Leading Edge最新文献

{"title":"Can elastic waveform inversion benefit from inverting multicomponent data?","authors":"C. P. Solano, R. Plessix","doi":"10.1190/tle42030184.1","DOIUrl":"https://doi.org/10.1190/tle42030184.1","url":null,"abstract":"Waveform inversion aims to retrieve high-resolution earth parameter volumes. Due to its high computational cost, acoustic approaches using low to mid seismic data frequencies are often applied in velocity model building. However, in the presence of large parameter contrasts, an elastic formulation should be preferred due to wave interferences that limit the applicability of phase- and kinematics-only approaches. The benefits of elastic waveform inversion have been demonstrated with inversion of hydrophone data in marine environments. Here, we extend the approach to inversion of the vertical geophone component. We propose a weighted cost function in the waveform inversion algorithm to jointly invert multicomponent data sets, and we compare the results to the inversion of single-component data. For this study, we use an ocean-bottom-node data set from the deepwater Gulf of Mexico around a salt dome. We show that slightly different velocity models, reverse time migration images, and angle gathers are retrieved when using hydrophone or vertical geophone data, further improving either the shallow or deeper sediments. The joint inversion combines the improvements brought by the single-component inversions. Though it doubles the cost, joint elastic waveform inversion of hydrophone and vertical geophone data can help velocity model building around salt bodies.","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45589729","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":"Is 3D frequency-domain FWI of full-azimuth/long-offset OBN data feasible? The Gorgon data FWI case study","authors":"S. Operto, P. Amestoy, H. Aghamiry, S. Beller, A. Buttari, L. Combe, V. Dolean, M. Gerest, G. Guo, P. Jolivet, J. L’Excellent, F. Mamfoumbi, T. Mary, C. Puglisi, A. Ribodetti, Pierre-Henri Tournier","doi":"10.1190/tle42030173.1","DOIUrl":"https://doi.org/10.1190/tle42030173.1","url":null,"abstract":"Frequency-domain full-waveform inversion (FWI) is potentially amenable to efficient processing of full-azimuth long-offset stationary-recording seabed acquisition carried out with a sparse layout of ocean-bottom nodes (OBNs) and broadband sources because the inversion can be performed with a few discrete frequencies. However, computing the solution of the forward (boundary-value) problem efficiently in the frequency domain with linear algebra solvers remains a challenge for large computational domains involving tens to hundreds of millions of parameters. We illustrate the feasibility of 3D frequency-domain FWI with a subset of the 2015/2016 Gorgon OBN data set in the North West Shelf, Australia. We solve the forward problem with the massively parallel multifrontal direct solver MUMPS, which includes four key features to reach high computational efficiency: an efficient parallelism combining message-passing interface and multithreading, block low-rank compression, mixed-precision arithmetic, and efficient processing of sparse sources. The Gorgon subdata set involves 650 OBNs that are processed as reciprocal sources and 400,000 sources. Monoparameter FWI for vertical wavespeed is performed in the viscoacoustic vertically transverse isotropic approximation with a classical frequency continuation approach proceeding from a starting frequency of 1.7 Hz to a final frequency of 13 Hz. The target covers an area ranging from 260 km2 (frequency ≥ 8.5 Hz) to 705 km2 (frequency ≤ 8.5 Hz) for a maximum depth of 8 km. Compared to the starting model, FWI dramatically improves the reconstruction of the bounding faults of the Gorgon horst at reservoir depths as well as several intrahorst faults and several horizons of the Mungaroo Formation down to a depth of 7 km. Seismic modeling reveals a good kinematic agreement between recorded and simulated data, but amplitude mismatches between the recorded and simulated reflection from the reservoir suggest elastic effects. Therefore, future works involve multiparameter reconstruction for density and attenuation before considering elastic FWI from hydrophone and geophone data.","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48431740","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":"President's Page: What does SEG mean to you?","authors":"Jim White","doi":"10.1190/tle42030150.1","DOIUrl":"https://doi.org/10.1190/tle42030150.1","url":null,"abstract":"President Ken Tubman invited staff to share its perspective as SEG continues its transformation. Having been a member and industry stakeholder leader for many years and executive director (ED) for more than two years now, I am honored to represent this hard-working group of individuals. This invitation led me to consider how people view the Society that we serve as