GEOPHYSICS最新文献_第6页

Automated litho-fluid and facies classification in well-logs: the Rock Physics perspective 井志中的岩流和岩相自动分类：岩石物理学视角

GEOPHYSICS Pub Date : 2024-04-01 DOI: 10.1190/geo2023-0533.1

R. Beloborodov, James Gunning, M. Pervukhina, Juerg Hauser, M. B. Clennell, Alan Mur, Vladimir Li

{"title":"Automated litho-fluid and facies classification in well-logs: the Rock Physics perspective","authors":"R. Beloborodov, James Gunning, M. Pervukhina, Juerg Hauser, M. B. Clennell, Alan Mur, Vladimir Li","doi":"10.1190/geo2023-0533.1","DOIUrl":"https://doi.org/10.1190/geo2023-0533.1","url":null,"abstract":"While accurate litho-fluid and facies interpretation from wireline log data is critical for applications like joint facies and impedance inversion of seismic data, extracting this information manually is challenging due to the complexity and high dimensionality of the logs. Traditional clustering methods also struggle with litho-fluid type inference due to different depth trends in petrophysical rock properties due to compaction and diagenesis. We introduce a Rock Physics Machine Learning workflow that automates litho-fluid classification and property depth trend modeling to address these challenges. This workflow employs a maximum-likelihood approach, explicitly accounting for depth-related effects via Rock Physics models, to infer litho-fluid types from borehole data. It utilizes a robust Expectation-Maximization algorithm to associate each litho-fluid type with a specific Rock Physics model instance, constrained within physically reasonable bounds. The workflow directly outputs litho-fluid type proportions and type-specific Rock Physics models with associated uncertainties, providing essential prior information for seismic inversion.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140756467","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}

引用次数: 0

Wavefield decomposition for viscoelastic anisotropic media 粘弹性各向异性介质的波场分解

GEOPHYSICS Pub Date : 2024-04-01 DOI: 10.1190/geo2023-0583.1

Qi Hao, I. Tsvankin

引用次数: 0

3D Monte Carlo geometry inversion using gravity data 利用重力数据进行三维蒙特卡洛几何反演

GEOPHYSICS Pub Date : 2024-02-15 DOI: 10.1190/geo2023-0498.1

Xiaolong Wei, Jiajia Sun, Mrinal Sen

{"title":"3D Monte Carlo geometry inversion using gravity data","authors":"Xiaolong Wei, Jiajia Sun, Mrinal Sen","doi":"10.1190/geo2023-0498.1","DOIUrl":"https://doi.org/10.1190/geo2023-0498.1","url":null,"abstract":"Diverse Monte Carlo methods have gained widespread use across a broad range of applications. However, the challenge of 3D Monte Carlo sampling remains due to the curse of dimensionality. To date, only a few works have been published regarding 3D Monte Carlo sampling. This study aims to develop an efficient 3D trans-dimensional Monte Carlo framework for reconstructing the spatial geometry of an anomalous body using gravity data. The proposed framework can also quantify the uncertainty of the shape of an anomalous body recovered from geophysical measurements. To improve the computational efficiency of 3D Monte Carlo sampling, we propose a sparse geometry parameterization strategy. This approach adequately approximates the shape of a complex 3D anomalous body using a set of simple geometries, such as an ellipsoid. Each ellipsoid can be characterized by a few parameters, including the centroid, axes, and orientations, significantly reducing the number of parameters to be sampled. During sampling, we randomly perturb the number, locations, sizes, and orientations of the ellipsoids. To impose prior structural constraints from other geophysical methods, such as seismic imaging, we design a new method by placing a fixed layer oriented along the top boundary of the anomalous body. The fixed layer is then connected to the randomly sampled ellipsoids using an alpha shape, allowing us to estimate the geometry of the anomalous source body. The current work focuses on the reconstruction of salt bodies. We start with a synthetic spherical salt model and then conduct a more realistic study using a simplified 3D SEG/EAGE salt model. Lastly, we apply our method to the Galveston Island salt dome, offshore Texas. The numerical results demonstrate that our framework can effectively recover the shape of an anomalous body and quantify the uncertainty of the reconstructed geometry.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139835232","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}

