Carbonate Reservoirs of the 6042 Deleni Well (Târnava Basin, Romania): Questions Arising for Future Exploration

J. Szilamér Kovács¹, Marcel A. Piteiu¹, Ioan I. Bucur², Emanoil Sãsãran², Ovidiu Gh. Pinca¹, and István Nagy^2
1S.N.G.N. Romgaz, 551025 Medias, Romania
²Babes-Bolyai University, Cluj-Napoca, Romania

In Transylvania (Romania), systematic hydrocarbon exploration had started after 1908, when the natural gas was rediscovered accidentally for the third time in the history, while searching for potash (Wanek, 2005).
In the last decades, intensive 2D seismic surveying opened the gates for oil-exploration; however the large number of dry wells crosscutting the Badenian Salt Formation generated some skepticism. So far, the 6042Deleni deep-penetration well is the only wildcat to witness oil-shows in the Transylvanian Depression, since 1990. It is located over an inverted block in the Târnava Basin, underlying roughly 2500m Neogene sediments. The Târnava Basin is an Upper Cretaceous extensional basin (Krézsek, 2006), in the south-central part of the Transylvanian Depression. At this location, the Pre-Salt sequence comprises 916m of Senonian deep-marine siliciclastics, Aptian-Albian outer-shelf, and Oxfordian – Tithonian (?Neocomian) shallow platform carbonates (Bucur et al., 2004).
This study makes an effort to put together industrial and academic data, in particularly those concerning (1) paleoenvironmental analysis, (2) diagenetic history of carbonates, (3) tectonic subsidence, deciphered from one dimensional back-stripping of sediments involving geophysical log data, in order to sum up the reservoir properties of Mesozoic sediments, encountered by this well.
And finally, temptation is made to predict reservoir properties within the Târnava basin, at marginal settings. As supported by 2D seismics, here end up theoretical migration pathways, while stratigraphic traps occur more frequently.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece