Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202113199
H. Feng, T. Kay, A. Knudsen, W. Wang, A. Ayre
Summary We present a 4D time-lapse Full Waveform Inversion (FWI) case study using a monitor and baseline seismic dataset acquired on the Sunrise SAGD project near Fort McMurray, Alberta. We applied a double-difference FWI method in the 4D study. The double-difference FWI takes the difference between the baseline and monitor seismic waveforms and inverts for velocity differences. We demonstrate the method is stable and less dependent on a starting model's accuracy lacking low frequencies in the FWI seismic input waveform. We also present a processing workflow to prepare input data for FWI. The results show our workflow is practical and efficient and produces the improved imaging of the SAGD steam chamber geometry.
{"title":"4D Time-Lapse Full Waveform Inversion Case Study for SAGD Steam Chamber Imaging","authors":"H. Feng, T. Kay, A. Knudsen, W. Wang, A. Ayre","doi":"10.3997/2214-4609.202113199","DOIUrl":"https://doi.org/10.3997/2214-4609.202113199","url":null,"abstract":"Summary We present a 4D time-lapse Full Waveform Inversion (FWI) case study using a monitor and baseline seismic dataset acquired on the Sunrise SAGD project near Fort McMurray, Alberta. We applied a double-difference FWI method in the 4D study. The double-difference FWI takes the difference between the baseline and monitor seismic waveforms and inverts for velocity differences. We demonstrate the method is stable and less dependent on a starting model's accuracy lacking low frequencies in the FWI seismic input waveform. We also present a processing workflow to prepare input data for FWI. The results show our workflow is practical and efficient and produces the improved imaging of the SAGD steam chamber geometry.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"110 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120930553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202010822
V. B. Ribeiro, J. Markov
Summary The most common use of aeromagnetic data is the identification of magnetic bodies and contacts. Edge enhancement techniques are crucial to the interpretation process because they allow more accurate mapping of these key features. However, most techniques used to enhance magnetic features have disadvantages of one type or another. The algorithm presented here allows the user to apply any combination of fourteen different enhancement filter techniques. This strategy has the advantage of letting the interpreter to compare the noise-to-signal ratio obtained for different methods and chose only the better results for a specific study case. We also included two different options to combine the results: a simple stacking approach where all filters considered have the same weight to compose the final map and one that divides the solutions in four different groups, according with the number of results obtained. By stacking the solutions obtained by different filters it is possible to enhance true edges while minimizing false peaks and mathematical artefacts. The method was tested on a synthetic data set and one real case to demonstrate the methods performance. The synthetic case was designed to simulate the presence of three sources at different depths with a strong unknown remanent component.
{"title":"Combining Edge Enhancement Images for More Reliable Detection of Magnetic Features: A Python implementation","authors":"V. B. Ribeiro, J. Markov","doi":"10.3997/2214-4609.202010822","DOIUrl":"https://doi.org/10.3997/2214-4609.202010822","url":null,"abstract":"Summary The most common use of aeromagnetic data is the identification of magnetic bodies and contacts. Edge enhancement techniques are crucial to the interpretation process because they allow more accurate mapping of these key features. However, most techniques used to enhance magnetic features have disadvantages of one type or another. The algorithm presented here allows the user to apply any combination of fourteen different enhancement filter techniques. This strategy has the advantage of letting the interpreter to compare the noise-to-signal ratio obtained for different methods and chose only the better results for a specific study case. We also included two different options to combine the results: a simple stacking approach where all filters considered have the same weight to compose the final map and one that divides the solutions in four different groups, according with the number of results obtained. By stacking the solutions obtained by different filters it is possible to enhance true edges while minimizing false peaks and mathematical artefacts. The method was tested on a synthetic data set and one real case to demonstrate the methods performance. The synthetic case was designed to simulate the presence of three sources at different depths with a strong unknown remanent component.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127356004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202112665
C. Tyagi, S. Leake, K. Mistry, C. Olsen, K. Sundøy
Summary Shallow hazard imaging of the near surface is a key input to de-risk drilling plans. Exploration-style seismic acquisition inherits the limitations, for example, coarse temporal sampling, lack of small reflection angles, and low-frequency source. Therefore, additional measurements using dedicated high-resolution (HR) site surveys are required, at an extra cost and planning. However, potentially ultra-high-resolution measurements are also recorded in marine towed-streamer exploration-style acquisitions in the form of near-field hydrophone (NFH) measurements, located above the seismic sources. If the NFH recordings can be processed to remove the source signature and preserve the reflection energy, a broadband data set can be created at zero offset from the source with higher resolution in the shallow compared to conventional 3D marine seismic data. The challenges associated with creating such a workflow are: 1) being able to remove the source signature from all the NFH data sets and preserve signal, 2) producing a product that is as reliable and effective at imaging shallow hazards as a dedicated shallow hazard survey, and 3) being able to interpolate sparse crossline measurements. The workflow presented here showcases the solutions for these challenges and illustrates a comparison between the produced data with HR and ultra-HR dedicated images.
