Large-scale controlled-source electromagnetic (CSEM) three-dimensional (3D) geophysical imaging is now receiving considerable attention for electrical-conductivity mapping of potential off shore oil and gas reservoirs. To cope with the typically large computational requirements of the 3D CSEM imaging problem, our strategies exploit computational parallelism and optimized finite-difference meshing. We report on an imaging experiment utilizing 32,768 tasks (and processors) on the IBM Blue Gene/L™ (BG/L) supercomputer at the IBM T. J. Watson Research Center. Over a 24-hour period, we were able to image a large-scale marine CSEM field dataset that previously required more than 4 months of computing time on distributed clusters utilizing 1,024 tasks on an InfiniBand® fabric. The total initial data-fitting errors (i.e., "misfits") could be decreased by 67% within 72 completed inversion iterations, indicating the existence of an electrically resistive region in the southern survey area below a depth of 1,500 m underneath the seafloor. The major part of the residual misfit stems from transmitter-parallel receiver components that have an offset from the transmitter sail line (broadside configuration). Modeling confirms that improved broadside data fits can be achieved by considering anisotropic electrical conductivities. While delivering a satisfactory gross-scale image for the depths of interest, the experiment provides important evidence for the necessity of discriminating between horizontal and vertical conductivities for maximally consistent 3D CSEM inversions.

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2008Inversion study of a large marine CSEM surveyAuthors: J. J. CarazzoneT. A. DickensK. E. GreenC. JingL. A. WahrmundD. E. WillenM. CommerG. A. NewmanJ. J. CarazzoneExxonMobil Upstream Research CompanySearch for more papers by this author, T. A. DickensExxonMobil Upstream Research CompanySearch for more papers by this author, K. E. GreenExxonMobil Upstream Research CompanySearch for more papers by this author, C. JingExxonMobil Upstream Research CompanySearch for more papers by this author, L. A. WahrmundExxonMobil Upstream Research CompanySearch for more papers by this author, D. E. WillenExxonMobil Upstream Research CompanySearch for more papers by this author, M. CommerLawrence Berkeley National LaboratorySearch for more papers by this author, and G. A. NewmanLawrence Berkeley National LaboratorySearch for more papers by this authorhttps://doi.org/10.1190/1.3063733 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract The Brazil RC Marine CSEM survey was collected in April of 2004 for the ExxonMobil Remote Reservoir Resistivity Mapping (R3M) Project. The portion of the survey reported here consisted of a total of 735 km of transmitter towlines arranged approximately on a 5 km × 5 km rectangular grid (see Figure 1). Vertical and horizontal electric field measurements were recovered at a total of 23 seafloor locations from a deployment of 36 seafloor instruments. Imaging of these CSEM data into full three‐dimensional conductivity volumes represents a formidable challenge due to the subtle effects of reservoir targets, the volume of data and its large dynamic range. In this presentation, we report on an initial round of inversion results obtained using both isotropic and anisotropic (VTI) imaging methods. Our results support the need for an anisotropic model to accurately represent subsurface resistivity.Permalink: https://doi.org/10.1190/1.3063733FiguresReferencesRelatedDetailsCited byInterpretations and Modeling1 April 2017A Review of High-Performance Computational Strategies for Modeling and Imaging of Electromagnetic Induction Data29 November 2013 | Surveys in Geophysics, Vol. 35, No. 1Ten years of marine CSEM for hydrocarbon explorationSteven Constable14 September 2010 | GEOPHYSICS, Vol. 75, No. 5Imaging CSEM data in the presence of electrical anisotropyGregory A. Newman, Michael Commer, and James J. Carazzone5 April 2010 | GEOPHYSICS, Vol. 75, No. 2Full‐azimuth, anisotropic 3D EM inversion applied to a low‐resistivity pay reservoir with well controlD. Crider, M. Scherrer, T. Pham, J.J. Zach, and M.A. Frenkel21 October 20104. Electrical and Electromagnetic MethodsMichael S. Zhdanov and Steven Constable21 March 20123D CSEM inversion strategy: an example offshore west of GreenlandA. Lovatini, M.D Watts, K. Umbach, and A. Ferster28 April 2014Marine CSEM methods for 3D hydrocarbon field mapping and monitoringJurgen J. Zach, Michael A. Frenkel, Anne-Marit Ostvedt-Ghazi, Patricia de Lugao, and David Ridyard28 April 2014Massively parallel electrical conductivity imaging of the subsurface: Applications to hydrocarbon exploration11 August 2009 | Journal of Physics: Conference Series, Vol. 180Exploration case studies in mature Gulf of Mexico basins using 3D marine CSEMH. Yuan, T. Pham, J.J. Zach, M.A. Frenkel, and D. Ridyard14 October 2009Application of 3D anisotropic CSEM inversion offshore west of GreenlandAndrea Lovatini, M. D. Watts, Kenneth E. Umbach, Arnie Ferster, Steve Patmore, and Jan Stilling14 October 2009Advances in marine Controlled Source Electromagnetic: The Santos Basin Project — BrazilAndrea Zerilli, Tiziano Labruzzo, Marco Polo Buonora, Paulo de Tarso Luiz Menezes, and Luiz Felipe Rodrigues14 October 2009 SEG Technical Program Expanded Abstracts 2008ISSN (print):1052-3812 ISSN (online):1949-4645Copyright: 2008 Pages: 3713 publication data© 2008 Copyright © 2008 Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 15 Dec 2008 CITATION INFORMATION J. J. Carazzone, T. A. Dickens, K. E. Green, C. Jing, L. A. Wahrmund, D. E. Willen, M. Commer, and G. A. Newman, (2008), "Inversion study of a large marine CSEM survey," SEG Technical Program Expanded Abstracts : 644-647. https://doi.org/10.1190/1.3063733 Plain-Language Summary PDF DownloadLoading ...

Marine controlled-source electromagnetic surveying has emerged as a new tool for remotely detecting reservoired hydrocarbons offshore. The technology was pioneered by university and government researchers over the past 25 years, and recently has benefited from development by contractors and the oil industry, including ExxonMobil. When integrated carefully with other geoscience information, primarily seismic, marine CSEM shows promise for adding considerable value in Upstream applications. Remote reservoir resistivity detection and imaging results from a recent ExxonMobil survey demonstrate this technology. Early Marine CSEM Development Offshore CSEM research began in the 1920's with studies of seafloor power cables, and saw the first commercial minerals survey offshore Cornwall, England a decade later. The research that led to today's commercial methods began in earnest much later, primarily at the British Geological Survey and UCSD Scripps Institution of Oceanography in the 1970's. Many other university and government groups started research on the technology about that time, and many continue to the present. Exxon began investigating marine CSEM in early 1981 using theory and computer modeling, and scoped the feasibility of field tests. Results looked promising for very deep water applications. However, the lack of suitable acquisition equipment, limited deep water opportunities, and the emphasis on the (then) new 3D marine seismic technology resulted in deferring further marine CSEM research.