Molecular correlation of free oil and inclusion oil of reservoir rocks in the Junggar Basin, China

Organic geochemistry of Carboniferous source rocks and their generated oils from the Eastern Junggar Basin, NW China

“…The molecular parameters of acyclic isoprenoids, terpanes and steranes for oils D15O and DN8O are similar to oils which were generated from the source rocks within the Middle Permian Pingdiquan Formation (P 2p ) and its age equivalent Lower Wuerho Formation (P 2w ), as documented in the previous studies (e.g., Zhou et al, 1989;Clayton et al, 1997;Pan and Yang, 2000;Chen et al, 2003a;Pan et al, 2003;Cao et al, 2005Cao et al, , 2006Cao et al, , 2012. Chen et al (2003a) and Pan et al (2003) documented molecular characteristics of oil DN1O from the interval 2760-2767 m of the Jurassic sandstone reservoir and oil components from oil-containing sandstone DN1-1 at 2764 m, respectively from borehole DN1 located near borehole DN8 (Fig. 1), demonstrating that the oil sample and oil components from the reservoir rock were derived from source rocks within the Permian Pingdiquan Formation (P 2p ).…”

“…However, oils from Permian source rocks were most likely generated from the central area of the Dongtaohaizi depression, south of the gasfield (Fig. 1, Chen et al, 2003a;Pan et al, 2003).…”

“…Numerous studies have demonstrated that the most important source rocks in the basin are within the Permian strata and for most reservoirs, especially in the northwestern area, oils are dominantly derived from three Permian source rocks, which from old to young are: (1) the Lower Permian Jiamuhe Formation, (2) the Lower Permian Fencheng Formation, and (3) the Middle Permian Lower Wuerhe Formation in the northwestern area and its ageequivalent analogs Pingdiquan Formation in the eastern area and the Lucaogou Formation in the southern basin margin (Jiang and Fowler, 1986;Jiang et al, 1988aJiang et al, ,b, 1990Zhou et al, 1989;Graham et al, 1990;Carrol et al, 1992;Zhang et al, 1993;King et al, 1994;Clayton et al, 1997;Carroll, 1998;Wang andKang, 1999, 2001;Pan and Yang, 2000;Pan et al, 2003;Cao et al, 2005Cao et al, , 2006.…”

“…In the present study, we document organic geochemical characteristics of these two sets of Carboniferous source rocks and oils in the Eastern Junggar Basin based on bulk and molecular parameters, and carbon isotopic compositions of individual n-alkanes. In addition, as demonstrated by previous studies, analysis of oil-bearing fluid inclusions and sequential extraction of oil-containing reservoir rocks are effective approaches to reveal geochemical signatures of the initial oil charges (Karlsen et al, 1993;Wilhelms et al, 1996;George et al, 1997George et al, , 1998George et al, , 2004George et al, , 2008Schwark et al, 1997;Jones and Macleod, 2000;Leythaeuser et al, 2000Leythaeuser et al, , 2007Pan and Yang, 2000;Pan et al, , 2003Pan et al, , 2005Pan et al, , 2007Gong et al, 2007;Yu et al, 2011Yu et al, , 2012. A large set of oil-containing volcanic reservoir rocks from the Kelameili gasfield were also analyzed to evaluate the source variations during the reservoir filling.…”

Oil-source correlation of Lower-Triassic oil seepages in Ni’erguan village, Southern Guizhou Depression, China

“…After the removal of the chloroform bitumen A and the subsequent acid treatment of the minerals, the included and crystal-enclosed organic matter in the mineral crystals and inclusions were obtained by Soxhlet extraction with chloroform; this extract is termed chloroform bitumen C Liu 1982, Fu andJia 1984;Xie et al 2000Xie et al , 2004. Numerous previous studies have indicated that the molecular signature of the initial oil charge could be effectively revealed with a geochemical analysis of oil, bearing fluid inclusions and the sequential extraction of oil reservoir rocks (Karlsen et al 1993;Wilhelms et al 1996;George et al 1997George et al , 1998George et al , 2004Schwark et al 1997;Leythaeuser et al 2000Leythaeuser et al , 2007Pan and Yang 2000;Pan et al , 2003Pan et al , 2005Pan et al , 2007Pan and Liu 2009;Gong et al 2007). In the present study, the T 1 d marlite was subjected to a practical sequential extraction method to recover the free, adsorbed (Bitm-A) and inclusion (Bitm-C) oils from the oil reservoir rocks to reconstruct the filling history of the oil reservoirs in Ni'erguan village.…”