{"title":"Utilizing near-field hydrophone data for high-resolution shallow hazard imaging","authors":"C. Tyagi, S. Leake, K. Mistry, C. Olsen, K. Sundøy","doi":"10.3997/2214-4609.202112665","DOIUrl":"https://doi.org/10.3997/2214-4609.202112665","url":null,"abstract":"Summary Shallow hazard imaging of the near surface is a key input to de-risk drilling plans. Exploration-style seismic acquisition inherits the limitations, for example, coarse temporal sampling, lack of small reflection angles, and low-frequency source. Therefore, additional measurements using dedicated high-resolution (HR) site surveys are required, at an extra cost and planning. However, potentially ultra-high-resolution measurements are also recorded in marine towed-streamer exploration-style acquisitions in the form of near-field hydrophone (NFH) measurements, located above the seismic sources. If the NFH recordings can be processed to remove the source signature and preserve the reflection energy, a broadband data set can be created at zero offset from the source with higher resolution in the shallow compared to conventional 3D marine seismic data. The challenges associated with creating such a workflow are: 1) being able to remove the source signature from all the NFH data sets and preserve signal, 2) producing a product that is as reliable and effective at imaging shallow hazards as a dedicated shallow hazard survey, and 3) being able to interpolate sparse crossline measurements. The workflow presented here showcases the solutions for these challenges and illustrates a comparison between the produced data with HR and ultra-HR dedicated images.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130844090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202113133
X. Song, G. Liu
Summary In this paper, a processing flow for estimating the near surface 2-D Vs velocity model using Rayleigh surface wave dispersion curve is established. Rayleigh surface wave dispersion energy diagram is extracted by frequency decomposition method. However, due to the low resolution of the extracted dispersive energy map, the window superposition method is introduced to superimpose the dispersive energy of multiple shot points in the same window on the dispersive energy map in the center of the common window. Then move the window along the direction of the acquisition line to extract the dispersive energy map at different positions. 2-D search is carried out on the periodic grid of phase velocity, and the dispersion points are selected from the superimposed energy peaks. Windowing and stacking can also smooth the lateral changes of the model and improve the signal-to-noise ratio. Then, the singular value decomposition based damped least square method is used to inverse the one-dimensional Vs velocity, and the inverse 1-D Vs velocity is interpolated to obtain the 2-D Vs velocity profile. The simulation data and the actual data of Yellowstone National Park shared by Sylvain pasquet and Ludovic bodet (2017) show the effectiveness of the processing process.
{"title":"New processing flow for surface wave dispersion curve inversion of near surface 2-D Vs model","authors":"X. Song, G. Liu","doi":"10.3997/2214-4609.202113133","DOIUrl":"https://doi.org/10.3997/2214-4609.202113133","url":null,"abstract":"Summary In this paper, a processing flow for estimating the near surface 2-D Vs velocity model using Rayleigh surface wave dispersion curve is established. Rayleigh surface wave dispersion energy diagram is extracted by frequency decomposition method. However, due to the low resolution of the extracted dispersive energy map, the window superposition method is introduced to superimpose the dispersive energy of multiple shot points in the same window on the dispersive energy map in the center of the common window. Then move the window along the direction of the acquisition line to extract the dispersive energy map at different positions. 2-D search is carried out on the periodic grid of phase velocity, and the dispersion points are selected from the superimposed energy peaks. Windowing and stacking can also smooth the lateral changes of the model and improve the signal-to-noise ratio. Then, the singular value decomposition based damped least square method is used to inverse the one-dimensional Vs velocity, and the inverse 1-D Vs velocity is interpolated to obtain the 2-D Vs velocity profile. The simulation data and the actual data of Yellowstone National Park shared by Sylvain pasquet and Ludovic bodet (2017) show the effectiveness of the processing process.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131929315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202113172
Y. Ren, S. Drewell, H. Masoomzadeh, S. Baldock, T. Seher, V. Danielsen, P. Dhelie
Summary Conventional deblending using random time delays has been the most popular technique in marine simultaneous source acquisition and processing for some time. Signal apparition using periodic time delays has recently emerged as an attractive alternative to conventional deblending. In this new technique, periodic modulation times are used to encode multiple sources during the acquisition of simultaneous source data. These data can later be decoded using the known modulation times to separate the simultaneous sources into the individual sources. This method has the potential to increase the density of seismic sources, which can improve subsurface sampling and reduce the acquisition time. In this paper, we present a new source separation method for seismic data encoded with periodic time delays and use it to process hexasource variable depth streamer data from the Utsira region in the North Sea. A comparison of our new method with a conventional deblending solution indicates similar separation quality.
