查干凹陷下白垩统烃源岩地球化学特征  

Geochemical characteristics of hydrocarbon source rocks of the Lower Cretaceous in the Chagan Sag

作　　者：刘军[1] 罗小平[1] 李辉[1] 李新军[2] 

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059 [2]中国石化中原油田分公司勘探开发科学研究院,河南濮阳457001

出　　处：《岩性油气藏》2013年第1期75-80,87,共7页Lithologic Reservoirs

基　　金：中国石化重大科研攻关项目"银-额盆地查干凹陷油气富集主控因素研究"(编号:P10001)资助

摘　　要：下白垩统巴音戈壁组、苏红图组湖相暗色泥岩是查干凹陷发育的主要烃源岩。从有机质丰度、有机质类型、有机质成熟度以及生物标志物特征等方面研究了查干凹陷下白垩统烃源岩的地球化学特征。研究结果表明:该烃源岩有机质丰度高,整体上为较好烃源岩;有机质类型属过渡型,其中巴音戈壁组有机质类型优于苏红图组,前者以Ⅱ1—Ⅱ2型为主,后者以Ⅱ2—Ⅲ型为主;有机质热演化程度较高,均达到了成熟阶段,部分处于高成熟—过成熟阶段;该烃源岩发育于湖相弱氧化-弱还原沉积环境,有机质母质为以低等水生生物为主、高等植物为辅的混源输入。Lacustrine dark mudstones of the lower Cretaceous Bayinggebi Formation and Suhongtu Formation are the main hydrocarbon source rocks in the Chagan Sag. This paper revealed the geochemical characteristics of the source rocks on the basis of the abundance, types and maturity of organic matter and biomarker analysis. The results show that hydrocarbon source rocks have high abundance of organic matter and belong to good hydrocarbon source rocks, and the type of organic matter belongs to transition type. The organic matter type of Bayinggebi Formation is superior to that of Suhongtu Formation. The former is mainly of Ⅱ1 - Ⅱ2, while the latter is mainly of Ⅱ 2 - Ⅲ. The organic matter of the hydrocarbon source rocks has a high degree of thermal evolution and is at maturity stage, even a high-post maturity stage. The hydrocarbon source rocks occurred in the weak oxidation-weak reducing environment, and the organic source material is mainly lower aquatic plants mixed with some higher plants.

关 键 词：烃源岩 地球化学 生物标志物 下白垩统 查干凹陷 

分 类 号：TE122.113[石油与天然气工程—油气勘探]