Main types of reservoir rocks and their petrophysical properties of the western oil-gas region of Ukraine

The effectiveness of exploration of hydrocarbon deposits, selection of optimal discovery technologies, and their development largely depend on the reliable forecast of reservoir rock types and their petrophysical properties. Here, we review the findings for lithological-stratigraphic complexes of the Western oil-gas region of Ukraine and establish the main types of reservoir rocks and their petrophysical properties for the Volyn-Podillya edge of the East European Platform, the Carpathian Foredeep (Outer and Inner zones), and the Transcarpathian depression. Methods included an analysis of the available geological-petrophysical information on lithological-petrographical, structural-textural peculiarities and petrophysical properties of deposits; laboratory investigations of cores; mathematical-statistical processing of data; study of the influence of thermobaric conditions and compound stressed state of the section upon the formation of different types of reservoir rocks and their capacity-filtration parameters; and construction of standard geological-petrophysical sections of the promising producing areas. According to the findings, in the sedimentary complex, there are reservoir rocks of different types (from low-porous consolidated? granular to composite porous-fractured-cavernous) due to the influence of sedimentary, geotectonic, thermobaric, geothermal, and other factors influencing their formation.