辫状河型冲积扇片流带特征与支撑砾岩成因研究——以准噶尔盆地西北缘现代白杨河冲积扇为例  

Research on the Sheetflow Zone and Frame⁃support Conglomerate in a Braided⁃river Alluvial Fan:Case study of the modern Poplar River alluvial fan,northwestern Junggar Basin

作　　者：刘大卫[1,2] 纪友亮 高崇龙[1] 靳军 杨召 段小兵 桓芝俊 张月 季梦瑶 LIU DaWei;JI YouLiang;GAO ChongLong;JIN Jun;YANG Zhao;DUAN XiaoBing;HUAN ZhiJun;ZHANG Yue;JI MengYao(College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Research Institute of Experiment and Detection,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China;Beijing Richfit Information Technology Co.,Ltd,CNPC,Beijing 100007,China;Exploration and Development Research Institute,Qinghai Oilfield Company,PetroChina,Dunhuang,Gansu 736202,China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国科学院地质与地球物理研究所,北京100029 [3]中国石油新疆油田分公司实验检测研究院,新疆克拉玛依834000 [4]北京中油瑞飞信息技术有限责任公司,北京100007 [5]中国石油青海油田分公司勘探开发研究院,甘肃敦煌736202

出　　处：《沉积学报》2020年第5期1026-1036,共11页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(41672098,41602133)。

摘　　要：冲积扇砂砾岩油藏是准噶尔盆地勘探热点,尤其是玛湖凹陷特大型砂砾岩油藏的发现,更加表明砾质冲积扇储层研究的必要。选取白杨河冲积扇为研究对象,对砾质辫状河型冲积扇内部片流带以及支撑砾岩的沉积特征和分布规律进行研究,结果表明:1)扇内片流带沉积介于扇根补给水道与扇中辫状水道沉积环境之间,与二者呈过渡接触,片流带规模可达千米级别,内部支撑砾岩的发育改善了片流带储层物性;2)识别出三类支撑砾岩,分别是片流支撑砾岩、沿层理面发育的支撑砾岩以及沟槽底部支撑砾岩,前两者均为超临界水流淘洗成因,后者则为径流改造成因;3)片流支撑砾岩发育于片流沉积,具有较好的成层性以及较高的线密度;沿层面发育的支撑砾岩发育于辫状沟槽沉积环境,形态受限于沟槽规模,可与交错层理砾岩匹配形成大规模优质岩相组合;沟槽底部发育的支撑砾岩发育于辫状水道底部,规模小但连通性好。综上,基于野外露头片流带以及支撑砾岩研究可以为井下砂砾岩油藏开发提供理论支撑。Alluvial fan conglomerate reservoirs have always been the main reservoir type in the Junggar Basin.In par⁃ticular,the discovery of an extra⁃large type of conglomerate reservoir in the Mahu Sag highlights the need for a study of gravel alluvial fan reservoirs.This article is based on a large amount of field data and literature reports in China and abroad.The Poplar River gravelly alluvial fan was selected for research into this type of deposit.The study focused on the sedimentary characteristics and distribution of the sheetflow of frame⁃support conglomerates.It was found that:(1)The sheetflow within the belt of sediments between the root feeder channel and the braided channel in the central part,and the transition of the two lithofacies.The sheetflow zone is kilometers in extent,and the internal frame⁃sup⁃port conglomerates improve reservoir properties.(2)Three types of frame⁃support conglomerates were identified:the frame⁃support conglomerate in the sheetflow,the frame⁃support conglomerate developed along the bedding planes and the frame⁃support conglomerate at the bottom of the channel.(3)The frame⁃support conglomerate in the sheet⁃flow occurs in sheetflow zone deposits,with good stratification and high linear density.The frame⁃support conglomer⁃ate developed along the bedding planes formed in the braided channel sedimentary environment.The limits of devel⁃opment and the scale of the channel matches the cross⁃bedding conglomerate to form large⁃scale,high⁃quality lithofa⁃cies assemblages.The frame⁃support conglomerates developed at the bottom of both the channel and the braided chan⁃nel are small but well⁃connected.In conclusion,this study of the sheetflow zone and frame⁃support conglomerate has provided theoretical support for the development of glutenite oil reservoirs in alluvial fans.

关 键 词：辫状河型冲积扇 片流带 颗粒支撑砾岩 粒度特征 分布模式 

分 类 号：P618.13[天文地球—矿床学]