古地理学报2024，Vol.26Issue(1)：17-27,11.DOI:10.7605/gdlxb.2024.01.011
南美奥连特盆地白垩系Napo组Main-M1亚段沉积体系重建及油气勘探意义
Sedimentary system reconstruction and implications for hydrocarbon exploration of the Cretaceous Napo Formation Main-M1 submember in Oriente Basin,South America
摘要
Abstract
The Oriente Basin of Ecuador is one of the most important hydrocarbon-bearing basins in the Andean Foreland Basin Group of South America.The Main-M1 submember of the Upper Cretaceous Napo Formation,as one of the main exploration and developement formations,has been controversial in terms of its depositional environment,and its depositional system and evolutionary process remain unclear.Based on core,well logs and borehole cuttings,the main sedimentary microfacies types,depositional sys-tems and evolutionary processes of Main-Mi submember were investigated in this study.The results show that the study area is located in a marine-continental transition environment with complex hydrodynamic conditions,and a tidal delta develops in the east,which gradually transitions into a shallow shelf environ-ment in the west.In the study area,eight types of sedimentary microfaces including subaqueous distributa-ry channel,subaqueous inter-channel,tidal channel,tidal sand bar,tidal flat,and tidal inter-channel,are recognized.According to the petrographic characteristics,the Main-M1 submember is further divided into three sub-layers.By analyzing the lithological assemblages of the three submembers,it is determined that during depositional of the Main-M1 submember,the Auca paleoarchelon gradually formed,and meanwhile the relative sea level of the study area rose due to the flexural effect.The three submembers overall show a gradual deepening upward trend and the tidal delta continuously retreated landward.Based on the reconstruction of the tidal delta-shelf depositional system during deposition of the Main-M1 submem-ber,the subaqueous distributary channel and the leading sand bar in the eastern part of the study area are considered to have certain exploration potential for lithologic reservoirs.关键词
潮汐三角洲/陆棚/沉积微相/沉积模式/Main-M1亚段/奥连特盆地/南美洲Key words
tidal delta/shelf/sedimentary microfacies/depositional model/Main-M1 submem-ber/Oriente Basin/South America分类
天文与地球科学引用本文复制引用
李发有,夏昌盛,郑乃熙,鲍志东,班舒悦,王光付,孙建芳,丁峰,孙钰,王腾宇,徐海,陈诗望..南美奥连特盆地白垩系Napo组Main-M1亚段沉积体系重建及油气勘探意义[J].古地理学报,2024,26(1):17-27,11.基金项目
中国石油化工股份有限公司科技部专项课题(编号:P23180)和国家重点研发计划专项(编号:2017YFC0603104,2018YFC0604304)联合资助.Co-funded by the special project of Department of Science and Technology,Sinopec(No.P23180)and National Key Research and Development Program of China(Nos.2017YFC0603104,2018YFC0604304) （编号:P23180）
