Geophysical exploration methods focus on different physical aspects of medium, and as one of them, controlled source electromagnetic (CSEM) exploits resistivity variations. Besides being a future-promising technique, CSEM is still regarded as immature in terms of interpretation of data and imaging. On the other hand, in literature, many CSEM alternative concepts have been proposed, which intrinsically indicates that there is no strict standards for this method yet. This dissertation concentrates on several marine exploration environment scenarios, which differ in fundamental physical properties as sea depth, target depth, target resistivity for classical CSEM applications and alternative CSEM concepts, for instance, where receivers are towed by the vessel as well. Relatedly, qualitative and quantitative references and findings have been given for a comprehensive approach of sensing performance. Moreover, suggestions are made if necessary. Furthermore, thesis also concerns imaging the prospect. It is well known that as a standard imaging technique, “inversion” is widely adopted in literature. However, in this work, “Em migration”, which is simply converted from seismic into electromagnetics, has been under study. Em migration is relatively a more recent imaging method and draws attention since it requires several order of magnitude less time than inversion does. In this dissertation, both sensitivity performance regarding varying physical parameters and correspondingly imaging via electromagnetic migration, are concerned for artificial and real datasets. Cases are studied under spoiling effects and finally a new imaging condition for electromagnetic migration is suggested and compared to the conventional one.
Controlled source electromagnetic (CSEM) & EM migration
ERTAS, OKTAY BURAK
2015/2016
Abstract
Geophysical exploration methods focus on different physical aspects of medium, and as one of them, controlled source electromagnetic (CSEM) exploits resistivity variations. Besides being a future-promising technique, CSEM is still regarded as immature in terms of interpretation of data and imaging. On the other hand, in literature, many CSEM alternative concepts have been proposed, which intrinsically indicates that there is no strict standards for this method yet. This dissertation concentrates on several marine exploration environment scenarios, which differ in fundamental physical properties as sea depth, target depth, target resistivity for classical CSEM applications and alternative CSEM concepts, for instance, where receivers are towed by the vessel as well. Relatedly, qualitative and quantitative references and findings have been given for a comprehensive approach of sensing performance. Moreover, suggestions are made if necessary. Furthermore, thesis also concerns imaging the prospect. It is well known that as a standard imaging technique, “inversion” is widely adopted in literature. However, in this work, “Em migration”, which is simply converted from seismic into electromagnetics, has been under study. Em migration is relatively a more recent imaging method and draws attention since it requires several order of magnitude less time than inversion does. In this dissertation, both sensitivity performance regarding varying physical parameters and correspondingly imaging via electromagnetic migration, are concerned for artificial and real datasets. Cases are studied under spoiling effects and finally a new imaging condition for electromagnetic migration is suggested and compared to the conventional one.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/121366