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1、2016年3月,第22卷,第1期,159-170页高校地质学报March2016,Vol.22,No.1,pp.159-170GeologicalJournalofChinaUniversitiesDOI:10.16108/j.issn1006-7493.2015237宁镇地区下志留统高家边组富有机质页岩孔隙结构11*12李晋宁,姚素平,孙超,丁海1.南京大学地球科学与工程学院,南京210023;2.安徽省煤田地质局勘查研究院,合肥230088摘要:通过氩离子抛光-场发射扫描电镜、小角X射线散射及低温氮气吸附实验,对宁镇地区下志留统仑山5井等高家边组底部富有
2、机质泥页岩孔隙结构进行分析,为下扬子区下志留统富有机质泥页岩的储层评价提供依据。研究表明:高家边组富有机质泥页岩含有大量的纳米级孔隙,包括有机质孔、矿物粒间孔、矿物粒内孔、微裂缝等,孔径分布复杂;优势孔径分布为介孔段,孔隙直径主要为2~50nm。影响孔径分布的主要因素是矿物组成,脆性矿物和黏土矿物对微孔和介孔都有一定的影响,而有机质含量对泥页岩总体孔隙特征的影响并不明显。关键词:宁镇地区;高家边组;氩离子抛光-场发射扫描电镜;小角X射线散射;低温氮气吸附;孔隙结构中图分类号:P618.13文献标识码:A文章编号:1006-7493(2016)01-0159-
3、12PoreStructureofOrganic-richShalesintheLowerSilurianGaojiabianFormationfromNingzhenArea,JiangsuProvince11*12LIJinning,YAOSuping,SUNChao,DINGHai1.SchoolofEarthSciencesandEngineering,NanjingUniversity,Nanjing210023,China;2.ExplorationResearchInstituteAnhuiProvincialBureauofCoalGeolo
4、gy,Heifei230088,ChinaAbstract:ToprovidedataforthereservoirevaluationofthelowerSilurianorganic-richshalesintheLowerYangtzeRegion,inthisstudyweanalyzethecharacteristicsofporestructuresoftheshalesbasedonthestudyofsamplesfromtheLunShan5wellintheNingzhenArea.Comprehensivemethodswereempl
5、oyed,mainlyincludingfieldemissionscanningelectronmicroscopy(FE-SEM),smallangleX-rayscattering(SAXS)andlow-temperaturenitrogenadsorption(LT-N2GA).Resultsindicatethattheporesintheshalesaregenerallynanoscaleandcanbeclassifiedintofourtypesingeneral,i.e.,organicpores,interparticlepores,
6、mineralmatrixporesandmicrofractures.Theinterparticleporesdominateamongthesemultipletypesofpores.Theporesizedistributionoftheshalesarecomplex,asmesopores(2~50nm)weredistributedmostwidelyandsomemicropores(<2nm)andmacropores(>50nm)havealsobeenobserved.Intermsofthecontrolsoftheporesize
7、distributionoftheshales,weconductacorrelationbetweenporevolumeandbrittleminerals(e.g.,quartz,pyriteandalbite)contents,claycontentsandTOC.Itisimpliedthatmineralcompositionsaretheprimarycontrol,contentsofbrittlemineralsandclaymineralsalsoplayacertaininfluence(especiallyformicroporesa
8、ndmesopores),whereasTOChas