渤海盆地秦南凹陷新生代以来构造-热演化史  

Cenozoic tectonic-thermal history reconstruction of the Qinnan Depression,Bohai Basin

作　　者：高玉飞 唐晓音 杨树春 赵欣妍 胡圣标[5] GAO Yufei;TANG Xiaoyin;YANG Shuchun;ZHAO Xinyan;HU Shengbiao(CNOOC Research Center,Beijing 100027,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Paleomagnetism and Tectonic Reconstruction,Ministry of Natural Resources,Beijing 100081,China;Key Laboratory of Petroleum Geomechanics,China Geological Survey,Beijing 100081,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]中海油研究总院,北京100027 [2]中国地质科学院地质力学研究所,北京100081 [3]自然资源部古地磁与古构造重建重点实验室,北京100081 [4]中国地质调查局油气地质力学重点实验室,北京100081 [5]中国科学院地质与地球物理研究所,北京100029

出　　处：《地质力学学报》2024年第4期622-632,共11页Journal of Geomechanics

基　　金：国家自然科学基金项目(42072181);中海石油有限公司科研项目(YXKY-ZX 012021)。

摘　　要：构造-热演化史是认识盆地形成及其动力学机制的重要窗口,也是烃源岩成熟生烃研究的核心问题。随着能源需求的增长以及陆地油气发现难度的增加,海域逐渐成为中国油气勘探的重要接替区与国家能源战略研究的重要领域。秦南凹陷位于渤海海域西北部,勘探前景良好,但勘探程度低,构造-热演化研究尚属空白。文章选取秦南凹陷3条地震剖面,建立25口人工井,进行了构造沉降史和热史模拟,恢复了秦南凹陷构造-热演化历史。研究结果表明:秦南凹陷新生代以来于孔店组—沙河街组四段沉积时期(65~42 Ma)、沙河街组三段沉积时期(42~38 Ma)以及东营组三段沉积时期(32.8~30.3 Ma)分别经历了3期裂陷拉张,总拉张系数为1.27~2.05;对应这3期拉张作用,秦南凹陷基底热流经历3期升高,在东营组三段沉积末期(30.3 Ma)基底热流达到峰值64.0~89.0 mW/m^(2),之后逐渐降低至今;秦南凹陷构造-热演化过程与断裂活动具有良好的耦合关系。研究获得的拉张系数、基底热流等参数对于了解渤海盆地构造演化的深部动力学机制以及指导研究区油气勘探具有重要意义。[Objective]Tectono-thermal history is important to understand basin evolution and its geodynamic mechanism and is the key question to be solved for source rock maturation study.With the increasing energy demand and difficulty in oil and gas discovery on land,sea basins have gradually become an important alternative for oil and gas exploration and a hotspot of national energy strategy research.The Qinnan Depression,located in the northwest of the Bohai Sea,has good exploration prospects.However,owing to the low level of exploration,research on the tectono-thermal evolution of Qinnan Depression is still limited.[Methods]In this study,25 artificial wells have been established based on 3 seismic profiles of the Qinnan Depression,and their tectonic subsidence and thermal history have been modeled to reconstruct the tectonicthermal evolution history using a multi-stage finite stretching model.[Results]The results indicate that since the Cenozoic era,the Qinnan Depression has undergone three stages of rifting and stretching during the sedimentary periods of the Kongdian Formation to fourth member of the Shahejie Formation(65–42 Ma),the third member of the Shahejie Formation(42–38 Ma),and the third member of the Dongying Formation(32.8–30.3 Ma),with a total stretching factor of 1.27–2.05.Corresponding to the three stages of stretching,the basal heat flow of the Qinnan Depression has experienced three stages of increase,reaching a peak of 64.0–89.0 mW/m^(2) at the end of the deposition of the third member of the Dongying Formation(~30.3 Ma),and then decreased gradually until present.[Conclusion]The Qinnan Depression underwent three phases of heating and two stages of cooling since the Cenozoic period.There is a good coupling relationship between the tectonic-thermal evolution process and fault activity in the Qinnan Depression.[Significance]The parameters such as tension system and basement heat flow history obtained in this study are of great significance for understanding the deep dynamic mechanisms of basin t

关 键 词：渤海盆地 秦南凹陷 构造沉降 热史演化 新生代 

分 类 号：P314[天文地球—固体地球物理学] P542[天文地球—地球物理学]