摘要
在全球异重流调研的基础上,总结异重流与经典浊流(鲍马序列)的鉴别标志是逆—正粒序组合、牵引流的沉积构造和水道化。前人基于大量钻井、岩心和地震等资料,在埕北低凸起东缘东三段识别出上述3个异重流鉴别标志,指出该层段发育异重流。本研究区与埕北低凸起东缘东三段具相似的构造位置,本文从古气候、古物源、古地貌、沉积构造及水道化特征等5方面开展类比,两者具相似性:①东营组气候偏湿热有利源区风化剥蚀;②物源面积与扇体面积的比值均为1∶2左右;③具相似坡度和三级阶梯式斜坡结构;④测井曲线呈逆—正粒序组合、岩心中见牵引流的沙纹层理;⑤地震剖面上,扇体具复合水道的外形,底部侵蚀下切,内部见多期水道相互叠置和水道内侧向加积,水道复合体呈“弯曲水道”的平面特征;综合认为,渤中凹陷东南缘东二下亚段扇体是异重流成因,提出了由近端复合水道和远端分支水道组成的沉积新模式。该研究成果以期为今后类似地质条件下的扇体研究提供更合理的成因解释。
On the basis of hyperpycnal flow study globally,distinguishing marks in summarizing the hyperpycnal flow and classical turbidity current(Bouma sequence)were clarified as inverse-normal sequence combination,sedimentary structure of tractive flow and channelization.Based on considerable drilling,cores and seismic data,the three aforementioned marks are identified in the third Edmember at east margin of Chengbei low uplift,indicating the development of hyperpycnal flow in this section.The study area has a tectonic position similar to that of the third Ed member.Comparisions are carried out in five aspects:paleo-climate,paleo-provenance,paleo-geomorphology,sedimentary structure and channelization characteristics,and both of them show the following similarities:①The humid climate is favorable for weathering and erosion of Dongyin Formation.②The ratio of provenance area to fan area is about 1∶2.③The slopes structures present similar angles and three-step stages.④Logging curves show inverse-positive grain sequence combination,and cores present tractive flow wavy lamination.⑤On the seismic profile,fans show composite channel shapes with eroded bottoms externally,and multi-stage channels overlapping and inner accretion internally,with curved channel compound on the plane.Based on the above analysis,it is concluded that fans of lower Ed_(2) of Dongying formation in southeastern margin,Bozhong Sag are hyperpycnal flow causes,and it further proposes a new sedimentary model comprising proximal composite channel and distal branching channels.The results in this study provide a more reasonable genetic explanation for fans study under similar geological conditions in the future.
作者
谢晓军
吴克强
张锦伟
廖计华
白海强
刘子玉
唐武
XIE Xiaojun;WU Keqiang;ZHANG Jinwei;LIAO Jihua;BAI Haiqiang;LIU Ziyu;TANG Wu(CNOOC Research Institute Ltd.,Beijing 100028,China;National Engineering Research Center of offshore Oil and Gas Exploration,Beijing 100028,China;CNOOC Limited China Ltd.,Beijing 100010,China)
出处
《中国海上油气》
CAS
CSCD
北大核心
2022年第3期28-37,共10页
China Offshore Oil and Gas
关键词
成因
异重流
东二下亚段
东南缘
渤中凹陷
genesis
hyperpycnal flow
lower Ed2of Dongying formation
southeastern margin
Bozhong Sag
作者简介
第一作者:谢晓军,男,高级工程师,2005年毕业于中国地质大学(北京),获博士学位,现主要从事海洋油气沉积储层综合研究工作。地址:北京市朝阳区太阳宫南街6号院海油大厦A座(邮编:100028)。E-mail:xiexj@cnooc.com.cn。
