Electrical properties of cambrian rocks in Volyno-Podillia

Abstract

In this article, we present the results of applying a petroelectrical research technique to complex terrigenous and carbonate reservoirs. There have been determined the petroelectrical properties and their relation to porosity and permeability of sandstones, dolomites and limestones (Cambrian deposits) from the Volodymyrska area, Volyno-Podillia. The aim of the research was to build petroelectrical models of reservoir rocks to ensure a comprehensive analysis of electrical parameters of rocks and their correlation with porosity and permeability. Determining effective resistivity of reservoir rocks can provide data on: changes in different types and groups of rocks, stratigraphic horizons, facies and geological sections; correlations between effective resistivity and mineral composition, pore structure, substance phase ratio, electric field intensity and frequency; resistance variations due to epigenetic transformation and metamorphic changes in rocks.Petrophysical laboratory studies included determining: bulk density of rocks (both dry and saturated with synthetic brine); effective porosity (obtained by nitration and synthetic brine saturation); residual water saturation factor (by centrifugation); permeability (by stationary nitrogen filtration method); interval time (P-wave velocity) and electrical resistivity. Laboratory research yielded data on the petroelectrical parameters of Cambrian sandstones, dolomites and limestones from the hydrocarbon prospective Volodymyrska area, as well as empirical correlations between petroelectrical parameters, porosity and permeability of the studied rocks.It There have been found correlations between electrical resistivity and porosity ratio, as well as resistance increase and the water saturation ratio in the laboratory and reservoir conditions, which may be used as a framework for geological interpretation of geophysical data. These correlation dependences are generally approximated by the power function. Data analysis shows that petroelectrometric studies are a powerful tool in laboratory and field research, being efficient enough to give extensive and useful information about rock properties. Laboratory data on electrical resistance of rocks may be employed to further reinforce the interpretation of the results of electrometric well logging and electric exploration.