Naslov
Low permeability Neogene lithofacies in Northern Croatia as potential unconventional hydrocarbon reservoirs

Autori
Malvić, Tomislav ; Sučić, Antonija ; Cvetković, Marko ; Resanović, Filip ; Velić, Josipa

Izvornik
Central European journal of geosciences (2081-9900) 6 (2014), 2; 182-194

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

Ključne riječi
low permeable lithofacies ; Neogene ; unconventional reservoir ; Drava Depression ; Croatia

Sažetak
Two examples of how to describe low permeable Neogene clastic lithofacies regarding outlining unconventional hydrocarbon lithofacies are presented. Both were selected from within the Drava Depression, the largest Croatian macrostructure of the Pannonian Basin System. The first example is the Beničanci Field, the largest Croatian hydrocarbon reservoir discovered in Badenian coarse-grained clastics, mostly breccia. Definition of low permeable lithofacies was connected with margins of existing reservoir, where reservoir lithology changed into transitional one, mostly depicted with marlitic sandstones. However, calculation of POS showed critical geological categories where probabilities are lower than in the producible reservoir with proven reserves. Possible new hydrocarbon volumes are located in the structural margins, along the oilwater contact, with POS of 9.375%. The assumed reserves in those areas can be classified as probable. The next example was the Cremušina Structure, where hydrocarbon reservoir was not proven, but entire structure had been located onto regional migration pathways. The Lower Pontian lithology is described from well logs as the fine- grained sandstones with large parts of silty or marly clastics. Consequently the average porosity is low for conventional reservoir classification (10.57%), but still is interesting one for considering such structure as potentially unconventional reservoir, like so called "tight" sandstones.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

Napomena
Acknowledgments: This work represents part of a thesis mentoring and accompanied geological researching onto project entitled "Stratigraphical and geomathematical research of petroleum geological systems in Croatia" (project no. 195- 1951293-0237 ; head J. Velić), which is financed by the Ministry of Science, Education and Sports of the Republic of Croatia and geological research project entitled "Development of geomathematical methods for analysis of Neogene depositional environments in the Croatian part of Pannonian Basin System" (head T. Malvić) financially supported by the University of Zagreb in programme "Supporting of researching 2" in the 2013. ; Online ISSN 1896- 1517.

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