employees.","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46031822","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":"Gas-hydrate interpretation from 3D seismic attributes: An example from the Gulf of Mexico","authors":"N. Nenov, V. Machado, S. Sukmono, Eriwaldo Teixeira","doi":"10.1190/tle42030216.1","DOIUrl":"https://doi.org/10.1190/tle42030216.1","url":null,"abstract":"Gas hydrates are a recognized drilling geohazard. If not mitigated, they may result in plugged blowout preventors, gas kicks, blowouts, borehole instability, gas leaks outside casings, and inadequate cementing operations. Gas hydrates located within the gas-hydrate stability zone (GHSZ) are difficult to interpret solely from seismic amplitudes. In this paper, we apply a multifaceted approach using the velocity pullup method in combination with 3D visualization of seismic attributes for the interpretation of gas hydrates within the GHSZ. The approach is applied to an area in the eastern part of the Gulf of Mexico in water depths greater than 2400 m. The practical outcome of this study is the choice of safe drilling locations outside of areas where gas hydrates have been interpreted to be present.","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48073453","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":"UAV magnetics over the Bjerkreim-Sokndal Intrusion, Rogaland, Norway: A first look","authors":"Madeline Lee, Y. Madriz, R. Gloaguen, S. McEnroe","doi":"10.1190/tle42020090.1","DOIUrl":"https://doi.org/10.1190/tle42020090.1","url":null,"abstract":"The Bjerkreim-Sokndal layered intrusion in Rogaland Anorthosite Province in southwestern Norway has been the focus of decades of research due to its complex geology, the presence of prominent remanent magnetic anomalies, and current economic interest in critical minerals. In 2021, collaborative geophysical fieldwork was conducted by the Norwegian University of Science and Technology and Helmholtz Institute Freiberg for Resource Technology. Despite challenging environmental conditions, more than 100 line-km of magnetic data were collected by a custom multirotor unmanned aerial vehicle (UAV) along the eastern margin of the Bjerkreim lobe of the Bjerkreim-Sokndal Intrusion. Data collection was focused over two areas. The first is an area in the south near the prominent Heskestad magnetic anomaly that is associated with large reversed magnetic remanence in a magnetite-ilmenite-gabbronorite unit. The second is an area in the north near Lake Teksevatnet that hosts mineralized zones and the Lauvneset magnetic anomaly. Initial analysis of the UAV-acquired magnetic data shows additional details on the geologic contacts of key units, especially where in-situ measurements are difficult to collect. UAV surveys help in the construction of an anomaly's geometry through incremental source-sensor separations at various flight altitudes above ground. The UAV data set is an intermediate step between ground and airborne surveys for multiscale interpretation and potentially extreme magnetic scales (from microscopic to planetary).","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42779605","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":"Utilizing UAV-based hyperspectral imaging to detect surficial explosive ordnance","authors":"Madison Tuohy, Jasper Baur, Gabriel Steinberg, Jalissa Pirro, Taylor Mitchell, A. Nikulin, John Frucci, Timothy S. de Smet","doi":"10.1190/tle42020098.1","DOIUrl":"https://doi.org/10.1190/tle42020098.1","url":null,"abstract":"Across postconflict regions of the world, explosive ordnance (EO), which includes remnant antipersonnel land mines, antivehicle/tank mines, unexploded cluster munitions, improvised explosive devices, and explosive remnants of war (ERW) such as unexploded ordnance and abandoned explosive ordnance, remains a critical humanitarian concern. Clearance and land release efforts anchored on manual geophysical detection and mechanical probing methods remain painstakingly slow, expensive, and dangerous to operators. As a result, postconflict regions impacted by EO contamination significantly lag in social and economic development. Developing, calibrating, and field testing more efficient detection methods for surficial EO is a crucial task. Unpiloted aerial systems featuring advanced remote sensing capabilities are a key technology that may allow the tide to turn in the EO crisis. Specifically, recent advances in hardware design have allowed for effective deployment of small, light, and less power consuming hyperspectral imaging (HSI) systems from small unpiloted aerial vehicles (UAVs). Our proof-of-concept study employs UAV-based HSI to deliver a safer, faster, and more cost-efficient method of surface land mine and ERW detection compared to current ground-based detection methods. Our results indicate that analysis of HSI data sets can produce spectral profiles and derivative data products to distinguish multiple ERW and mine types in a variety of host