Reduction of Fault Uncertainty Using Vertical Seismic Profiling Data

in: 78th EAGE Conference & Exhibition, EAGE, Vienna, Austria

Abstract

Due to the limited resolution of seismic reflection data in imaging near vertical structures, structural models can have significant uncertainties related to fault geometry and position. These uncertainties can be reduced by performing a history matching analysis on a large number of structural models generated stochastically. This work investigates about the integration of vertical seismic profiling data as another way to constrain and reduce such uncertainties. Because travel-times are not sufficiently sensitive to fault geometry perturbations, we rely on phase distortion of seismograms as they propagate through faulted models. To extract instantaneous phase information from seismograms, we use the empirical mode decomposition algorithm; an instantaneous phase misfit is then defined as the L2 norm of two instantaneous phase functions. A numerical experiment was carried out in which 60 fault networks were generated stochastically from an interpretation of multiple cross sections, the 60 models were then ranked from the most similar up to the most dissimilar from a randomly chosen reference model. Results show that the proposed misfit can successfully constrain fault geometry and position.

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BibTeX Reference

@INPROCEEDINGS{,
    author = { Irakarama, Modeste and Cupillard, Paul and Caumon, Guillaume },
     title = { Reduction of Fault Uncertainty Using Vertical Seismic Profiling Data },
 booktitle = { 78th EAGE Conference & Exhibition },
      year = { 2016 },
  location = { Vienna, Austria },
organization = { EAGE },
       doi = { 10.3997/2214-4609.201600681 },
  abstract = { Due to the limited resolution of seismic reflection data in imaging near vertical structures, structural models can have significant uncertainties related to fault geometry and position. These uncertainties can be reduced by performing a history matching analysis on a large number of structural models generated stochastically. This work investigates about the integration of vertical seismic profiling data as another way to constrain and reduce such uncertainties. Because travel-times are not sufficiently sensitive to fault geometry perturbations, we rely on phase distortion of seismograms as they propagate through faulted models. To extract instantaneous phase information from seismograms, we use the empirical mode decomposition algorithm; an instantaneous phase misfit is then defined as the L2 norm of two instantaneous phase functions. A numerical experiment was carried out in which 60 fault networks were generated stochastically from an interpretation of multiple cross sections, the 60 models were then ranked from the most similar up to the most dissimilar from a randomly chosen reference model. Results show that the proposed misfit can successfully constrain fault geometry and position. }
}