Full wavefield angle gathers for high-contrast thin interbed models

Abstract

Methods, apparatuses, and media related to full-wavefield angle gather generation are provided for high-contrast thin interbed modeling for reservoir characterization of a survey area. A method can include a logging tool having one or more sonic generators and one or more logging data recording sensors in a wellbore. The one or more sonic generators can be used to generate sonic waves to produce reflections in a survey area. The logging data recording sensors can be used to receive logging data based on the reflections and transmit the logging data to at least one memory. The method can use a computer system to perform generation of a full-wavefield angle gather. The method can generate, by the computer system, a high-contrast thin interbed model from the full-wavefield angle gather.

Description

Technical Field

[0001] This disclosure relates to computer-implemented methods, apparatus, and media for generating full-field angle gathers to reduce amplitude distortion in amplitude-offset / angle modeling of high-contrast thin interlayer models, thereby improving lithological identification and fluid discrimination in the fields of seismic exploration and reservoir characterization. Background Technology

[0002] Traditional linear amplitude-offset (AVO) or amplitude-angle (AVA) analysis / inversion is commonly used to improve lithological identification and fluid discrimination in seismic exploration and reservoir characterization. Traditional linear AVO / AVA analysis / inversion assumes that the input angle gather contains only the first reflection (which can be referred to as the "first wave" or "initial wave"). However, eliminating interlayer multiples and PSP (P-wave to S-wave and then to P-wave) converted waves while retaining the first reflection is a highly challenging task, as these often overlap with the first wave. Multiples and PSP converted waves affect the inversion results and lead to biases in the interpretation of the results. Therefore, assessing the impact of multiples and PSP converted waves on (1) the AVO response and (2) the inversion results based on linear AVO theory is crucial for ensuring the correct execution of AVO analysis / inversion in field data analysis. Therefore, it is necessary to calculate the full wavefield angle gather.

[0003] Traditional ray-based Zoeppritz theory methods only handle single-reflection waves. Ray tracing-based methods face difficulties in calculating higher-order multiples and converted waves. The offset-domain Kennett method is commonly used in AVO studies to simulate the full wavefield in the offset domain. However, converting data from the offset domain to the angular domain can introduce amplitude distortion. Therefore, it is necessary to address the challenges in traditional AVO forward modeling methods. Summary of the Invention

[0004] One or more embodiments provide a full-wavefield angle gather for a high-contrast thin interlayer model, which employs a hybrid approach, apparatus, and medium to characterize reservoirs in a seismic exploration area.

[0005] In one aspect, a method is provided for generating full-field angle gathers in a high-contrast thin interbedded model for reservoir characterization in an exploration area. The method may include: placing a logging tool comprising one or more acoustic generators and one or more logging data recording sensors in a wellbore; using one or more acoustic generators to generate acoustic waves to produce reflections in the exploration area; using one or more logging data recording sensors to receive reflection-based logging data, transferring the logging data to at least one memory, and storing the logging data in at least one memory; generating full-field angle gathers via a computer system; generating a high-contrast thin interbedded model based on the full-field angle gathers via the computer system; and displaying one or more images of the high-contrast thin interbedded model based on the full-field angle gathers.

[0006] In one aspect, a method is provided for generating a full-field angle gather for exploring reservoir characteristics in a high-contrast thin interbedded model. The method may include: placing a logging tool comprising one or more acoustic generators and one or more logging data recording sensors in a wellbore; generating acoustic waves using the one or more acoustic generators to produce reflections in the exploration area; receiving reflection-based logging data using the one or more logging data recording sensors, transferring the logging data to at least one memory, and storing the logging data in at least one memory; generating the full-field angle gather by a computer system; generating the high-contrast thin interbedded model based on the full-field angle gather by the computer system; and displaying one or more images of the high-contrast thin interbedded model based on the full-field angle gather.

[0007] In one aspect, generating full-wavefield angle gathers may also include calculating angle gathers containing only the primary wave.

[0008] In one aspect, a Zoeppritz-based ray tracing algorithm is used to compute angle gathers containing only the first wave.