{"title":"Deblending using periodic time delays for hexasource variable depth streamer data","authors":"Y. Ren, S. Drewell, H. Masoomzadeh, S. Baldock, T. Seher, V. Danielsen, P. Dhelie","doi":"10.3997/2214-4609.202113172","DOIUrl":"https://doi.org/10.3997/2214-4609.202113172","url":null,"abstract":"Summary Conventional deblending using random time delays has been the most popular technique in marine simultaneous source acquisition and processing for some time. Signal apparition using periodic time delays has recently emerged as an attractive alternative to conventional deblending. In this new technique, periodic modulation times are used to encode multiple sources during the acquisition of simultaneous source data. These data can later be decoded using the known modulation times to separate the simultaneous sources into the individual sources. This method has the potential to increase the density of seismic sources, which can improve subsurface sampling and reduce the acquisition time. In this paper, we present a new source separation method for seismic data encoded with periodic time delays and use it to process hexasource variable depth streamer data from the Utsira region in the North Sea. A comparison of our new method with a conventional deblending solution indicates similar separation quality.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134042256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202112950
P. Bridger, J. White, J. Williams, G. Williams, S. Hannis
Summary The Bunter Sandstone Formation in the Southern North Sea is an important potential CO2 storage reservoir and is likely to form an integral part of the UK’s carbon capture and storage ambition for industrial clusters in northeast England. In this study, a geological model is developed for the Bunter Sandstone Connected Aquifer in the Southern North Sea. This region is structurally-bound by large faults and salt features that are thought to compartmentalise it from surrounding Bunter Sandstone aquifer(s). Notable features of the Bunter Sandstone Connected Aquifer include a seismic polarity reversal in the top Bunter Sandstone horizon, and the ‘seabed outcrop’, a location at which the Bunter Sandstone subcrops a thin Quaternary sequence. Several storage sites have been identified within the Bunter Sandstone Connected Aquifer, and this model will provide an opportunity to assess regional pressurization, geomechanical modelling and estimates of CO2 storage capacity in the context of injection at multiple locations.
{"title":"Geological Characterization of the Hydraulically-Connected Bunter Sandstone Formation Saline Aquifer in the Southern North Sea","authors":"P. Bridger, J. White, J. Williams, G. Williams, S. Hannis","doi":"10.3997/2214-4609.202112950","DOIUrl":"https://doi.org/10.3997/2214-4609.202112950","url":null,"abstract":"Summary The Bunter Sandstone Formation in the Southern North Sea is an important potential CO2 storage reservoir and is likely to form an integral part of the UK’s carbon capture and storage ambition for industrial clusters in northeast England. In this study, a geological model is developed for the Bunter Sandstone Connected Aquifer in the Southern North Sea. This region is structurally-bound by large faults and salt features that are thought to compartmentalise it from surrounding Bunter Sandstone aquifer(s). Notable features of the Bunter Sandstone Connected Aquifer include a seismic polarity reversal in the top Bunter Sandstone horizon, and the ‘seabed outcrop’, a location at which the Bunter Sandstone subcrops a thin Quaternary sequence. Several storage sites have been identified within the Bunter Sandstone Connected Aquifer, and this model will provide an opportunity to assess regional pressurization, geomechanical modelling and estimates of CO2 storage capacity in the context of injection at multiple locations.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134281275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202113158
B. Plotnikov, I. Karimov, R. Volkov, D. Ignatova
Summary Unconventional reservoirs are unique geological objects without generally accepted and widely proofed effective approaches for core studying, well data interpretation and reservoir properties prediction. Horizontal wells with multi-stage hydraulic fracturing are widely used to provide the maximum possible stimulated rock volume (SRV) and increase initial and accumulated oil rates production. Natural fracture and brittleness provide the main contribution to the efficiency of multi-stage hydraulic fracturing. Prediction of these properties in the interwell space is a complex question that requires modern and advanced solution. To deals with this question authors used Bayesian classification and azimuthal AVO analysis. As a result brittleness and anysotropy properties of resrviour were predicted.
