Compensating for estimation smoothing in kriging
- 121 Downloads
Smoothing is a characteristic inherent to all minimum mean-square-error spatial estimators such as kriging. Cross-validation can be used to detect and model such smoothing. Inversion of the model produces a new estimator—compensated kriging. A numerical comparison based on an exhaustive permeability sampling of a 4-ft2 slab of Berea Sandstone shows that the estimation surface generated by compensated kriging has properties intermediate between those generated by ordinary kriging and stochastic realizations resulting from simulated annealing and sequential Gaussian simulation. The frequency distribution is well reproduced by the compensated kriging surface, which also approximates the experimental semivariogram well—better than ordinary kriging, but not as well as stochastic realizations. Compensated kriging produces surfaces that are more accurate than stochastic realizations, but not as accurate as ordinary kriging.
Key wordsordinary kriging bias smoothing conditional simulation compensated kriging
Unable to display preview. Download preview PDF.
- Deutsch, C. V., and Journel, A. G., 1992, GSLIB—Geostatistical Software Library and user's guide: Oxford Univ. Press, New York, 340 p. and two diskettes.Google Scholar
- Giordano, R., Salter, S. and Mohanty, K., 1985. The effect of permeability variation on the flow of porous media: Soc. Petroleum Engineers, Paper SPE 14354, 31 p.Google Scholar
- Isaaks, E. H., and Srivastava, R. M., 1989, An introduction to applied geostatistics: Oxford Univ. Press, New York, 561 p.Google Scholar
- Olea, R. A., 1996, XVAN: A computer program for the analysis of spatial estimation errors: Computers & Geosciences, v. 22, in press.Google Scholar