Petrophysical rock typing of complex reservoirsin the Visevian and Tournaisian formations of the Berezivske fieldbased on filtration capacity and elastic propertiesusing the Winland Method and Pore Geometry Structure Method

Petrophysical rock typing of reservoirs based on well logging data is always relevant. The justified principles of such typing enhance the interpretation capabilities of well logging data using reservoir models for estimating hydrocarbon reserves and predicting their productivity. The main objective of this paper was to consider the role and possibilities of rock reservoir typing based on the interpretation results of well logging data in a well 203 of the Berezivske field of the Dnipro-Donetsk depression for the visean and tournaisian formations using the integration of Winland Method and Pore Geometry Structure (PGS) Method. The authors have generated a correlation between effective pore size, absolute permeability coefficient and porosity coefficient based on Winland equation. Six different rock reservoir types were identified with the determination of effective pore size (from 0,025 to 1,8 μm). The equations were created according to the PSG rock typing methodology based on the correlation between pore geometry and pore structure parameters for each identified group. It was established that the prevailing effective pores in reservoirs were compacted pores: only a few reservoirs (type 1) were characterized by the presence of primary pores (b=0.4934). The presence of various types of secondary pores (b=0.14÷0.016) was identified in other reservoirs. For the first time in this field, the authors used Winland Method and Pore Geometry Structure (PGS) Method to classify and evaluate the relationships between elastic parameters and the inner parameters of pores for different rock reservoir types. The results showed that the proposed methodologies are essential for evaluating the elastic properties of rocks based on porosity and permeability coefficients in the form of pore geometry and pore structure.