Pore aperture size (r36) calculation from porosity or permeability to distinguish dry and producing wells

Abstract

Four hundred eighty sandstone core samples obtained from three different hydrocarbon charged formations of different geologic ages (Pliocene; Miocene and Cretaceous) and different geographic locations (Egypt and Hungary) are used to correlate the effective pore aperture size adopted by Winland (r35) and new r36 of the present work. These pore aperture percentiles (r35 and r36) are calculated with different empirical equations and correlated with each other to declare which one is effective, simple, and has no additional sources of error. In the present work, new r36 was calculated two times: first from porosity only (Or36) and the second time from permeability only (Kr36). Both are correlated to r35.The calculated coefficient of correlations between Or36 and r35 were (R2 = 0.54, 0.71, and 0.73) for the Bahariya, Szolnok, and El Wastani formations, respectively. However, the correlation between Kr36 and r35 is showing very high coefficient of correlations (R2 = 0.9963, 0.9927, and 0.9957) for the Bahariya, Szolnok, and El Wastani formations, respectively. The novel Kr36 could be very helpful to discriminate between dry (pore aperture size 0.5 μm or 5000 A°) in case of absent of porosity data. Model verification indicates a very close matching between Kr36 and Wr35 vertical profiles in Baltim level III main reservoir (Miocene in age). This confirms the beneficial application of Kr36, which is derived from permeability only, instead of Winland-r35 in all reservoir lithofacies.