1887

Abstract

Summary

Many prevalent methods for estimating time-lapse velocity changes from the shifts between vintages of time-lapse seismic data make use of a 1D approximation: that seismic energy propagates vertically through a horizontally layered Earth of homogeneous and isotropic layers. While this approximation has produced operational benefits, it is in conflict with real seismic data propagating through real Earth structures. Here we present a method of estimating production related time-lapse velocity changes from pre-stack seismic data without assuming vertical seismic propagation through a horizontally layered Earth. Instead seismic energy is modeled by ray tracing through an existing interval velocity model, previously estimated for seismic imaging. A tomographic system of equations can be formed from these ray paths and the shifts between time-lapse vintages measured in either the pre-stack data (before migration) or image (after migration) domains. Assuming isotropic velocity changes and negligible changes in reflector depths, the solution of this system yields the causal time-lapse velocity changes. We demonstrate that these estimated velocity changes are correctly positioned and are of the right magnitude, whereas those estimated using the aforementioned 1D approximation are not.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201700810
2017-06-12
2024-04-26
Loading full text...

Full text loading...

References

  1. Fuck, R.F., Bakulin, A. and Tsvankin, I.
    , 2009, Theory of traveltime shifts around compacting reservoirs: 3D solutions for heterogeneous anisotropic media, Geophysics, v. 74, D25–D36.
    [Google Scholar]
  2. Grandi, A., Wauquier, S., Cumming, H. and Deplante, C.
    , 2009, Quantitative 4D time lapse characterization: three examples, 79th Conference and Exhibition, SEG, Extended Abstracts.
    [Google Scholar]
  3. Hatchell, P. and Bourne, S.
    , 2005, Rocks under strain: strain-induced time-lapse time shifts and observed for depleting reservoirs, The Leading Edge, 1222–1225.
    [Google Scholar]
  4. Herwanger, J.V. and Horne, S.A.
    , 2009, Linking reservoir geomechanics and time-lapse seismic: Predicting anisotropic velocity changes and seismic attributes, Geophysics, v. 74, W13–W33.
    [Google Scholar]
  5. Kudarova, A., Hatchell, P., Brain, J. and MacBeth, C.
    , 2016, Offset-dependence of production-related 4D time-shifts: real data examples and modeling, 86th Conference and Exhibition, SEG, Extended Abstracts.
    [Google Scholar]
  6. Landro, M. and Stammeijer, J.
    , 2004, Quantitative estimation of compaction and velocity changes using time-lapse impedance and traveltime changes, Geophysics, v. 69, 949–957.
    [Google Scholar]
  7. Rickett, J., Duranti, L., Hudson, T., Regel, B. and Hodgson, N.
    , 2007, 4D time strain and the seismic signature of the geomechanical compaction at Genesis, The Leading Edge, 644–647.
    [Google Scholar]
  8. Roste, T., Stovas, A. and Landro, M.
    , 2006, Estimation of layer thickness and velocity changes using time-lapse prestack seismic data, Geophysics, v. 71, S219–S234.
    [Google Scholar]
  9. Stork, C.
    , 1992, Reflection tomography in the postmigrated domain, Geophysics, v. 57, 680–692.
    [Google Scholar]
  10. Vesnaver, A.L., Accaino, F., Bohm, G., Madrussani, G., Pajchel, J., Rossi, G. and Dal Moro, G.
    , 2003, Time-lapse tomography, Geophysics, v. 68, 815–823.
    [Google Scholar]
  11. Williamson, P.R., Cherrett, A.J. and Sexton, P.A.
    , 2007, A new approach to warping for quantitative time-lapse characterisation, 70th Conference and Exhibition, EAGE, Extended Abstracts.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201700810
Loading
/content/papers/10.3997/2214-4609.201700810
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error