| Popis: |
The article provides the results of the hydrocarbon compounds (HCS) molecular composition in open and closed pores of the Bazhenov horizon source rocks studying. Extraction with solvents of different polarity allows to withdraw additional HCS from both open and closed pores of rock samples, and their composition systematically differs both in the distribution of normal alkanes and in the values of biomarker parameters characterizing the maturity and sedimentary conditions. HCS in open pores is more thermally maturated than HCS in closed pores, and in both cases, maturity can decrease in blocked pores, especially in those sealed with soluble in alcohol-benzene resins-asphaltenes. The values of parameters Pr/Ph and dia/(dia+reg)C27 are higher for bitumen in open pores, but the values of C29/C30 and H35S/H34S are much higher for bitumen in closed pores, and can vary in blocked pores with respect to the open ones. As a result, a improved model of HCS distribution in the pore space was proposed, which shows the presence of residual light HCS in open pores, as well as two types of blocked pores, in which HCS are sealed by different resins-asphaltenes in both open and closed pore spaces. |
