Research of Geochemistry Characteristics and Source of Crude Oils from the Honghe Oilfield in the Ordos Basin

Crude oil samples of Honghe Oilfield in the Ordos Basin were collected systematically,and geochemical analyses were carried out,the hydrocarbon group composition and characteristics of biomarkers of crude oils were studied,on the basis of this research,the oil source were discussed at the same time.The research results show that the crude oils of Honghe Oilfield in the Mesozoic Ordos Basin have similar geochemical characteristics,reflects that they came from the same source.Their organic matters came from the mixed source of aquatic organism and higher plants,especially the higher plants made greater contribution to the oil generation.Crude oil formed in reduction to weak reduction and fresh or brackish water environment.Crude oils are all mature.The crude oils were mainly originated from the oil shale which located in the bottom of Chang-7 oil-bearing formation.