Evaluation of the impact of rock fracturing on the reservoir properties on the example of the hydrocarbon-bearing sandstones in the Polish part of the Western Carpathians - a case study

AGH University of Science and Technology, Faculty of Drilling, Oil and Gas, 30 A. Mickiewicz Av., 30-059 Krakow, Poland

^* Corresponding author: kulynych@agh.edu.pl

Abstract

So far, the largest documented reserves of oil in the Skole unit are found in the Wańkowa-Łodyna-Brzegi fold, where the reservoir rock is composed of the sandstones belonging to layers of the menilite series. The oil inflow from Inoceramian, Hieroglyphic and Krosno layers was also obtained from this fold. These layers characterized by a low level of reservoir parameters, are associated with the presence of a system of fractures. The impact of fracturing on the permeability of these sandstones is of interest to the oil industry. The aim of the research was to carry out measurements of the basic geometric parameters of fractures, i.e: the length of the fracture trace, the assessment of the degree of mineral fill, the openness and the determination of the angle and azimuth of fracture dip. Then, linear densities, surface coefficients of fracture and the fracture permeability coefficient were calculated for each measuring field. Obtained research results in the form of diagrams, tables and diagrams showed that inoceramian sandstones belong to rocks of low-class reservoir capacity. The analyzed sandstones are characterized by low permeability and have a low effective porosity. The results of the analyzes carried out simultaneously confirmed the effect of the fracturing of inoceramian sandstones on their potential permeability.