{"title":"Brittleness prediction and azimuthal AVO analysis in unconventional reservoir for multi stage hydraulic fracturing efficiency improving","authors":"B. Plotnikov, I. Karimov, R. Volkov, D. Ignatova","doi":"10.3997/2214-4609.202113158","DOIUrl":"https://doi.org/10.3997/2214-4609.202113158","url":null,"abstract":"Summary Unconventional reservoirs are unique geological objects without generally accepted and widely proofed effective approaches for core studying, well data interpretation and reservoir properties prediction. Horizontal wells with multi-stage hydraulic fracturing are widely used to provide the maximum possible stimulated rock volume (SRV) and increase initial and accumulated oil rates production. Natural fracture and brittleness provide the main contribution to the efficiency of multi-stage hydraulic fracturing. Prediction of these properties in the interwell space is a complex question that requires modern and advanced solution. To deals with this question authors used Bayesian classification and azimuthal AVO analysis. As a result brittleness and anysotropy properties of resrviour were predicted.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132846093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202112679
F. Jiang, P. Norlund
Summary Assisted fault interpretation leveraging machine learning techniques has become a promising way to identify faults in seismic. In geophysical exploration, faults are often considered as a sealing surface which traps hydrocarbons and forms reservoir zones. Thus, correctly identifying fault locations is critical. Fault identification can be treated as a semantic segmentation issue where we classify each seismic pixel into one of a given set of categories, such as fault or non-fault. To be successful we need to combine pixel-level accuracy with global-level feature identification. In this abstract, we propose a novel deep learning network with multi-scale dilated convolution to identify fault locations. It is based on adaptions of a convolutional neural network architecture which has been used for image classification and semantic segmentation. The motivation is that dilated convolution supports exponentially expanding receptive fields without losing resolution or coverage. We implemented multiple dilated convolution layers with variable dilation rates to systematically aggregate multi-scale seismic information. Several tests are shown and demonstrate the improvement of identification accuracy with higher resolution.
{"title":"Assisted Fault Interpretation by Multi-scale Dilated Convolutional Neural Network","authors":"F. Jiang, P. Norlund","doi":"10.3997/2214-4609.202112679","DOIUrl":"https://doi.org/10.3997/2214-4609.202112679","url":null,"abstract":"Summary Assisted fault interpretation leveraging machine learning techniques has become a promising way to identify faults in seismic. In geophysical exploration, faults are often considered as a sealing surface which traps hydrocarbons and forms reservoir zones. Thus, correctly identifying fault locations is critical. Fault identification can be treated as a semantic segmentation issue where we classify each seismic pixel into one of a given set of categories, such as fault or non-fault. To be successful we need to combine pixel-level accuracy with global-level feature identification. In this abstract, we propose a novel deep learning network with multi-scale dilated convolution to identify fault locations. It is based on adaptions of a convolutional neural network architecture which has been used for image classification and semantic segmentation. The motivation is that dilated convolution supports exponentially expanding receptive fields without losing resolution or coverage. We implemented multiple dilated convolution layers with variable dilation rates to systematically aggregate multi-scale seismic information. Several tests are shown and demonstrate the improvement of identification accuracy with higher resolution.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132280177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202113141
K. Kayama, H. Mikada, J. Takekawa, S. Xu
Summary Fluid channels generated in the annulus of incompletely cemented cased holes are problematic in developing oil, gas, or geothermal resources. The dispersion curves of borehole modes in sonic logging bring additional information on the cement bonding conditions to cement bond logs. Our research investigated the effects of the different central arc angles of a fluid channel in the annulus of a cased borehole on the dispersion curves using numerical experiments. Synthetic 3D numerical models are used to simulate wave propagation. We used a modified matrix pencil algorithm to estimate the dispersion curves both in fast and slow formations. Our results indicated that S-wave velocity measurement by flexural dispersion is stable in all cases in fast formation while only possible in the widest arc angle case in slow formation. The monopole can be utilized to detect large fluid channels. Symmetric flexural in monopole response are useful regardless of the source orientation using monopole source. We notice that the slowness of symmetric flexural is sensitive to the small angle of the fluid channel but not for the large angle case. Moreover, symmetric flexural gives a valuable response to determine fluid layer thickness that is not depending on the fluid position.
