西湖凹陷天台斜坡新生代构造差异特征及其形成机制  

Cenozoic Tectonic Difference and Its Formation Mechanism of the Tiantai Slope in the Xihu Sag

作　　者：祁鹏 郭刚 崔敏 王欣 李峰 李林致 QI Peng;GUO Gang;CUI Min;WANG Xin;LI Feng;LI Linzhi(CNOOC Research Institute Ltd.,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《现代地质》2023年第2期307-315,共9页Geoscience

基　　金：国家科技重大专项(2016ZX05024-002);中海油(中国)有限公司“十四五”重大科技项目(KJGG2022-0301);中海油(中国)有限公司科技攻关项目(2021-KT-YXKY-03)。

摘　　要：天台斜坡位于西湖凹陷西斜坡的南段,经过35年勘探,仅钻探4口井,尚未取得商业油气发现,基础油气地质条件不明确制约了油气勘探进程。针对该斜坡构造特征缺乏系统研究的问题,以三维地震资料精细解释和综合地质分析为基础,系统总结了天台斜坡不同区段的新生代构造样式及其几何学特征和形成机制。天台斜坡自北往南依次表现为双向断层控制的北段复杂斜坡、反向断层控制为主的中段复杂缓坡和顺向断层控制为主的南段简单缓坡。天台斜坡构造特征的区段差异性与其新生代构造演化过程密切相关,从断陷阶段延续到断拗阶段的不均一伸展作用,在其北、中、南段分别控制了不同的断裂发育程度及构造组合样式,并在北段和中段之间形成了特殊的弧形断裂发育带。The Tiantai slope is located in the southern section of the western slope of the Xihu Sag.After 35 years of exploration,only four wells have been drilled and no commercial discoveries have been made,and the poorly-known geological conditions have restricted the local oil and gas exploration.Based on three-dimensional(3D)seismic data interpretation and comprehensive geological analysis,the Cenozoic tectonic style of the different sections of the Tiantai slope,and its geometrical features and formation mechanism are systematically summarized.From north to south,the Tiantai slope is characterized by a complex slope in the northern section(controlled by two-way faults),a complex gentle slope in the middle section(controlled by antithetic faults),and a simple gentle slope in the southern section(controlled by a synthetic fault).The regional structural differences of the Tiantai slope are closely related to its Cenozoic tectonic evolution.From Paleocene to Eocene,the differential extension may have controlled the different degrees of fault development and structural styles in the northern,middle and southern sections of the Tiantai slope.A special arc-shaped fault development zone may have formed between the northern and middle sections.

关 键 词：构造差异 伸展转换 弧形断裂 天台斜坡 西湖凹陷 

分 类 号：P618.13[天文地球—矿床学]