琼东南盆地松南—宝岛凹陷北部断阶带演化过程及对成藏的控制作用  

Evolution of the northern step-fault zone in the Songnan-Baodao Sag of the Qiongdongnan Basin and its control on reservoir formation

作　　者：龚宇 佟殿君[2] 焦垚祺 高铭恒 周晨 许延成 刘辉[2] 方璇 GONG Yu;TONG Dianjun;JIAO Yaoqi;GAO Mingheng;ZHOU Chen;XU Yancheng;LIU Hui;FANG Xuan(Research Institute of Hainan Branch of CNOOC China Limited,Haikou 570100,China;Hubei Key Laboratory of Marine Geological Resources,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中海石油(中国)有限公司海南分公司研究院,海南海口570100 [2]中国地质大学海洋地质资源湖北省重点实验室,湖北武汉430074

出　　处：《天然气地球科学》2024年第2期300-312,共13页Natural Gas Geoscience

基　　金：中海油重大科技项目“南海深水盆地油气运聚成藏分析与突破方向”(编号:KJGG-2022-0103);国家自然科学基金面上项目(编号:42172125)联合资助。

摘　　要：松南—宝岛凹陷是琼东南盆地继陵水凹陷之后所发现的又一个具有巨大油气勘探潜力的重要深水勘探区,其北部断阶带构造背景复杂,新生代以来经历了多期应力场的变形和叠加演化,所形成的复杂的构造系统对深水区大中型油气田的形成具有重要的控制作用。运用覆盖研究区的新采集和处理的高精度3D地震资料以及新的勘探成果资料,在精细地震剖面构造地层综合解释的基础上,结合断层活动性定量分析、沉降史反演以及构造演化史恢复等技术,系统地开展北部断阶带的几何学、运动学以及动力学研究。研究结果表明,北部断阶带为由F2断裂、F2-1断裂、F12断裂和F12-1断裂所构成的右阶斜列式同向叠覆式断阶带,经历了由始新世NE向的高角度正断层向渐新世的近EW向的低角度伸展拆离断层的演变过程,并控制了中央坳陷带大型拆离盆地的发育。断层相互叠接部位形成的大型转换带成为控制源—汇系统、始新统和崖城组主力烃源岩和陵三段扇三角洲和辫状河三角洲大型储集体的关键构造因素。The Songnan-Baodao Sag is another important deepwater exploration area with huge oil and gas ex⁃ploration potential discovered after the Lingshui Sag in the Qiongdongnan Basin.The structural background of the northern step-fault zone is complex,and it has undergone multiple stages of stress field deformation and su⁃perimposed evolution since the Cenozoic era.The complex structural system formed has an important control⁃ling effect on the formation of large and medium-sized oil and gas fields in the deep water area.This paper sys⁃tematically studies the geometry,kinematics,and dynamics of the Songnan-Baodao northern step-fault zone us⁃ing newly collected and processed high-precision 3D seismic data and new exploration results covering the re⁃search area,based on comprehensive interpretation of fine seismic profile structures and strata,combined with techniques such as quantitative analysis of fault activity,inversion of subsidence history,and restoration of tec⁃tonic evolution history.The research results show that the Songnan-Baodao northern step-fault zone is a right step oblique and co directional superimposed step-fault zone composed of No.2 fault,No.2-1 fault,No.12 fault,and No.12-1 fault.It has undergone the evolution process from a high angle normal fault in the direction of Eo⁃cene NE to a high angle and low angle extensional detachment fault in the direction of Oligocene near EW,and has controlled the development of large detachment basins in the central depression zone.The large transition zones formed at the overlapping positions of the faults have become the key structural factors controlling the main source rocks,source sink systems,and large reservoirs in the fan delta and braided river delta of the third member of the Eocene and Yacheng Formation.

关 键 词：叠覆式断阶带 构造演化 转换带 成藏控制作用 松南—宝岛凹陷 

分 类 号：TE121.2[石油与天然气工程—油气勘探]