渤海莱州湾凹陷古近系沙四段上亚段沉积体系研究

Depositional System of the Upper Sha4 Formation(Paleogene) in Laizhouwan Sag,Bohai Bay

运用含油气盆地沉积学的理论和方法,在大量岩心、录井、测井及地震资料分析基础上,查明了渤海莱州湾凹陷古近系沙四段上亚段沉积体系的类型、特征及分布规律。莱州湾凹陷古近系沙四段上亚段发育有扇三角洲、盐湖沉积体系,扇三角洲靠近东部和北部盆缘断裂发育,东北部发育碳酸盐浅滩,向沉积中心区域依次发育膏盐沉积和盐岩沉积为盐湖相。扇三角洲分布区为优质油气储层发育,是油气勘探的重点区带。盐岩沉积是形成有利的岩性油气成藏组合带的良好条件。

The utilization the oil and gas bearing basin sedimentology's theory and the method,based on the massive core,the logging,the well logging and the seismic data analysis,the deposition system's type,the characteristic and the distributed rule of the upper Sha4 Formation(Paleogene) in Laizhouwan Sag,Bohai Bay has been verified.Laizhouwan Sag developed the fan delta and the saline lack deposit system.The fan delta developed in the eastern and northern of the fault basin boundary.Shallow carbonate developed in the northeast part that connected with Miaoxi Sag.Gypsum deposits and salt deposits developed to the central region.The fan delta distribution area,developed high quality reservoir of oil gas,is the oil-gas exploration key area belt.Salt deposits would be the formation of favorable conditions for lithologic trap reservoir.