渤海湾盆地沧东凹陷孔二段细粒沉积旋回及其对有机质分布的影响  

Cycles of fine-grained sedimentation and their influences on organic matter distribution in the second member of Paleogene Kongdian Formation in Cangdong Sag,Bohai Bay Basin,East China

作　　者：赵贤正[1] 蒲秀刚[1] 鄢继华[2] 金凤鸣[1] 时战楠 柴公权[1] 韩文中[1] 刘岩[3] 姜文亚[1] 陈长伟[1] 张伟[1] 方正 解德录 ZHAO Xianzheng;PU Xiugang;YAN Jihua;JIN Fengming;SHI Zhannan;CHAI Gongquan;HAN Wenzhong;LIU Yan;JIANG Wenya;CHEN Changwei;ZHANG Wei;FANG Zheng;XIE Delu(PetroChina Dagang Oilfield Company,Tianjin 300280,China;China University of Petroleum(East China),Qingdao 266580,China;Yangtze University,Wuhan 430100,China)

机构地区：[1]中国石油大港油田公司,天津300280 [2]中国石油大学(华东),山东青岛266580 [3]长江大学,武汉430100

出　　处：《石油勘探与开发》2023年第3期468-480,共13页Petroleum Exploration and Development

基　　金：国家重点研发计划(2020YFA0710504,2022YFF0801204);中国石油天然气股份有限公司科技重大专项(2019E-26)。

摘　　要：基于陆相水进-水退旋回(T-R旋回)层序地层学理论,通过对渤海湾盆地沧东凹陷官108-8井古近系孔店组二段连续500m完整取心及化验资料分析,开展湖相盆地细粒沉积岩的高频旋回特征研究。通过应用测井岩性组合判别方法,搭建孔二段细粒沉积岩的五级高频旋回地层格架。采用不同尺度及方法表征细粒沉积岩高频旋回特征,研究表明五级T旋回陆源碎屑矿物含量高、古盐度低、古气候偏潮湿、纹层密度大,五级R旋回则表现为碳酸盐矿物含量高、古盐度高、古气候偏干旱、纹层密度小。高频旋回变化控制了有机质的丰度与类型,T旋回中TOC值较高,除了有较高的陆源有机碳含量外,水体内生有机质也较为丰富,显示湖泊的初级生产力较高,有利于页岩油的形成与富集。According to the theory of sequence stratigraphy based on continental transgressive-regressive(T-R)cycles,a 500 m continuous core taken from the second member of Kongdian Formation(Kong 2 Member)of Paleogene in Well G108-8 in the Cangdong Sag,Bohai Bay Basin,was tested and analyzed to clarify the high-frequency cycles of deep-water fine-grained sedimentary rocks in lacustrine basins.A logging vectorgraph in red pattern was plotted,and then a sequence stratigraphic framework with five-order high-frequency cycles was formed for the fine-grained sedimentary rocks in the Kong 2 Member.The high-frequency cycles of fine-grained sedimentary rocks were characterized by using different methods and at different scales.It is found that the fifth-order T cycles record a high content of terrigenous clastic minerals,a low paleosalinity,a relatively humid paleoclimate and a high density of laminae,while the fifth-order R cycles display a high content of carbonate minerals,a high paleosalinity,a dry paleoclimate and a low density of laminae.The changes in high-frequency cycles controlled the abundance and type of organic matter.The T cycles exhibit relatively high TOC and abundant endogenous organic matters in water in addition to terrigenous organic matters,implying a high primary productivity of lake for the generation and enrichment of shale oil.

关 键 词：细粒沉积 高频旋回 纹层密度 有机质 古近系孔店组二段 沧东凹陷 渤海湾盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]