environments.","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45008799","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":"UAV-towed scalar magnetic gradiometry: A case study in relation to iron oxide copper-gold mineralization, Nautanen (Arctic Sweden)","authors":"A. Døssing, M. Kolster, T. Rasmussen, J. T. Petersen, Eduardo L. S. da Silva","doi":"10.1190/tle42020103.1","DOIUrl":"https://doi.org/10.1190/tle42020103.1","url":null,"abstract":"Scalar magnetic surveying using unmanned aerial vehicle (UAV) platforms is slowly gaining momentum within geophysical applications. So far, only a handful of studies have dealt with UAV-towed scalar field measurements, while even fewer have considered towed scalar difference measurements (or gradients). In this paper, we demonstrate the possibilities and benefits of deploying precisely positioned noise-minimized UAV-towed scalar transverse horizontal difference (THD) measurements for mineral exploration purposes. UAV-towed gradiometry bird data are presented from the Nautanen area in northern Sweden and compared with ground magnetic surveys. This area is known for its iron oxide copper-gold mineralizations. The UAV survey spans a total area of 2.5 km2. It was covered using an average line spacing of 30 m and a constant flight altitude above ground level of 30 m. High-quality scalar total-field and THD data were collected with a dynamic noise level of the raw scalar data of about ±0.05 nT. Comparison with the ground magnetic data shows a strong correlation between magnetic anomaly lows and highs across the survey areas. A map with new structural information is presented based on subtle magnetic structures identified in discrete derivatives of the total magnetic intensity anomaly and THD data. Such systems may replace high-quality heliborne systems and reduce costs of the geophysical exploration phase. However, mapping with UAV-towed systems is not straightforward. With typical UAV flight speeds of only 10–12 m/s, the wind often disturbs the 3D attitude of the bird during flights. Hence, advanced processing is required to obtain the intended gradients. Similar challenges are less important in surveying, where the survey speed often greatly exceeds the wind speed.","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47447273","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":"Seismic Soundoff: The global water crisis and how to stop it","authors":"A. Geary","doi":"10.1190/tle42020144.1","DOIUrl":"https://doi.org/10.1190/tle42020144.1","url":null,"abstract":"Paul Bauman discusses his Global Sustainability Lecture, “A strategy for improving rural water supply development in Sub-Saharan Africa.” He highlights how water impacts all 17 of the United Nations Sustainable Development Goals. He outlines the impact of 2 billion people living with water stress and how it could reach more than 5 billion in the next 10 years. Bauman also shares why every geoscientist needs to be aware of this crisis, how it impacts their work, and what actions can address the issue.","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47840393","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":"President's Page: Boosting SEG's career development offerings","authors":"A. Small, Ge Jin, M. Capello","doi":"10.1190/tle42020086.1","DOIUrl":"https://doi.org/10.1190/tle42020086.1","url":null,"abstract":"Your SEG is kicking off the new year with some exciting career development initiatives and collaborations with partner societies and supporting companies!","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48506927","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":"Introduction to this special section: Drone geophysics","authors":"C. Walter, Timothy S. de Smet, H. Bedle","doi":"10.1190/tle42020088.1","DOIUrl":"https://doi.org/10.1190/tle42020088.1","url":null,"abstract":"Technological advancements in geophysical sensors and sensor platforms over the past decade have given rise to the rapidly growing and innovative field of drone-based geophysics. As improvements in reliability, payload capacity, coverage capability, resolution, data quality, cost, and personnel safety continue to be realized, the widespread application of drone geophysics marks an exciting new era of innovation in near-surface geophysics. Since July 2017, when the first special section on drone geophysics was published in The Leading Edge, we have witnessed the rapid development and expansion of this applied-geophysics subfield to a point where there are now entire annual conferences, such as the SEG Summit on Drone Geophysics founded in 2020, dedicated to its continued advancement. Increasingly, it has become clear that drone geophysics is here to stay and is one of the most influential, widespread, and game-changing technology advancements in applied geophysics in recent years.","PeriodicalId":35661,"journal":{"name":"Leading Edge","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44322683","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}