Geochemistry and possible origin of petroleum in Palaeozoic reservoirs from Halahatang Depression

Oil charging history and pathways of the Ordovician carbonate reservoir in the Tuoputai region, Tarim Basin, NW China

“…Figure 4 shows the distribution of tricyclic terpanes (TTs) and hopanes in m/z 191 mass chromatographs of saturates from selected oil samples. The content of tricyclic terpanes (TTs) is relatively higher than hopanes in all Tuoputai oils, and the relative content of C 23 TT is higher than that of C 21 TT with a C 21 TT/C 23 TT ratio lower than 1.0, which is consistent with the majority of oils from other oilfields in the Tabei Uplift Chang et al 2013a;Xiao et al 2016).…”

“…The source of the Ordovician oil reservoir in the Tabei Uplift of the Tarim Basin has long been a controversial issue, because the oils are of high thermal maturity and there are few wells of sufficient depth to penetrate the potential source rock intervals (Li et al 2010a, b;Chang et al 2013a). However, more and more studies have indicated that oils in the Tabei Uplift are sourced from MiddleUpper Ordovician carbonate source rocks Zhang and Huang 2005;Wang et al 2008;Yu et al 2011;Chang et al 2013a).…”

“…However, more and more studies have indicated that oils in the Tabei Uplift are sourced from MiddleUpper Ordovician carbonate source rocks Zhang and Huang 2005;Wang et al 2008;Yu et al 2011;Chang et al 2013a). …”

Distribution and geochemical significance of phenylphenanthrenes and their isomers in selected oils and rock extracts from the Tarim Basin, NW China

“…1) are of typical lacustrine mudstone origin (Li et al 2004;Xiao et al 2004;Song et al 2015). Oils from Ordovician carbonate reservoirs were derived from Paleozoic carbonate source rocks (Zhang and Huang 2005;Wang et al 2008;Chang et al 2013). Dibenzothiophene, dibenzofuran, and their alkylated homologues are effective molecular markers in inferring depositional environment, maturation assessment and in tracing oil charging pathways (Bao et al 1996;Wang et al 2014;Li et al 2008;Zhang and Philp.…”

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

“…Source-related biomarker ratios for extracts from previous studies in the Tarim Basin are shown in Table 5 (Cai et al, 2009b;Chang et al, 2013;Guo et al, 2008;Li et al, 2012;Zhang et al, 2000Zhang et al, , 2004Zhu et al, 2014a). Based on the correlation of the sourcerelated biomarker ratios from endmember oils and source rocks, it can be concluded that EM1 oil originated from Cambrian-Lower Ordovician source rocks, while the EM2 and EM3 oils originated from Middle-Upper Ordovician source rocks at different stages of maturity; the maturity of the EM2 oil being lower than EM3.…”