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1、西安石油大学大学毕业设(论文)银川盆地页岩气形成条件分析摘要:银川盆地南起青铜峡,北至石嘴山,西依贺兰山,东靠鄂尔多斯盆地西缘,南北长165km,东西宽42~60km,总面积7790km2,银川盆地在地质构造上被称为“银川地堑”。银川盆地整体呈北北东走向,基底呈南北高、中部低的船形,盆地中心位于平罗、贺兰、银川、永宁一带,最深部位大体位于平罗-银川一线以西及永宁、灵武之间的断陷处,在纵剖面上由平罗往北和由永宁向南又呈断阶状抬升。整个盆地为一东缓西陡的“向斜盆地”。为研究银川盆地页岩气形成条件,通过查阅相关文献以及对平凉组岩矿特征,含气页岩分布,页岩气有机地球化学的研究,对其地化特征做出初步
2、评价:银川盆地3口参数井仅银参1井曾采样进行生油分析。2036.5~3358.9m井段累积暗色泥质岩厚度为515.9m。其中,清水营组暗色泥岩层厚度为290.4m,有利生油层段为3204~328lm,泥岩单层厚度约为5m,最大单层厚度达20.5m,并含有黄铁矿颗粒;有机碳含量TOC为0.47%~0.5%,氯仿沥青“A”含量为0.0797%,有机质丰度一般;干酪根组分中类脂组分含量为64.71%~72.24%,生油岩属Ⅱ型;镜质组反射率Ro为0.69%,全烃色谱资料计算OEP为1.18,说明该段有机质已经进入成熟阶段。灵武坳陷、银川北凹陷、常信凹陷和平罗凹陷都处在有利的生烃范围。初步推测,清
3、水营组成熟生油岩面积大于200km2。但是对古近系的清水营组中、下部的沉积环境、岩性以及生烃能力的认识还不清楚。目前,要解决这些问题则需要利用现有的资料寻找隐含着的地质信息,进行合理的推测,页岩气的勘探前景也未知。关键词:银川盆地;页岩气;鄂尔多斯盆地;向斜盆地;地化特征39西安石油大学大学毕业设(论文)ConditionsForOccurrenceOfShaleGasInYinchuanBasinAbstract:SouthofYinchuanBasinsinceQingtongxia,northtoShizuishan,HelanMountaininthewest,Eastonthew
4、esternmarginoftheOrdosBasin,165kmlongfromnorthtosouth,east-westwidthof42~60km.Withatotalareaof7790km2andYinchuanBasiningeologicalstructureissaidto"Yinchuangraben".YinchuanbasinisaNNEstrike,thebasementwasNorthSouthhighandlowinthemiddleoftheboatshaped,basin,locatedinthecenterofthePingluo,Helan,Yinch
5、uan,Yongningarea,thedeepestgrossareaislocatedinbetweenthePingluo-YinchuanlinewestandYongning,Lingwufaultdepressionat,inlongitudinalsectionbyPingluotothenorthandYouYongningSouthandwasbrokenorderformuplift.Thewholebasinisasteepslopeinthewest"synclinalbasin".ForthestudyofYinchuanbasinshalegasformatio
6、nconditions,byconsultingrelevantliteratureanddistributionofPingliangFormationCharacteristicsofrocksandminerals,includingshalegas,shalegasoforganicgeochemistryresearch,makeapreliminaryevaluationofitscharacteristics:Yinchuanbasin3parameterwellsonlysilverreference1wellwassampledforsourceanalysis.2036
7、.5~3358.9mwellscumulativedarkmudstonethicknessis515.9m.TheQingshuiyinggroupofdarkmudstonelayerthicknessis290.4m,Lishengreservoirsof3204to328lm,mudstonethicknessapproximatelyis5m,themaximummonolayerthicknessreache