[0009] In one aspect, generating a full-wavefield angle gather may also include: generating a full-wavefield tau-p gather using Kennett modeling; generating a tau-p gather that does not contain one or more multiples and / or one or more PSP converted waves; and generating a tau-p gather containing only one or more multiples and / or one or more PSP converted waves by subtracting the tau-p gather that does not contain one or more multiples and / or one or more PSP converted waves from the full-wavefield tau-p gather.

[0010] In one aspect, generating a full-wavefield angle gather may also include converting a tau-p gather containing only one or more multiples and / or one or more PSP converted waves into an offset ray parameter gather by applying elliptic time difference correction.

[0011] In one aspect, generating full-wavefield angle gathers may also include generating angle gathers containing only one or more multiple waves and / or one or more PSP converted waves by using a slowness-angle mapping to convert offset ray parameter gathers into angle gathers.

[0012] In one aspect, generating full-wavefield angle gathers may also include using a Zoeppritz-based ray tracing algorithm to compute angle gathers containing only the primary wave.

[0013] In one aspect, generating a full-wavefield angle gather may also include generating a full-wavefield angle gather by adding an angle gather containing only primary waves obtained by Zoeppritz-based ray tracing to an angle gather containing only one or more multiple waves and / or one or more PSP converted waves.

[0014] In one aspect, generating a full-wavefield gather may also include: generating a full-wavefield tau-p gather using Kennett modeling; generating a tau-p gather that does not contain one or more multiples; and generating a tau-p gather containing only one or more multiples by subtracting the tau-p gather that does not contain one or more multiples from the full-wavefield tau-p gather.

[0015] In one aspect, generating a full-wavefield gather may also include: generating a full-wavefield tau-p gather using Kennett modeling; generating a tau-p gather that does not contain one or more PSP converted waves; and generating a tau-p gather containing only one or more PSP converted waves by subtracting the tau-p gather that does not contain one or more PSP converted waves from the full-wavefield tau-p gather.

[0016] In one aspect, an apparatus is provided for generating full-field angle gathers in a high-contrast thin interbedded model for reservoir characterization in an exploration area. The apparatus may include: a logging tool configured to be placed in a wellbore; the logging tool including one or more acoustic generators configured to generate acoustic waves to produce reflections in the exploration area; the logging tool including one or more logging data recording sensors configured to receive and transmit reflection-based logging data; at least one memory storing the transmitted logging data, the at least one memory including instructions; and at least one processor configured to execute the instructions stored in the at least one memory to: generate full-field angle gathers; generate a high-contrast thin interbedded model based on the full-field angle gathers; and display one or more images of the high-contrast thin interbedded model based on the full-field angle gathers. Attached Figure Description

[0017] The teachings of the invention can be readily understood by taking into account the accompanying drawings and the following description:

[0018] Figure 1 This is a schematic diagram showing a top view of a survey area containing incident points of different seismic sources according to one embodiment;

[0019] Figure 2 It is a schematic diagram showing a cross-sectional view of an environment according to one embodiment, including the incident point of the seismic source, the seismic receiver, the well location, the well casing, various transmission rays, and various incident angles.

[0020] Figure 3 This is a schematic diagram illustrating a high-performance computing system according to one embodiment;

[0021] Figure 4 This is a schematic diagram showing a cross-sectional view of an environment including a wellbore and a logging tool according to one embodiment, wherein the logging tool includes at least one acoustic generator and at least one logging data recording sensor;

[0022] Figure 5 This is a flowchart illustrating a hybrid approach used according to one embodiment to generate a full-wavelength angle gather to produce a high-contrast thin interlayer model;

[0023] Figure 6 This is a graph showing a P-wave velocity model (P-wave velocity model) with high contrast thin interlayers for generating full-wave field angle gathers according to one embodiment.

[0024] Figure 7A This is a graph showing a gather containing only the first wave, generated by a ray tracing method according to one embodiment;

[0025] Figure 7B This is a graph showing a Tau-p gather containing only multiples and converted waves according to one embodiment;

[0026] Figure 7C This is a graph showing a full-wavefield angle gather generated using the conventional Kennett method according to one embodiment;

[0027] Figure 7D This is a graph showing the full-wavefield angle gather according to one embodiment;

[0028] Figure 8 It is shown in Figure 7C Traditional full-field angle gathers and based on Figure 7D A graph comparing zero-angle traces between full-wave field angle gathers in one embodiment;

