黔东南凯里地区奥陶系原油及灰岩缝洞油苗地球化学特征与成因

作    者:黄羚1,李洋2,李国军1,徐政语1,熊绍云1,李昌1
单    位:1 中国石油勘探开发研究:杭州地质研究:;2中国石油大学(北京)
基金项目:受全国油气资源战略选区调查与评价项目“黔南桂中海相地层油气资源前景评价”资助
摘    要:
对黔东南凯里地区虎47 井中奥陶统大湾组轻质原油及其附近露头的中下奥陶统大湾组和红花园组灰岩晶洞和裂缝中的残余油苗进行了色谱、色-质谱及碳同位素测试分析,根据其分子地球化学特征和有机质成熟度,进行了油源对比。结果表明:原油及油苗的干酪根均来源于藻类植物,形成于还原环境;甲基菲指数揭示原油呈成熟油特征,而油苗则呈高成熟油特征。经碳同位素对比(特别是单体烃同位素对比)认为,原油及油苗均是来源于本区下寒武统牛蹄塘组泥质烃源岩,但形成期次有所不同,为同源不同期的产物。
关键词:黔东南地区;奥陶系;油苗;有机质成熟度;地球化学特征;油源对比

Geochemical Characteristics and Origin of Ordovician Well Crude Oil and Oil Seepages from Limestone Fractures and Vugs in Kaili Area, Southeastern Guizhou

Author's Name: Huang Ling, Li Yang, Li Guojun, Xu Zhengyu, Xiong Shaoyun, Li Chang
Institution: PetroChina Hangzhou Research Institute of Geology
Abstract:
It is found that beside the light crude oil from lower Ordovician Dawan rock in Well Hu-47 in Kaili area(southeastern Guizhou), abundant residual seepage oils are present in middle Ordovician Dawan and lower Ordovician Honghuayan limestone fractures and vugs at some oil seepage sites in this area. The oil samples from the Well Hu-47 and these oil seepages are analyzed by GC, GC-MS and GC-IRMS. The molecule geochemical characteristics and or ganic mater maturity indicate that the kerogen in both crude oil and seepage oils came from algae that formed in reducing environment. Methylphenanthrene indice (MPI) reveal that the crude oil is mature and the seepage oils are higher mature. There is the lower Cambrian Niutitang argillaceous source rock in this area. According to the correlation of the oil-source rock through carbon isotope testing to individual hydrocarbon, it is confirmed that both of the crude oil and the seepage oils derived from the identical Niutitang source rock but they formed in different phases.
Keywords: Ordovician; Crude oil; Oil seepage; Maturity of organic matter; Geochemical characteristics; Oil-source correlation; Southeastern Guizhou
投稿时间: 2012-05-24  
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