Typification of oils in the Timan-Pechora province according to the composition of hydrocarbon biomarkers (steranes and terpanes)

Distinctive compositional features of cyclic saturated hydrocarbon biomarkers have been established in oils from the main petroliferous lithostratigraphic complexes of various structural zones in the Timan-Pechora petroliferous province (TPPP). Four geochemical families (types) of oils in TPPP are recognized based on the variations in the geochemical parameters of steranes and terpanes including sterane ratios C27/C29 and C28/C29, K1 mat and K2 mat, diasterane/regular sterane, pregnane (C21–22)/sterane (C21–22 + C27–29), as well as terpane Ts/Tm parameters, adiantane C29/hopane C30, neoadiantane/adiantane, tryciclic terpane/pentacyclic terpane, hopane/sum of C29 steranes, etc. The distribution of various types of oil in the sedimentary sequence of TPPP makes it possible to infer source rocks for each of the four selected types.