琼东南盆地崖北凹陷崖城组沉积相及煤系烃源岩分布  

The Sedimentary Facies and Coal Measures Source Rock Distribution of Yacheng Formation in Yabei Sag,Qiongdongnan Basin

作　　者：吴玉坤[1,2] 胡明毅[1,2] 刘志峰 张洋 印斌浩 

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100 [2]长江大学地球科学学院,湖北武汉430100 [3]中海油研究总院,北京100027

出　　处：《天然气地球科学》2013年第3期582-590,共9页Natural Gas Geoscience

基　　金：国家科技重大专项"近海大中型油气田形成条件及勘探技术"(编号:2011ZX05023);国家科技重大专项"海洋深水区油气勘探关键技术"(编号:2011ZX05025)联合资助

摘　　要：崖北凹陷主力烃源岩是崖城组煤系烃源岩,而煤系的分布受控于沉积相带。为弄清煤系烃源岩分布特征,为油气勘探工作提供参考,通过对区域地质背景、古生物、岩性组合、水动力条件、古地形及与现代沉积类比等综合分析,指出崖北凹陷崖城组主要发育潮坪—潟湖沉积体系。崖城组沉积时期,潮坪之上地势宽广、平坦,并生长着蕨类和红树林等高等植物,有利于煤系的形成和聚集;而凹陷内相对封闭的水动力条件又有利于煤系的保存。因此,潮坪具备了煤系形成、聚集和保存的有利条件,是发育煤系烃源岩的有利沉积相带。崖北凹陷内的潮坪主要发育在南部和东南部缓坡带,其中东南部缓坡带崖城组埋藏深,有机质热演化程度高,推测其已生成油气。The primary source rock of Yabei Sag was coal measures of Yacheng Formation in Oligocene and its distribution was controlled by sedimentary facies. According to the analysis of regional geological set- ting, paleontology, lithology assemblage, tectonic feature, paleo-topography etc, the sedimentary facies of Yacheng Formation are mainly tidal flat, lagoon and partly fan-delta. The tidal flat grows on the place where the slope is gentle and the topography is broad. Sporopollen analysis showed that there were a lot of mangrove trees in Yabei Sag during the period, which could form coal after death. The relative closed hy- drodynamic condition in the sag is favorable for the formation of coal measures. Therefore, tidal flat bears favorable conditions for the formation, accumulation and preservation of coal measures and is a favorable sedimentary facies belt for the development of coal measures source rocks. Tidal flat in the Yabei Sag is mainly developed in the south and southeast gentle slope. Yacheng Formation in the southeast gentle slope has greater burial depth and higher thermal maturation of organic matter, indicating the formation of oil and gas.

关 键 词：崖北凹陷 崖城组 煤系 烃源岩 琼东南盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]