吴起薛岔地区长8油层组储层岩石学特征研究

The research of petrological characteristics of Chang 8 oil-bearing layer in WuqiXuecha area

吴起薛岔地区是近年来延长油田的潜力目标开发区,其长8油层组油藏分布面积和储量潜力大。因此,本文通过钻井岩心、铸体薄片、扫描电镜观察和粒度、X衍射全岩分析、黏土矿物定量分析,对研究区长8油层组储层岩石学特征进行了研究。结果显示,研究区长8油层组岩性主要由灰褐色细粒岩屑长石砂岩组成,长石砂岩次之,具有"低石,高长石"特点;碎屑颗粒多为次棱角状,分选性中等,胶结类型以孔隙及加大孔隙型为主;填隙物含量均大于15%,主要以绿泥石膜、水云母、方解石以及铁方解石等自生矿物为主,以及少量高岭石和网状粘土等。

WuqiXuecha area is a potential area of Yangchang oilfield in recent years.Its Chang 8 oil-bearing layer has large oil-bearingareaand great reserves potential.In this paper,the petrological characteristics of Chang 8 oil-bearing layerare studied by the observation of drilling core,casting thin section,scanning electron microscopeand the analysis of granularity,X ray diffraction method,the quantitative mineral clay.The results show that the lithology of Chang 8 oil-bearing layeris mainly composed of grey-brown fine-grained lithic feldspar sandstone,followed by feldspar sandstone,and characterized by" low quartz,high feldspar.The reservoir of Chang 8 oil-bearing laye is mainly characterized by sub-angular detrital particles,medium sorting,and the cementation type of pore andenlarged-pore,and contains more than 15 % of the interstitial fillings,which mainly consistedby authigenic mineral,such as chlorite film,hydromica,calcite and calcite,and a small amount of kaolinite and reticulate clay.