Hydrocarbon Accumulation in Jurassic Low Metamorphic and Ophiolitic Assemblage

Vasiljevic, Taska T., Borisa R. Vuckovic, NIS Naftagas, Novi Sad, Serbia and Montenegro

In the southeast part of the Pannonian basin traps associated with large, shallow and simple structures formed in the Tertiary sediments or its basement have been explored, after many years of hydrocarbon exploration and production. Further explorations go toward grater depth and more complex geological setting of Mesozoic sequence.

The exploration area belongs to Middle Banat, Vojvodina. Integrated analyses and inter­pretation of geophysical (3D seismic survey, well logs), petrologic (core analyses), lithos­tratigrafic and biostratigraphic data gave the base for evaluation of geological model. Mesozoic formations proved to be oil-bearing and the discovery of oil and gas-condensate fields makes this area prospective.

Studied area belongs to the Vardar zone, near contact zone with Tisza Mega-unit. The area underwent intense structural deformations (over thrusting, horizontal displacement, rotation of micro blocks) through, at least, two phases of tectonics. The first one was early alpine phase, which placed Mesozoic units in the relationship (strike slip or wrench tecton­ics with great displacements). Second tectonics’ stage was compressive, forming Neogene’s basin and reactivating older faults in reverse sense, to overcome shortening. The subduc­tion zone between Tisza and Vardar unit complicated much more structural setting of micro­blocks in the studied area.

The detailed understanding of the structural framework and correct positioning of the fault could impact strongly planning of appraising and development wells. The methodolo­gy employed in processing of seismic data (Kirchhoff 3D Prestack Depth Migration) improved significantly seismic quality and give opportunity for detailed interpretation.