Application of 17α(H)-diahopanes in oil-source correlation of Triassic Yanchang formation in Zhoujiawan area, Ordos Basin, China

ABSTRACT

17α(H)-diahopane are extensively distributed in Yanchang formation source rocks of Ordos Basin, but the content varies greatly. The content of 17α(H)-diahopane is pretty low in Chang 7 oil shale, whereas it is very high in Chang 9 mudstones. Low diahopane abundance of Chang 8₁ reservoir extracts and similar crossplots of Ts/C29Ts and C₃₀ diahopane/C₃₀ hopane show that Chang 8₁ oils come from Chang 7 oil shale. However, Chang 8₂ and Chang 9 reservoir extracts are similar to Chang 9 source rocks in most of geochemical parameters, which indicates that the oil is derived from Chang 9 source rocks.

KEYWORDS:

• 17α(H)-diahopane
• GC-MS analysis
• oil-source correlation
• saturated hydrocarbon
• Zhoujiawan area

Funding

Funding for this research was provided by programs from the National Basic Research Program of China-973 (No. 2014CB239005) and Natural Science Foundation of China (No. 41502146).