措勤盆地它日错地区郎山组烃源岩生物标志物特征

郎山组是措勤盆地内的主力烃源岩,位于措勤盆地它日错凹陷的郎山组烃源岩为研究揭示该区有机质生源构成、沉积环境和成熟度提供了珍贵的素材。在野外调查的基础上,应用色谱和色谱-质谱分析技术,对郎山组烃源岩展开了生物标志物研究。结果表明:郎山组烃源岩遭受了1~2级的生物降解作用;正构烷烃、类异戊二烯烃、萜烷和甾烷等相关参数反映了烃源岩的母质为混合来源,并以低等水生生物(如藻类)为主。烃源岩的形成环境为相对还原的低盐度环境。烃源岩有机质热演化程度较高,达到了高成熟阶段。生物标志物参数进一步反映了郎山组烃源岩具有良好的生烃潜力,对该区油气勘探提供了重要的参考资料。

The biomarkers characteristic of Source Rocks of Langshan Formationin Taricuo Area, Cuoqin Basin

Langshan Formation is the chief hydrocarbon source layer in Taricuo depression at the north of Cuoqin basin. Langshan Formation source rocks have provided precious materials for the study of the organic matter composition, sedimentary environment and maturity. Based on field investigation, the application of Gas Chromatography and Gas Chromatography-Mass Spectrometry analysis technology, the authors researched biomarker characteristics of the source rocks. The results suggest that the source rocks underwent 1-2 levels of biodegradation. The relevant parameters such as n-alkanes, isoprenoids, terpanes and steranes reflect that the parent material of Langshan Formation source rocks are mixed sources which are mainly lower aquatic organisms, like algae. The source rocks formed in a relative reducing and low salinity environment. The thermal evolution of organic matter come up to the high mature stage. The biomarker characteristics reflect the source rocks have a good hydrocarbon generation potential. It has provided important reference data for oil and gas exploration in this area.