GEOPHYSICS最新文献

{"title":"Highest-Resolution High-Signal-to-Noise Ratio Sonic Slowness and Application to Brothers Volcano, Kermadec Arc, New Zealand","authors":"Song Xu","doi":"10.1190/geo2023-0347.1","DOIUrl":"https://doi.org/10.1190/geo2023-0347.1","url":null,"abstract":"High-resolution and accurate acquisition of underground sonic properties is essential for energy detection and earth exploration. An effective method is proposed to accurately calculate sonic slowness at the highest resolution (receiver spacing of 0.5 ft) with high signal-to-noise ratio (S/N) ratio. The method utilizes super-virtual interferometry to reconstruct a large number of waveforms for slowness extraction using redundant information from overlapping inter-receiver spacing. Synthetic calculations are used to verify the validity of the method, especially in the case of strong noise interference and the presence of damaged channels in the array receivers, to accurately calculate the formation sonic slowness. The theory is applied to process and interpret low data-quality field measurements acquired at Brothers Volcano from the International Ocean Discovery Program (IODP). The processing analysis shows that in the case of very weak formation signals, the residual tool waves from the wireline sonic logging can still interfere with the high-resolution processing, while this method can effectively suppress this interference and accurately obtain the formation sonic velocity.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139593499","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}

{"title":"A new method for estimation of Rayleigh wave group velocity spectrum","authors":"Jiazhe Li, Xianhai Song, Xueqiang Zhang, Shichuan Yuan, Limin Wang, Kai Zhang","doi":"10.1190/geo2023-0458.1","DOIUrl":"https://doi.org/10.1190/geo2023-0458.1","url":null,"abstract":"Shear-wave velocity is commonly used to understand the characteristics of the subsurface, which can be retrieved by inverting the phase or group velocity in Rayleigh wave surveys. Now, many studies have shown the advantage of analyzing group velocity over phase velocity to obtain the S-wave velocity. However, previous methods often suffer from poor resolution in estimating group velocity. In order to improve the resolution of the group velocity and reduce uncertainty in extracting dispersion curves, we propose a new method for estimation of the Rayleigh wave group velocity spectrum based on the slant stack and adaptive generalized S-transform with energy reassignment. This method incorporates the adaptive generalized S-transform and the energy reassignment technique to enhance the time-frequency representation, and then calculates the group velocity at each frequency using the slant stack. By conducting experiments with synthetic seismic records, it is evident that the new method has high resolution and accurate multimode group velocity calculations. Furthermore, when applied to a field dataset and synthetic record with noise, the method shows better results and noise robustness. This confirms the superior performance of the method at generating high-resolution dispersion images of the group velocity compared to previous approaches. The method will become an efficient tool in Rayleigh wave exploration.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139594962","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}

{"title":"To: “From classical reflectivity-to-velocity inversion to full-waveform inversion using phase-modified and deconvolved reverse time migration images,” Chen Tang and George A. McMechan, 2017, GEOPHYSICS, 82, no. 1, S31–S49, https://doi.org/10.1190/geo2016-0033.1.","authors":"Chen Tang, G. McMechan","doi":"10.1190/geo2024-0120-errata.1","DOIUrl":"https://doi.org/10.1190/geo2024-0120-errata.1","url":null,"abstract":"<jats:p> </jats:p>","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139593817","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}

{"title":"Can towed-streamer seismic data be used for elastic wave imaging? Synthetic and field data examples","authors":"Rui Gong, Jianhua Geng, P. Yu, Xueying Hu","doi":"10.1190/geo2022-0534.1","DOIUrl":"https://doi.org/10.1190/geo2022-0534.1","url":null,"abstract":"In marine seismic exploration, towed-streamer seismic data acquisition stands out as a prevalent and economical approach. This data records scalar pressure and captures P waves including those that are converted from sub-seabed S waves. Theoretically, towed-streamer seismic data can be used to reconstruct S-wave fields for elastic wave imaging via backward extrapolation. Our research applies an acoustic-elastic coupled equation that includes a pressure term to perform elastic reverse time migration, using the pressure seismic data as the boundary condition for backward extrapolation. The feasibility of employing towed-streamer seismic data for elastic wave imaging of complex subsurface structures is confirmed through synthetic and field data examples. The investigation demonstrates how the smoothness of velocity and density models impacts the quality of elastic reverse time migration using towed-streamer seismic data. We find that using smooth velocity and density models for elastic wave imaging can enhance imaging quality by utilizing transmitted S waves. Furthermore, certain nonphysical S waves generated during backward extrapolation can contribute to PS images, as evidenced by a synthetic data example. Overall, the results indicate that the towed-streamer seismic data for elastic wave imaging has potential in marine seismic exploration. Moving forward, it is crucial to focus on refining the quality of PS images and reducing artifacts caused by the backward extrapolated nonphysical waves.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139595697","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}

