The research studied petroleum from Permian-Carboniferous fields from the Usinsk oil deposit in the north-east of the Komi Republic, Russia, well-bores No. 5339 (middle production zone) and No. 2956 (upper and middle production zone). Permian-Carboniferous petroleum has high viscosity (up to 11980 MPas), density (up to 0.987 g/cm3), average grade of sulphur (up to 2.5% mass) and are hard to recover. The element, component and micro-element composition of the petroleum and its fractions was established. The share of vanadyl and nickel porphyrins was measured by chromatographic separation. The research has established that the petroleum and fractions from the Usinsk oil deposit are a complex mixture of hydrocarbons and hetero-organic compounds with an elevated aromatic level and with oxygen-containing compounds playing the most important part. Total content of micro-elements in the studied samples does not exceed 0.5% mass of the petroleum's mass. The concentration of microelements in petroleum is reducing in this order: Cl, Ca, Na, V, Ni, Mg, Fe, Si, Ba, Cs, Cu, Zn, Mn, Co, Cd, P. The share of vanadyl porphyrins (VO-P) is higher than that of nickel porphyrins (NiP). The distribution of VO-P by fractions for the petroleum in both well-bores is the same and reduces in terms of resins-asphaltens-oils. The distribution of NiP does not have a clear correlation. This distribution can be associated with the chemical composition, thermodynamic and kinematic stability.