内蒙古二连盆地凝灰岩潜山多期风化壳形成及油气成藏效应.docx

March2014，Vol.20，No.1，pp.114-121GeologicalJournalofChinaUniversities内蒙古二连盆地凝灰岩潜山多期风化壳形成及油气成藏效应李浩1,2，高先志3，杨德相4，王会来3，王1.同济大学海洋与地球科学学院，上海200092；苗22.中国石化股份有限公司石油勘探开发研究院无锡石油地质研究所，无锡 214126；3.中国石油大学（北京）地球科学学院，北京 1022494；4.中国石油华北油田勘探开发研究院，任丘062552摘要：火山喷发的多期性是导致凝灰岩潜山纵向多期风化壳（带）发育的重要原因。从地球化学、测井响应特征和岩石学证实了二连盆地凝灰岩潜山多期风化壳（带）的存在及其特征：（1）哈31井凝灰岩地层在1062~1080m和1165~1179m两个井段表现为K，Na，Ca等元素淋滤，CIA指数较大，而Al，Fe，Mn，P等元素相对富集，S/A指数变小；（2）这两个层段测井响应表现为风化壳的特征，而且其测井曲线在纵向上具旋回特征并有连井上的可对比性；（3）不同喷发期次形成的凝灰岩结构、组分以及粒度不同。凝灰岩潜山多期风化壳（带）的存在对潜山油气藏的形成具有重要作用，成藏效应主要表现在储集层垂向分带性、风化壳油藏（晚期风化壳中）和内幕油藏（早期风化壳中）纵向叠置和复式油气聚集成藏模式等3个方面。文中对多期凝灰岩古风化壳的认识扩展了火山岩潜山的勘探深度，为火山岩潜山内幕油气勘探提供了理论依据。关键词：凝灰岩；风化壳；潜山内幕；成藏效应；二连盆地中图分类号：P618.130.2文献标识码：A文章编号：1006-7493（2014）01-0114-08FormationofMultipleEpisodesofPaleo-weatheringCrustofTuff-buriedHillsanditsEffectonHydrocarbonAccumulationErlianBasin,InnerMongolia,ChinaLIHao1,2，GAOXianzhi3，YANGDexiang4，WANGHuilai3，WANGMiao2SchoolofOceanandEarthScience,TongjiUniversity,Shanghai200092,China;WuxiPetroleumGeologyResearchInstituteofSINOPEC,Wuxi214126,China;CollegeofGeosciences,ChinaUniversityofPetroleum,Beijing102249,China;ResearchInstituteofPetroleumExplorationandDevelopment,PetroChinaHuabeiOilfieldCompany,Renqiu062552,ChinaAbstract:Multipleepisodesofvolcaniceruptionsleadtothedevelopmentofmultiplelayersofweatheringcrustverticallyintuffburiedhill.Geochemical,petrologicandloggingdatajointlydemonstratetheexistenceofmultipleepisodesofweatheringcrustinthetuffburiedhill.ForwellHa-31,weatheringcrustsweredevelopedat1062~1080mand1165~1179mandshowK,Na,Caleaching,largerCIAindex,smallerS/Aindex,andrelativelyrichAl,Fe,Mn,P,etccontentwhichareinaccordancewiththeresponsetoconventionalwelllogging.Additionally,forsingewellinlogging,itshowssomedegreeofcyclicityvertically,andthiskindofcyclicitycanbecorrelatedamongmulti-wells.Moreover,tuffsoriginatedfromdifferenteruptionperiodsshowdifferentstructures,composition,andsizes.Fromabove,wecanconcludethattuffswereformedinmultipleepisodesandmultipleweatheredcrustsweredevelopedvertic