引用次数: 0

An extended Gauss-Newton method for full waveform inversion 用于全波形反演的扩展高斯-牛顿法

GEOPHYSICS Pub Date : 2024-02-15 DOI: 10.1190/geo2022-0673.1

Ali Gholami

{"title":"An extended Gauss-Newton method for full waveform inversion","authors":"Ali Gholami","doi":"10.1190/geo2022-0673.1","DOIUrl":"https://doi.org/10.1190/geo2022-0673.1","url":null,"abstract":"Full waveform inversion (FWI) is a large-scale nonlinear ill-posed problem for which computationally expensive Newton-type methods can become trapped in undesirable local minima, particularly when the initial model lacks a low-wavenumber component and the recorded data lacks low-frequency content. A modification to the Gauss-Newton (GN) method is proposed to address these issues. The standard GN system for multisource multireceiver FWI is reformulated into an equivalent matrix equation form, with the solution becoming a diagonal matrix rather than a vector as in the standard system. The search direction is transformed from a vector to a matrix by relaxing the diagonality constraint, effectively adding a degree of freedom to the subsurface offset axis. The relaxed system can be explicitly solved with only the inversion of two small matrices that deblur the data residual matrix along the source and receiver dimensions, which simplifies the inversion of the Hessian matrix. When used to solve the extended source FWI objective function, the Extended GN (EGN) method integrates the benefits of both model and source extension. The EGN method effectively combines the computational effectiveness of the reduced FWI method with the robustness characteristics of extended formulations and offers a promising solution for addressing the challenges of FWI. It bridges the gap between these extended formulations and the reduced FWI method, enhancing inversion robustness while maintaining computational efficiency. The robustness and stability of the EGN algorithm for waveform inversion are demonstrated numerically.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139834921","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}

引用次数: 0

TWO-DIMENSIONAL IMAGING OF ELASTIC PROPERTIES OF ROCK CORE SAMPLES FROM MEASUREMENTS OF ANGLE-DEPENDENT ULTRASONIC REFLECTION COEFFICIENTS 通过测量随角度变化的超声波反射系数对岩心样品的弹性特性进行二维成像

GEOPHYSICS Pub Date : 2024-02-15 DOI: 10.1190/geo2023-0505.1

Daria Olszowska, Gabriel Gallardo-Giozza, C. Torres‐Verdín

{"title":"TWO-DIMENSIONAL IMAGING OF ELASTIC PROPERTIES OF ROCK CORE SAMPLES FROM MEASUREMENTS OF ANGLE-DEPENDENT ULTRASONIC REFLECTION COEFFICIENTS","authors":"Daria Olszowska, Gabriel Gallardo-Giozza, C. Torres‐Verdín","doi":"10.1190/geo2023-0505.1","DOIUrl":"https://doi.org/10.1190/geo2023-0505.1","url":null,"abstract":"Laboratory and field measurements often fail to identify small-scale variations in rock elastic properties. Due to limited spatial resolution, conventional laboratory methods cannot properly describe rock formations exhibiting a high degree of heterogeneity, thereby masking differences between stiff and compliant layers. Continuous sample measurements can mitigate this problem but are not widely used by the industry. We build upon our previous work and apply laboratory angle-dependent ultrasonic reflection coefficient (ADURC) measurements to achieve detailed two-dimensional descriptions of the elastic properties of complex rock samples. This method successfully yields high-resolution information on P- and S-wave velocities, as well as bulk density, across the surface of rock samples. Elastic properties are estimated using a nonlinear inversion algorithm that matches laboratory measurements with numerical simulations. Angle-dependent ultrasonic reflection coefficient data acquired at various sample locations enable detailed rock descriptions, where the effective measurement area is determined by the size of the receiver, measurement frequency, and incidence angle. Consequently, the sampling area is smaller compared to triaxial loading and acoustic transmission tests, where the resolution is controlled by sample size. Measurements conducted on samples exhibiting different levels of spatial complexity validate the capability of the ADURC method to identify small-scale heterogeneities. For the reported experiments, variations in angle-dependent reflectivity give rise to corresponding variations in the estimated P- and S-wave velocities and density which can exceed 60%. These small-scale variations across heterogeneous rock samples are often overlooked by conventional laboratory methods.#xD;#xD;","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139835439","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}

