the anisotropy of the formation.

[0104] Exemplarily, in some specific embodiments, the definition of the increment of the offset-depth ratio is as follows. For example, when the offset-depth ratio of 0.5 is defined as the near offset, the increment of the offset-depth ratio at the offset-depth ratio of 0.8 is 0.3.

[0105] In some embodiments, for example, the velocity corresponding to the offset-depth ratio of the maximum end point (i.e., the first offset-depth ratio defining value) in the near-offset range (obtained from the velocity information analyzed) can be set as the near-offset velocity. Similarly, the mid-offset velocity and the far-offset velocity can be set.

[0106] Specifically, the principle of the preset P-wave anisotropy parameter is the same as that of setting the S-wave anisotropy parameter, and it can be calculated based on the P-wave near-offset velocity, the P-wave mid-offset velocity, and the P-wave far-offset velocity, and then combined with the corresponding offset-depth ratio range interval.

[0107] Specifically, based on the second offset-depth ratio increment and the preset P-wave anisotropy parameter, the P-wave anisotropy velocity corresponding to the offset of the seismic data corresponding to the second offset-depth ratio increment can be obtained by an incremental adjustment method to calculate the P-wave anisotropy velocity. The principle is the same as that of obtaining the target S-wave velocity in the subsequent step S1100, and will not be elaborated here.

[0108] S300. Perform a first velocity analysis on the target gather to obtain an equivalent velocity;

[0109] S400. Process the equivalent velocity and the P-wave velocity to obtain the S-wave velocity;

[0110] It should be noted that in some embodiments, step S400 may include the following steps: inversely deduce the P-S wave velocity ratio according to the equivalent velocity and the P-wave velocity through the equivalent velocity formula; wherein, the expression of the equivalent velocity formula is:

[0111] v c(x) =v p(x) ·2 / 1+gama;

[0112] In the formula, v c(x) represents the equivalent velocity, v p(x) represents the P-wave velocity, and gama represents the P-S wave velocity ratio;

[0113] Obtain the S-wave velocity based on the ratio of the equivalent velocity to the P-S wave velocity ratio.

[0114] S500. Based on the P-wave velocity and S-wave velocity, the first traveltime is obtained using the double-square-root processing method;

[0115] It should be noted that the principle and logic for obtaining the first traveltime are the same as those for obtaining the second traveltime using the double-square-root processing method based on the P-wave velocity and S-wave anisotropy velocity. Referring to the subsequent description, it will not be elaborated here.

[0116] S600. The target gather is migrated using the first traveltime to obtain a migrated gather. The migrated gather is used as the target gather, and then the step of performing the first velocity analysis on the target gather to obtain the equivalent velocity is returned. This is repeated until the preset number of iterations is reached. The latest equivalent velocity is used as the target equivalent velocity, and the latest target gather is used as the target migrated gather;

[0117] Among them, the migration processing is to perform migration adjustment on the target gather using the obtained first traveltime.

[0118] S700. The target P-to-S velocity ratio is obtained by processing the target equivalent velocity and the P-wave velocity; the S-wave correction velocity is obtained based on the ratio of the P-wave correction velocity to the P-to-S velocity ratio;

[0119] Among them, the principle and logic for obtaining the target P-to-S velocity ratio by processing the target equivalent velocity and the P-wave velocity are the same as those in step S400 and its related embodiments, and will not be elaborated here.

[0120] S800. The target migrated gather is cut based on the first depth-offset ratio corresponding to each seismic data in the target migrated gather to obtain a preset number of first gather segments;

[0121] It should be noted that the first gather segments include the first near-offset gather, the first mid-offset gather, and the first far-offset gather; the first depth-offset ratio is based on the ratio of the offset corresponding to the seismic data to the depth information, and the offset represents the distance between the seismic source generating the seismic data and the geophone receiving the seismic data. Step S800 may include the following steps: The seismic data in the target migrated gather with a first depth-offset ratio less than or equal to the first depth-offset ratio threshold are classified into the first near-offset gather; the seismic data in the target migrated gather with a first depth-offset ratio greater than the first depth-offset ratio threshold and less than or equal to the second depth-offset ratio threshold are classified into the first mid-offset gather; the seismic data in the target migrated gather with a first depth-offset ratio greater than the second depth-offset ratio threshold are classified into the first far-offset gather.