{"title":"Bayesian joint inversion of seismic and electromagnetic data for reservoir litho-fluid facies including geophysical and petrophysical rock properties","authors":"J. Crepaldi, L. D. de Figueiredo, Andrea Zerilli, Ivan S. Oliveira, J. Sinnecker","doi":"10.1190/geo2022-0546.1","DOIUrl":"https://doi.org/10.1190/geo2022-0546.1","url":null,"abstract":"A Bayesian approach is proposed to estimate litho-fluid facies and other rock properties conditioned on seismic and electromagnetic data for reservoir characterization. Prior distributions are assumed to be facies-related Gaussian modes of geophysical rock properties directly acquired or converted from petrophysical properties by calibrated rock physics modeling. An original generalization includes two distributions in the same marginalization integral, analytically solved under a linearized Gaussian assumption to provide a facies model likelihood conditioned on geophysical data. Since computing this probability for all possible facies configurations may be impractical, a Markov Chain Monte Carlo algorithm efficiently samples models to provide a full posterior distribution. The linearized Gaussian approach allows the computation of the conditional distributions of geophysical and petrophysical rock properties by applying local deterministic inversions over the many sampled facies models. The inversion uses simulated geophysical data from a 1D synthetic model based on the geological scenario and a well from a selected marine oil field. Two other wells from the same reservoir were used to gather prior distributions. Data from the well, calibration of the rock physics modeling, and facies matching between the priors and the synthetic model are presented and discussed. Numerical tests validate nonlinear forward modeling adaptations on the assumed linearized Gaussian approach. The simulated stand-alone and joint geophysical datasets are then inverted for litho-fluid facies models under different prior inputs. Two challenging geoelectric scenarios were also tested, one with lower resistivity contrasts and another with a misguided background model. All results demonstrate a gain in precision and accuracy when associating both geophysical signals to estimate the oil column. Facies-conditioned inversions for the rock properties also show potential for quantitative reservoir interpretations.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139596995","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}

{"title":"Random noise attenuation of 3D multi-component seismic data using fast adaptive prediction filter","authors":"Zhiyong Wang, Guochang Liu, Chao Li, Lanting Shi, Zixu Wang","doi":"10.1190/geo2023-0195.1","DOIUrl":"https://doi.org/10.1190/geo2023-0195.1","url":null,"abstract":"Random noise in seismic records affects the accuracy of effective signal identification, making it difficult for subsequent seismic data processing, imaging, and interpretation. Therefore, random noise attenuation has always been an important step in seismic data processing, especially for 3D data. In recent years, multi-component exploration has been developed rapidly. However, the common method for processing multi-component data is to process each component separately resulting in the correlation between multi-component data being neglected. For 3D multi-component data, we propose a multi-component adaptive prediction filter (MAPF) based on noncausal regularized nonstationary autoregressive models to implement random noise attenuation in the t- x- y domain. The MAPF for multi-component signals can be used to identify the potential correlations and differences between each pair of components, providing not only a robust analysis of individual components but also effective information about the consistency and differences between each component with more information and constraints compared to traditional single-component prediction. Moreover, it can obtain smooth non-stationary prediction coefficients by solving the least squares problem with shaping regularization. The example results demonstrate that the MAPF method is superior to the traditional adaptive prediction filtering (APF) method. Furthermore, since the multi-component method requires more coefficients and takes longer time to predict than the single-component method, we further propose a fast multi-component adaptive prediction filter (FMAPF) combining the data pooling and coefficient reconstruction strategies. The example results demonstrate that the FMAPF method is effective at denoising and greatly improves computational efficiency. The method comes with a slight decrease in computational accuracy.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139596483","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}

{"title":"Geophysics Dissertation Abstracts","authors":"","doi":"10.1190/geo2024-0118-geodis.1","DOIUrl":"https://doi.org/10.1190/geo2024-0118-geodis.1","url":null,"abstract":"Geophysics publishes abstracts of dissertations and titles of master’s theses in print and online. Recent graduates are invited to submit their abstracts or titles by completing and submitting the appropriate form found at http://seg.org/dissertationabstracts . Abstracts and titles will be reviewed and accepted or rejected based on their relevance to the readers of Geophysics. Abstracts must be written in English and defended in 2020 or later.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139600476","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}

