青海柴达木盆地北缘构造带九龙山地区侏罗系储层特征

The Jurassic clastic reservoirs in the Jiulongshan area, northern Qaidam Basin, Qinghai

通过对九龙山地区重点探井岩心样品的观测、薄片鉴定、扫描电镜分析,结合储层物性和压汞数据,系统研究了九龙山地区侏罗系碎屑岩储层的岩石学特征、物性特征、成岩作用及孔隙演化规律。结果表明,碎屑岩储层主要以粗砂岩、中砂岩和细砂岩为主;胶结物类型主要为碳酸盐类胶结物、硅质胶结和自生黏土矿物;孔隙类型以残余粒间孔隙和溶蚀孔隙为主,孔隙与吼道匹配关系较好;储集岩成分成熟度低、结构成熟度中等-差;颗粒间主要以点-线接触为主;储集岩成岩作用较强,主要处于中成岩阶段A期。

The petrological,physical and diagenetic characteristics and porosity evolution of the Jurassic clastic reservoirs are based on the examination of the representative core samples and thin sections,scanning electron photomicrographs,physical properties and mercury-injection data on the Jurassic clastic reservoirs in the Jiulongshan area,northern Qaidam Basin,Qinghai. The Jurassic clastic reservoirs consist mainly of coarse-grained sandstones,medium-grained sandstones and fine-grained sandstones. The cement types contain the carbonate cements,siliceous cements and authigenic clay minerals. The porosity types include the residual primary intergranular pores and solution openings,and the porosity and permeability are well correlated. The reservoir rocks have low compositional maturity and moderate to poor textural maturity,with the point-line contact types. At present,the reservoir rocks are tentative to be in Phase A of the anadiagenetic stages.