[0122] S900. A second velocity analysis is performed on the first gather segments to obtain the first velocity information of the first gather segments;

[0123] Among them, the velocity analysis can adopt the conventional velocity analysis method for seismic wave data, which is not within the scope defined by the embodiments of the present invention and will not be elaborated here. Exemplarily, in some specific embodiments, velocity analysis can be performed on the segmented gathers respectively, and three velocity models can be obtained, namely the near-offset velocity, the mid-offset velocity, and the far-offset velocity. The differences among these three velocity models characterize the anisotropy of the formation. The velocity model here refers to the velocity model for the equivalent velocity.

[0124] S1000. Determine the first depth-offset ratio increment corresponding to each seismic data in all first gather segments based on a preset first depth-offset ratio threshold value.

[0125] It should be noted that in some embodiments, step S1000 may include: determining the first depth-offset ratio increment corresponding to each seismic data according to the difference between the first depth-offset ratio of each seismic data in the first mid-offset gather and the first far-offset gather and the first depth-offset ratio threshold value; wherein, the first depth-offset ratio increment corresponding to each seismic data in the first near-offset gather is determined to be 0.

[0126] Exemplarily, in some specific embodiments, the definition of the depth-offset ratio increment is as follows. For example, when the defined depth-offset ratio 0.5 is the near offset, the depth-offset ratio increment at the depth-offset ratio of 0.8 is 0.3.

[0127] S1100. Based on the first depth-offset ratio increment, the shear wave correction velocity, and a preset shear wave anisotropy parameter, obtain the target shear wave velocity corresponding to the seismic data corresponding to the first depth-offset ratio increment; obtain the shear wave anisotropy velocity according to the target shear wave velocities corresponding to all first gather segments.

[0128] It should be noted that the shear wave anisotropy parameter includes the shear wave mid-offset parameter and the shear wave far-offset parameter, and the shear wave correction velocity includes the shear wave near-offset velocity, the shear wave mid-offset velocity, and the shear wave far-offset velocity; in some embodiments, based on the first depth-offset ratio increment, the shear wave correction velocity, and a preset shear wave anisotropy parameter, obtaining the target shear wave velocity corresponding to the seismic data corresponding to the first depth-offset ratio increment may include the following steps:

[0129] Based on the shear wave correction velocity, set the shear wave anisotropy parameter by combining the range interval values of the first depth-offset ratios corresponding to the first mid-offset gather and the first far-offset gather.

[0130] Among them, the expression of the shear wave mid-offset parameter is:

[0131]

[0132] In the formula, g s_mid represents the shear wave mid-offset parameter; v s_mid represents the shear wave mid-offset velocity; v s_near represents the shear wave near-offset velocity; rodmid Indicates the range interval value of the first deviation depth ratio corresponding to the first intermediate deviation gather;

[0133] The expression of the shear wave far deviation parameter is:

[0134]

[0135] In the formula, g s_far Indicates the shear wave far deviation parameter; v s_far Indicates the shear wave far deviation velocity; rod far Indicates the range interval value of the first deviation depth ratio corresponding to the first far deviation gather;

[0136] When the seismic data corresponding to the first deviation depth ratio increment belongs to the first intermediate deviation gather, the first increment adjustment is performed on the shear wave near deviation velocity based on the product of the first intermediate deviation parameter and the first deviation depth ratio increment, and the target shear wave velocity at the offset corresponding to the seismic data is obtained;

[0137] When the seismic data corresponding to the first deviation depth ratio increment belongs to the first far deviation gather, the second increment adjustment is performed on the shear wave near deviation velocity based on the product of the shear wave far deviation parameter and the first deviation depth ratio increment, and the target shear wave velocity at the offset corresponding to the seismic data is obtained.

[0138] Exemplarily, the principles of the first and second increment adjustments are as follows:

[0139] v s(x) = V s_near ·(1 + g s ·Δord)

[0140] In the formula, V s(x) Indicates the target shear wave velocity, V s_near Indicates the shear wave near deviation velocity, g s Indicates the shear wave anisotropy parameter (including g s_mid and g s_far ), and Δord indicates the first deviation depth ratio increment.

[0141] S1200. Based on the P-wave velocity and the shear wave anisotropy velocity, the second travel time is obtained by using the double square root processing method, and dynamic correction is performed on the target transversely isotropic medium according to the second travel time.