引用次数: 0

TWO-DIMENSIONAL IMAGING OF ELASTIC PROPERTIES OF ROCK CORE SAMPLES FROM MEASUREMENTS OF ANGLE-DEPENDENT ULTRASONIC REFLECTION COEFFICIENTS 通过测量随角度变化的超声波反射系数对岩心样品的弹性特性进行二维成像

GEOPHYSICS Pub Date : 2024-02-15 DOI: 10.1190/geo2023-0505.1

Daria Olszowska, Gabriel Gallardo-Giozza, C. Torres‐Verdín

{"title":"TWO-DIMENSIONAL IMAGING OF ELASTIC PROPERTIES OF ROCK CORE SAMPLES FROM MEASUREMENTS OF ANGLE-DEPENDENT ULTRASONIC REFLECTION COEFFICIENTS","authors":"Daria Olszowska, Gabriel Gallardo-Giozza, C. Torres‐Verdín","doi":"10.1190/geo2023-0505.1","DOIUrl":"https://doi.org/10.1190/geo2023-0505.1","url":null,"abstract":"Laboratory and field measurements often fail to identify small-scale variations in rock elastic properties. Due to limited spatial resolution, conventional laboratory methods cannot properly describe rock formations exhibiting a high degree of heterogeneity, thereby masking differences between stiff and compliant layers. Continuous sample measurements can mitigate this problem but are not widely used by the industry. We build upon our previous work and apply laboratory angle-dependent ultrasonic reflection coefficient (ADURC) measurements to achieve detailed two-dimensional descriptions of the elastic properties of complex rock samples. This method successfully yields high-resolution information on P- and S-wave velocities, as well as bulk density, across the surface of rock samples. Elastic properties are estimated using a nonlinear inversion algorithm that matches laboratory measurements with numerical simulations. Angle-dependent ultrasonic reflection coefficient data acquired at various sample locations enable detailed rock descriptions, where the effective measurement area is determined by the size of the receiver, measurement frequency, and incidence angle. Consequently, the sampling area is smaller compared to triaxial loading and acoustic transmission tests, where the resolution is controlled by sample size. Measurements conducted on samples exhibiting different levels of spatial complexity validate the capability of the ADURC method to identify small-scale heterogeneities. For the reported experiments, variations in angle-dependent reflectivity give rise to corresponding variations in the estimated P- and S-wave velocities and density which can exceed 60%. These small-scale variations across heterogeneous rock samples are often overlooked by conventional laboratory methods.#xD;#xD;","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139775697","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}

引用次数: 0

3D Monte Carlo geometry inversion using gravity data 利用重力数据进行三维蒙特卡洛几何反演

GEOPHYSICS Pub Date : 2024-02-15 DOI: 10.1190/geo2023-0498.1

Xiaolong Wei, Jiajia Sun, Mrinal Sen

{"title":"3D Monte Carlo geometry inversion using gravity data","authors":"Xiaolong Wei, Jiajia Sun, Mrinal Sen","doi":"10.1190/geo2023-0498.1","DOIUrl":"https://doi.org/10.1190/geo2023-0498.1","url":null,"abstract":"Diverse Monte Carlo methods have gained widespread use across a broad range of applications. However, the challenge of 3D Monte Carlo sampling remains due to the curse of dimensionality. To date, only a few works have been published regarding 3D Monte Carlo sampling. This study aims to develop an efficient 3D trans-dimensional Monte Carlo framework for reconstructing the spatial geometry of an anomalous body using gravity data. The proposed framework can also quantify the uncertainty of the shape of an anomalous body recovered from geophysical measurements. To improve the computational efficiency of 3D Monte Carlo sampling, we propose a sparse geometry parameterization strategy. This approach adequately approximates the shape of a complex 3D anomalous body using a set of simple geometries, such as an ellipsoid. Each ellipsoid can be characterized by a few parameters, including the centroid, axes, and orientations, significantly reducing the number of parameters to be sampled. During sampling, we randomly perturb the number, locations, sizes, and orientations of the ellipsoids. To impose prior structural constraints from other geophysical methods, such as seismic imaging, we design a new method by placing a fixed layer oriented along the top boundary of the anomalous body. The fixed layer is then connected to the randomly sampled ellipsoids using an alpha shape, allowing us to estimate the geometry of the anomalous source body. The current work focuses on the reconstruction of salt bodies. We start with a synthetic spherical salt model and then conduct a more realistic study using a simplified 3D SEG/EAGE salt model. Lastly, we apply our method to the Galveston Island salt dome, offshore Texas. The numerical results demonstrate that our framework can effectively recover the shape of an anomalous body and quantify the uncertainty of the reconstructed geometry.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139775712","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}

