层序地层分析技术在冲积扇沉积相研究中的应用

Application of sequence stratigraphy technology in research of alluvial fan sedimentary facies

(1.中海石油有限公司湛江分公司,广东湛江524057;2.地航时代科技有限公司,北京100083;3.中国石油大学,北京102249)

Li Lin,Zhanjiang Branch,CNOOC,Zhanjiang 524057,China

涠西南凹陷Y6构造区流沙港组三段（流三段）地震资料品质差、井资料少,使该区沉积相研究成为一大难题。应用层序地层分析技术,以从宏观到微观、逐级剖析的层序地层解释思路为指导,以年代地层剖面研究为手段,对流三段储层沉积相进行了深入研究。用层序地层解释系统在Wheeler域进行体系域解释和沉积相分析,实现了量化计算冲积扇物源方向;在优选年代地层剖面实现有效的层序地层追踪基础上,分别对冲积扇边界及顶、底界进行追踪和识别;再根据年代地层剖面特征划分出冲积扇亚相,确定了有利勘探区带冲积扇扇中的分布范围。

In Y6 structure region of Southwestern Weizhou Sag,the 3rd member of Liushagang Formation has bad seismic data and little well data，which results in difficulty for sedimentary facies research.By adopting sequence stratigraphy technology,taking the interpretation clue “from macro to micro,analyzing step by step” as guide,and research on chronostatigraphic profiles as means,the sedimentary facies of the 3rd member of Liushagang Formation were studied.Firstly,sequence strata interpretation was applied in Wheeler domain to carry out system tract interpretation and sedimentary facies analysis,and realize quantitatively computing provenance direction of alluvial fan.Then,based on optimizing chronostatigraphic profile to realize effective tracing sequence strata,the boundary,top and bottom of the alluvial fan were traced and identified.Finally,the subfaices of alluvial fan were classified in terms of the characteristics of chronostatigraphic profiles,and the distribution of the middle alluvial fan was identified.