Saturated hydrocarbon geochemical characteristics of the oil sand from Beipiao Formation in Jinyang Basin，western Liaoning Province: A case study of SZK02 Well

There have been found four oil and gas shows from SZK02 well in Jinyang Basin. Using gas chromatography and gas chromatography mass spectrometry techniques, the authors studied the characteristics of biomarker compounds of Beipiao Formation oil sand. Thin fluorescent display identification shows that disseminated oily bitumen widely exists between rock grains; the characteristics of biomarker compounds of oil sand reveal abundant n-alkanes and high level of Pr/Ph ratio and show dominant distribution of re(H)-hopanes and rearranged sterane, which suggests that the oil sand was formed in an oxidized lacusrtine facies environment. The organic matter evolution is at a mature to highly mature stage. According to the distribution and geochemical compositions of biomarkers, the oil sand could be divided into two types. Type one is found to be located at the shallow depth of the SZK02 well, which reflects abundant re-drimane, Ts, C30-re(H)-hopanes and structurally-unknown C30-re(H)-hopanes. Type two is found to be located at the deep depth of the SZK02 well, which generally has abundant 8β-homodrimane, relatively low Ts/Tm ratios and dominant C30-hopanes in the pentacyclic triterpenoid. The results of oil and source correlation show that oil sand is mainly derived from two different source rocks.