OIL- AND GAS-BEARING CAPACITY LITHOFACIES CRITERIA ANALYSIS OF MAIKOP DEPOSITS IN THE NORTHWESTERN BLACK SEA SHELF

The article focuses on the results of Oligocene-Lower Miocene complexes of the Black Sea West shelf litho-facial oil and gas occurrence criteria determination. A number of oil and gas fields have been discovered in Maikop deposits within South oil and gas Region of Ukraine for the last decade. Most of these deposits are concentrated in Ukrainian part of the Black Sea and Azov Sea waters. Search and exploration of these fields is complicated by the high level of vertical and lateral heterogeneity of Maikop deposits, due to litho-facial zonality of the basin and cyclical nature of sedimentary process, also by variety of hollow space types even within one lithotype. This work was made for hydrocarbon potential estimation of explored area, and to determine criteria which control collectors and seals spreading regularity and also their combination in reservoirs and relation with oil-and gas- bearing rocks. Following criteria were identified as main in litho-facial sense: litho-stratigraphic (composition of deposits, porosity, permeability, reservoir rocks stratigraphic levels extent, structural features and geological units completeness, erosion zone boundaries) and paleogeographic (reservoir facies). Initial data for this article were drilling data of 55 parametric and exploration wells of the Black sea North-West shelf, core material analysis, geophysical wells research (GWR) and geological interpretation of seismic data results. Following methods were used in research: litho-facial analyses, GWR data and geological and industrial information analyses, cycle stratigraphic analysis and well log correlations, particle size and texture analysis, litho-petrographic methods, paleogeographic reconstruction method