[0142] It should be noted that in some embodiments, obtaining the second travel time by using the double square root processing method based on the P-wave velocity and the shear wave anisotropy velocity may include the following steps:

[0143] Obtain the reflection time of the target reflection interface in the target transversely isotropic medium at zero offset;

[0144] Based on the longitudinal wave velocity and the target P-to-S wave velocity ratio, the inverse equivalent velocity is processed, and according to the product of the inverse equivalent velocity and half of the reflection time, the equivalent depth of the target reflection interface is obtained;

[0145] Obtain the offset parameter corresponding to each seismic data; the offset parameter includes the projection position from the shot point of the offset to the imaging point and the distance from the geophone point of the offset to the imaging point;

[0146] Based on the equivalent depth, longitudinal wave velocity, and shear wave anisotropic velocity, combined with the offset parameter, the second travel time is obtained through the double square root processing method;

[0147] The expression of the double square root processing method is:

[0148]

[0149] In the formula, t(x) represents the second travel time, x sou represents the projection position from the shot point of the offset to the imaging point, z eff represents the equivalent depth, V p(x) represents the longitudinal wave velocity, X rec represents the distance from the geophone point of the offset to the imaging point, V s(x) represents the shear wave anisotropic velocity.

[0150] To explain the principle of the technical solution of the present invention in detail, the overall process of the present invention will be described below in conjunction with some specific embodiments. It is easy to understand that the following is an explanation of the technical principle of the present invention and should not be regarded as a limitation of the present invention.

[0151] First of all, it should be noted that as Figure 4 shown, the concept of the PS wave is that the wave excited by the source is a longitudinal wave (P wave), and when reflected, it is converted into a shear wave (S wave), and at the same time, it is recorded in the form of an S wave at the geophone point. Because the velocities of the P wave and the S wave are different, usually, the P wave velocity is faster than the S wave velocity. We use the parameter gama to represent the P-to-S wave velocity ratio, that is, gama = v p / v s , where v p is the propagation velocity of the longitudinal wave, and v s is the propagation velocity of the shear wave.

[0152] As Figure 5 shown, it is an example of the specific implementation process of the embodiment of the present invention, and the implementation principle is as follows:

[0153] The double square root calculation formula for the travel time of the PS wave is:

[0154]

[0155] where x souIndicates the distance from the shot point to the imaging point (i.e., the projection position corresponding to the reflection point, which is the projection point corresponding to the green line in Figure 4 ) at this offset, represents the distance from the geophone point to the imaging point at this offset, and z eff represents the equivalent depth at this offset, and V p(x) and V s(x) respectively represent the longitudinal and transverse wave anisotropic velocities at this offset.

[0156] z eff = v c(x) ·t0 / 2 (2)

[0157] V c(x) is the equivalent wave anisotropic velocity at this offset, which can be obtained by velocity analysis picking. t0 refers to the reflection time of a certain reflection interface at zero offset, and it is necessary to go through multiple rounds of velocity analysis iteration to obtain a better equivalent velocity.

[0158] V p(x) = V p_near ·(1 + g p ·Δord) (3)

[0159] V s(x) = v p(x) / gama (4)

[0160] V c(x) = v p(x) ·2 / 1 + gama (5)

[0161] In formula (3), V p(x) is the velocity obtained by the PP wave anisotropic method. The initial setting value of gama in formula (4) is 2. Using the picked v c(x) and the known V p(x) to obtain a new gama, and then using formula (4) to obtain V s(x) , using formula (1) to migrate to obtain a new gather, and re-picking v c(x) , and successively updating the velocity model. Among them, Δord represents the increment of the offset-depth ratio. For example, when defining the offset-depth ratio of 0.5 as near offset, the increment of the offset-depth ratio at the offset-depth ratio of 0.8 is 0.3; gama is the longitudinal and transverse wave velocity ratio mentioned above; g p is the longitudinal wave anisotropic parameter.

[0162] After iterating several rounds of V c(x) , the migrated gather is also divided into 3 segments according to the offset-depth ratio, and v c_near , V c_mid , v c_far are respectively obtained. Using formula (4), v s_near , v s_mid , v s_far are obtained.

