Seismostratigraphic Interpretation of Upper Cretaceous Reservoir from the Carpathian Foreland, Southern Poland

Abstract

The Upper Cretaceous complex in the central part of the Carpathian Foreland (southern Poland) is relatively poorly recognized and described. Its formations can be classified as unconventional reservoir due to poor reservoir properties as well as a low recovery factor. The main aim of the article is to expand knowledge with conclusions resulting from the analysis of the latest seismic data with the application of seismic sequence stratigraphy. Moreover, the seismic attributes analysis was utilized. The depositional architecture recognition based on both chronostratigraphic horizons and Wheeler diagram interpretations was of paramount importance. A further result was the possibility of using the chronostratigraphic image for tectonostratigraphic interpretation. Two distinguished tectonostratigraphic units corresponding to megasequences were recognized. A tectonic setting of the analyzed interval is associated with global processes noticed by other authors in other parts of the central European Late Cretaceous basin, but also locally accompanied by evidence of small-scale tectonics. This study fills the gap on the issue of paleogeography in the Late Cretaceous sedimentary basin of the Carpathian Foreland. It presents the first results of detailed reconstruction of the basin paleogeography and an attempt to determine the impact of both eustatic and tectonic factors on sedimentation processes.

Examples of Paleokarst in Mesozoic Carbonate Formations in the Carpathian Foreland Area

“…Above the mentioned breccia, a dense network of multidirectional fractures and cracks, both low angle and high angle, can be observed in the XRMI image, among which it is possible to distinguish fractures filled with low-resistivity material (most likely clay) or cemented with high-resistivity material (presumably calcite). It is worth mentioning that locally, in addition to calcite cements, anhydrite cements have also been found in Jurassic formations (based on an analysis of core material), mainly present within Jurassic organic buildups [36,37]. Among the fractures described above, a large group are fractures widened by dissolution processes.…”