3-D Basin Modeling of the Serbian Banat Region of the Pannonian Basin: Evaluating the Impact of Tectonic Inversion upon Hydrocarbon Potential

Yilmaz, Hulya ¹; Pigott, John D.¹; Radivojevic, Dejan ²; Pigott, Kulwadee L.¹; Milovanovic, Ivana ²
(1)University of Oklahoma, Norman, OK. (2) NIS, Novi Sad, Serbia.

3D basin modeling of the Eastern Banat region of the Serbian Pannonian Basin reveals the effects of tectonic inversion upon its petroleum systems and delineates possible new hydrocarbon exploration play concepts. For the analysis, two regional 2D seismic lines incorporating 28 well boreholes and 26 virtual wells were integrated into a 3D post Triassic basin volume. For geovalidation, the geochemical data included vitrinite reflectance and pyrolysis, kerogen types, TOC, and bottom hole temperature data. Along the East-West regional seismic line, a best fit for kinetic maturities requires one major tectonic extension event from ~7.3 to ~5.2 Ma with rifting betas ranging from ~1.11 to ~1.18 associated with the development of the North Banat graben. As the deepest portions of the graben west of the Kikinda Szeged horst contain coarser clastics of the Upper Miocene Endrod which westward becomes finer grained, this apparent facies dilemma is best explained as Endrod sediments upon the North Backa High initiating as distal downlaps before the High was uplifted revealing present day termination onlaps. Subsequent units then prograded from the west.

Major source rocks are Type II Badenian and Endrod sediments with maximum measured TOC' s of 4.34 and 2.18, respectively. The deepest borehole in the graben reveals that Endrod to have entered the early maturity at 5.51 Ma, shortly after the maximum crustal stretching event. Modeled migration pathways follow clastic sand conduits and/or permeable faults and end in reservoirs upon the highs. For impermeable faults, hydrocarbon terminates in the downdip position. Traps suggested by the 3D basin modeling are drapped anticlines, angular unconformities, fault traps, buttress or onlap sands, sandstone pinchouts, and updip facies changes. Principle reservoirs are clastic fluvial-lacustrine deltaic sands and possible fractured basement highs.

This study demonstrates the power of 3D basin modeling to define thermal histories of basin inversion while designating new hydrocarbon play concepts which may provide analogues for tectonically inverted portions of the Pannonian Basin elsewhere.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.