1887

Abstract

Summary

Geologic facies distributions are commonly represented in geomodels by categorical variables that are intrinsically non-Gaussian and thus difficult to calibrate in ensemble Kalman filter-like algorithms.

For certain types of stochastic models such as the truncated plurigaussian, it is possible to directly update model variables in such a way that the resulting realizations appear to be samples from the posterior. For other types of models, this is not possible. One common approach has been to invert flow data using the ensemble Kalman filter (EnKF) to obtain “probability maps” which are then used to condition facies realizations. Data matches obtained in this method are generally poor, however, because the probability map neglects important joint probabilities of model parameters imposed by flow data. In this paper, we propose a data assimilation method with a post-processing step that resembles the post-smoothed maximum-likelihood (ML) reconstruction method described in ). Disregarding the categorical feature of the facies model, reservoir properties are first updated using an EnKF-like assimilation method to honor flow data. In the post-processing step a penalty term forcing model variables to take discrete values is jointly minimized with the distance to the posterior realizations to solve for facies models that match data. The distance to posterior realizations is quantified using the ensemble representation of the posterior covariance, which represents the joint probability of model parameters. The matrix inversion lemma is used in solving the minimization problem to avoid inversion of the covariance.

The ability of the ensemble to accurately represent information in data is demonstrated on two linear examples and a nonlinear reservoir flow example. Comparison is made with approaches that use only the probability map to represent the assimilated data. The results show better data matches obtained with the proposed method and reflect the importance of the information captured by the updated ensemble from the data with respect to the joint probabilities of model variables.

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2014-09-08
2024-04-25
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References