引用次数: 0

An extended Gauss-Newton method for full waveform inversion 用于全波形反演的扩展高斯-牛顿法

GEOPHYSICS Pub Date : 2024-02-15 DOI: 10.1190/geo2022-0673.1

Ali Gholami

{"title":"An extended Gauss-Newton method for full waveform inversion","authors":"Ali Gholami","doi":"10.1190/geo2022-0673.1","DOIUrl":"https://doi.org/10.1190/geo2022-0673.1","url":null,"abstract":"Full waveform inversion (FWI) is a large-scale nonlinear ill-posed problem for which computationally expensive Newton-type methods can become trapped in undesirable local minima, particularly when the initial model lacks a low-wavenumber component and the recorded data lacks low-frequency content. A modification to the Gauss-Newton (GN) method is proposed to address these issues. The standard GN system for multisource multireceiver FWI is reformulated into an equivalent matrix equation form, with the solution becoming a diagonal matrix rather than a vector as in the standard system. The search direction is transformed from a vector to a matrix by relaxing the diagonality constraint, effectively adding a degree of freedom to the subsurface offset axis. The relaxed system can be explicitly solved with only the inversion of two small matrices that deblur the data residual matrix along the source and receiver dimensions, which simplifies the inversion of the Hessian matrix. When used to solve the extended source FWI objective function, the Extended GN (EGN) method integrates the benefits of both model and source extension. The EGN method effectively combines the computational effectiveness of the reduced FWI method with the robustness characteristics of extended formulations and offers a promising solution for addressing the challenges of FWI. It bridges the gap between these extended formulations and the reduced FWI method, enhancing inversion robustness while maintaining computational efficiency. The robustness and stability of the EGN algorithm for waveform inversion are demonstrated numerically.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139775365","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}

引用次数: 0

Revisiting two notable methods for improving the deblending performance of marine towed-streamer acquisition 重新审视改善海洋拖曳流媒体购置的拆借性能的两种显著方法

GEOPHYSICS Pub Date : 2024-02-14 DOI: 10.1190/geo2022-0621.1

Yangkang Chen, Min Zhou, Ray Abma

{"title":"Revisiting two notable methods for improving the deblending performance of marine towed-streamer acquisition","authors":"Yangkang Chen, Min Zhou, Ray Abma","doi":"10.1190/geo2022-0621.1","DOIUrl":"https://doi.org/10.1190/geo2022-0621.1","url":null,"abstract":"Marine towed-streamer blended data are usually challenging to deblend because of the low dimensionality of the data. While the present ocean-bottom-cable (OBC) surveys produce well-sampled 3D receiver gathers, towed-streamer data have a lower sparsity in the transformed f - k domain. Here, we revisit two practical strategies to improve deblending performance. In the first strategy, we revisit applying 3D deblending to 2D surveys, which considers the shot domain as a sparsity-constrained domain. We compare the sparseness of the 2D and 3D FFT transformed domains by drawing the coefficients decaying curves. The 3D FFT transformed domain is much sparser than the 2D FFT transformed domain, according to the sparseness comparison. Thus, 3D deblending can obtain better performance than 2D deblending. In the second strategy, we revisit an improved deblending approach that combines traditional deblending and popcorn reconstruction, and other methods of coding sources. The popcorn shooting technique adds an extra level of constraint to the inversion because each source is coded with a different popcorn pattern. Thus, when deblending, convolution and deconvolution for each source with a predefined popcorn pattern will attenuate the interference that does not belong to the selected source. For both scenarios revisited here, we use both synthetic and field data examples with different complexity to demonstrate their superior performance.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139837584","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}

引用次数: 0

Revisiting two notable methods for improving the deblending performance of marine towed-streamer acquisition 重新审视改善海洋拖曳流媒体购置的拆借性能的两种显著方法

GEOPHYSICS Pub Date : 2024-02-14 DOI: 10.1190/geo2022-0621.1

Yangkang Chen, Min Zhou, Ray Abma

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引用次数: 0