Seismic profile noise removal method and device based on Kirchhoff inverse migration

Abstract

The application provides a seismic profile noise removing method and device based on Kirchhoff reverse migration, which comprises the following steps: picking up noise events on a pre-stack time migration profile manually according to a given migration velocity; generating corresponding shot record of the picked noise events by using Kirchhoff integral reverse migration processing; mapping the generated shot record to source shot record, removing noise events based on FK transformation; converting the shot record after removing noise events back to the pre-stack time migration profile by using Kirchhoff integral forward migration processing. The seismic profile noise removing method provided by the application can remove noise events from the pre-stack time migration profile quickly and effectively without damaging effective information in the profile and avoiding forming local blank zone on the profile, thus ensuring the imaging quality of the seismic profile.

Description

Technical Field

[0001] This invention belongs to the field of seismic data processing technology, and relates to a method for removing noise from seismic profiles, and more particularly to a method and apparatus for removing noise from seismic profiles based on Kirchhoff retrograde migration. Background Technology

[0002] Because real seismic records contain various types of coherent and incoherent noise, it is difficult to achieve comprehensive and detailed noise removal during the denoising process of seismic data. Therefore, the final imaging profile usually contains noise information with different characteristics. To address the noise information in the profile, it is generally possible to directly identify and pick out the in-phase axes within the profile, and then use FK equal-aperture filtering techniques to remove it. However, directly removing noise from the profile can easily damage the effective in-phase axes of the profile or create local blank bands in the profile, thus affecting the quality of the profile.

[0003] Therefore, how to provide a method for removing noise from seismic profiles that neither damages the effective information in the profiles nor creates local blank zones on the profiles, thereby improving the quality of the profiles, has become an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for removing noise from seismic profiles based on Kirchhoff retrograde migration. The method does not damage the effective information in the profile and avoids the formation of local blank bands on the profile, thereby achieving fast and effective removal of noise in-phase axes from pre-stack time-migrated profiles while ensuring the imaging quality of the seismic profile.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for removing seismic profile noise based on Kirchhoff retrograde migration, the seismic profile noise removal method comprising:

[0007] Manually pick out noisy in-phase axes on the pre-stack time migration profile based on the given migration rate;

[0008] Kirchhoff integral inverse offset processing is used to generate the corresponding shot gather record of the picked noise phase axis.

[0009] The generated shot gather record is mapped to the source shot gather record, and noisy in-phase axes are removed based on the FK transform;

[0010] Kirchhoff integral positive migration processing was used to convert the shot gather records after removing noisy phase axes back to the pre-stack time migration profile.

[0011] Since the noise in seismic profiles originates from the noise information in seismic records, and the mapping relationship between the two is based on the Kirchhoff integral formula, this invention uses Kirchhoff inverse migration to remove noise from seismic profiles. First, the noise is mapped to the shot gather record and removed using Kirchhoff integral inverse migration. Then, a noise-free migration profile is generated using Kirchhoff integral forward migration. This method does not damage the effective information in the profile and avoids the formation of local blank bands on the profile. Thus, it achieves rapid and effective removal of noise in-phase axes in pre-stack time-migrated profiles while ensuring the imaging quality of seismic profiles, and has great application potential in actual production.

[0012] Preferably, the calculation formula for the Kirchhoff integral inverse offset process is as follows:

[0013]

[0014] In the formula: x is the horizontal coordinate; t is time; sec0(x,t) is the noise in-phase axis picked up on the pre-stack time migration profile; S hot0 (x,t) represents the noise in-phase axis in the shot gather record obtained after inverse offset; ds represents the surface element of the integral; W D (x,t) is the weighting factor of Kirchhoff's integral.

[0015] Preferably, the calculation formula for the positive offset processing of the Kirchhoff integral is as follows:

[0016]

[0017] In the formula: x is the horizontal coordinate; t is time; s proc (x,t) represents the new shot set record after denoising; Sec proc (x,t) represents the denoised Kirchhoff integral pre-stack time migration profile; ds represents the integral's surface element; W D (x,t) is the weighting factor of Kirchhoff's integral.

