济阳坳陷郑家-王庄油田生物降解稠油成熟度及油源研究

Maturity and Oil Source of Biodegradation Viscous Crude in Zhengjia-Wangzhuang Oilfield of Jiyang Depression

济阳坳陷郑家王庄油田原油生物降解程度为 2～ 8级 ,生物降解是导致原油稠化的主要原因。根据甾烷、萜烷及甲基菲等成熟度参数估算 ,母源成熟度 (Ro)在 0 7～ 0 9左右。原油地球化学分析表明 ,残留烷烃中含有较高的植烷、伽马蜡烷、β 胡萝卜烷 ,甾烷分布中C2 7高 ,重排甾烷与 4 甲基甾烷含量不高 ;芳烃馏份含有脱羟基维生素E ;非烃沥青质的瞬时裂解产物中甾烷分布与残留烷烃的甾烷分布特征相似 ;单体正构烷烃与沥青质总碳同位素特征也与沙四段烃源岩可对比 ;这些证据与已报道的沙四段烃源岩特征十分相似 。

The biodegradation extent of viscous crude in Zhengjia-Wangzhuang Oilfield is level 2～8, the biodegradation is the main cause of oil densification.The sterane, terpane and methylphenanthrene are used to evaluate the oil maturation, it's found all oil is matured, the vitrinite reflectance (R_o) of oil source rock is estimated at 0.7～0.9. Higher phytane, gammacerane, β-carotane, C_(27) sterane concentration and lower rearranged sterane, 4-methylsterane are evidence among the residual alkane of crude oil. There exists dehydroxy lation vitamin E in aromatic fraction.The distribution of sterance in transient cracking products of non-asphaltine is similar with that of residual alkane.Asphaltine and alkane carbon isotope values of viscous crude are similar with Es_4 oil source rock. All of these indicates the viscous crude of Zhenjia-Wangzhuang oilfield comes from the contribution of Es_4 oil source rock.