Naslov
Interdepence of Petrophysical Properties and Depth: Some Implications of Multivariate Solution on Distinction Between the Lower pontian Hydrocarbon-bearing Sandstone Units in the Western Part of the Sava Depression

Autori
Saftić, Bruno ; Peh, Zoran ; Velić, Josipa ; Juttner, Ivanka

Izvornik
Geologia Croatica (1330-030X) 54 (2001), 2; 259-277

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
pješčenjačke kolektorske stijene; kolektorska svojstva; višestruka statistička analiza; genetske stratigrafske sekvencije; donji pont; naftna i plinska polja; Savska depresija; Panonski bazen; Hrvatska
(Sandstone reservoir rocks; reservoir properties; Multivariate analysis; Genetic stratigraphyc sequence; Lower pontian; Oil and gas fields; Sava depression; Pannonian basin; Croatia)

Sažetak
Statistical analysis of reservoir data from the lower pontian clastics (the most important hydrocarbon reservoir rocks in the Sava depression), supports established knowledge of the interdepence of petrophysical properties and depth. Irrespective of the focus that the reservoir data may be studied and presented, depths always emerges as a fundamental reservoir descriptor. this is particularly evident when studyng the defferences between widely spaced oil and gas fielda, when the numerical model completely separates the two sets of descriptors variables, indicating two different sources of their internal variability. Porosity and permeability belong to "intrinsic rock properties" while depth must be ascribed to other sources, e. g. tectonic subsidence. Discriminant function weighted with depth (DF1) has such group centroid values, that zones can be drawn within a particular field that coincide with structural relationship. On the function marked with reservoir properties (DF2), group centroid values are higher close to the axes of palaeotransport channels, where sandstone layers are the thickest and particles are best sorted. Group centroid values on the third function (DF3) depict the areas of relaticely higher permeability in the apical parts of structures, possibly caused by fracturing due to folding, or by cementation of other parts of reservoir, where the circulation of pore waters was more pronounced. In the case of the most thoroughly investigated Žutica field, the inverse relationship between depth and porosity becomes evident when compared with the direction of palaeotransport and thickness of reservoir rocks on the respective structure and thickness maps.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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