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- Volume 28, Issue 12, 2010
First Break - Volume 28, Issue 12, 2010
Volume 28, Issue 12, 2010
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Mitigating the environmental footprint of towed streamer seismic surveys
Authors P.M. Fontana and P. ZickermanPhilip M. Fontana and Peter Zickerman address the environmental issues involved in marine seismic surveying which are attracting increasing attention from regulatory authorities around the world.
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Multi-azimuth 3D survey in the Barents Sea
Authors M. Buia, C. Cirone, J. Leutscher, S. Tarran and B. WebbMichele Buia, Carmine Cirone, Johan Leutscher, Steve Tarran and Bruce Webb describe the acquisition and processing of a seismic survey over the Goliat area in the Barents Sea, north of Norway, the first multi-azimuth (MAZ) 3D survey in the area.
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A towed streamer 3D seismic survey in the Arctic marginal ice zone
Authors A. Ross, S. Viceer, S. Hildebrand, C. Morrison and E. JolleyAllan Ross, Shazia Viceer, Sophie Hildebrand, Charlie Morrison and Elizabeth Jolley describe the planning, operation, and results of a notable streamer survey along the edge of the polar ice pack in the Canadian Beaufort Sea.
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Time-lapse acquisition with a dual-sensor streamer over a conventional baseline survey
Authors A. Day, M. Widmaier, T. Høy and B. OsnesAnthony Day, Martin Widmaier, Torben Høy and Berit Osnes, PGS, describe an experiment to validate the use of a dual-sensor streamer for time-lapse acquisition.
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Variable-depth streamer – a broadband marine solution
Authors R. Soubaras and R. DowleRobert Soubaras and Robert Dowle explain how a broadband solution leveraging the benefits of towing variable depth solid streamers and proprietary deghosting processing techniques can resolve a longstanding challenge in marine seismic acquisition.
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3D diffraction and mode-converted scattering signatures of base metal deposits, Bathurst Mining Camp, Canada
Authors A. Malehmir, G. Bellefleur and C. MüllerThe localized and isolated nature of base-metal deposits can generate a complex scattered wavefield that may include P-P, P-S, S-P, and S-S events. Multi-component VSP data have previously confirmed the presence of several wave types scattered by a deep-seated base metal deposit at Halfmile Lake, Bathurst Mining Camp, Canada. However, mode-converted waves scattered from a massive sulphide deposit have not previously been recognized on surface seismic data. In this study, we used 3D surface seismic data acquired with an explosive source and vertical geophones to investigate the possible presence of P-P, P-S, S-P, and S-S events scattered at a base metal, lens-shaped body at about 1.2 km depth. We show that this body produces a diagnostic P-P diffraction and use finite-difference modelling to show it could produce mode-converted scattered signals. Results from a target-oriented azimuthal scattering analysis based on 3D prestack migration reveal amplitude anomalies at the location of the base metal lens for S-P waves and possibly P-S waves. The identification of these events confirms that mode-converted waves scattered from the deep sulphide lens were recorded on the 3D data. However, the real potential of these complementary wave modes for mineral exploration will only be realistically evaluated using P- and S-wave sources and multi-component receivers.
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Quantification of shale volume from borehole logs calibrated by SEM analysis: a case study
Authors M. Mohammadlou, M.B.E. Mørk and H. LangelandThe presence of mixed carbonate and siliciclastic rocks complicates the choice of appropriate petrophysical tools for shale volume estimation. In this case study, conventional uranium-corrected gamma-ray and spectral gamma-ray logs were initially used for shale volume estimation. The results, however, were not supported by the nuclear magnetic resonance (NMR) log. Significant discrepancies were found in the reservoir where a considerable shale volume was estimated from the gammaray logs. Scanning electron microscope (SEM) analysis verified that potassium is present in clay and as potassium feldspar. Knowing the proportion of minerals from SEM analysis allows calibration of the spectral gamma-ray log for the potassium content of the clay at selected depths. Calibrated spectral gamma-ray values at the selected depths and the uniformity of the spectral gamma-ray logs are used to correlate the spectral gamma-ray logs over the intervals between the selected depths. The corrected spectral gamma-ray logs were used to recalculate shale volume, and resulted in a significantly reduced estimate. Validation of the result with the NMR log confirms the SEM and gamma-ray calibrated shale volume estimates, and suggests that the NMR log is a valuable tool for shale volume evaluation.
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Volumes & issues
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Volume 42 (2024)
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Volume 41 (2023)
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Volume 40 (2022)
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Volume 39 (2021)
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Volume 38 (2020)
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Volume 37 (2019)
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Volume 36 (2018)
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Volume 35 (2017)
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Volume 34 (2016)
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Volume 33 (2015)
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Volume 32 (2014)
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Volume 31 (2013)
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Volume 30 (2012)
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Volume 29 (2011)
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Volume 28 (2010)
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Volume 27 (2009)
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Volume 26 (2008)
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Volume 25 (2007)
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Volume 24 (2006)
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Volume 23 (2005)
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Volume 22 (2004)
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Volume 21 (2003)
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Volume 20 (2002)
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Volume 19 (2001)
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Volume 18 (2000)
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Volume 17 (1999)
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Volume 16 (1998)
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Volume 15 (1997)
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Volume 14 (1996)
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Volume 13 (1995)
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Volume 12 (1994)
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Volume 11 (1993)
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Volume 10 (1992)
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Volume 9 (1991)
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Volume 8 (1990)
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Volume 7 (1989)
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Volume 6 (1988)
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Volume 5 (1987)
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Volume 4 (1986)
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Volume 3 (1985)
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Volume 2 (1984)
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Volume 1 (1983)