Searched for: department%3A%22Geoscience%255C%252B%2526%255C%252BEngineering%22
(21 - 40 of 542)
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Zhubayev, A. (author), Houben, M.E. (author), Smeulders, D.M.J. (author), Barnhoorn, A. (author)We have conducted ultrasonic experiments, between 0.3 and 1 MHz, to measure velocity and attenuation (Q?1) anisotropy of P- and S-waves in dry Whitby Mudstone samples as a function of stress. We found the degree of anisotropy to be as large as 70% for velocity and attenuation. The sensitivity of P-wave anisotropy change with applied stress is...journal article 2015
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Boullenger, B. (author), Verdel, A. (author), Paap, B. (author), Draganov, D.S. (author)Ambient-noise seismic interferometry (ANSI) applied to passive body-wave measurements retrieves an estimate of the reflection response as if from a source at a receiver position. Often, the limited compliance with theoretical assumptions causes erroneous absolute amplitudes of the retrieved physical reflections, and additional artefacts....conference paper 2015
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- Laera, A. (author), Brinkgreve, R.B.J. (author) conference paper 2015
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Kumar, A. (author)A seismic survey should be designed such that imaging of the acquired data leads to a sufficiently accurate subsurface image. For that purpose, methods for acquisition geometry analysis and design are available. These methods are used to judge whether an acquisition geometry is suited for the specified objectives. Conventional 2D and 3D...doctoral thesis 2015
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Fonseca, R.M. (author)In this dissertation we have investigated theoretical and numerical aspects of the Ensemble Optimization (EnOpt) technique for model based production optimization. We have proposed a modified gradient formulation for robust optimization which we show to be theoretically more robust than the earlier existing formulation. Through a series of...doctoral thesis 2015
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Van Beek, V.M. (author)Backward erosion piping is an internal erosion mechanism during which shallow pipes are formed in the direction opposite to the flow underneath water-retaining structures as a result of the gradual removal of sandy material by the action of water. It is an important failure mechanism in both dikes and dams where sandy layers are covered by a...doctoral thesis 2015
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- Afanasyev, M. (author), Huisman, H. (author), Van Paassen, L.A. (author), Heimovaara, T.J. (author) conference paper 2015
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Bertotti, G. (author), Boniface, N. (author), De Bresser, H.P. (author), Manya, S. (author), Nkotagu, H. (author), Ruitenbeek, F. (author)The UDSM, supported by group of geoscientists from Universities of the Netherlands has been able to establish the first Master program in Petroleum Geology of the country. With the crucial financial support of BG-Group 13 students has enrolled for the program. Courses have been given in the first year covering a wide range of relevant...conference paper 2015
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Blacquiere, G. (author), Berkhout, A.J. (author)In marine acquisition both a direct wavefield and a ghost wavefield are produced as well as recorded. Hence, the seismic data can be considered to be a natural blend of four wavefields related to the real sources, ghost sources, real detectors and ghost detectors respectively. We consider deghosting to be deblending ('echo-deblending'), leading...conference paper 2015
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Caporal, M. (author), Blacquiere, G. (author)Seismic sources deployed during a particular survey are historically chosen to be equal. However, from a physical point of view the constraint of using only identical source units is not required. We suggest to abandon this constraint and to replace, or reinforce, traditional broadband sources with narrower-band devices, together representing a...conference paper 2015
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Justiniano, A. (author), Jaya, M. (author), Diephuis, G. (author)The objective of this study is to characterise the Jurassic Posidonia Shale Formation at Block Q16 located in the West Netherlands Basin. The characterisation was carried out through combining rock-physics modelling and seismic inversion techniques. The results show that the Posidonia Shale Formation can be followed easily laterally from the...conference paper 2015
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Spruit, R. (author)Diaphragm walls are potentially ideal retaining walls for deep excavations in densely built-up areas, as they cause no vibrations during their construction and provide structural elements with high strength and stiffness. In the recent past, however, several projects using diaphragm walls as soil and water retaining elements have encountered...doctoral thesis 2015
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Yuan, J. (author), Hicks, M.A. (author)A numerical model for the design and analysis of electro-osmosis consolidation in soft clay is used to study a well-documented full-scale field test. The large-strain model, which considers coupled electro-osmosis flow, hydraulic flow and electric density flow in a deformable elasto-plastic porous medium, is briefly introduced first. It is then...journal article 2015
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Weemstra, C. (author), Wapenaar, C.P.A. (author), Van Dalen, K.N. (author)In this work we investigate a modification of the formulation of the theory underlying seismic interferometry (SI) by multidimensional deconvolution (MDD). The current formulation, and hence method, relies on separation of waves traveling inward and outward of a volume bounded by receivers. As a consequence, it is predominantly useful when...conference paper 2015
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Minato, S. (author), Ghose, R. (author)The spatial heterogeneity along a fracture is a key determinant for fracture-associated hydraulic properties. We propose a new method to estimate the heterogeneous compliance distribution of a fracture from the reflection response at the fracture surface. For this purpose, we formulate a data-driven approach for Green's function retrieval based...conference paper 2015
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- Draganov, D.S. (author), Wapenaar, C.P.A. (author) conference paper 2015
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Yuan, J. (author)Consolidation of soft clay creates a lot of problems in foundation engineering, because of the very low clay permeability and high compressibility. Primary consolidation takes a long time to complete if the material is left consolidating under atmospheric evaporation, and traditional dewatering techniques, such as surcharge preloading, vacuum...doctoral thesis 2015
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Liu, K. (author), Vardon, P.J. (author), Arnold, P. (author), Hicks, M.A. (author)Hysteresis is a well-known phenomenon that exists in the soil water retention behaviour of unsaturated soils. However, there is little research on the effects of hysteresis on slope stability. If included in slope stability analyses, commonly the suction in the unsaturated zone is taken as non-hysteretic. In this paper, the authors investigate...conference paper 2015
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Bloemsma, M.R. (author)Sedimentary deposits are important archives of the Earth’s history. In addition, they are of key economical and societal importance because they contain natural resources (e.g., hydrocarbons and drinking water). Hence, it is of utmost importance that we understand the mechanisms controlling the heterogeneity, morphology and spatial distribution...doctoral thesis 2015
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Ashoori, E. (author), Jansen, J.D. (author)There is a general consensus that the most efficient method for large-scale well location optimization is gradient-based with gradients computed with an adjoint formulation. Handels et al. (2007) (later published in journal form as Zandvliet et al., 2008), were the first to use the adjoint method for well placement optimization for which they...report 2015
Searched for: department%3A%22Geoscience%255C%252B%2526%255C%252BEngineering%22
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