{"title":"Effect of the azimuthal fluid channel in a cased borehole on multipole dispersions","authors":"K. Kayama, H. Mikada, J. Takekawa, S. Xu","doi":"10.3997/2214-4609.202113141","DOIUrl":"https://doi.org/10.3997/2214-4609.202113141","url":null,"abstract":"Summary Fluid channels generated in the annulus of incompletely cemented cased holes are problematic in developing oil, gas, or geothermal resources. The dispersion curves of borehole modes in sonic logging bring additional information on the cement bonding conditions to cement bond logs. Our research investigated the effects of the different central arc angles of a fluid channel in the annulus of a cased borehole on the dispersion curves using numerical experiments. Synthetic 3D numerical models are used to simulate wave propagation. We used a modified matrix pencil algorithm to estimate the dispersion curves both in fast and slow formations. Our results indicated that S-wave velocity measurement by flexural dispersion is stable in all cases in fast formation while only possible in the widest arc angle case in slow formation. The monopole can be utilized to detect large fluid channels. Symmetric flexural in monopole response are useful regardless of the source orientation using monopole source. We notice that the slowness of symmetric flexural is sensitive to the small angle of the fluid channel but not for the large angle case. Moreover, symmetric flexural gives a valuable response to determine fluid layer thickness that is not depending on the fluid position.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122232645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-18DOI: 10.3997/2214-4609.202112997
Y. Nikonenko, M. Charara, M. Spasennykh
Summary A large number of studies have been published on the topic of acoustic wavefield modeling in anisotropic media. All of them are based on the choice of the suitable wave equation for numerical implementation. However, these wave equations are usually cumbersome, have an unclear physical nature, are computationally demanding, and generate artificial pseudo shear modes, which are considered as artifacts in the seismic imaging process. Duveneck and Bakker (2011) derived a system of coupled differential wave equations based on Hooke’s law and equation of motion only. Despite all the advantages, these equations are unstable for a certain configuration of anisotropic parameters and generate S-wave artifacts. Liu et al. (2009) , on the other hand, derived an unconditionally stable single wave equation that turned out to be difficult to model. Moreover, it is responsible only for the P-wave mode. Nikonenko and Charara (2020) have shown that this single wave equation is just one mode for the Duveneck coupled equations and proposed a possible fully explicit scheme for its solution. We continue this approach making the solution optimal and extending it to other cases of anisotropy. Numerical examples illustrate the absence of artifacts and the accuracy of the proposed method.
关于各向异性介质中声波场建模的研究已经发表了大量的论文。所有这些都是基于选择合适的波动方程进行数值实现。然而，这些波动方程通常是繁琐的，具有不明确的物理性质，计算要求高，并产生人为的伪剪切模式，这被认为是地震成像过程中的伪影。Duveneck和Bakker(2011)仅基于胡克定律和运动方程推导了耦合微分波动方程系统。尽管有这些优点，但这些方程在某些各向异性参数配置下是不稳定的，并且会产生s波伪影。另一方面，Liu et al.(2009)推导了一个无条件稳定的单波方程，结果证明该方程很难建模。此外，它只负责p波模式。Nikonenko和Charara(2020)已经证明，该单波方程只是Duveneck耦合方程的一个模态，并提出了其解的可能的全显式格式。我们继续使用这种方法，使解决方案最优，并将其扩展到其他各向异性的情况。数值算例表明该方法不存在伪影，具有较高的精度。
{"title":"Optimized acoustic wavefield modelling in transversely isotropic media","authors":"Y. Nikonenko, M. Charara, M. Spasennykh","doi":"10.3997/2214-4609.202112997","DOIUrl":"https://doi.org/10.3997/2214-4609.202112997","url":null,"abstract":"Summary A large number of studies have been published on the topic of acoustic wavefield modeling in anisotropic media. All of them are based on the choice of the suitable wave equation for numerical implementation. However, these wave equations are usually cumbersome, have an unclear physical nature, are computationally demanding, and generate artificial pseudo shear modes, which are considered as artifacts in the seismic imaging process. Duveneck and Bakker (2011) derived a system of coupled differential wave equations based on Hooke’s law and equation of motion only. Despite all the advantages, these equations are unstable for a certain configuration of anisotropic parameters and generate S-wave artifacts. Liu et al. (2009) , on the other hand, derived an unconditionally stable single wave equation that turned out to be difficult to model. Moreover, it is responsible only for the P-wave mode. Nikonenko and Charara (2020) have shown that this single wave equation is just one mode for the Duveneck coupled equations and proposed a possible fully explicit scheme for its solution. We continue this approach making the solution optimal and extending it to other cases of anisotropy. Numerical examples illustrate the absence of artifacts and the accuracy of the proposed method.","PeriodicalId":265130,"journal":{"name":"82nd EAGE Annual Conference & Exhibition","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115754907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：