查干凹陷下白垩统层序地层格架与演化

EVOLUTION AND SEQUENCE STRATIGRAPHIC FRAMEWORK OF LOWER CRETACEOUS IN CHAGAN DEPRESSION

郭彦如 于均民 樊太亮

Guo Yanru Yu Junmin Fan Tailiang

查干凹陷位于银额盆地东北角,依据地震、岩性、古生物、地化及测井等资料,其白垩系可划分出 1个一级层序、2个二级及 7个三级层序。巴音戈壁组一、二段沉积时期形成层序Ⅰ,Ⅱ;苏红图组沉积时期,形成层序Ⅲ,Ⅳ,Ⅴ;银根组沉积时期形成层序Ⅵ,Ⅶ。查干凹陷已有钻井显示,58%的油气层段分布于低位体系域中,30%的分布于高位体系域,12%的分布在湖侵体系域。

Lower Cretaceous of Chagan depression,situated in the northwest corner of YinE basin,can be divided into one first-order sequence;two second-order sequences and seven third-order sequences according to its data of seism,lithology,palaeobiography, geochemistry and well-logging etc.Ⅰ annd Ⅱ order sequences were shaped during Ⅰ and Ⅱ member deposition of Bayin Gebi Formation,Ⅲ,Ⅳ and Ⅴ-order sequences were formed in the deposition of Suhongtu Formation while Ⅵ and Ⅶ-order sequences formed in the deposition of Yingen Formation.Well-logging data collected from Chagan depression indicate that 58% oil and gas bearing-formation are distributed in lowstand system tracts,30% in highstand system tracts and 12% in lake ingression system tracts.

10.11743/ogg20020214