新都地区上沙溪庙组砂岩储层特征研究

Research of Sandstone Reservoirs Characteristics of Upper Shaximiao Formation in Xindu Area

新都地区中侏罗统上沙溪庙组是重要的产气层位。通过普通薄片、铸体薄片、扫描电镜及孔隙结构和物性特征等方面的分析,对新都地区上沙溪庙组砂岩储层特征进行了综合研究。结果表明:研究区上沙溪庙组储层岩石类型为中-细粒长石岩屑砂岩和岩屑砂岩,为低孔、低渗储层;储集空间主要为次生粒间溶孔;储层的发育受沉积相和成岩作用的控制,曲流河三角洲前缘水下分流河道砂体孔渗性一般较好,河口砂坝砂岩孔渗性次之;绿泥石环边胶结作用、溶蚀作用及少量发育的破裂作用对砂岩储层具有建设性作用。

The upper Shaximiao Formation of middle Jurassic is important gas productive strata in Xindu area.By means of ordinary lamella,casting lamella,electron microscope scanning,pore texture and physical characteristics analysis,the sandstone reservoir characteristics of Shaximiao Formation in Xindu area have comprehensive studied.The results show that：the upper Shaximiao formation reservoir sandstone is mainly medium to fine feldspathic litharenite and litharenite.The reservoirs are mainly of low porosity and low permeability.The main reservoir space is secondary intergranular dissolved pores.The development of reservoir is controlled by the sedimentary facies and diagenesis.The meandering river delta front subaqueous distributary channel sand bodies generally have good porosity and permeability,and the debouch bar sand bodies came second.while the chlorite rims cementation,corrosion and fracturing have constructive effects for the sandstone reservoirs.