[0018] Preferably, the weighting factor of the Kirchhoff integral is calculated as follows:

[0019]

[0020] In the formula: r0 and r are the propagation distances of the incident ray and the diffracted ray, respectively; θ0 and θ are the angles between r0, r and the surface element normal vector n, respectively; v(x,t) is the offset velocity.

[0021] Secondly, the present invention provides an apparatus for seismic profile noise removal based on Kirchhoff retrograde migration, the apparatus comprising:

[0022] The noise in-phase axis pickup module is used to manually pick out the noise in-phase axis on the pre-stack time migration profile according to a given migration rate;

[0023] The Kirchhoff integral inverse offset processing module is used to generate the corresponding shot gather record of the picked noise phase axis using Kirchhoff integral inverse offset processing.

[0024] The noisy in-phase axis removal module is used to map the generated shot gather record to the source shot gather record and remove noisy in-phase axes based on FK transform;

[0025] The Kirchhoff integral positive migration processing module is used to convert the shot gather records after removing noise in-phase axes back to the pre-stack time migration profile using Kirchhoff integral positive migration processing.

[0026] Thirdly, the present invention provides an electronic device, the electronic device comprising:

[0027] At least one processor; and

[0028] A memory communicatively connected to the at least one processor; wherein,

[0029] The memory stores a computer program that can be executed by the at least one processor, such that the at least one processor can perform the seismic profile noise removal method based on Kirchhoff retrograde migration described in the first aspect.

[0030] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a processor to execute the seismic profile noise removal method based on Kirchhoff retrograde migration as described in the first aspect.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] This invention utilizes Kirchhoff inverse migration for seismic profile noise removal. First, Kirchhoff integral inverse migration is used to map noise onto the shot gather record for removal. Then, Kirchhoff integral forward migration is used to generate a noise-free migration profile. This method does not damage the effective information in the profile and avoids the formation of local blank bands on the profile. Thus, it achieves rapid and effective removal of noise in-phase axes in pre-stack time-migrated profiles while ensuring the quality of seismic profile imaging. It has great application potential in actual production. Attached Figure Description

[0033] Figure 1 This is a flowchart of the seismic profile noise removal method provided in Example 1;

[0034] Figure 2It is the noisy in-phase axis picked up based on the pre-stack time migration profile in the method provided in Example 1;

[0035] Figure 3 It is obtained by using Kirchhoff integral inverse offset processing in the method provided in Example 1. Figure 2 The source shot gather record mapped to the shot gather record of the picked-up noise in phase axis;

[0036] Figure 4 It is obtained by FK filtering based on the sight velocity in the shot gather domain in the method provided in Example 1. Figure 3 Noise-laden shafts removed from the process;

[0037] Figure 5 It is obtained by using Kirchhoff integral positive offset processing in the method provided in Example 1. Figure 3 Pre-stack time offset profile after removing picked-up noise in-phase axes;

[0038] Figure 6 This is a schematic diagram of the device structure for eliminating seismic profile noise provided in Example 2;

[0039] Figure 7 This is a schematic diagram of the electronic device structure for seismic profile noise removal provided in Example 3. Detailed Implementation

[0040] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0041] Example 1

[0042] This embodiment provides a method for noise removal from seismic profiles based on Kirchhoff retrograde migration. Taking a pre-stack time migration profile obtained after processing seismic data from a certain work area in the Yellow Sea as an example, such as... Figure 1 As shown, the seismic profile noise removal method includes the following steps:

[0043] S110. Manually pick out the noisy in-phase axes on the pre-stack time migration profile according to the given migration velocity. The result is as follows: Figure 2 The horizontal line pointed to by the middle arrow;

[0044] S120. The corresponding shot gather record of the picked-up noise phase axis is generated using Kirchhoff integral inverse offset processing. The relevant calculation formula is as follows:

[0045]

