Geostatistical Stochastic Elastic Iinversion - An Efficient Method for Integrating Seismic and Well Data Constraints

摘要

We present a new stochastic algorithm for the inversion of multi-angle seismic reflection data and well logs. The probability distribution of P- and S-impedances in the subsurface is characterised by a set of representative and mutually-independent samples, or realisations. Each of these realisations not only fits the observed data to within defined tolerances, but also satisfies lateral and vertical spatial correlations from geostatistics. Thanks to a judicious choice of the form of the geostatistical constraints, and a number of optimisations that this form makes possible, this algorithm is extremely rapid. A typical inversion, generating 100 realisations over a study area, takes around one day of computation on a modest workstation. Nevertheless, the algorithm allows for complex stratigraphic geometries, which normally require more expensive inversion schemes.