[0029] Figure 9 It is shown in Figure 7C Traditional full-field angle gathers and based on Figure 7D A graph comparing the AVA curves extracted at approximately 0.115 seconds reflection between full-wavelength angle gathers in one embodiment;

[0030] Figure 10 It is shown in Figure 7C Traditional full-field angle gathers and based on Figure 7D A graph comparing the AVA curves extracted at approximately 0.29 seconds reflection between full-wavelength angle gathers in one embodiment; and

[0031] Figure 11 This is a graph showing a high-contrast thin interlayer model based on full-wave field angle gathers. Detailed Implementation

[0032] Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. It should be noted that, where possible, similar or identical reference numerals are used in the drawings, and similar or identical elements may be represented.

[0033] The accompanying drawings depict embodiments of the present disclosure and are for illustrative purposes only. Those skilled in the art will readily recognize from the following description that alternative embodiments exist without departing from the general principles of the present disclosure.

[0034] Throughout the specification, the terms “method,” “means,” and “technique” are used interchangeably and have the same meaning.

[0035] Throughout the specification, the terms “interlayer multiples” and “multiples” are used interchangeably and have the same meaning.

[0036] Throughout this specification, the terms "inter-layer multiples," "multiples," and "PSP converted waves" are used. Although these terms are used in plural form, it should be understood that embodiments may include one or more multiples, one or more inter-layer multiples, and / or one or more converted waves.

[0037] Figure 1-4 Exemplary embodiments of apparatus, methods, and media for capturing seismic and well logging data are shown.

[0038] Figure 1 This is a schematic diagram showing a top-down view of a survey area containing incident points of different seismic sources according to one embodiment. More specifically, Figure 1Seismic survey area 101, a land-based region, is shown. Reference numeral 102 indicates the top strata of survey area 101. Those skilled in the art will recognize that seismic survey areas can generate detailed images of the local geology to determine the location and size of potential hydrocarbon (oil and gas) reservoirs, thereby establishing well sites 103. In these survey areas, seismic waves are reflected back from subsurface rock strata when emitted from one or more seismic sources located at different incident points 104. A blast is an example of a seismic source generated by a seismic device. The seismic waves reflected back to the surface are captured by seismic data recording sensors 105, transmitted from seismic data recording sensors 105 via one or more data transmission systems (typically wireless), and stored for post-processing and analysis by a high-performance computing system. While this example shows the top strata 102 of land-based survey area 101, it should be understood that this is merely an example, and the method and system can also be applied to survey areas on the surface or bottom of the ocean.

[0039] Figure 2 This is a schematic diagram showing a cross-sectional view of a seismic survey area 101, including the incident point of the seismic source, the seismic receiver, the well location, the wellbore, various transmission rays, and various incident angles, according to one embodiment. More specifically, in Figure 2 In the figures, the cross-sectional view of the subsurface portion above the seismic survey area is indicated by reference numeral 201, and different types of strata are shown by reference numerals 102, 203, and 204. Although the seismic survey area in this example is based on land, it should be understood that this is only an example, and the system and method can also be applied to survey areas on the surface or bottom of the ocean. Figure 2 A common-center gather is shown, where seismic data is ordered according to surface geometry to simulate individual reflection points on Earth. In this example, data from one or more shot points or blast points and receivers can be combined into a single image gather, or used individually depending on the type of analysis to be performed. Although Figure 2 A planar reflector and corresponding image gather category are shown, but other types or categories of image gathers known in the art may also be used, the selection of which may depend on the presence of various subsurface conditions or events. One or more shot points or blast points represent seismic sources located at the surface, marked by reference numeral 104, at different incident points or sites where these seismic sources are activated at the surface.

[0040] like Figure 2As shown, seismic energy or seismic sources from multiple incident points 104 will be reflected from the interface between different strata. These reflections will be captured by multiple seismic data recording sensors 105, each placed at a different offset distance 210 and at the well site 103. Since all incident points 104 and all seismic data recording sensors 105 are placed at different offset distances 210, the survey seismic data or set (also referred to in the art as a "gathering") will be recorded at different incident angles 208. Incident points 104 generate downward propagating rays 205, which are captured at the surface by upward propagating reflections from the seismic data recording sensors 105. In this example, a well site 103 with a derrick is shown connected to a wellbore 209, where multiple measurements are performed along the wellbore 209 using techniques known in the art. The wellbore 209 is used to acquire logging data, which may include P-wave velocity (Vp), S-wave velocity (Vs), density, etc. Figure 2 Other sensors shown can be placed within the survey area to capture seismic data. Seismic data can be used to examine the dependence of amplitude, signal-to-noise ratio, time difference, frequency content, phase, and other seismic properties on incident angle, offset distance, azimuth, and other geometric properties that are crucial for data processing and imaging in the seismic survey area.

