Inkluzje fluidalne w halicie oraz bituminy w solach ewaporatów mioceńskich ukraińskiego Przedkarpacia jako wskaźnik występowania nagromadzeń węglowodorów w niżej leżących utworach

Abstract

Fluid inclusions in halite and bitumens in rock salt from Miocene evaporites in the Ukrainian Fore-Carpathian region: as indicators of hydrocarbon accumulations in the underlying strata.A b s t r a c t. Fluid inclusions in halite from Miocene rock salt of the Ukrainian Carpathian Foredeep Basin in locations where evaporites overlie oil and gas reservoir rocks are characterized by their high methane content and the presence of oil droplets in some of them. They are thus similar to fluid inclusions reported from geochemical aureoles around oil and gas accumulations in the Zechstein (Upper Permian) of western Poland (Kovalevych et al., 2008). Geochemical analyses of bitumen in bulk samples of rock salt (including content and distribution of n-alkanes and isoprenoids, carbon isotope ratios) suggest a varied origin: hydrocarbon extracted from halite from boreholes located in proximity (proved or assumed) of oil and gas deposits (Lopushna-7, Grynivka-525) are probably related to organic material dispersed within the rock salt itself, and those from the barren areas (Verkhniy Strutyn-29) are most probably cogenetic with oil accumulated in the deposits of the Boryslav-Pokuttya Nappe.