Boreskov

PP‐21Oils from the Kuyumbinskoye field have the tricyclane index 2C 19‐20 /C 23‐26 >1, atypical formarine oils, low С 35 homohopane and C 29 steranes concentrations, higher diasterane andhopane contents.The decreased concentrations of C 29 steranes in the Kuyumba oils were reported earlierin [3]. These variations are interpreted to result from admixture of hydrocarbon from othersources.This work was supported by RFBR (10‐05‐00705) and the Earth Sciences DivisionProgram N 15.References[1]. Kontorovich, A.E., et al. (1999) Russian Geology and Geophysics 40, N 11, 1647‐1665.[2]. Kontorovich, A.E., et al. (2005) Petroleum Frontiers 20, N 3, 11‐26.[3]. Larichev, A. I., et al. (1999) Some compositional features of relict hydrocarbons from Riphean and Vendianoils of the Siberian Platform. Petroleum geology at the turn of centuries. Forecast, prospecting,exploration and development of oil fields. Proceedings, V.1: The fundamentals of petroleum geology.St‐Petersburg, VNIGRI, 280‐289.168