Land time-lapse CSEM: Collecting, modeling and inversion of CSEM data for a steam-injected oil field

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...

Probing the solution space of an EM inversion problem with a genetic algorithm

In an inversion for the subsurface conductivity distribution using frequency-domain Controlled-Source Electromagnetic data, various amounts of horizontal components may be included. We investigate which combination of components are best suited to invert for a vertical transverse isotropic (VTI) subsurface. We do this by probing the...

Controlled-Source Electromagnetics for Reservoir Monitoring on Land

The main goal of exploration geophysics is to obtain information about the subsurface that is not directly available from surface geological observations. The results are primarily used for finding potential reservoirs that contain commercial quantities of hydrocarbons. A number of possible geophysical methods exists these days to achieve such a...

Inversion of multi-transient EM data from anisotropic media

Forward modelling demonstrates that resistivity anisotropy has a huge effect on Multi-Transient ElectroMagnetic step and impulse responses. The earth is never isotropic – even a stack of isotropic layers behaves anisotropically – and there is a great need to ccount for resistivity anisotropy in order to delineate the true target depth and target...