鄂尔多斯盆地红河油田原油地球化学特征及油源分析

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

通过对鄂尔多斯盆地红河油田中生界原油系统地采样和地球化学分析,研究了原油的族组成和生物标志化合物特征,在此基础上分析了油源。研究结果表明,红河油田中生界各油层组原油的地球化学特征相似,反映了这些油层组原油来自相同的油源。油源母质为混合型,水生生物和陆源高等植物对烃类生成均有贡献,且以陆源高等植物贡献较大。原油形成于还原—弱还原条件下的淡水或微咸水湖泊沉积环境。原油的成熟度一致,均为成熟原油。原油主要来源于该区延长组长7底部的油页岩。

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.