[0163]

[0164] V s(x) =V s_near ·(1+g s ·Δord) (8)

[0165] Where V p_near 、v p_mid and V p_far are the longitudinal wave correction velocities selected in velocity analysis, rod mid and rod far Represents the range of the deviation depth ratio of the medium deviation and the far deviation, for example, if the deviation depth ratio of the medium deviation is 0.5-1.5, then the value of is 1.0. Using formula (8), we can obtain all the parameters required by formula (1) and perform anisotropic dynamic correction. The last point to note is that when formula (1) is used to perform dynamic correction on the gather, the v in formula (2) is used. s(x) , is through v p(x) Calculated in reverse.

[0166] Specifically, some specific application examples are as follows Figure 6 As shown in the figure, during velocity analysis, the converted wave common imaging point gather is divided into three parts of data: near, medium and far deviation according to the deviation depth ratio, and velocity analysis is performed separately. The cutting effect is shown in the figure. Figure 6 , near bias set ( Figure 6 Left box), mid-bias gathers ( Figure 6 middle box) and far-offset gathers ( Figure 6 right box).

[0167] For example, in some specific implementations, taking mid-offset velocity analysis as an example, Figure 7 As shown in FIG, through velocity analysis, the velocity that can level the mid-deviation track gather is obtained.

[0168] In the same way, we obtain the near-offset velocity and the far-offset velocity, and then use the above dynamic correction formula to complete the dynamic correction of the gather. The dynamic correction effect is as follows: Figure 8 As shown in the figure, the far-offset gathers are well leveled, achieving the ideal NMO effect.

[0169] The time-distance curve fitting formula used in the present invention adopts the double square root formula. An important advantage of the double square root formula is that it can specifically express the relationship between the propagation path and the propagation time. However, in the previous double square root formula, the converted wave velocity was used to obtain the interface depth, while the P-wave velocity was used to obtain the P-wave downward travel time, which led to the inconsistency between the geometric model and the physical model. Therefore, it is necessary to try to change the method of obtaining the interface depth and restore the true converted wave propagation path as much as possible geometrically to best fit the converted wave time-distance curve.

[0170] On the other hand, as Figure 9 shown, an embodiment of the present invention provides a PS-wave VTI medium dynamic correction device 900 based on segmented velocity modeling, which may include:

[0171] A first module 901, configured to obtain seismic data of a target transversely isotropic medium to be dynamically corrected, and then organize a common conversion point gather and a common midpoint gather; use the common conversion point gather as the target gather; the seismic data corresponding to the common conversion point gather is obtained based on PS waves; the seismic data corresponding to the common midpoint gather is obtained based on PP waves;

[0172] A second module 902, configured to analyze the P-wave velocity and the P-wave correction velocity based on the common midpoint gather;

[0173] A third module 903, configured to perform a first velocity analysis on the target gather to obtain an equivalent velocity;

[0174] A fourth module 904, configured to process the converted wave velocity based on the equivalent velocity and the P-wave velocity;

[0175] A fifth module 905, configured to obtain a first travel time by using the double square root processing method based on the P-wave velocity and the converted wave velocity;

[0176] A sixth module 906, configured to perform migration processing on the target gather through the first travel time to obtain a migrated gather, use the migrated gather as the target gather, and then return to execute the third module until a preset number of iterations is reached. Use the latest equivalent velocity as the target equivalent velocity and the latest target gather as the target migrated gather;

[0177] A seventh module 907, configured to process the target P-wave to converted wave velocity ratio based on the target equivalent velocity and the P-wave velocity; obtain the converted wave correction velocity based on the ratio of the P-wave correction velocity to the P-wave to converted wave velocity ratio;

[0178] The eighth module 908 is configured to cut the target migration gather based on the first depth-offset ratio corresponding to each seismic data in the target migration gather to obtain a preset number of first gather segments; the first gather segments include a first near-offset gather, a first mid-offset gather, and a first far-offset gather; the first depth-offset ratio is based on the ratio of the offset corresponding to the seismic data to the depth information, and the offset represents the distance between the seismic source that generates the seismic data and the geophone that receives the seismic data;

[0179] The ninth module 909 is configured to perform a second velocity analysis on the first gather segments to obtain first velocity information of the first gather segments;

[0180] The tenth module 910 is configured to determine the first depth-offset ratio increment corresponding to each seismic data in all the first gather segments based on a preset first depth-offset ratio threshold;

[0181] The eleventh module 911 is configured to obtain the target shear wave velocity corresponding to the seismic data corresponding to the first depth-offset ratio increment based on the first depth-offset ratio increment in combination with the shear wave correction velocity and a preset shear wave anisotropy parameter; and obtain the shear wave anisotropy velocity according to the target shear wave velocities corresponding to all the first gather segments;

[0182] The twelfth module 912 is configured to obtain a second travel time by using the double square root processing method based on the P-wave velocity and the shear wave anisotropy velocity, and perform NMO correction on the target transversely isotropic medium according to the second travel time.

