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Werthmüller, D. (author), Mulder, W.A. (author), Slob, E.C. (author)
Controlled-source electromagnetic (CSEM) surveys are a common geophysical investigationtool in the search for, amongst other, groundwater, hydrocarbons, and minerals. The nu-merical modelling of CSEM data requires the solution of the Maxwell equations. These canbe simplified in the particular case of CSEM, as the frequencies used in surveys are...
journal article 2019
document
Slob, E.C. (author), Mulder, M. (author)
We have developed explicit expressions and the corresponding computer code for all homogeneous space Green’s functions for coupled electromagnetic fields and poroelastic waves. The Green’s functions are derived from the basic equations in closed form in the wavenumber- and space-frequency domains. They are given for point sources of any type....
journal article 2016
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Maas, P.J. (author), Grobbe, N. (author), Slob, E.C. (author), Mulder, W.A. (author)
For multi-parameter problems, such as the seismoelectric system, sensitivity analysis through resolution functions is a low-cost, fast method of determining whether measured fields are sensitive to certain subsurface parameters. We define a seismoelectric resolution function for the inversion of a bulk density perturbation. The synthetic data...
conference paper 2015
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Grobbe, N. (author), Maas, P. (author), Slob, E.C. (author), Mulder, W.A. (author)
conference paper 2015
document
Moradi Tehrani, A. (author), Slob, E.C. (author), Mulder, W. (author)
Frequency-to-time transformations are of interest to controlled-source electromagnetic methods when time-domain data are inverted for a subsurface resistivity model by numerical frequency-domain modeling at a selected, small number of frequencies whereas the data misfit is determined in the time domain. We propose an efficient, Prony-type method...
journal article 2012
document
Wirianto, M. (author), Mulder, W.A. (author), Slob, E.C. (author)
In the application of controlled source electromagnetics for reservoir monitoring on land, the timelapse signal measured with a surface-to-surface acquisition can reveal the lateral extent on the surface of resistivity changes at depth in a hydrocarbon reservoir under production. However, a direct interpretation of the time-lapse signal may...
conference paper 2012
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Kavian, M. (author), Slob, E.C. (author), Mulder, W.A. (author)
Macroscopic measurements of electrical resistivity require frequency-dependent effective models that honor the microscopic effects observable in macroscopic measurements. Effective models based on microscopic physics exist alongside with empirical models. We adopted an empirical model approach to modify an existing physical model. This provided...
journal article 2012
document
Kavian, M. (author), Slob, E.C. (author), Mulder, W.A. (author)
We measured the electric parameters for four different configurations of unconsolidated homogeneous and layered sands as a function of frequency, water saturation, and salinity under fluid flow conditions. Our objective is to determine if the effect of heterogeneities at scales much smaller than the skin depth can be captured by introducing...
journal article 2011
document
Hunziker, J.W. (author), Slob, E.C. (author), Mulder, W. (author)
In marine time-domain controlled-source electromagnetics (CSEM), there are two different acquisition methods: with horizontal sources for fast and simple data acquisition or with vertical sources for minimizing the effects of the airwave. Illustrations of the electric field as a function of space and time for various source antenna orientations,...
journal article 2011
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Wirianto, M. (author), Mulder, W.A. (author), Slob, E.C. (author)
In the application of controlled source electromagnetics for reservoir monitoring on land, repeatability errors in the source will mask the time-lapse signal due to hydrocarbon production when recording surface data close to the source. We demonstrate that at larger distances, the airwave will still provide sufficient illumination of the target....
journal article 2011
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Wirianto, M. (author), Mulder, W.A. (author), Slob, E.C. (author)
journal article 2010
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Slob, E.C. (author), Hunziker, J.W. (author), Mulder, W.A. (author)
journal article 2010
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Mulder, W.A. (author), Wirianto, M. (author), Slob, E.C. (author)
We modeled time-domain EM measurements of induction currents for marine and land applications with a frequency-domain code. An analysis of the computational complexity of a number of numerical methods shows that frequency-domain modeling followed by a Fourier transform is an attractive choice if a sufficiently powerful solver is available. A...
journal article 2007
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