  1. Aanonsen, S.I., Nævdal, G., Oliver, D.S., Reynolds, A.C. and Vallès, B.
    [2009] Ensemble Kalman filter in reservoir engineering — a review. SPE Journal, 14(3), 393–412.
    [Google Scholar]
  2. Agbalaka, C.C. and Oliver, D.S.
    [2011] Joint updating of petrophysical properties and discrete facies variables from assimilating production data using the EnKF. SPE Journal, 16(2), 318–330, doi:10.2118/118916‑PA.
    https://doi.org/10.2118/118916-PA [Google Scholar]
  3. Andersen, T. et al.
    [2006] Method for conditioning the reservoir model on 3d and 4d elastic inversion data applied to a fluvial reservoir in the north sea (spe100190). 68th EAGE Conference & Exhibition.
    [Google Scholar]
  4. Armstrong, M. et al.
    [2011] Plurigaussian Simulations in Geosciences. Springer Berlin Heidelberg, 2nd edn., ISBN 978-3-642-19607-2, doi:10.1007/978‑3‑642‑19607‑2_3.
    https://doi.org/10.1007/978-3-642-19607-2_3 [Google Scholar]
  5. Astrakova, A. and Oliver, D.
    [2014] Conditioning truncated pluri-gaussian models to facies observations in ensemble-kalman-based data assimilation. Mathematical Geosciences, 1–23, ISSN 1874–8961, doi: 10.1007/s11004‑014‑9532‑3.
    https://doi.org/10.1007/s11004-014-9532-3 [Google Scholar]
  6. Capilla, J.E. and Llopis-Albert, C.
    [2009] Gradual conditioning of non-gaussian transmissivity fields to flow and mass transport data: 1. theory. Journal of hydrology, 371(1), 66–74.
    [Google Scholar]
  7. Chen, Y. and Oliver, D.S.
    [2009] Cross-covariances and localization for EnKF in multiphase flow data assimilation. Comput. Geosci., Online First, doi:10.1007/s10596‑009‑9174‑6.
    https://doi.org/10.1007/s10596-009-9174-6 [Google Scholar]
  8. [2013] Levenberg-Marquardt forms of the iterative ensemble smoother for efficient history matching and uncertainty quantification. Computational Geosciences, 17(4), 689–703, ISSN 1420–0597, doi:10.1007/s10596‑013‑9351‑5.
    https://doi.org/10.1007/s10596-013-9351-5 [Google Scholar]
  9. Dovera, L. and Della Rossa, E.
    [2011] Multimodal ensemble kalman filtering using gaussian mixture models. Computational Geosciences, 15, 307–323, ISSN 1420-0597, doi:10.1007/s10596‑010‑9205‑3.
    https://doi.org/10.1007/s10596-010-9205-3 [Google Scholar]
  10. Evensen, G.
    [1994] Sequential data assimilation with a nonlinear quasi-geostrophic model using Monte Carlo methods to forecast error statistics. J. Geophys. Res., 99(C5), 10143–10162.
    [Google Scholar]
  11. Galli, A., Beucher, H., Le Loc’h, G., Doligez, B. and Group, H.
    [1994] The pros and cons of the truncated Gaussian method. In: Geostatistical Simulations. Kluwer Academic, Dordrecht, 217–233.
    [Google Scholar]
  12. Gaspari, G. and Cohn, S.E.
    [1999] Construction of correlation functions in two and three dimensions. Quarterly Journal of the Royal Meteorological Society, 125(554), 723–757.
    [Google Scholar]
  13. Hager, W.W.
    [1989] Updating the inverse of a matrix. SIAM Review, 31(2), 221–239.
    [Google Scholar]
  14. Hu, L., Zhao, Y., Liu, Y., Scheepens, C. and Bouchard, A.
    [2013] Updating multipoint simulations using the ensemble kalman filter. Computers & Geosciences, 51(0), 7 – 15, ISSN 0098–3004, doi: 10.1016/jxageo.2012.08.020.
    https://doi.org/http://dx.doi.org/10.1016/jxageo.2012.08.020 [Google Scholar]
  15. Jafarpour, B. and Khodabakhshi, M.
    [2011] A probability conditioning method (PCM) for nonlinear flow data integration into multipoint statistical facies simulation. Math. Geosci., 43, 133–164, ISSN 1874-8961, doi: 10.1007/s11004‑011‑9316‑y.
    https://doi.org/10.1007/s11004-011-9316-y [Google Scholar]
  16. Liu, N. and Oliver, D.S.
    [2005] Ensemble Kalman filter for automatic history matching of geologic facies. Journal of Petroleum Science and Engineering, 47(3–4), 147–161.
    [Google Scholar]
  17. Lorentzen, R.J., Flornes, K.M. and Nævdal, G.
    [2012] History matching channelized reservoirs using the ensemble Kalman filter. SPE Journal, 17(1), 137-151.
    [Google Scholar]
  18. Nuyts, J., Baete, K., Bequé, D. and Dupont, P.
    [2005] Comparison between MAP and postprocessed ML for image reconstruction in emission tomography when anatomical knowledge is available. IEEE transactions on medical imaging, 24(5), 667–75, doi:10.1109/TMI.2005.846850.
    https://doi.org/10.1109/TMI.2005.846850 [Google Scholar]
  19. Oliver, D.S., Chen, Y. and Nasvdal, G.
    [2011] Updating Markov chain models using the ensemble Kalman filter. Comput. Geosci., 15(2), 325–344, doi:10.1007/s10596‑010‑9220‑4.
    https://doi.org/10.1007/s10596-010-9220-4 [Google Scholar]
  20. Sarma, P. and Chen, W.
    [2009] Generalization of the ensemble Kalman filter using kernels for non-gaussian random fields, SPE-119177. SPE Reservoir Simulation Symposium, 2–4 February, The Woodlands, Texas, USA.
    [Google Scholar]
  21. Sebacher, B., Hanea, R. and Heemink, A.
    [2013] A probabilistic parametrization for geological uncertainty estimation using the ensemble kalman filter (enkf). Computational Geosciences, 17(5), 813–832.
    [Google Scholar]
  22. Skjervheim, J.A. and Evensen, G.
    [2011] An ensemble smoother for assisted history matching (SPE–141929). SPE Reservoir Simulation Symposium, 21–23 February, The Woodlands, Texas.
    [Google Scholar]
  23. Zachariassen, E., Skjervheim, J., Vabø, J., Lunt, I., Hove, J. and Evensen, G.
    [2011] Integrated work flow for model update using geophysical monitoring data. 73rd EAGE Conference & Exhibition.
    [Google Scholar]
  24. Zhang, Y., Oliver, D.S., Chen, Y., Skaug, H.J. et al.
    [2014] Data assimilation by use of the iterative ensemble smoother for 2d facies models. SPE Journal, (Preprint), doi:10.2118/170248‑PA.
    https://doi.org/10.2118/170248-PA [Google Scholar]
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