STEPHANESCU, M., Institute of Geology and Geophysics, Bucharest, Romania; and N. BALTES, Oil and Gas Research Institute, Bucharest, Romania

ABSTRACT: Do Hydrocarbon Prospects Still Exist in the Eastern Carpathian Cretaceous Flysch?

Cretaceous strata are involved in almost all of the East Carpathian nappes; however, only the Ceahlau, Bobu, Teleajen, Macala, and Audia nappes are composed mainly of Cretaceous flysch.

In all of these nappes, the presence of reservoir rocks has been established. Seeps occurring in the Teleajen nappe and shows obtained from the Macala nappe suggest the presence of effective hydrocarbon source rocks. Structural traps are present in all nappes. Stratigraphic trapping conditions apparently are restricted to the Teleajen nappe.

The Teleajen nappe involves 40-400-m-thick black Hauterivian shales (source rock), 500 m of Barremian-Aptian shaly-sandy flysch (source rock), 2000 m of Albian shaly-sandy or sandy-shaly flysch (possible source rock), up to 1000 m of Vraconian-Cenomanian sandy flysch (reservoir rock), and 20-200 m of Cenomanian-Turonian shaly flysch (possible source rock). Particularly in the external parts of the Teleajen nappe, the sandy flysch grades laterally into shaly-sandy flysch, thus providing for potential stratigraphic traps. Reservoir rocks are involved in folds and structures controlled by reverse faults. In the outcropping part of the Teleajen nappe, such structures are deeply eroded to the degree that potential seals are breached. However, in the western parts of the Teleajen nappe, suc structures are sealed by the more internal Ceahlau and Bobu nappes.

We conclude that hydrocarbon prospects do still exist in the internal, underthrusted parts of the Teleajen nappe.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.