草湖凹陷东部地区石炭系层序划分与沉积体系

根据T.Cross的高分辨率层序地层学原理,通过对地质、钻井、测井、地震资料的综合分析,将研究区石炭系地层划分出2个长期地层旋回(相当于Ⅲ级层序),主要发育陆源碎屑岩层序。识别出了2种类型的沉积体系:滨岸-扇三角洲沉积体系和潮坪-泻湖沉积体系。在层序地层格架内分析了各旋回的沉积体系构成和生、储、盖发育情况,指出垂向上LSC2下部为本区相对有利的储集层段;平面上,草1-草6井区附近的滨岸-扇三角洲砂体是本区相对有利的勘探目标。

Sequence division and sedimentary system of Carboniferous in eastern Caohu sag

Based on the principles of T. Cross high resolution sequence stratigraphy, the Carboniferous in the study area is divided into three long- term stratigraphic cycles (corresponding to I - grade sequence), where terrestrial clastic rock sequences are mainly developed, through comprehensive analysis of geologic, drilling, logging and seismic data. Two types of sedimentary system are identified in the study area, including shoreland - fan delta and tidal - lagoon. The component of sedimentary system and the development of source, reservoir and cap rocks in each cycle are analyzed in the framework of sequence stratigraphy. Vertically, the lower LSC2 is relatively favorable reservoir in the study area, while laterally the shoreland -fan delta sandbodies in the vicinity of Caol - Cao6 well-blocks are relatively favorable exploration targets in the study area.