Area and cross-section distribution of viscous waxy oils in deposits located in the southeast of West Siberia

Abstract

The paper considers the resource potential of viscous waxy oils occurring in the southeast of West Siberia, Tomsk region in particular. Now the study of such oils is the extremely urgent issue caused by the large-scale development of difficult-to-recover oil reserves. The authors have obtained the data on composition and properties of oils from new wells in Tomsk region. The database of oils at the Institute of Petroleum Chemistry SB RAS was supplemented with descriptions of the properties of 16 oils from the wells of Mayskoye, Sredne-, Zapadno- and Yuzhno-Mayskoye oilfields located in Festivalnaya, Vostochno- and Yuzhno-Festivalnaya areas and of 3 oils from Kiev-Eganskoe oilfield. By physicochemical properties (density at 20 °C, viscosity at 20 and 50 °C, congelation point, sulfur and paraffin contents and yields of distillate fractions at 200 and 300 °C) the oils were estimated and classified according to the specifications to oils coming into the pipeline transportation system for subsequent export. The obtained geochemical characteristics of oils on composition of n-alkanes testify to oxidative, less often sub-oxidative conditions for accumulation of oil-generating organic matter and to a wide range of oils thermal transformation (from slight to significant). The specificity of occurrence and location of viscous waxy oils in the southeast of West Siberia was analyzed. It was ascertained that the deposits of the most viscous oils with high sulfur, paraffin, resin and asphaltene contents and high gas content are located in the area of the basin transition sedimentogenesis. The analysis of the specific occurrence and location enables one to give correct prediction of spatial zoning and detection of viscous waxy oils.

Keywords

• viscous waxy oils
• physicochemical oil properties
• geochemical characteristics of oils
• age of oil-enclosing rocks
• West Siberian oil- and gas bearing basin