Review article
History of geostatistical analyses performed in the Croatian part of the Pannonian Basin System
Tomislav Malvić
; INA-Industry of Oil Plc., Sector for Geology and Geological Engineering, Šubiceva 29, 10000 Zagreb
Abstract
Development of geostatistics, applied in the analyses of the hydrocarbon reservoir in Croatia, can be followed through four main stages. The first included variogram analysis in one dimension mostly performed in the area of the Bjelovar Subdepression. The second encompassed Simple and Ordinary Kriging techniques for porosity mapping, the first cokriging map and calculation of mean square error as validation tool for maps. It was followed by work on application of "jack-knifing" sampling technique and making algorithm for Lagrange multiplicator estimation. The last stage was period of work with Indicator Kriging for lithofacies mapping, and using of simulation (Gaussian and Indicator) mostly for estimation of zonal uncertainty. The selection of reservoir variables applicable for geostatistical mapping mostly included porosity (variable with theoretically normal distribution) and thickness (with normal distribution in special cases). Geostatistical maps are the best visual outcomes for reservoir properties when 20 or more hard data is available. This limit often can be reduced on datasets of 10 points when secondary variable is available.
Keywords
geostatistics; kriging; cokriging; simulations; Pannonian Basin System; Neogene; Croatia
Hrčak ID:
86215
URI
Publication date:
31.8.2012.
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