摘要
以气相色谱、气相色谱一质谱为技术手段．对额济纳旗大狐狸山地区干泉组烃源岩的生物标志化合物进行研究，剖析生物标志化合物指示的母质来源、沉积环境、成熟度等方面的信息。干泉组烃源岩饱和烃气相色谱为”前峰型”的单峰分布，主峰碳以C18为主，说明有机质来源以海相有机质为主，Pr／Ph介于0．3～0．6之间，指示强还原的沉积环境。干泉组烃源岩具有长侧链的三环萜烷丰富、伽马蜡烷含量高和C27甾烷分布占优势的生物标志化合物组合特征，高伽马蜡烷含量揭示烃源岩有机相为咸水沉积环境，藿烷／甾烷比值的平均值为0．59，表明藻类对有机质的贡献高于细菌。C27甾烷丰度较高，说明低等水生生物藻类是生烃母质的主要生源。干泉组烃源岩甲基菲指数介于0．35--0．50，其折算的镜质体反射率Rc为2．00～2．09，与实测的镜质体反射率指示意义一致．说明干泉组烃源岩热演化处于过成熟阶段。
Based on gas chromatography and gas chromatography mass spectrometry techniques, the authors studied biomarker char- acteristics of the Ganquan Formation source rocks in Dahulishan area of Ejin Banner, analyzed the information and petroleum geo- logical significance indicated by sources of organic matter, sedimentary environment and maturity as well as some other factors. Gas chromatographic peak of saturated hydrocarbons from Ganquan Formation source rocks shows the single peak distribution of the＂ frontal peak＂, with the main peak of carbon being Cls,indicating that the main sources of organic matter were of marine organic substances; Pr/Ph ratios range from 0.3 to 0.6, indicating a strongly reducing sedimentary environment. Biomarker assemblages of Ganquan Formation source rocks have abundant tricyclic terpane with long side chains, contain high level of gammacerane, and show dominant distribution of C~ steranes. High content of gammacerane in organic matter suggests that organic facies source rocks were formed in a saltwater sedimentary environment. The average hopanes / steranes ratio of 0.59 implies that algae made more contribution to organic matter than bacteria, and high level of Cw steranes suggests that alga was the main source of hydrocarbon precursors. The methylphenanthrene index of Ganquan Formation, which is an effective molecular parameter for measuring thermal evolution of organic matter, ranges from 0.35 to 0.50, and the conversion of vitrinite reflectance Rc from this index is 2.00-2.09, indicating that Ganquan Formation source rocks were at the over-mature stage of thermal evolution.
出处
《地质通报》
CAS
CSCD
北大核心
2013年第4期652-660,共9页
Geological Bulletin of China
基金
中国地质调查局项目<西北地区中小盆地群油气资源远景调查>(编号:1212010733506)
湖北省自然科学基金项目(编号:2010CDB04305)
中国石油科技创新基金研究项目(编号:2010D-5006-0105)
湖北省教育厅重点项目(编号:D20131201)
