吐哈盆地胜北洼陷中下侏罗统水西沟群天文旋回地层划分  

Stratigraphic division of astronomical cycle in early-middle Jurassic Shuixigou Group in the Shengbei subsag of Tuha Basin

作　　者：苟红光[1] 林潼[2] 房强[3,4] 张华[1] 李山 程祎 尤帆 GOU Honguang;LIN Tong;FANG Qiang;ZHANG Hua;LI Shan;CHENG Yi;You Fan(Research Institute of Exploration and Development,Tuha Oilfield Company,PetroChina,Hami 839009,Xinjiang,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing,100083,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences(Beijing),Beijing 100083,China;School of Ocean Sciences,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国石油吐哈油田公司勘探开发研究院,新疆哈密839009 [2]中国石油勘探开发研究院,北京100083 [3]中国地质大学(北京)生物地质与环境地质国家重点实验室,北京100083 [4]中国地质大学(北京)海洋学院,北京100083

出　　处：《岩性油气藏》2024年第6期89-97,共9页Lithologic Reservoirs

基　　金：国家自然科学基金委企业创新发展联合基金“环青藏高原盆山体系动力学与天然气富集机理”(编号:U22B6002);中国石油天然气股份有限公司攻关性应用性科技专项“深地煤岩气成藏理论与效益开发技术研究”(编号:2023ZZ18);中国石油“十四五”前瞻性基础性重大科技项目“不同类型大气田(区)成藏主控因素及领域评价”(编号:2021DJ0605)联合资助。

摘　　要：根据自然伽马测井数据,对吐哈盆地胜北洼陷沁探1井中下侏罗统水西沟群开展旋回地层学分析和沉积噪声模拟,并利用识别出的地层中的米兰科维奇旋回信号来研究地球轨道周期对湖平面变化的驱动作用,进而进行天文旋回地层划分。研究结果表明:①吐哈盆地胜北洼陷中下侏罗统水西沟群在自然伽马曲线中可识别出12.8~51.1 m,3.0~11.9 m,1.1~3.6 m和1.3~2.4 m的沉积旋回,比例关系为21.0∶5.0∶1.5∶1.0。根据天文调谐与相关系数估算出水西沟群沉积速率为3.3~11.7 cm·ka-1。②天文调谐后的时间域序列显示水西沟群长偏心率周期为405 ka、短偏心率周期为99~131 ka、斜率周期为32.6~35.0 ka、岁差周期为20.0~24.8 ka,证明吐哈盆地中下侏罗统沉积过程受到米兰科维奇旋回控制。沁探1井八道湾组(未钻穿)、三工河组和西山窑组的持续时间分别为3.0±0.1 Ma,4.1±0.1 Ma和9.0±0.1 Ma。③地球轨道旋回对陆相湖盆的湖平面升降具有明显的驱动作用,沁探1井水西沟群的沉积噪声模拟证明了~1.5 Ma超长周期可控制台北凹陷早—中侏罗世湖平面的变化。The natural gamma-ray(GR)logging data of the early-middle Jurassic Shuixigou Group from QinTan 1 borehole in Shengbei subsag,Tuha basin,was selected to analyze cyclostratigraphy and simulate sedimentary noise for the identification of stratigraphic Milankovitch signals and determination of the Earth’s orbital cycle’s forcing the lake level variations within the Tuha Basin.The stratigraphic division of Shuixigou Group was analyzed.The results show that:(1)The sedimentary cycles of 12.8~51.1 m,3~11.9 m,1.1~3.6 m,and 1.3~2.4 m were identified in the GR curves of the Early-Middle Jurassic Shuixigou Group in the Shengbei subsag of Tuha Basin,with a ratio of 21∶5∶1.5∶1,and the sedimentary rates of the Shuixigou Group are estimated as 3.6~11.7 cm·ka-1 through astronomical calibration and correlation coefficient.(2)The sedimentary records of the Shuixigou Group were forced by the Milankovitch cycles,as evidenced by the presence of 405 ka long eccentricity,99~131 ka short eccentricity,32.6~35.0 ka obliquity,and 20.0~24.8 ka precession cycles during the Middle and Early Jurassic in Tuha basin.The durations of Badaowan Formation(not drilled through),Sangonghe Formation and Xishanyao Formation in Qintan 1 borehole are 3.0±0.1 Ma,4.1±0.1 Ma and 9.0±0.1 Ma,respectively.(3)The fluctuation of lake level forced by the Earth’s orbital cycles of terrestrial lake basins,the simulation of lake level change by sedimentary noise confirms that the ultra-long period of~1.5 Ma forced the lake level change of the Shuixigou Group in Taibei sag.

关 键 词：旋回地层学 米兰科维奇旋回 天文年代标尺 沉积速率 沉积噪声模拟 湖平面变化 水西沟群 侏罗系 胜北洼陷 吐哈盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探] P588.2[天文地球—岩石学]