准噶尔盆地西北缘二叠系下乌尔禾组储层控制因素分析

Analysis of reservoir control factors for Xiawuerhe formation of Permian in northwestern margin of Junggar Basin

以现场岩心观测为基础,结合岩石薄片、铸体薄片、扫描电镜、阴极发光、物性分析、压汞分析等资料,对准噶尔盆地西北缘二叠系八区下乌尔禾组碎屑岩储层岩石学特征、物性及孔隙结构特征、储集空间类型及其控制因素进行系统的分析,结果表明:研究区以砂砾岩、细砾岩沉积为主,整体粒度较粗,颗粒分选差,磨圆次棱角-次圆状。砾石成分主要为火山碎屑岩,填隙物以泥质为主。储层物性差,非均质性强,低孔低渗。储层储集空间以原生孔隙为主,其次为方沸石、钠长石等晶内溶蚀孔隙。储集空间的发育主要受构造运动、成岩作用、碎屑颗粒以及填隙物组分等因素的影响。

Based on the core observation,lithologic features, physical properties and pore structure characteristics, space type and influencing factors of Permian clastic reservoir in Eight area in northwestern margin of Junggar Basin are studied by methods of thin section analysis, casting thin sections, scanning electron microscope, cathodoluminescence, porosity and per-meabihty analysis, mercury intrusion data etc. The research shows that the rock types of studied area are mainly sandy conglomerate and fine conglomerate, which are characterized by coarse grain size, poor sorting and subangular SA, subroundrd sub- rnd roundness. The ingredient of conglomerates is mainly volcanic fragmental rock and interstitial materi al are mainly argillaceous components. The reservoir physical characteristics is poor. Heterogeneity is strong, low porosity and low permeability. The main pore type is primary porosity, the second is intracrys talline solution pore which formed by the dissolution of analcime, albite etc.. Reservoir space is influ enced by tectonic movement,diagenesis,ingredient of detrital grain and filler content components etc.