[0183] The content of the method embodiment of the present invention is applicable to the apparatus embodiment of the present invention. The functions specifically implemented by the apparatus embodiment are the same as those of the above method embodiment, and the beneficial effects achieved are also the same as those of the above method.

[0184] On the other hand, an embodiment of the present invention further provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the above method for predicting the bottom boundary of the hydrate stability zone is implemented. The electronic device may be any intelligent terminal including a tablet computer, a vehicle-mounted computer, etc.

[0185] It can be understood that the content in the above method embodiment is applicable to the device embodiment of the present invention. The functions specifically implemented by the device embodiment are the same as those of the above method embodiment, and the beneficial effects achieved are also the same as those of the above method embodiment.

[0186] As Figure 10 shown, Figure 10 FIG. schematically shows the hardware structure of an electronic device according to another embodiment. The electronic device includes:

[0187] The processor 1001 can be implemented in the form of a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, etc., and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present invention;

[0188] The memory 1002 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM), etc. The memory 1002 can store an operating system and other application programs. When implementing the technical solutions provided in the embodiments of this specification through software or firmware, the relevant program codes are stored in the memory 1002 and are called by the processor 1001 to execute the network node population optimization method in the embodiments of the present invention;

[0189] The input / output interface 1003 is used to implement information input and output;

[0190] The communication interface 1004 is used to implement communication interaction between this device and other devices, and can implement communication through a wired method (such as USB, network cable, etc.) or through a wireless method (such as a mobile network, WIFI, Bluetooth, etc.);

[0191] The bus 1005 transmits information between the various components of the device (such as the processor 1001, the memory 1002, the input / output interface 1003, and the communication interface 1004);

[0192] Among them, the processor 1001, the memory 1002, the input / output interface 1003, and the communication interface 1004 are communicatively connected to each other inside the device through the bus 1005.

[0193] The electronic device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solutions in this embodiment.

[0194] The content of the method embodiments of the present invention is applicable to the electronic device embodiments of the present invention. The functions specifically implemented by the electronic device embodiments of the present invention are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above methods.

[0195] Another aspect of the embodiments of the present invention further provides a computer-readable storage medium storing a program, which when executed by a processor implements the foregoing method.

[0196] It should be noted that the computer-readable medium shown in the embodiments of the present invention can be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present invention, a computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on a computer-readable medium can be transmitted using any appropriate medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0197] The content of the method embodiments of the present invention is applicable to the embodiments of this computer-readable storage medium. The functions specifically implemented by the embodiments of this computer-readable storage medium are the same as those of the foregoing method embodiments, and the beneficial effects achieved are also the same as those achieved by the foregoing method.

[0198] The embodiments of the present invention also disclose a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. The processor of a computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to cause the computer device to execute the foregoing method.

[0199] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a part of code, and the above-mentioned module, segment of a program, or part of code contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, as well as the combination of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0200] It should be noted that although several modules of devices for action execution are mentioned in the above detailed description, such a division is not mandatory. In fact, according to the embodiments of the present invention, the features and functions of two or more of the above-mentioned modules or units can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0201] From the description of the above embodiments, those skilled in the art can easily understand that the example embodiments described herein can be implemented by software, or can be implemented by a combination of software and necessary hardware. Therefore, the technical solutions according to the embodiments of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the embodiments of the present invention.

[0202] In some alternative embodiments, the functions / operations mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the functions / operations involved, two consecutive blocks shown may actually be executed substantially simultaneously or the blocks can sometimes be executed in the reverse order. In addition, the embodiments presented and described in the flowcharts of the present invention are provided by way of example for the purpose of providing a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logical flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and in which sub-operations described as part of a larger operation are executed independently.

[0203] In addition, although the present invention has been described in the context of functional modules, it should be understood that, unless otherwise stated to the contrary, one or more of the functions and / or features may be integrated in a single physical device and / or software module, or one or more functions and / or features may be implemented in separate physical devices or software modules. It should also be understood that a detailed discussion of the actual implementation of each module is not necessary for understanding the present invention. Rather, considering the attributes, functions, and internal relationships of the various functional modules in the devices disclosed herein, the actual implementation of the modules will be understood within the ordinary skills of an engineer. Thus, those skilled in the art can implement the present invention as set forth in the claims without undue experimentation. It should also be understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present invention, which is determined by the full scope of the appended claims and their equivalents.

