Results of pore space structure evaluation and complex analysis of petrophysical data for Zarichna area samples

Nowadays due to high depletion of conventional hydrocarbon sources in Ukraine, investigations and exploration of unconventional hydrocarbon reservoirs became very important. In this work samples from Zarichna area (southern part of Dnieper-Donets Basin), were investigated. The purpose of studies was to estimate the petrophysical parameters of the sample collection, to determine their pore space structure and to decide if these samples can be identified as poor-porous oil and gas reservoirs. Studied samples have predominately clastic and carbonate composition with organogenic inclusions. Macro- and micropetrographic analysis were carried out during the lithological and petrographic study of samples. Accordingly to the conducted petrophysical parameters studies and on the basis of statistical analysis of relationships between the properties of Zarichna area samples collection, few samples of rocks were chosen as promising poor-porous reservoirs for the next studies. Rock physics data obtained during the experiment under the variable pressure conditions were used for the assessment of pore space structure. This assessment made the estimation of different types of pores content possible. The analysis of all obtained data made clear that only dolomite limestones and some sandstones from the whole sample collection can be identified as compacted reservoir rocks due to presence of fracture porosity.