[0041] Figure 3 This is a schematic diagram illustrating a high-performance computing system according to one embodiment. The system receives (typically wirelessly) seismic data associated with seismic waves from a seismic data recording sensor 105 and stores the seismic data in at least one memory for post-processing and analysis via a computer-implemented method and apparatus according to one or more embodiments. The analyzed or processed seismic data can be accessed via a personal computer system. More specifically, Figure 3A data transmission system 300 is shown for wirelessly transmitting seismic data from a seismic data recording sensor 105 to a system computer 305 coupled to one or more storage devices 310 for storing the seismic data in a database. The data transmission system can also wirelessly transmit seismic data directly from the seismic data recording sensor 105 to one or more storage devices 310 for storing the seismic data in a database, which can be accessed by the system computer 305. Wireless transmission is indicated by reference numeral 302. The one or more storage devices 310 may also store other computer software instructions or programs to implement the apparatus and methods described in the embodiments. The system computer 305 may be coupled (e.g., wirelessly) to one or more output storage devices 320 that can receive the results of computer-implemented processes or methods executed by the system computer 305. A personal computer system 325 may be coupled (e.g., wirelessly) to one or more output storage devices 320 and / or the system computer 305 so that a user can use the user interface of the personal computer system 325 to input information or obtain the results of computer-implemented processor methods executed by the system computer 305. One or more storage devices 320 may also store other computer software instructions or programs to implement the apparatus and methods described in the embodiments.

[0042] The user interface of the personal computer system 325 may include, for example, one or more of the following: a keyboard, mouse, joystick, button, switch, electronic pen or stylus, gesture recognition sensor (e.g., for recognizing gestures of the user, including body part movements), input sound device or voice recognition sensor (e.g., microphone for receiving voice commands), output sound device (e.g., speaker), trackball, remote control, portable (e.g., cellular or smartphone) phone, tablet computer, pedal or foot switch, virtual reality device, etc. The user interface may also include a haptic device to provide haptic feedback to the user. The user interface may also include, for example, a touchscreen. Furthermore, the personal computer system 325 may be a desktop computer, laptop computer, tablet computer, mobile phone, or any other personal computing system.

[0043] The processes, functions, methods, and / or computer software instructions or programs in the apparatus and methods described in the embodiments may be recorded, stored, or fixed in one or more non-transitory computer-readable media (computer-readable storage (recording) media), which include program instructions (computer-readable instructions) executable by a computer to cause one or more processors to execute (implement or implement) the program instructions. The media may also be included alone or in combination with program instructions, data files, data structures, etc. The media and program instructions may be specially designed and constructed, or may be well-known and usable by those skilled in the art of computer software. Examples of non-transitory computer-readable media include magnetic media, such as hard disks, floppy disks, and magnetic tapes; optical media, such as CD-ROMs and DVDs; magneto-optical media, such as optical discs; and hardware devices specifically configured for storing and executing program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, etc. Examples of program instructions include machine code (e.g., generated by a compiler) and files containing higher-level code that can be executed by a computer using an interpreter. The program instructions may be executed by one or more processors. The described hardware device can be configured as one or more software modules that are recorded, stored, or embedded in one or more non-transitory computer-readable media to perform the above-described operations and methods, and vice versa. Furthermore, the non-transitory computer-readable media can be distributed among computer systems connected via a network, and program instructions can be stored and executed in a distributed manner. In addition, the computer-readable media can also be embodied in at least one application-specific integrated circuit (ASIC) or field-programmable logic array (FPGA).

