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- Volume 37, Issue 11, 2019
First Break - Volume 37, Issue 11, 2019
Volume 37, Issue 11, 2019
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Estimating rock physical parameters using anisotropic 3D seismic data to characterize unconventional Vaca Muerta oil shale deposits in the Neuquèn Basin, western Argentina
Authors David Curia and Paul VeekenSummaryAcquisition and processing of wide azimuth large offset and high fold (WA/LO/HF) 3D seismic data in the Aguada Federal concession is presented. Preserved amplitude/azimuthal workflows (e.g. anisotropy analysis, pre-stack elastic inversion, reservoir characterization) facilitate the quantitative interpretation.
Layering, fracture distribution and stress cause measurable velocity anisotropy. Well ties and residual normal move-out help to determine the anisotropy parameters (η, ε and δ). Non-hyperbolic 4th-order move-out improves flattening of gather reflections. Sinusoidal residual move-out on common-offset, common-azimuth gathers is diagnostic for HTI anisotropy. Azimuthal Residual Move-out (ARMO) on gathers improves the seismic quality. Anisotropic 3D tomographic raytracing and velocity model building increase the depth imaging efficiency. The new processing better focuses the seismic reflections and boosts higher frequencies. The migration repositions the energy in depth and the mismatch of geologic markers at the well locations is reduced.
Higher fidelity datasets are better suited for seismic inversion, reservoir characterization and fracture prediction. The anisotropic workflow serves to estimate Vp, Vs, density, total organic contents, Young’s modulus E and pore pressure. Delineation of Vaca Muerta sweet spots is thus made possible. Seismic anisotropy analysis allows optimization of the well landing point, selection of well spacing and a preferred trajectory orientation.
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Low-powered autonomous underwater vehicles for large-scale ocean-bottom acquisition
Authors Fabio Mancini, Henry Debens and Ben HollingsAbstractIn this paper we propose the use of autonomous underwater vehicles to enable faster and cheaper ocean bottom seismic acquisition. Our effort is focused on buoyancy-driven vehicles as this method of propulsion is extremely low-powered, enabling the units to have very long endurance and, therefore, making them suited to seismic acquisition on a large scale. We show that, for development-style surveys, these units can potentially double the acquisition efficiency. Furthermore, their ease of deployment makes them suited to acquisitions purposely designed for velocity estimation via full-waveform inversion, either on their own or in hybrid configuration with a streamer vessel.
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Redefining marine towed-streamer acquisition
Authors Martin Widmaier, David O’Dowd and Carine RoalkvamAbstractThe demand for better seismic data has increased in the search for new offshore energy resources. The launch of multisensor towed streamer technology in 2007 can be considered as a key milestone in marine seismic acquisition and imaging technology development (Widmaier et al., 2015) as high resolution imaging and quantitative interpretation has clearly benefited from the availability of true broadband data. Recent successful applications of full waveform inversion (Shen et al., 2017) are another breakthrough for seismic exploration technology.
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Which high-precision clock to choose for high performance and competitive OBN?
Authors Cyril Boissy and Nicolas VorobyevAbstractTwo different high-precision clock technologies are available for OBN manufacturers: OCXO clocks and CSAC clocks. The CSAC clock is being pushed by the oil majors, although it is extremely expensive. Technological progress is being made by the OCXO manufacturers. Their attractive price and their better market availability make them an attractive compromise for the OBN manufacturers who wish to segment their OBN product offerings besides their CSAC-based OBN. OCXO and CSAC clocks’ key parameters and performances are reviewed below. Their advantages and limitations, both technically, economically and strategically, are studied.
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CSEM acquisition methods in a multi-physics context
Authors Lucy MacGregor, James Tomlinson and Kim Gunn MaverAbstractMarine Controlled Source ElectroMagnetic (CSEM) measurements, which determine sub-surface resistivity, have become increasingly successful, and especially in the Barents Sea the method is a key driver in exploration activity. Electrical resistivity data can be acquired in a number of different ways. Traditional measurement of resistivity through well logging has now been complemented by measurements made from the seafloor using a number of different methods, each with unique features and benefits that make CSEM more applicable as part of hydrocarbon exploration and exploitation de-risking and reservoir management.
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Advanced imaging solutions for tailored multi-source and multi-vessel surveys
AbstractIn recent years there has been increased creativity in the design of seismic acquisition campaigns aimed at maximizing the illumination and sampling of the subsurface. When combined with innovations in imaging technology, these new acquisition methodologies can provide significant improvements to images of the subsurface in both exploration and production settings.
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Vertical dipole CSEM: 3D acquisition and data impact from infrastructure
By Eide KjetilAbstractMarine CSEM methods for subsurface investigations were developed nearly 30 years ago (Cox, 1981), and have found extensive applications within the offshore hydrocarbon exploration industry over the past 15 years (e.g. Constable, 2010). These methods detect contrasts in electrical conductivity, exploiting the fact that the electrical conductivity of hydrocarbon-saturated reservoirs is significantly smaller than in the surrounding sediments (Ell-ingsrud et al., 2002). While marine CSEM has proven itself as a valuable tool in exploration and mapping of frontier areas, there is growing increased interest in applying CSEM for near-exploration and reservoir monitoring applications. A vertical-based time domain EM exploration method (Barsukov et al., 2007) has been developed by the Norwegian geophysical company PetroMarker, founded in 2005. In the past the method has primarily been used for exploration, but since the vertical method relies on a stationary acquisition mode with very high accuracy in transmitter positioning it allows both repeatability and freedom of operation close to existing infrastructure and installations, and in vulnerable environments. Over the past few years there have also been improvements in receiver technology, allowing efficient 3D acquisition. We will present improvements to the method and a 3D field data example. We will also present investigations of the impact of the method on field data from infrastructure.
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Gas potential evaluation offshore Croatia to trigger renewed exploration
AbstractSince 1973, several gas fields have been discovered and put into production in the northern and central Adriatic Sea offshore Croatia (Figure 1).
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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)