Multiple-sourced features of marine oils in the Tarim Basin, NW China – Geochemical evidence from occluded hydrocarbons inside asphaltenes

De-convoluting crude oil mixtures from Palaeozoic reservoirs in the Tabei Uplift, Tarim Basin, China

“…generally not less than 90%). This conclusion is also supported by previous studies which verified the oils in the Palaeozoic reservoirs of the Tarim Basin originated from the Cambrian-Lower Ordovician and Middle-Upper Ordovician marine source rocks having different maturities (Li et al, 2010(Li et al, , 2015Yu et al, 2011;Zhu et al, 2012Zhu et al, , 2013Zhu et al, , 2014bTian et al, 2012b;Tian, 2013).…”

“…1. The Tz62 Silurian oil (sample 61 from the Tazhong Uplift) that was identified as the endmember oil generated from the Cambrian-Lower Ordovician source rocks (Li et al, 2010(Li et al, , 2015Tian et al, 2012b;Tian, 2013) was added to the sample set to meet the needs of geological interpretation.…”

“…A similar conclusion was drawn by Hanson et al (2000). An increasing number of studies suggest that marine oils from Palaeozoic reservoirs are actually mixtures generated from two marine source rocks (Li et al, 2010(Li et al, , 2015Yu et al, 2011;Zhu et al, 2012Zhu et al, , 2013Zhu et al, ,2014bTian et al, 2012b ;Tian, 2013 contribute to the oils and when and how the mixing process occurred. Li et al (2010Li et al ( , 2015 showed that the majority of oils in the Tazhong Uplift are mixtures derived from two source rocks and calculated the percentage contributions of the CambrianLower Ordovician ranging from 19% to 100% by combining carbon isotopic compositions and concentrations of n-alkanes (averaged d…”

Determination of the series of even carbon numbered n-alk-1-enes trapped inside geomacromolecules

“…However, recent studies have shown that a series of even carbon numbered n-alk-1-enes are present in the trapped fractions of asphaltenes (Yang et al, 2009;Zhao et al, 2010Zhao et al, , 2012Tian et al, 2012) and solid bitumens (Cheng et al, 2012(Cheng et al, , 2013. They may be stable in these geomacromolecules owing to the protection afforded by the matrix, which inhibits transformation of the trapped n-alk-1-enes during later geochemical processes.…”

Multiple charges to Sinian reservoirs in the middle Sichuan basin, SW China: Insight from the adsorbed/occluded hydrocarbons in solid bitumens

“…The occluded hydrocarbons can be well preserved by the macromolecular structures and have been found useful in the study of organic matter with depleted soluble fractions (Cheng et al, 2012), oil (bitumen)-source correlation (Liao and Geng, 2002;Cheng. et al, 2014a) and identification of mixed-source reservoirs (Zhao et al, 2010;Tian et al, 2012aTian et al, , 2012b.…”