[0044] One or more databases may include a collection of data and supporting data structures that can be stored, for example, in one or more storage devices 310 and 320. For example, one or more storage devices 310 and 320 may be embodied as one or more non-transitory computer-readable storage media, such as non-volatile memory devices, such as read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), and flash memory, USB drives, volatile memory devices (e.g., random access memory (RAM)), hard disks, floppy disks, Blu-ray discs, or optical media (e.g., CD-ROMs and DVDs), or combinations thereof. However, examples of storage devices 310 and 320 are not limited to those described above, and the storage can be implemented by various other devices and structures understood by those skilled in the art.

[0045] Figure 4 This is a schematic diagram showing a cross-sectional view of an environment including a wellbore and a logging tool according to one embodiment, wherein the logging tool includes at least one acoustic generator and at least one logging data recording sensor. Figure 4An oil drilling system 400 on land 405 is shown, including a drilling rig 410. The drilling rig 410 supports the insertion of a logging tool 415 into a wellbore 420. The logging tool 415 includes one or more acoustic generators (sound sources) for generating one or more acoustic waves, which are transmitted to one or more formations to generate reflected or reflected waves in the formations. Although this example shows one or more formations in a land-based exploration area, it should be understood that this is only an example, and the method and system can also be applied to exploration areas on the surface or bottom of the ocean. The logging tool 415 also includes one or more logging data recording sensors. The one or more logging data recording sensors receive and record logging data, which includes reflected data received by the one or more logging data recording sensors in response to acoustic waves emitted into the one or more formations by the one or more acoustic generators. The logging data may include P-wave velocity (Vp), S-wave velocity (Vs), and density as an indicator of porosity. This logging process for recording logging data may also be referred to as acoustic logging. The logging vehicle 425 can be coupled to the logging tool 415 to assist in the running and lifting of the logging tool 415, and communicate with the logging tool 415 to acquire logging data, which is then transmitted wirelessly and / or via wired means to one or more storage devices (e.g., Figure 3 Storage device 310 in the middle, so that by Figure 3 The high-performance computer system shown is used for further processing.

[0046] Figure 5 This is a flowchart illustrating a hybrid approach used according to one embodiment to generate a full-wavefield angle gather to produce a high-contrast thin interlayer model. In a preferred embodiment, well logging data may be input in the form of one or more subsurface seismic models for P-wave velocity (Vp), S-wave velocity (Vs), and / or density. Figure 5 Operations 500, 510, and 550 are used in this process. This well logging data is used to generate (produce) a high-resolution subsurface elastic model, also known as a seismic model, for P-wave velocity (Vp), S-wave velocity (Vs), and / or density. Figure 6 An example of this earthquake model is shown.

[0047] Although model-based logging data is the preferred data for generating full-field angle gathers, in order to... Figure 5 The reservoir characterization of the survey area shown sometimes reduces amplitude distortion in amplitude-offset / angle modeling in high-contrast thin interbedded models, but the density can be estimated from the measured P-wave velocity (Vp) and S-wave velocity (Vs), or measured using special logging tools (such as sonic logging tools or neutron porosity logging tools).

[0048] about Figure 5The high-contrast thin interlayer model is generated using a hybrid approach to produce full-wavelength angle gathers. One or more embodiments can utilize the Zoeppritz method and the tau-p domain Kennett method to achieve more accurate full-wavelength angle gather simulations for AVO analysis / inversion using a hybrid approach. The primary reflection can be calculated directly using a Zoeppritz-based ray tracing algorithm. Therefore, normal time difference (NMO) correction, geometric spread correction, and offset-angle conversion steps are unnecessary, and the primary reflection does not contain any artifacts for the high-contrast thin interlayer model. The angle gathers of multiples and / or PSP converted waves are indirectly obtained through tau-p domain Kennett modeling. To separate multiples from PSP converted waves, the Kennett modeling method is modified to calculate tau-p gathers that do not contain multiples and / or PSP converted waves associated with any reflectors. Therefore, as... Figure 5 As shown, well logging data stored in one or more storage devices (e.g., storage devices 310 and 320) is used to generate a full-wavefield tau-p gather in operation 500 through Kennett modeling, and a tau-p gather excluding multiples and / or PSP converted waves is generated in operation 510. The well logging data can be input into operations 500 and 510 in the form of one or more subsurface seismic models for P-wave velocity (Vp), S-wave velocity (Vs), and / or density. Therefore, both full-wavefield tau-p gathers and tau-p gathers excluding multiples and / or PSP converted waves can be obtained in operations 500 and 510.

