松辽盆地南部地区营城组典型火山机构地质特征

Geological Characteristics of Typical Volcanic Edifices of Yingcheng Formation in Southern Songliao Basin

在松辽盆地地质背景研究的基础上,根据盆地南部地区营城组火山岩地质特征对火山机构进行分类,描述其地质特征,并讨论其储层特征。将研究区火山机构分成3类9种,即熔岩类火山机构、碎屑岩类火山机构和复合火山机构3类;熔岩类火山机构包括粗面质熔岩火山机构、玄武质熔岩火山机构、安山质熔岩火山机构、英安质熔岩火山机构和流纹质熔岩火山机构,碎屑岩类火山机构包括玄武质碎屑岩火山机构、安山质碎屑岩火山机构和流纹质碎屑岩火山机构,以及复合火山机构共计9种。并统计了不同类型流纹质火山机构储层的储集空间类型及孔隙度,结果表明:流纹质复合火山机构储集空间类型复杂,储层溶蚀孔缝十分发育,储层物性最好;流纹质碎屑岩火山机构储层溶蚀孔缝较为发育,储层物性中等;流纹质熔岩火山机构储集空间类型单一,储层物性最差。将长岭断陷火山机构内部储层分为高孔高渗型、中孔中渗型和低孔低渗型3类,且有利储层受岩性影响较小,受岩相影响较大。

This study aims to construct the volcanic edifices,and discuss the characteristics of the different volcanic edifices and the reservoir of Yingcheng Formation in the southern area of Songliao Basin.The volcanic edifices of the study area are divided into 3 kinds and 9 types(trachytic lava,basaltic lava,andesitic lava,dacitic lava,rhyolitic lava,basaltic clastic rock,andesitic clastic rock,rhyolitic clastic rock,and composite volcanic edifices).In addition,the statistics of different reservoir types and porosity suggest that the rhyolitic composite volcanic edifices have the best reservoir characteristics,and the solution pores are important pore type;rhyolitic clastic volcanic edifices have the worse and the worst reservoir characteristics belong to the rhyolitic lava.The reservoir in Changling fault depression is divided into three types:high porosity-high permeability reservoir,middle porositymiddle permeability reservoir,and low porosity-low permeability reservoir.The favorable reservoir is mainly affected by lithofacies rather than lithology.