Available on ORBi since
04 November 2013
Article (Scientific journals)
Case studies of incorporation of prior information in electrical resistivity tomography: comparison of different approaches
Caterina, David  ; Hermans, Thomas  ; Nguyen, Frédéric 
2014 • In Near Surface Geophysics, 12 (4), p. 451-465
Peer reviewed
 

Files


Full Text
Caterina_et_al_NSG_2014.pdf
Author postprint (4.57 MB)

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
prior information; inversion; electrical resistivity tomography; reference model; structural constraint; geostatistical constraint
Abstract :
[en] Many geophysical inverse problems are ill-posed and their solution non-unique. It is thus important to reduce the amount of mathematical solutions to more geologically plausible models by regularizing the inverse problem and incorporating all available prior information in the inversion process. We compare three different ways to incorporate prior information for electrical resistivity tomography (ERT): using a simple reference model or adding structural constraints to Occam's inversion and using geostatistical constraints. We made the comparison on four real cases representing different field applications in terms of scales of investigation and level of heterogeneities. In those cases, when electromagnetic logging data are available in boreholes to control the solution, it appears that incorporating prior information clearly improves the correspondence with logging data compared to the standard smoothness constrain. However, the way to incorporate it may have a major impact on the solution. A reference model can often be used to constrain the inversion; however, it can lead to misinterpretation if its weight is too strong or the resistivity values inappropriate. When the computation of the vertical and/or horizontal correlation length is possible, the geostatistical inversion gives reliable results everywhere in the section. However, adding geostatistical constraints can be difficult when there is not enough data to compute correlation lengths. When a known limit between two layers exists, the use of structural constrain seems to be more indicated particularly when the limit is located in zones of low sensitivity for ERT. This work should help interpreters to include their prior information directly into the inversion process through an appropriate way.
Disciplines :
Geological, petroleum & mining engineering
Author, co-author :
Caterina, David  
Hermans, Thomas  ;  Université de Liège - ULiège > Département ArGEnCo > Géophysique appliquée
Nguyen, Frédéric ;  Université de Liège - ULiège > Département ArGEnCo > Géophysique appliquée
 These authors have contributed equally to this work.
Language :
English
Title :
Case studies of incorporation of prior information in electrical resistivity tomography: comparison of different approaches
Publication date :
August 2014
Journal title :
Near Surface Geophysics
Publisher :
EAGE Holding, Houten, Netherlands
Volume :
12
Issue :
4
Pages :
451-465
Peer reviewed :
Peer reviewed
Funders :
F.R.S.-FNRS - Fonds de la Recherche Scientifique
Fondation Roi Baudouin - Prix Ernest Dubois

Statistics


Number of views
166 (74 by ULiège)
Number of downloads
410 (39 by ULiège)

Scopus citations®
 
36
Scopus citations®
without self-citations
20

Bibliography


Similar publications



Contact ORBi