[0204] If a function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0205] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a predefined sequence of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution device, apparatus, or equipment (such as a computer-based device, a device including a processor, or other devices that can fetch and execute instructions from the instruction execution device, apparatus, or equipment), or in combination with these instruction execution devices, apparatuses, or equipment. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in combination with an instruction execution device, apparatus, or equipment.

[0206] More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection (electronic device) having one or more wirings, a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable media can even be paper or other suitable media on which a program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, then editing, interpreting, or otherwise processing it as appropriate, and then storing it in a computer memory.

[0207] It should be understood that various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution device. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: a discrete logic circuit having logic gate circuits for implementing logical functions on data signals, an application specific integrated circuit having appropriate combinational logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0208] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0209] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

[0210] The above has specifically described the preferred embodiments of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A dynamic correction method for PS waves in VTI media based on piecewise velocity modeling, characterized in that, The following steps are involved: Acquire seismic data of a target transversely isotropic medium to be subjected to dynamic correction, and then organize the data to obtain a common transition point gather and a common center point gather; and use the common transition point gather as a target gather; The seismic data corresponding to the common conversion point gathers are obtained based on PS waves; the seismic data corresponding to the common center point gathers are obtained based on PP waves; Obtaining the P-wave velocity and the P-wave corrected velocity based on the common center point gather analysis; Performing a first velocity analysis on the target gather to obtain an equivalent velocity; Obtaining a shear wave velocity according to the equivalent velocity and the longitudinal wave velocity; Obtaining a first travel time based on the longitudinal wave velocity and the shear wave velocity using a double square root processing method; performing an offset process on the target gather using the first traveltime to obtain an offset gather, using the offset gather as the target gather, and then returning to the step of performing a first velocity analysis on the target gather to obtain an equivalent velocity until a preset number of iterations is reached, using the latest equivalent velocity as a target equivalent velocity, and using the latest target gather as a target offset gather; A target longitudinal-to-straight wave velocity ratio is obtained based on the target equivalent velocity and the longitudinal-wave velocity; a shear-wave corrected velocity is obtained based on a ratio of the longitudinal-wave corrected velocity to the longitudinal-to-straight wave velocity ratio; The target offset gather is cut based on a first offset-to-depth ratio corresponding to each piece of seismic data in the target offset gather to obtain a preset number of first gather segments; the first gather segments include a first near-offset gather, a first mid-offset gather, and a first far-offset gather; the first offset-to-depth ratio is based on a ratio of an offset distance corresponding to the seismic data to depth information, the offset distance representing a distance between a source generating the seismic data and a detection point receiving the seismic data; performing a second velocity analysis on the first trace gather segment to obtain first velocity information of the first trace gather segment; Determining a first offset depth ratio increment corresponding to each of the seismic data in all the first gather segments based on a preset first offset depth ratio limit value; Based on the first offset depth ratio increment, the shear wave correction velocity, and a preset shear wave anisotropy parameter, a target shear wave velocity corresponding to the seismic data corresponding to the first offset depth ratio increment is obtained; and a shear wave anisotropy velocity is obtained based on the target shear wave velocities corresponding to all first gather segments. Based on the longitudinal wave velocity and the shear wave anisotropic velocity, a second travel time is obtained using the double square root processing method, and dynamic correction is performed on the target transversely isotropic medium according to the second travel time.

