川西侏罗系上沙溪庙组砂岩中绿泥石的成岩耗水作用及其油气地质意义  

Water Consumption in Diagenetic Stage for Chlorite in Sandstone of the Middle Jurassic Upper Shaximiao Formation in West Sichuan and Its Oil-Gas Geological Significance

作　　者：张慧娟[1] 时志强[1] 安红艳[1] 曾德勇[1] 张华[1] 

机构地区：[1]成都理工大学沉积地质研究院,成都610059

出　　处：《四川地质学报》2010年第4期431-435,共5页Acta Geologica Sichuan

摘　　要：通过对川西坳陷中侏罗统上沙溪庙组砂岩储层样品的普通薄片和铸体薄片观察分析,讨论了砂岩中绿泥石环边胶结物的特征、形成期次以及油气地质意义。研究表明,富SiO2的孔隙流体对初期形成的绿泥石环边胶结物产生溶蚀作用。如果孔隙流体性质呈现适合石英胶结物形成时,当流体渗透过绿泥石环边到达石英碎屑颗粒表面,由于对绿泥石环边的溶蚀作用使得流体中SiO2浓度降低,则不足以形成石英胶结物,从而保护了孔隙空间不被充填。在成岩过程中矿物蚀变成绿泥石发生的"成岩耗水"作用使得地层水减少,地层压力降低,与围岩形成压力差,有利于油气运移和富集。This paper deals with characteristics of rim cements of chlorite in sandstone of the Middle Jurassic Upper Shaximiao Formation in west Sichuan and their oil-gas geological significance based on thin section observation.The study indicates that acid pore fluids in sandstone reservoir of the Middle Jurassic Shaximiao Formation were derived from the underlying Upper Triassic Xujiahe Formation.These acid fluids corroded detrital minerals in the sandstone during which authigenic chlorite was formed and associated water consumption in diagenetic stage resulted in decrease in formation pressure which was beneficial to migration and enrichment of oil and gas.

关 键 词：绿泥石 环边胶结物 上沙溪庙组 川西 

分 类 号：P618.130[天文地球—矿床学]