Integration of Seismic Information in Reservoir Models: Global Stochastic Inversion

Stochastic inversion of facies from seismic data based on sequential simulations and probability perturbation method

Geophysics ◽

10.1190/geo2011-0417.1 ◽

2012 ◽

Vol 77 (4) ◽

pp. M53-M72 ◽

Cited By ~ 65

Author(s):

Dario Grana ◽

Tapan Mukerji ◽

Jack Dvorkin ◽

Gary Mavko

Keyword(s):

Perturbation Method ◽

Optimization Problems ◽

Synthetic Seismograms ◽

Perturbation Approach ◽

Reservoir Properties ◽

Stochastic Inversion ◽

The Real ◽

Probabilistic Information ◽

Reservoir Models ◽

Probability Perturbation Method

We presented a new methodology for seismic reservoir characterization that combined advanced geostatistical methods with traditional geophysical models to provide fine-scale reservoir models of facies and reservoir properties, such as porosity and net-to-gross. The methodology we proposed was a stochastic inversion where we simultaneously obtained earth models of facies, rock properties, and elastic attributes. It is based on an iterative process where we generated a set of models of reservoir properties by using sequential simulations, calculated the corresponding elastic attributes through rock-physics relations, computed synthetic seismograms and, finally, compared these synthetic results with the real seismic amplitudes. The optimization is a stochastic technique, the probability perturbation method, that perturbs the probability distribution of the initial realization and allows obtaining a facies model consistent with all available data through a relatively small number of iterations. The probability perturbation approach uses the Tau model probabillistic method, which provides an analytical representation to combine single probabilistic information into a joint conditional probability. The advantages of probability perturbation method are that it transforms a 3D multiparameter optimization problem into a set of 1D optimization problems and it allowed us to include several probabilistic information through the Tau model. The method was tested on a synthetic case where we generated a set of pseudologs and the corresponding synthetic seismograms. We then applied the method to a real well profile, and finally extended it to a 2D seismic section. The application to the real reservoir study included data from three wells and partially stacked near and far seismic sections, and provided as a main result the set of optimized models of facies, and of the relevant petrophysical properties, to be the initial static reservoir models for fluid flow reservoir simulations.

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