CLASTIC HETEROFACIAL SEDIMENTS IN THE SEDIMENTARY COMPLEXES OF THE SOUTHERN OIL AND GAS REGION OF UKRAINE

Abstract

In this article the author carried out sedimentary and genetic modeling of facies parameters within heterogeneous geological bodies based on the analysis of geological and geophysical materials in the Southern Ukrainian oil and gas region. Special attention was paid to clastic facies and parameters demonstrating the degree of heterogeneity and a wide range of facial settings of the sedimentation basin. The data from lithological, geochemical, and geophysical field studies of wells was interpreted to predict hydrocarbon traps. This resulted in the facial diagnostic of the groups of geological bodies of clastic rocks coexisting with sediments of both tectonic and ridge morphological structure of the study area. Such diagnostics allowed us to build a prognostic lithologicfacial (sedimentation) section. Based on the modeling of the Vendian top (Vendian is a stratigraphic unit partially corresponding to Ediacaran) and the Jurassic base, a schematic map of the Paleozoic sediments was constructed for the first time, which made it possible to identify zones of the potential distribution of the former reef structures. The article presents the spatial forecast of hydrocarbon reservoir distribution in geological bodies of oil and gas bearing complexes within the PreDobruja Trough. The data allow forecasting a large number of traps, mainly small ones, formed by clusters of cavernous dolomites, limestones, and mixed rocks confined to certain cyclical elements and, in particular, associated with diastems. Most of such traps are caused by metasomatic dolomitization and paleokarst.

Keywords

• oil and gas
• geological bodies of fractured facies
• cluster groups
• pre-dobruja trough