[0049] Referring to operation 520, a tau-p gather containing only multiples and / or PSP converted waves is generated by subtracting the tau-p gather (generated in operation 510) that does not contain multiples and / or PSP converted waves from the full-wavefield tau-p gather (generated in operation 500 via Kennett modeling). In operation 530, the tau-p gather containing only multiples and / or PSP converted waves is converted into a migration ray parameter gather containing only multiples and / or PSP converted waves by applying elliptic time difference correction. Then, in operation 540, the ray parameter gather is converted into an angle gather containing only multiples and / or PSP converted waves by using a slowness-angle mapping. Using logging data stored in one or more storage devices (e.g., storage devices 310 and 320), preferably via a Zoeppritz-based ray tracing algorithm, a ray-tracing-based gather containing only primary waves is generated in operation 550. The logging data may be in the form of one or more subsurface seismic models. In operation 560, a full-wavelength angle gather is generated by adding a ray-tracing-based angle gather containing only primary waves from operation 550 to an angle gather containing only multiple waves and / or PSP converted waves from operation 540. This full-wavelength angle gather is used in operation 570 to generate a high-contrast thin interlayer model via amplitude-offset / angle analysis / inversion. One or more images of the high-contrast thin interlayer model based on the full-wavelength angle gather can be displayed on a computer device (e.g., Figure 3 On the monitor of a personal computer system 325.

[0050] In the Kennett modeling method, reflectivity and propagation time are separated. For each reflector, the reflection coefficients for upward, downward, PS, and SP converted waves are explicitly calculated. Therefore, in Kennett modeling, any reflection coefficient can be modified while keeping other coefficients and propagation time calculations unchanged. Thus, any wave modes associated with any reflector can be eliminated. To obtain a tau-p gather containing only primary waves, different reflection coefficients are modified by setting all reflection coefficients except for downward P-wave propagation, upward P-wave propagation, and upward P-wave reflection coefficients to zero. To eliminate multiples of reflectors within a given range, the downward reflection coefficients of these reflectors are set to zero. Multiples and PSP converted waves can then be separated by subtracting from a full-wavefield tau-p gather, a tau-p gather containing only primary waves, and a tau-p gather containing no multiples. For example, a tau-p gather containing only inter-layer multiples can be obtained by subtracting a tau-p gather containing no multiples from a full-wavefield tau-p gather. A gather containing only the PSP converted wave can be obtained by subtracting the gather containing only the primary wave and the gather containing only the multiple wave from the full-wavelength gather. In operation 530, the tau-p gather containing only the multiple wave and / or the PSP converted wave is converted into an offset ray parameter gather containing only the multiple wave and / or the PSP converted wave, then converted to the angular domain in operation 540, and added to the angular gather containing only the primary wave obtained by ray tracing in operation 550, so that a full-wavelength angular gather is finally obtained in operation 560, which is used to generate a high-contrast thin interlayer model in operation 570. The generated high-contrast thin interlayer model is then displayed in operation 580 as shown in... Figure 3 The monitor of the personal computer system 325 shown.

[0051] One or more embodiments can obtain a full-wavefield angular gather containing both primary and multiple waves associated with a given reflector, or an angular gather containing only primary and converted waves associated with a specific range of reflectors. Therefore, the intensity of the multiples and PSP converted waves of any given reflector can be examined, and their impact on the analysis / inversion results can be evaluated separately.

[0052] Figure 6-11 A method for generating full-wavefield angle gathers by using a model with high-contrast thin interlayers is shown, and the results are compared with those of conventional methods. Figure 6This is a graph illustrating a high-contrast, thinly interbedded P-wave velocity model (P-wave velocity model) for generating full-field angular gathers, according to one embodiment. The P-wave velocity model based on the measured P-wave velocity (Vp) is an example of a seismic model. As mentioned above, the shear wave velocity model based on the measured shear wave velocity (Vs) (S-wave velocity model) is also an example of a seismic model, while the density model based on the measured density is another example. Although... Figure 6 A P-wave velocity model is shown, but it should be understood that, according to other embodiments, an S-wave velocity model and a density model need to be input. Figure 5 Operations 500, 510, and 550 are used to generate full-wavefield angle gathers.

