摘要
鄂尔多斯盆地晚三叠世长7期发育了一套半深湖—深湖相优质烃源岩,其有机质丰度在延长组生油岩中最高,是该盆地最主要的油源岩。岩石薄片镜下观察显示长7段优质烃源岩呈纹层状,有机质十分发育;有机地球化学分析表明,其形成于水体较深的还原沉积环境下,有机质丰度高,干酪根类型为Ⅰ,Ⅱ型,有机质来源以贫13C的湖生低等生物——藻类为主,并且有机质已达到成熟演化阶段;综合测井资料认为,研究区延长组烃源岩在长71、长72、长73均有分布,优质烃源岩主要分布在长73油层组,且厚度大,分布面积广。对这套优质烃源岩的精细研究,在马岭地区石油勘探以及低渗透储集层油藏成藏机理的深化认识上具有重要意义。
A set of high-qualify source rocks with semi-deep to deep lacustrine fileies develop in Chang 7 of Yanchang Formation at Late Triassic in Ordos Basin. The abundance of organic matter is highest in Yanchang Formation source rock. This oil source rock is tile most important source rocks in Ordos Basin. Rock slice observations show that the Chang 7 high quality source rocks are characterized by the extraordinary development of organic matter laminas. The analyses of the detailed geochemical data show that the Chang 7 high-quality source rocks form under the reductive sedimentary condition with deep water body. The abundance of organic matter is high and the kerogen is Type Ⅰ - Ⅱ. The main organic matters originate from alga, a low form of lacustrine organism poor in 13C, ant the organic matters are in maturation and higtl maturation evolution stage. The comprehensive logging data show that in study area, the source rocks of Yanchang Formation mainly distribute in Chang 71, Chang 72 and Chang 73, the high-quality source rocks mainly distribute in Chang 73 oil-bearing series with in large thickness and wide distribution. The precise delimitation on this high-quality source rock is of great importance for oil exploration and deep understanding on petroleum accumulation mechanism of low permeability reservoir in Maling Area.
出处
《断块油气田》
CAS
2014年第1期24-27,共4页
Fault-Block Oil & Gas Field
基金
中国石油科技创新项目课题"中国西部典型髙酸值油藏的成因机理解剖"(2008D-5006-01-10)
关键词
烃源岩
延长组长7油层组
马岭地区
鄂尔多斯盆地
source rock
Chang 7 oil-bearing series of Yanchang Formation
Maling Area
Ordos Basin