2. The PS-wave VTI medium dynamic correction method based on segmented velocity modeling according to claim 1, wherein The method of obtaining the P-wave velocity and the P-wave corrected velocity based on the common center point gather analysis includes the following steps: Performing a third velocity analysis on the common midpoint gather to obtain an initial velocity model in the time domain; converting the velocity and time information in the initial velocity model to obtain first depth information corresponding to each piece of seismic data in the common midpoint gather; Obtaining a second offset-depth ratio of each piece of seismic data based on a ratio of offset to depth information corresponding to the seismic data in the common center point gather; Cut the common midpoint gather based on the second offset depth ratio to obtain a preset number of second gather segments; the second gather segments include a second near-offset gather, a second mid-offset gather, and a second far-offset gather; Perform a fourth velocity analysis on the second gather segments to obtain second velocity information corresponding to each piece of the seismic data in the second gather segments; Preset a P-wave correction velocity based on the second velocity information of the second gather segments; the P-wave correction velocity includes a P-wave near-offset velocity, a P-wave mid-offset velocity, and a P-wave far-offset velocity; Determine a second offset depth ratio increment corresponding to each piece of the seismic data in all the second gather segments based on a preset third offset depth ratio threshold value; Based on the second offset depth ratio increment and in combination with preset P-wave anisotropic parameters, obtain the P-wave anisotropic velocity at the offset corresponding to the seismic data corresponding to the second offset depth ratio increment, and use the P-wave anisotropic velocity as the P-wave velocity.

3. The PS-wave VTI medium dynamic correction method based on piecewise velocity modeling according to claim 1, wherein The step of cutting the target migrated gather based on the first offset depth ratio corresponding to each piece of the seismic data in the target migrated gather to obtain a preset number of first gather segments includes the following steps: Divide the seismic data in the target migrated gather with the first offset depth ratio less than or equal to the first offset depth ratio threshold value into the first near-offset gather; Divide the seismic data in the target migrated gather with the first offset depth ratio greater than the first offset depth ratio threshold value and less than or equal to the second offset depth ratio threshold value into the first mid-offset gather; Divide the seismic data in the target migrated gather with the first offset depth ratio greater than the second offset depth ratio threshold value into the first far-offset gather.

4. The PS-wave VTI medium dynamic correction method based on segmented velocity modeling according to claim 1, wherein, The step of processing to obtain the S-wave velocity based on the equivalent velocity and the P-wave velocity includes the following steps: Inversely deduce the P-to-S velocity ratio through the equivalent velocity formula according to the equivalent velocity and the P-wave velocity; Obtain the S-wave velocity based on the ratio of the equivalent velocity to the P-to-S velocity ratio.

5. The PS-wave VTI medium dynamic correction method based on segmented velocity modeling according to claim 1, wherein, The step of determining a first offset depth ratio increment corresponding to each piece of the seismic data in all the first gather segments based on a preset first offset depth ratio threshold value includes the following steps: Determine the first offset depth ratio increment corresponding to each piece of the seismic data according to the difference between the first offset depth ratio corresponding to each piece of the seismic data in the first mid-offset gather and the first far-offset gathers and the first offset depth ratio threshold value; Wherein, the first offset depth ratio increment corresponding to each piece of the seismic data in the first near-offset gather is determined to be 0.

6. The PS-wave VTI medium dynamic correction method based on segmented velocity modeling according to claim 1, wherein, The S-wave anisotropic parameters include an S-wave mid-offset parameter and an S-wave far-offset parameter, and the S-wave correction velocity includes an S-wave near-offset velocity, an S-wave mid-offset velocity, and an S-wave far-offset velocity; the step of obtaining the target S-wave velocity corresponding to the seismic data corresponding to the first offset depth ratio increment based on the first offset depth ratio increment in combination with the S-wave correction velocity and preset S-wave anisotropic parameters includes the following steps: Based on the S-wave correction velocity, set the S-wave anisotropic parameters in combination with the range interval values of the first offset depth ratios corresponding to the first mid-offset gather and the first far-offset gathers; Wherein, the expression of the S-wave mid-offset parameter is: where g s_mid represents the deviation parameter in the shear wave; v s_mid represents the deviation velocity in the shear wave; v s_near represents the near deviation velocity of the shear wave; rod mid represents the range interval value of the first deviation depth ratio corresponding to the first intermediate deviation gather; The expression of the shear wave far deviation parameter is: where g s_far represents the shear wave far offset parameter; v s_far represents the shear wave far offset velocity; rod far represents the range interval value of the first offset depth ratio corresponding to the first far offset gather. When the seismic data corresponding to the first offset depth ratio increment belongs to the first mid-offset trace gather, performing a first incremental adjustment on the shear wave near-offset velocity based on a product of the shear wave mid-offset parameter and the first offset depth ratio increment to obtain a target shear wave velocity at the offset distance corresponding to the seismic data; When the seismic data corresponding to the first offset ratio increment belongs to the first far-offset track set, a second incremental adjustment is performed on the shear wave near-offset velocity based on the product of the shear wave far-offset parameter and the first offset ratio increment to obtain a target shear wave velocity at the offset distance corresponding to the seismic data.

