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J4 ›› 2015, Vol. 21 ›› Issue (4): 653-.

• 汇源系统与储层地质学专栏(二) • 上一篇    下一篇

“源-汇”体系主导下的断陷湖盆陡坡带扇三角洲发育 模式探讨:以苏丹Muglad盆地Fula凹陷为例

吴 冬,朱筱敏*,刘常妮,李雨彤   

  • 出版日期:2015-12-20 发布日期:2016-01-04

DiscussionOnDepositionalModelsofFanDeltasinSteepSlopeBelt oftheRiftBasinundertheGuidanceofSource-to-SinkSystem Theory:ACaseStudyfromtheFulaSub-basin,MugladBasin,Sudan

WU Dong, ZHU Xiaomin*, LIU Changni, LI Yutong   

  • Online:2015-12-20 Published:2016-01-04

摘要:

断陷湖盆陡坡带粗粒三角洲地质研究对于油气勘探至关重要。通过岩心、测井和地震资料综合分析,在苏丹Muglad 盆地Fula凹陷陡坡带识别出两类扇三角洲,分别为Jake区锥状扇三角洲和Keyi区片状扇三角洲。Jake区物源供给充足,早 白垩世持续供源,形成的锥状扇三角洲岩石颗粒较粗,分选-磨圆差,砂体厚度较厚,分布范围较广;Keyi区物源供给不 足,形成的片状扇三角洲岩石颗粒较细,分选-磨圆更好,砂体厚度较薄,分布范围有限。文章将“源-汇”体系理论引入 到陡坡带粗粒三角洲研究中,通过对母岩剥蚀供源、搬运以及汇聚条件分析,对两类扇三角洲进行成因解释,并建立相应 模式,同时指出,“源-汇”体系只有作为一个整体研究,才能较好地预测断陷湖盆陡坡带扇三角洲分布。

关键词: “源-汇”体系;断陷湖盆;陡坡带;扇三角洲;Fula凹陷

Abstract:

 Thecoarse-graineddelta,developedinsteepslopebeltofariftbasin,usuallyplaysanimportantroleinoilandgas exploration.Basedontheanalysisofcore,loggingandseismicdata,twotypesoffandeltasarerecognizedinsteepslopebeltinthe FulaSub-basin,MugladBasin,Sudan.Thetaper-shapedfandeltainJakeAreaiscomposedofrelativelycoarse-grainedsandstoneand conglomeratewithmorethicknessandwidedistribution.Thesortingandgroundingarepoorinthistypeoffandeltadeposition.Onthe contrary,thegrainismuchfinerintheplatyfandeltainKeyiAreawhilethesortingandgroundingarerelativelygood.Thesandbody isthinandlimitedspread.ThesourceissufficientinJakeAreabutinsufficientinKeyiAreaduringtheEarlyCretaceous.Thispaper bringsthetheoryofsource-to-sinksystemintothefandeltaresearch.Throughthestudyaboutclasticsupplying,transportingand accumulating,theexplanationofthesetwotypesoffandeltasaregiven,andthedepositionalmodelsarebuilt.Onlyberegardedasa whole,thesource-to-sinksystemstudycanbeutilizedtopredictthefandeltadepositioninsteepslopebeltoftheriftbasin.

Key words: sourcetosinksystem;riftbasin;steepslopebelt;fandelta;FulaSub-basin