下刚果盆地Madingo组海相烃源岩岩相特征和沉积模式

发布时间：2018-04-27 18:28

本文选题：下刚果盆地 + Madingo组　；参考：《石油学报》2017年10期

【摘要】：通过薄片镜下观察、扫描电镜、X射线衍射和常微量元素测量等分析结果,根据细粒沉积物矿物组成、岩石组构、微古生物与典型矿物特征,在下刚果盆地Madingo组海相烃源岩中识别出了6种烃源岩岩相:粉砂质细粒岩相、富放射虫细粒岩相、磷质细粒岩相、富有孔虫细粒岩相、灰质细粒岩相(灰泥)和黏土质细粒岩相。细粒沉积物岩相、微古生物化石、微常量元素和地震资料综合分析表明Madingo组海相烃源岩中发育含生物硅的生物沉积、含磷酸岩质的上升流沉积、富含硅质碎屑颗粒的悬浮沉积和粒序层理的底流沉积。下刚果盆地Madingo组海相烃源岩的沉积背景总体上属于裂后期陆架内部低能水介质条件下的还原环境,其沉积早期在大陆架内部发育半封闭—封闭的局限海环境,堆积了富含放射虫的优质烃源岩;Campanian期以后,区域地质背景转变为开阔陆架,发育与陆架上升流相关的富含磷酸盐与有孔虫的优质烃源岩。
[Abstract]:According to the results of SEM X-ray diffraction and trace element measurement, according to the mineral composition, rock fabric, micropaleontology and typical mineral characteristics of fine-grained sediments, In the marine source rocks of the Madingo formation in the Lower Congo Basin, six types of source rock facies were identified: silty fine-grained facies, radiolarine-rich fine-grained lithofacies, phosphorous fine-grained facies, foraminifera-rich fine-grained lithofacies. Fine grained lime-grained lithofacies (plaster) and clay fine-grained lithofacies. A comprehensive analysis of micropaleontological fossils, microconstant elements and seismic data shows that biogenic silicon-bearing biogenic deposits and upwelling deposits of phosphatite have been developed in the marine source rocks of the Madingo formation. Suspension deposition of siliceous clastic particles and bottom flow deposition of sequence stratification. The sedimentary setting of marine source rocks of Madingo formation in Lower Congo Basin is generally a reduction environment under the low energy water medium condition in the continental shelf during the late stage of the rift. The early sedimentary environment developed in the continental shelf is semi-enclosed and confined sea environment. After the Campanian period of high quality hydrocarbon source rocks rich in radiolarian, the regional geological background changed to open shelf and developed high quality source rocks rich in phosphate and foraminifera associated with upwelling of shelf.
【作者单位】：中国地质大学构造与油气资源教育部重点实验室;中国地质大学资源学院;中海油研究总院;
【基金】：国家重大科技专项(2016ZX05032-001)资助
【分类号】：P618.13

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