ensi3d

3D Ensemble Space Inversion and Nonstationary Geostats

This comprehensive tutorial demonstrates fast, efficient calibration of a complex 3D model. It complements a previous tutorial on a similar subject. However it shows how calibration results can be better, and can be achieved more easily, with recent software advances.

Pilot points are used in an innovative way. They support hydraulic property characterization of a model domain using spatially varying geostatistics based on a user-supplied collection of “conceptual points”. Nevertheless, pilot point deployment is relatively simple. There is no need to build a covariance matrix for these pilot points. Parameter field realism is taken care of in other ways.

Following model calibration, uncertainty analysis is undertaken in three complementary ways – linear, iterative ensemble smoother (IES) and data space inversion (DSI). All perform well when given an ENSI head start. 

All in all, the numerical cost of fitting data well, and of then exploring post-calibration uncertainty is very small.