摘要
陆丰凹陷是珠江口盆地(东部)的古近系勘探重要探区,近三十年来受限于钻井数量与仅有的二维地震资料,其盆缘洼陷海丰33洼缺乏断裂特征与洼陷结构的研究。在新三维地震资料构造解释基础上,本文对洼陷边界断裂、主干伸展断裂、张扭断裂进行识别,并对断裂活动性进行了分析,研究结果表明:(1)海丰33洼发育伸展断裂和张扭断裂,三组深大断裂——北部海丰33断裂、南部陆丰03断裂与北西部的海丰32断裂分别控制形成了主洼、南次洼、北次洼的洼陷格局;(2)北西部海丰32断裂受到左旋张扭应力场的作用,显示了张扭性断裂特征,在晚文昌—早恩平组沉积期断裂活动最强,地层沉降中心沿走滑分量迁移,北次洼沉积较厚上文昌组地层;(3)海丰33洼北西部发育的海丰32断阶构造带邻近烃源岩,张扭断裂控制了该构造带的圈闭类型与运移条件,为海丰33洼勘探的有利区带。
Lufeng sag is an important exploration area of Paleogene in the eastern part of Pearl River Mouth basin.In the recent 30 years,limited by the number of drilled wells and the two-dimensional seismic data,Haifeng 33 sub-sag,a basin marginal sub-sag,lacks the study of fault characteristics and sub-sag structure.Based on the structural interpretation of new 3D seismic data,the boundary faults,main extensional faults and transtensional faults of the sub-sag are identified,and the fault activity is analyzed.The results show that:①Extensional faults and transtensional faults are developed in Haifeng 33 sub-sag.Three deep faults-Haifeng 33 fault in the north,Lufeng 03 fault in the south,and Haifeng 32 fault in the northwest respectively control the formation of the pattern of main sub-sag,southern secondary sub-sag,and northern secondary sub-sag.②Haifeng 32 fault in the northwest is affected by the left lateral transtensional stress field,showing the characteristics of transtensional fault.The active faulting period is mainly in the Late Wenchang-Early Enping depositional stage.The subsidence center began to move along the strike-slip component,resulting in thicker Upper Wenchang formation strata in the northern secondary sub-sag.③The Haifeng 32 step-fault structural zone in the northwest of Haifeng 33 sub-sag is adjacent to the source rock.The transtensional faults control the trap types and migration conditions of the structural zone which is one of the important exploration areas in Haifeng 33 sub-sag.
作者
李敏
张素芳
邱欣卫
肖张波
贺勇
何雁兵
LI Min;ZHANG Sufang;QIU Xinwei;XIAO Zhangbo;HE Yong;HE Yanbing(CNOOC China Limited,Shenzhen Branch,Shenzhen,Guangdong 518054,China)
出处
《中国海上油气》
CAS
CSCD
北大核心
2023年第3期45-52,共8页
China Offshore Oil and Gas
基金
中海油“十三五”科技重点项目“南海东部油田上产2000万吨关键技术研究(编号:CNOOC-KJ135ZDXM37SZ)”部分研究成果。
关键词
珠江口盆地
陆丰凹陷
海丰33洼
张扭断裂
洼陷结构
Pearl River Mouth basin
Lufeng sag
Haifeng 33 sub-sag
transtensional fault
sub-sag structure