[0046] In the formula: x is the horizontal coordinate; t is time; sec0(x,t) is the noise in-phase axis picked up on the pre-stack time migration profile; S hot0(x,t) represents the noise in-phase axis in the shot gather record obtained after inverse offset; ds represents the surface element of the integral; W D (x,t) is the weighting factor of the Kirchhoff integral, and its calculation formula is:

[0047]

[0048] In the formula: r0 and r are the propagation distances of the incident ray and the diffracted ray, respectively; θ0 and θ are the angles between r0, r and the surface element normal vector n, respectively; v(x,t) is the offset velocity;

[0049] S130. Map the generated shot gather record to the source shot gather record, and remove noisy in-phase axes based on FK transform, specifically:

[0050] S hot0 (x,t) is mapped to the source gun set record S. Ori (x,t) in (e.g.) Figure 3 As shown), based on the FK transform algorithm, noisy in-phase axes (such as...) are removed from the source shot gather record. Figure 4 As shown), the new gun set record S is obtained. proc (x,t);

[0051] S140. Using Kirchhoff integral positive migration processing, the shot gather record after removing noise in-phase axes is converted back to the pre-stack time migration profile. The relevant calculation formula is as follows:

[0052]

[0053] In the formula: x is the horizontal coordinate; t is time; s proc (x,t) represents the new shot set record after denoising; Sec proc (x,t) represents the denoised Kirchhoff integral pre-stack time migration profile; ds represents the integral's surface element; W D (x,t) is the weighting factor of the Kirchhoff integral, and its calculation formula is:

[0054]

[0055] In the formula: r0 and r are the propagation distances of the incident ray and the diffracted ray, respectively; θ0 and θ are the angles between r0, r and the surface element normal vector n, respectively; v(x,t) is the offset velocity.

[0056] The process of removing [illegible characters] is carried out using Kirchhoff integral positive offset processing. Figure 4 The new shot gather record after the noise-in-phase axis shown is converted back to the pre-stack time migration profile, thus obtaining the noise-removed pre-stack time migration profile (e.g.). Figure 5 (As shown).

[0057] Depend on Figure 5 The horizontal line indicated by the arrow and Figure 2 The comparison of the horizontal lines indicated by the arrows clearly shows that the noisy in-phase axes in the pre-stack time migration profile have been effectively eliminated, thus verifying the effectiveness of the present invention.

[0058] Therefore, this invention, based on Kirchhoff inverse migration for seismic profile noise removal, first uses Kirchhoff integral inverse migration to map noise onto the shot gather record for removal, and then uses Kirchhoff integral forward migration to generate a noise-free migration profile. This method does not damage the effective information in the profile and avoids the formation of local blank bands on the profile, thus achieving rapid and effective removal of noise in-phase axes in pre-stack time-migrated profiles while ensuring the quality of seismic profile imaging. It has great application potential in actual production.

[0059] Example 2

[0060] This embodiment provides a device for seismic profile noise removal based on Kirchhoff retrograde migration, such as... Figure 6 As shown, the device includes: a noise in-phase axis pickup module 110, a Kirchhoff integral inverse offset processing module 120, a noise in-phase axis rejection module 130, and a Kirchhoff integral positive offset processing module 140. Wherein:

[0061] The noise in-phase axis pickup module 110 is used to manually pick out the noise in-phase axis on the pre-stack time migration profile according to a given migration rate.

[0062] Kirchhoff integral inverse offset processing module 120 is used to generate the corresponding shot gather record of the picked noise phase axis using Kirchhoff integral inverse offset processing.

[0063] The noise in-phase axis removal module 130 is used to map the generated shot gather record to the source shot gather record and remove noise in-phase axes based on FK transform;

[0064] Kirchhoff integral positive migration processing module 140 is used to convert the shot gather record after removing the noise in phase axis back to the pre-stack time migration profile using Kirchhoff integral positive migration processing.