7. The dynamic correction method for PS waves in VTI media based on segmented velocity modeling according to claim 1, characterized in that The method of obtaining a second travel time based on the longitudinal wave velocity and the shear wave anisotropy velocity by using the double square root processing method comprises the following steps: Acquiring a reflection time of a target reflection interface in the target transversely isotropic medium at zero offset; Obtaining an inverse equivalent velocity based on the P-wave velocity and the target P-wave and S-wave velocity ratio, and obtaining an equivalent depth of the target reflection interface according to the product of the inverse equivalent velocity and half the reflection time; Obtaining offset parameters corresponding to each of the seismic data; the offset parameters include the projection position of the shot point to the imaging point under the offset and the distance from the detector point to the imaging point under the offset; Obtaining the second travel time based on the equivalent depth, the P-wave velocity, and the S-wave anisotropic velocity in combination with the offset parameter by a double square root processing method; The expression of the double square root processing method is: Where \(t(x)\) represents the second travel time, \(x\) sou represents the projection position from the shot point to the imaging point at the offset, \(z\) eff represents the equivalent depth, \(v\) p(x) represents the P-wave velocity, \(x\) rec represents the distance from the geophone point to the imaging point at the offset, \(v\) s(x) represents the shear-wave anisotropic velocity.

8. A PS-wave VTI medium dynamic correction device based on segmented velocity modeling, characterized in that include: The first module is used to obtain seismic data of the target transversely isotropic medium to be corrected, and then to obtain common conversion point gathers and common center point gathers; taking the common conversion point gather as the target gather; The seismic data corresponding to the common conversion point gathers are obtained based on PS waves; the seismic data corresponding to the common center point gathers are obtained based on PP waves; The second module is used to obtain the P-wave velocity and the P-wave corrected velocity based on the common center point gather analysis; The third module is used to perform a first velocity analysis on the target gather to obtain an equivalent velocity; A fourth module is configured to obtain a shear wave velocity according to the equivalent velocity and the longitudinal wave velocity; A fifth module is configured to obtain a first travel time based on the longitudinal wave velocity and the shear wave velocity using a double square root processing method; a sixth module, configured to perform an offset process on the target gather using the first traveltime to obtain an offset gather, use the offset gather as the target gather, and then return to execute the third module until a preset number of iterations is reached, use the latest equivalent velocity as the target equivalent velocity, and use the latest target gather as the target offset gather; A seventh module is configured to obtain a target longitudinal-to-severe wave velocity ratio based on the target equivalent velocity and the longitudinal-wave velocity; and obtain a shear-wave corrected velocity based on a ratio of the longitudinal-wave corrected velocity to the longitudinal-to-severe wave velocity ratio. The eighth module is configured to cut the target migration gather based on the first depth-offset ratio corresponding to each piece of seismic data in the target migration gather, so as to obtain a preset number of first gather segments; the first gather segments include a first near-offset gather, a first mid-offset gather, and a first far-offset gather; the first depth-offset ratio is based on the ratio of the offset corresponding to the seismic data to the depth information, and the offset represents the distance between the seismic source that generates the seismic data and the geophone that receives the seismic data; The ninth module is configured to perform a second velocity analysis on the first gather segments to obtain first velocity information of the first gather segments; The tenth module is configured to determine a first depth-offset ratio increment corresponding to each piece of seismic data in all the first gather segments based on a preset first depth-offset ratio threshold value; The eleventh module is configured to obtain a target shear wave velocity corresponding to the seismic data corresponding to the first depth-offset ratio increment by combining the first depth-offset ratio increment with the shear wave correction velocity and a preset shear wave anisotropy parameter; and obtain a shear wave anisotropy velocity according to the target shear wave velocities corresponding to all the first gather segments; The twelfth module is configured to obtain a second travel time by using the double square root processing method based on the P-wave velocity and the shear wave anisotropy velocity, and perform NMO correction on the target transversely isotropic medium according to the second travel time.

9. An electronic device, characterized in that, It includes a processor and a memory; The memory is used for storing programs; The processor executes the programs to implement the method according to any one of claims 1 to 7.

10. A computer storage medium storing a program executable by a processor, characterized in that, The programs executable by the processor, when executed by the processor, are used to implement the method according to any one of claims 1 to 7.

Images