Source, oil charging history and filling pathways of the Ordovician carbonate reservoir in the Halahatang Oilfield, Tarim Basin, NW China

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).…”

“…Previous studies have been reported that most oils originating from Middle-Upper Ordovician source rocks have relatively low abundances of C 26 , C 27 TAS (C 26 20S, C 26 20R ? C 27 20S, C 27 20R) and a high content of C 28 TAS, while oils from CambrianLower Ordovician source rocks feature higher concentrations of C 26 , C 27 TAS relative to C 28 TAS (Zhang et al 2002;Mi et al 2007;Li et al 2012;Xiao et al 2016). Figure 5 shows that the Ordovician oils in the studied region have relatively low contents of C 26 , C 27 TAS and a high content of C 28 TAS, with a ratio of C 26 /C 28 20S TAS \ 0.50 and C 27 /C 28 20R TAS \ 0.60 (Fig.…”

“…Shi et al (2012) reported that the Ordovician reservoirs in the Tuoputai region have been charged twice, and the early oil charge occurred from 420 to 405 Ma and the second from 8 to 2 Ma based on the integrated analyses of microthermometry, petrography, laser Raman spectrum and confocal laser scanning microscopy of fluid inclusions. Ni et al (2016) and Xiao et al (2016) reported that there were two phases of oil charging in the Halahatang Depression, west of the Tuoputai region, the first phase was from the Middle to Late Silurian , and the second occurred during the middle .…”

“…By combining multiple molecular indicators, such as the total content of pyrrolic nitrogen compounds and 4-/1-MDBT, Wang et al (2004aWang et al ( , 2008 determined that oils charge from south to north generally in the Tahe Oilfield. Much work has also been done, using various geochemical parameters, on the oil filling history and migration orientation of Ordovician reservoirs in other oilfields in the Tabei Uplift, including the Lunnan Oilfield (Wang et al 2004b;Zhang and Huang 2005;Gong et al 2007;Lu et al 2008;Zhu et al 2013), the Yakela Oilfield (Li et al 2013a, b) and the Halahatang Oilfield (e.g., Chang et al 2013b;Fang et al 2016;Xiao et al 2016). However, little work has been done on the oil reservoir geochemistry of the Tuoputai region in the Tabei Uplift.…”

Hydrocarbon charge history of the Paleogene reservoir in the northern Dongpu Depression, Bohai Bay Basin, China

“…Since 1990s, many new methods such as fluid inclusion studies, reservoir bitumen analysis and diagenetic mineral dating have been widely used. In recent years, the fluid inclusion method has been widely used and has achieved good results (Zhao et al 2013;Guo et al 2012;Yang et al 2014;Xiao et al 2012Xiao et al , 2016Jiang et al 2015a, b, c;Liu et al 2007aLiu et al , b, 2013Gui et al 2015;Wu et al 2013;Wang et al 2015a, b). Fluid inclusions can provide valuable information on the reservoir pressure and temperature at the time of the fluid migration and entrapment as well as on the compositions of the fluids involved in diagenesis and may thus provide important insight into the mineral diagenesis and fluid dynamics within sedimentary basins (Dolníček et al 2012;Shan et al 2015;Wang et al 2015a, b;Guo et al 2014;Lü et al 2015;Li 2016).…”