[0053] Figure 7A A graph showing a gather containing only the first wave, obtained in operation 550 by a ray tracing method according to an exemplary embodiment, is shown. Figure 7B This is a graph showing a Tau-p gather containing only multiple waves and converted waves obtained in operation 520 according to an exemplary embodiment. Figure 7C This is a graph showing the full-wavefield angle gather generated using the conventional Kennett method. Figure 7D This is a graph showing the full-wave field angle gather obtained in operation 560 according to one embodiment.

[0054] Figure 8 It shows in Figure 7C The traditional full-field angle gathers obtained and based on Figure 7D A curve 800 comparing zero-angle traces between full-wave field angle gathers obtained in one embodiment. Figure 8 The diagram shows a zero-angle track 810 corresponding to a conventional method, and a zero-angle track 820 corresponding to an embodiment of the present invention. For example... Figure 8 As shown, the zero-angle trace corresponding to the conventional method is noisy due to artificial oscillations (artifacts). In contrast, the zero-angle trace corresponding to the embodiment of the present invention provides a smooth curve. This smooth curve has fewer artifacts. This smooth curve has fewer oscillations and amplitudes. Therefore, the smooth curve of the zero-angle trace corresponding to the embodiment of the present invention is clearer than the zero-angle trace corresponding to the conventional method, which is distorted due to artifacts (noise).

[0055] Figure 9 It shows in Figure 7C The traditional full-field angle gathers obtained and based on Figure 7DA curve 900 compares the AVA curves extracted at a reflection of approximately 0.115 seconds between full-wavelength angle gathers obtained in one embodiment. Reference numeral 910 indicates an AVA curve extracted from a conventional full-wavelength angle gather. Reference numeral 920 indicates an AVA curve extracted from a full-wavelength angle gather according to an embodiment. The AVA curves extracted according to the embodiments of the present invention are clearer than those extracted by conventional methods, which are distorted due to artifacts (noise). The AVA curves extracted from the full-wavelength angle gathers according to the embodiments are smoother than the selected AVA curves from conventional full-wavelength angle gathers.

[0056] Figure 10 It shows in Figure 7C The traditional full-field angle gathers obtained and based on Figure 7D Curve 1000 compares the AVA curves extracted at approximately 0.29 seconds of reflection between full-wavelength angle gathers obtained in one embodiment. Reference numeral 1010 indicates the AVA curve extracted from a conventional full-wavelength angle gather. Reference numeral 1020 indicates the AVA curve extracted from the full-wavelength angle gather according to the embodiment. The AVA curves extracted according to the embodiment of the present invention are clearer than those extracted by conventional methods, which are distorted due to artifacts (noise). The AVA curves extracted from the full-wavelength angle gathers according to the embodiment are smoother than those extracted from conventional full-wavelength angle gathers, resulting in a superior high-contrast thin interlayer model due to less noise (less artifacts).

[0057] Figure 11 Curve 1100 is shown as a high-contrast thin interlayer model based on a full-wavefield angle gather, used to identify the location of oil and / or gas to guide drilling. The figure illustrates the capture of full-wavefield data generated from the proposed modeling method through inversion, and displays seismic traces of multiples and converted waves in the inversion parameters, which helps geologists identify the effects of multiples and converted waves. Curve 1100 can be displayed, for example... Figure 3 On the display of the computing device of the personal computer system 325. Although Figure 11 A single seismic trace / well is displayed, but multiple seismic traces / wells can also be displayed graphically.

[0058] Although embodiments of the present disclosure have been shown and described, modifications can be made by those skilled in the art without departing from the spirit or teachings of the invention. The embodiments described herein are exemplary only and not restrictive. Various variations and modifications of the methods, systems, and apparatus are possible and are all within the scope of the invention. Therefore, the scope of protection is not limited to the embodiments described herein, but only to the claims. The scope of the claims should include all equivalents of the subject matter of the claims.

