摘要
通过对东南沿海地区下白垩统野外剖面的实际观测,结合对其有机质丰度、类型和成熟度的地球化学分析,研究了烃源岩特征,讨论了油气潜力。结果表明,中国东南沿海地区下白垩统发育有早晚两期泥页岩类烃源岩,早期可以福建地区的坂头组暗色泥岩为代表,晚期可以浙江地区的馆头组暗色泥岩和暗色钙质泥岩为代表;烃源岩的有机质丰度总体达到中等—好质量烃源岩标准,并且早期优于晚期;有机质类型以III型为主,见II型及I型,晚期烃源岩好于早期;有机质热演化总体大部分进入高过成熟演化阶段,部分受火山作用影响较小的有机质尚处于成熟演化阶段;因此,综合评价认为,对于早期烃源岩,粤北地区成烃潜力较大,对于晚期烃源岩,浙江沿海和闽西地区的潜力较大。这一研究可能揭示了区域油气勘探的新领域。
By detailed field survey and organic geochemical analyses including organic matter abundance,type,and maturity of the Lower Cretaceous strata in the coastal Southeast China,the source rock features of the strata were obtained.These features allow a discussion on the hydrocarbon resource potential of the strata.The results demonstrate that there are in general two sets of argillaceous hydrocarbon source sequences,i.e.,the early Lower Cretaceous represented by the black mudstone of the Bantou Formation in Fujian Province and the late Lower Cretaceous represented by the black mudstone or calcareous mudstones of the Guantou Formation in Zhejiang Province.The organic matter abundance of the sources reached the moderate to good quality by the hydrocarbon source rock standards,and the average TOC values and the chloroform bitumen＂A＂of the early stage sources are high.The type of organic matter is mainly Type III,Types II and I can also be found and generally the types of late stage sources are better than those of early stage sources.The thermal maturity of most samples is high to over mature,and organic matter that was not significantly affected by volcanism is still in maturing stage.Thus,a relatively comprehensive hydrocarbon resource evaluation indicates that the favorable regions are the northern Guangdong Province for the early Lower Cretaceous,and the coastal region of Zhejiang Province and the western Fujian Province for the late Lower Cretaceous.These results may provide new petroleum targets for oil-gas exploration in Southeast China.
出处
《高校地质学报》
CAS
CSCD
北大核心
2011年第2期206-219,共14页
Geological Journal of China Universities
基金
自然科学基金(41092010,40872086)
中石化海相油气前瞻性课题(YPH08115)资助
关键词
下白垩统
烃源岩
油气潜力
中国东南部
Lower Cretaceous
source rock
hydrocarbon resource potential
Southeast China