{"title":"Dispersion and attenuation characteristics of obliquely incident SV wave in a fluid-saturated porous rock containing aligned penny-shaped fractures","authors":"Wenhao Wang, Shengqing Li, Junxin Guo, Long Zhao, Shangjing Guo, Yuanda Su, Xiao-Ming Tang","doi":"10.1190/geo2023-0170.1","DOIUrl":"https://doi.org/10.1190/geo2023-0170.1","url":null,"abstract":"Owing to the complex structural characteristics of aligned fractured rocks with a fluid-saturated porous background, many existing single-wave attenuation mechanism models cannot accurately characterize measuring multiband SV wave data. Moreover, the coupled effect of wave-induced fluid flow between fractures and the background (FB-WIFF) and elastic scattering (ES) from the fractures leads to ambiguity in the elastic response of the SV wave. Using Biot’s theory and mixed boundary constraints, we derived exact solutions to the scattering problem for a single penny-shaped fracture with an oblique incident SV wave. Furthermore, we developed a theoretical model for a set of aligned fractures by using Foldy's scheme. The numerical results showed that the FB-WIFF, ES of fractures, and their coupling effects were mainly responsible for wave dispersion and attenuation. The FB-WIFF occurs primarily in the low-frequency seismic exploration frequency band, whereas the ES of the fracture surface depends on the relationship between the wavelength and fracture size. In addition, we validated the accuracy and effectiveness of our model by comparing it with an existing interpolation approximation model and previous experimental measurements. The analysis results of this work can explain the acoustic response of SV wave experimental data in different frequency bands and theoretically support fracture detection and characterization.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139605084","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}

{"title":"Time-Frequency Phase Retrieval for Deconvolutive Short-Time Fourier Transform","authors":"Mohsen Kazemnia Kakhki, Ahmadreza Mokhtari, W. Mansur","doi":"10.1190/geo2023-0563.1","DOIUrl":"https://doi.org/10.1190/geo2023-0563.1","url":null,"abstract":"Cohen class distributions are well-known time-frequency distributions that have been widely used to analyze different signals. However, they are impractical for signal filtering as they only provide amplitude spectra and suffer from cross-term. In this paper, deconvolutive STFT (DSTFT) is developed by estimating phase spectra and updating moduli to address residual cross-terms. We use DSTFT moduli as weights and apply a weighted least squares technique to estimate a high-resolution and almost cross-term-free Wigner-Ville distribution. Through numerical tests, we demonstrate that choosing the optimal window length can minimize cross-terms in STFT and DSTFT spectrograms, and employing thresholding or re-weighting techniques can eliminate weights associated with noise. The performance of the proposed method is demonstrated using synthetic and two real seismic wavefield separation problems, including ground roll removal in seismic shot records and polarization analysis in seismology. The results show the high performance of the proposed method in estimating phase spectra and filtering seismic data.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139604216","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}

{"title":"HTI ANISOTROPY PARAMETERS INVERSION VIA AZIMUTHAL SEISMIC VELOCITY ANISOTROPY AND ITS APPLICATION TO ANISOTROPIC 3D IN-SITU STRESS ESTIMATION","authors":"Huan Cao, Yang Zhao, Chenggang Xian, Hengyu Tang, Lanlan Yan, Da Shuai, Lele Zhang, Yinghao Shen, Shichang Li","doi":"10.1190/geo2023-0377.1","DOIUrl":"https://doi.org/10.1190/geo2023-0377.1","url":null,"abstract":"The anisotropic parameters inversion in horizontal transverse isotropy (HTI) medium plays an important role in predicting the fracture density as well as the anisotropic in-situ stress for unconventional reservoirs. The current industry practice is to use the azimuthal PP-wave reflection coefficient to estimate the HTI anisotropic parameters. Based on the linear slip theory, this study adapts azimuthal P-wave phase velocity to calculate the HTI anisotropic parameters and demonstrates superiority against the conventional azimuthal PP-wave reflection coefficient. Specifically, we first verify that the azimuthal P-wave phase velocity is more feasible for the HTI elliptical fitting rather than the azimuthal PP-wave reflection coefficient due to the analytical formulations. Second, we sort the prestack wide-azimuth (WAZ) data into offset vector tile (OVT) sectors and perform the AVO (Amplitude Versus Offset) inversion at each azimuth. Third, the elliptical fitting is applied to the obtained azimuthal P-wave phase velocities to estimate the HTI anisotropic parameters, fracture density, and fracture direction. Fourth, based on the HTI mechanical earth model (MEM), we formulate the 3D in-situ stress as a function of the obtained elastic parameters and fracture compliance, which exhibits a potential for computational efficiency. Finally, field examples from the Zhaotong area, China demonstrate that the estimated fracture density and anisotropic in-situ stress present high accuracy and resolution compared with conventional methods. The dominant stress regime in the study area is a strike-slip faulting regime with a governing orientation of NE-SW and presents good alignments with well logs, which demonstrates the reliability and accuracy of our proposed method for predicting fracture density and anisotropic in-situ stress.","PeriodicalId":509604,"journal":{"name":"GEOPHYSICS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139606773","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}