摘要
塔里木盆地西南山前地区甫沙断陷甫沙8井侏罗系砂岩油气勘探取得了突破,但该区域侏罗系整体勘探程度低,物源特征以及沉积体系尚不清楚,明显制约了其油气勘探进程。利用测井、岩心与地震等资料,本研究在系统分析甫沙断陷侏罗系物源特征的基础上,明确了侏罗系沉积相类型及其展布规律。研究认为,甫沙断陷侏罗系存在南、北两大物源体系,南部西昆仑山物源供给能力强,北部斜坡区供源能力较弱,母岩主要为元古界变质岩、古生界岩浆岩和二叠系沉积岩。侏罗纪甫沙断陷发育一个完整的裂陷旋回,先后经历了初始断陷期、强烈断陷期和断-拗转换期3个演化阶段。共识别出扇三角洲、辫状河三角洲和湖泊3种沉积相类型,南部陡坡带主要发育冲积扇—扇三角洲—湖泊沉积体系,北部缓坡带主要发育辫状河三角洲—湖泊沉积体系,且该沉积相展布具有继承性发育的特征,受控于古地貌、物源供给、盆地的裂陷活动等因素。综合以上研究,认为初始断陷期(莎里塔什组沉积时期)南部构造转换带控制的辫状河三角洲砂体可作为甫沙断陷有利勘探目标。
A significant breakthrough in the exploration of Jurassic sandstone oil and gas was achieved in well Fusha 8,located in the piedmont area of the southwestern Tarim Basin.However,the overall exploration level of the Jurassic remains low.The characteristics of the provenance and the sedimentary systems within the basin are still unclear,which hinders the process of exploration.This paper uses logging data,core samples,and seismic data to clarify the types and distribution of sedimentary facies through a systematic analysis of the Jurassic provenance characteristics in the Fusha fault depression.It is concluded that there are two major provenance systems in the Jurassic strata of the Fusha fault depression:the western Kunlun Mountains in the south exhibit a strong provenance supply capacity,while the northern slope area displays a weaker provenance.The provenance areas are mainly composed of Proterozoic metamorphic rocks,Paleozoic magmatic rocks and Permian sedimentary rocks.The Jurassic basin underwent a complete rifting cycle,which can be categorized into three evolution stages:the initial rifting stage,the intense rifting stage,and the rifting-depression transition stage.In the study area,three sedimentary facies were identified:fan delta,braided river delta and lacustrine facies.The southern steep slope zone mainly develops an alluvial fan-fan delta-lacustrine sedimentary system,while the northern gentle slope zone is mainly characterized by a braided river delta-lacustrine sedimentary system.The distribution of the Jurassic sedimentary system in the Fusha fault depression,located in the piedmont area of the southwestern Tarim Basin,exhibits vertical inheritance development,and is influenced by factors such as palaeogeomorphology,provenance supply,and basin rifting activities.Based on this research,it is proposed that the braided river delta sandbodies controlled by the southern tectonic transition zone during the sedimentary period of the Shalitashi Formation(initial rifting stage)represent favorable exploration targets within the region.
作者
黎立
孙春燕
董尧
罗强
屈洋
朱世发
LI Li;SUN Chunyan;DONG Yao;LUO Qiang;QU Yang;ZHU Shifa(Research Institute of Petroleum Exploration and Development,Tarim Oilfield Company,PetroChina,Xinjiang Korla 841000,China;R&D Center for Ultra-Deep Complex Reservoir Exploration and Development,CNPC,Xinjiang Korla 841000,China;Engineering Research Center for Ultra-deep Complex Reservoir Exploration and Development,Xinjiang Uygur Autonomous Region,Xinjiang Korla 841000,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China)
出处
《古地理学报》
北大核心
2025年第4期870-885,共16页
Journal of Palaeogeography:Chinese Edition
基金
中国石油天然气集团有限公司科技项目“超深层碎屑岩油气分布规律与区带目标优选”(编号:2023ZZ14YJ02)资助。
关键词
物源分析
沉积相
甫沙断陷
侏罗系
塔里木盆地
provenance analysis
sedimentary facies
Fusha fault depression
Jurassic
Tarim Basin
