Oil families and their potential sources in the northeastern Timan Pechora basin, Russia

摘要

Oil and rock samples collected throughout the northeastern Timan Pechora basin identify key oil families and correlate these oil families to stratigraphic units that sourced them based on distinctive molecular characteristics. Three distinctive hydrocarbon systems have been identified within the northeastern Timan Pechora basin. Hydrocarbons, both oil and gas, are found in elastic and carbonate reservoirs from the Lower Silurian to the Triassic, Three major oil families have been identified based on physical properties, gas chromatography: liquid chromatography, and gas chromatography-mass spectrometry. Family A oils are found in Permian-Silurian reservoirs within the Sorokin swell and Upper Devonian reservoirs within the eastern and western edges of the Khoreyver depression. This oil family is sourced from an Upper Devonian bitumen-laminated carbonate mudstone informally known as the domanik facies. Family B oils are found only in Upper Devonian reservoirs within the central Khoreyver depression. This oil family is most likely sourced from Upper Devonian hypersaline marine mudstones with significant bacterial input. Many of the family B oils were generated at temperatures less than that for peak oil generation. Family C oils are found in Carboniferous-Lower Devonian reservoirs within the northern Sorokin swell. This family is sourced from marine mudstones that have Gloecapsamorpha prisca, as well as other marine algae, present. Organic-rich Lower Devonian and Silurian shales contain similar molecular characteristics and are potential sources for the family C oils. [References: 13]