Claims

1. A method for generating full-field angle gathers in a high-contrast thin interlayer model for reservoir characterization in an exploration area, the method comprising: A logging tool, comprising one or more acoustic generators and one or more logging data recording sensors, is placed in the wellbore; The one or more sound wave generators are used to generate sound waves to produce reflections in the survey area; The well logging data is received based on the reflection using one or more well logging data recording sensors, the well logging data is transmitted to at least one memory, and the well logging data is stored in at least one memory; Full-wavelength angle gathers are generated using a computer system; The high-contrast thin interlayer model is generated using the computer system based on the full-wavelength angle gathers; and One or more images of the high-contrast thin interlayer model are displayed based on the full-wavelength angle gather. The generation of the full-wavelength angle gather using the computer system further includes: Kennett modeling was used to generate full-wavefield tau-p gathers; Generate tau-p gathers that do not contain one or more multiples and / or one or more PSP converted waves; and A tau-p gather containing only one or more multiples and / or one or more PSP converted waves is generated by subtracting the tau-p gather that does not contain one or more multiples and / or one or more PSP converted waves from the full-wavefield tau-p gather.

2. The method according to claim 1, wherein, Generating full-wavefield angle gathers using the computer system also includes calculating angle gathers containing only the primary wave.

3. The method according to claim 2, wherein, The Zoeppritz-based ray tracing algorithm is used to calculate the angle gather containing only the first wave.

4. The method according to claim 1, wherein, Generating the full-wavefield angle gather using the computer system also includes converting a tau-p gather containing only one or more multiples and / or one or more PSP converted waves into an offset ray parameter gather by applying elliptic time difference correction.

5. The method according to claim 4, wherein, Generating the full-wavefield angle gather using the computer system also includes generating an angle gather containing only one or more multiples and / or one or more PSP converted waves by using a slowness-angle mapping to convert the offset ray parameter gather into the angle gather.

6. The method according to claim 5, wherein, Generating the full-wavelength angle gather using the computer system also includes using a Zoeppritz-based ray tracing algorithm to calculate angle gathers containing only the first wave.

7. The method according to claim 6, wherein, Generating the full-wavelength angle gather using the computer system also includes generating the full-wavelength angle gather by adding an angle gather containing only primary waves obtained by Zoeppritz-based ray tracing to an angle gather containing only one or more multiple waves and / or one or more PSP converted waves.

8. An apparatus for generating full-wavefield angle gathers in a high-contrast thin interlayer model for reservoir characterization in an exploration area, the apparatus comprising: A logging tool includes one or more acoustic generators configured to generate acoustic waves to produce reflections in the exploration area, and one or more logging data recording sensors configured to receive logging data based on the reflections, the logging tool being configured to transmit the logging data; At least one memory storing the transmitted logging data, said at least one memory including instructions; and At least one processor is configured to execute the instructions stored in the at least one memory to achieve: Generate full-wave field angle gathers; The high-contrast thin interlayer model is generated based on the full-wavelength angle gathers; and One or more images of a high-contrast thin interlayer model are displayed based on the full-wavelength angle gather. Generating the full-wave field angle gather further includes: Kennett modeling was used to generate full-wavefield tau-p gathers; Generate tau-p gathers that do not contain one or more multiples and one or more PSP converted waves; and A tau-p gather containing only one or more multiples and one or more PSP converts is generated by subtracting the tau-p gather that does not contain one or more multiples and / or does not contain one or more PSP converts from the full-wavefield tau-p gather.

9. The apparatus according to claim 8, wherein, Generating the full-wavefield angle gather also includes calculating the angle gather containing only the primary wave.

10. The apparatus according to claim 9, wherein, The Zoeppritz-based ray tracing algorithm is used to calculate the angle gather containing only the first wave.

11. The apparatus according to claim 8, wherein, Generating the full-wavefield angle gather also includes converting a tau-p gather containing only one or more multiples and / or one or more PSP converted waves into an offset ray parameter gather by applying elliptic time difference correction.

12. The apparatus according to claim 11, wherein, Generating the full-wavefield angle gather also includes generating an angle gather containing only one or more multiple waves and / or one or more PSP converted waves by using a slowness-angle mapping to convert the offset ray parameter gather into the angle gather.

13. The apparatus according to claim 12, wherein, Generating the full-wavefield angle gather also includes using a Zoeppritz-based ray tracing algorithm to compute angle gathers containing only the primary wave.

14. The apparatus according to claim 13, wherein, Generating the full-wavelength angle gather also includes adding the angle gather containing only primary waves obtained by Zoeppritz-based ray tracing to the angle gather containing only one or more multiple waves and one or more PSP converted waves.

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