Searched for: collection%3Air
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Schaller, A.M. (author)
Geophysical methods are widely used for hydrocarbon exploration and time-lapse measurements. One method that can be applied in place of or in addition to the routinely used seismic method, is the Controlled-Source ElectroMagnetic (CSEM) method. The work described in this thesis explores various aspects to improve the land CSEM method for...
doctoral thesis 2018
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Staal, X.R. (author)
Seismic imaging projects aim to reveal the structure of the earths crust from seismic data. These projects typically include three separate processing steps, being: • attenuation of multiple reflections in the seismic data. • estimating seismic wave propagation velocities from the seismic data. • mapping the measured reflection data to the...
doctoral thesis 2015
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Bensdorp, S. (author)
In petroleum production and exploration, having good information about a hydrocarbon reservoir is paramount to successful exploitation. A popular tool is to probe the electric conductivity in a well to obtain direct information of the well surrounding. As wells are nowadays mostly horizontally drilled, this information is becoming more important...
doctoral thesis 2015
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Zhubayev, A.S. (author)
Theoretical and experimental studies in the past have shown the sensitivity of seismic waves to soil/rock properties, such as composition, porosity, pore fluid, and permeability. However, quantitative characterization of these properties has remained challenging. In case of unconsolidated soils, the inherently loose and heterogeneous nature...
doctoral thesis 2014
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Kutscha, H. (author)
Many seismic data processing and imaging processes require densely and regularly sampled data, whereas the actual measurements are mostly irregularly and sparsely sampled. Therefore, seismic data reconstruction methods are utilised as a pre-processing step. Within the class of transformation-based reconstruction techniques, observed seismic data...
doctoral thesis 2014
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Haffinger, P.R. (author)
Full waveform inversion is a tool to obtain high-resolution property models of the subsurface from seismic data. However, the technique is computationally expens- ive and so far no multi-dimensional implementation exists to achieve a resolution that can directly be used for seismic interpretation and characterisation. In this thesis we discuss a...
doctoral thesis 2013
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Doulgeris, P. (author)
The recording and storage capacity of modern seismic acquisition systems is continuously growing, enabling denser sampling and the acquisition of better-quality data. One big hurdle is survey time, since the duration of a survey is directly proportional to the number of sources fired. The proposed way forward is to deploy nearly simultaneous...
doctoral thesis 2013
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Mahdad, A. (author)
Seismic imaging is one of the most common geophysical techniques for hydrocarbon exploration. Seismic acquisition is a trade-off between economy and quality. In conventional acquisition, the time intervals between successively firing sources are large enough to avoid interference in time. To obtain an efficient survey, the spatial source...
doctoral thesis 2012
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Chitu, D.A. (author)
The estimation of a velocity model is an important step in seismic imaging. To a large extend, seismic data interpretation is implicitly based on this model. Thus, the velocity model influences important conclusions such as size and shape of the reservoir and the expected volume of producible hydrocarbons. In the Common Focus Point (CFP)...
doctoral thesis 2011
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Dey, A.K. (author)
The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes. Currently, the seismic value chain paradigm is in...
doctoral thesis 2011
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Van Groenestijn, G.J.A. (author)
Surface-related multiple reflections are often considered noise in the seismic reflection measurements. By seismic processes, such as migration and inversion, they can be mistakenly seen as primary reflections and give an erroneous image of the earth. Therefore, a method is needed to separate the multiples from the primaries. This thesis...
doctoral thesis 2010
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Hörchens, L. (author)
The detection of inhomogeneities in plates or plate-like structures constitutes a major problem in the field of non-destructive testing. For a few decades, classical techniques based on X-ray radiography have - as far as possible - been complemented and replaced by the usage of vibrations or acoustical waves due to the fact that these are less...
doctoral thesis 2010
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van der Burg, D.W. (author)
To estimate rock and pore-fluid properties of oil and gas reservoirs in the subsurface, techniques can be used that invert seismic data. Hereby, the detailed information about the reservoir that is available at well locations, such as the thickness and porosity of individual layers, is extrapolated to all locations in the reservoir on the basis...
doctoral thesis 2007
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Zwartjes, P.M. (author)
In seismic exploration an image of the subsurface is generated from seismic data through various data processing algorithms. When the data is not acquired on an equidistantly spaced grid, artifacts may result in the final image. Fourier reconstruction is an interpolation technique that can reduce these artifacts by generating uniformly sampled...
doctoral thesis 2005
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Poot, H. (author)
During the last decades many different seismic inversion algorithms have been developed. Since the problem to be solved is non-linear and does not have a unique solution, every method makes use of its own approximations and assumptions. As a step towards a new approach to the inversion of seismic data we have designed and partly implemented a...
doctoral thesis 2004
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Cox, B.E. (author)
Seismic images of the structure of the earth are a prerequisite for finding new hydrocarbon reservoirs. The quality of a seismic images is highly dependent on the accuracy of the velocity model of the subsurface. Conventional imaging consists of an iterative process between obtaining the image using a velocity model, and updating this model by...
doctoral thesis 2004
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van den Berg, S.M. (author)
doctoral thesis 2003
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Van Dongen, K.W.A. (author)
doctoral thesis 2002
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Sevink, G.J.A. (author)
doctoral thesis 1996
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