[0065] In the Kirchhoff integral inverse offset processing module 120, the calculation formula for the Kirchhoff integral inverse offset processing is as follows:

[0066]

[0067] In the formula: x is the horizontal coordinate; t is time; sec0(x,t) is the noise in-phase axis picked up on the pre-stack time migration profile; S hot0 (x,t) represents the noise in-phase axis in the shot gather record obtained after inverse offset; ds represents the surface element of the integral; W D(x,t) is the weighting factor of the Kirchhoff integral, and its calculation formula is as follows:

[0068]

[0069] In the formula: r0 and r are the propagation distances of the incident ray and the diffracted ray, respectively; θ0 and θ are the angles between r0, r and the surface element normal vector n, respectively; v(x,t) is the offset velocity.

[0070] In the Kirchhoff integral positive offset processing module 140, the calculation formula for the Kirchhoff integral positive offset processing is as follows:

[0071]

[0072] In the formula: x is the horizontal coordinate; t is time; s proc (x,t) represents the new shot set record after denoising; Sec proc (x,t) represents the denoised Kirchhoff integral pre-stack time migration profile; ds represents the integral's surface element; W D (x,t) is the weighting factor of the Kirchhoff integral, and its calculation formula is as follows:

[0073]

[0074] In the formula: r0 and r are the propagation distances of the incident ray and the diffracted ray, respectively; θ0 and θ are the angles between r0, r and the surface element normal vector n, respectively; v(x,t) is the offset velocity.

[0075] The apparatus provided in this embodiment can execute the seismic profile noise removal method based on Kirchhoff retrograde migration provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0076] Example 3

[0077] This embodiment provides an electronic device for implementing a seismic profile noise removal method based on Kirchhoff retrograde migration, such as... Figure 7 As shown, this electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. This electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present application described and / or claimed herein.

[0078] like Figure 7As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0079] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as secondary storage area, optical disc, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0080] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the seismic profile noise removal method based on Kirchhoff retromigration.

[0081] In some embodiments, the Kirchhoff-based retrograde seismic profile noise reduction method can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the Kirchhoff-based retrograde seismic profile noise reduction method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the Kirchhoff-based retrograde seismic profile noise reduction method by any other suitable means (e.g., by means of firmware).

[0082] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0083] Computer programs used to implement the methods of this application may be written in any combination of one or more programming languages. These computer programs may be provided to the processor of a general-purpose computer, a special-purpose computer, or other programmable target-determining device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0084] In the context of this application, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0085] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0086] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0087] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0088] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired information of the technical solution of this application can be achieved, and this is not limited herein.

[0089] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A seismic profile noise removal method based on Kirchhoff reverse migration to avoid the formation of local blank zones on the profile, characterized in that, The seismic profile noise removal method includes: Manually pick out noisy in-phase axes on the pre-stack time migration profile based on the given migration rate; Kirchhoff integral inverse offset processing is used to generate the corresponding shot gather record of the picked noise phase axis. The generated shot gather record is mapped to the source shot gather record, and noisy in-phase axes are removed based on the FK transform; The shot gather record after removing noise in-phase axes was converted back to the pre-stack time migration profile using Kirchhoff integral positive migration processing. The calculation formula for the Kirchhoff integral inverse offset process is as follows: In the formula: The horizontal coordinate; For time; The noise in-phase axis picked up on the pre-stack time-shift profile; This refers to the noise in-phase axis in the shot gather record obtained after inverse offset; The element is the integral element; The weighting factor for Kirchhoff's integral; The formula for calculating the positive offset processing of the Kirchhoff integral is as follows: In the formula: The horizontal coordinate; For time; This is the new gun set record after noise reduction processing; This is the Kirchhoff integral pre-stack time migration profile after noise reduction. The element is the integral element; The weighting factor is the Kirchhoff integral.

2. The seismic profile noise removal method according to claim 1, characterized in that, The weighting factor of the Kirchhoff integral is calculated as follows: In the formula: , These represent the propagation distances of the incident ray and the diffracted ray, respectively. and They are respectively , The angle between the vector and the normal vector n of the surface element; This represents the offset speed.

3. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the seismic profile noise removal method based on Kirchhoff reverse migration as described in claim 1 or 2.

4. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the seismic profile noise removal method based on Kirchhoff retrograde migration as described in claim 1 or 2.

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