【摘要】 为研究玛湖凹陷二叠系下乌尔禾组沸石成因及溶蚀机制,开展了岩石薄片鉴定、荧光分析、场发射扫描电子显微镜观察、电子探针分析、能谱分析和包裹体测试。结果表明:①研究区沸石族矿物以浊沸石为主,片沸石次之,偶见方沸石、斜发沸石和辉沸石,沸石既有高温成因类型,也有低温成因类型。②沸石成因主要包括2类:早成岩期以火山物质蚀变为主,该类沸石胶结的岩心多疏松易散;晚成岩期以孔隙水结晶为主,岩心多致密。片沸石、方沸石、斜发沸石和辉沸石成因以凝灰质的蚀变为主,浊沸石成因既有凝灰质蚀变,又包括孔隙水结晶成因。③平面上,沸石类型及含量分布特征受控于沉积相带,溶蚀差异则受控于有机酸的供给。浊沸石多发育于扇三角洲前缘厚层粗粒砂砾岩中,片沸石多发育于扇三角洲平原前端富含凝灰质砾岩中。在接近深水区烃源岩发育区的三角洲前缘部位或裂缝发育带附近的砂砾岩储层中,浊沸石溶蚀程度高,优质储层发育。该研究成果对含沸石族储层研究和玛湖凹陷二叠系下乌尔禾组油气勘探均具有指导作用。更多还原

【Abstract】 In order to study the genesis and dissolution mechanism of zeolites in the Lower Urhe Formation of Permian in Mahu Depression,thin section identification,fluorescence analysis,field emission scanning electron microscopy,electron probe analysis,energy spectrum analysis and inclusion test were carried out. The results show that:(1)The mainly zeolite group minerals in the study area are turbidite,followed by heulandite,analcite,clinoptilolite and zeolites. The zeolites have both high-temperature and low-temperature genesis types.(2)The genesis of zeolites mainly includes two types:in the early diagenetic stage,it is dominated by alteration of volcanic materials,and the cores cemented by zeolites are mostly loose and easy to disperse;in the late diagenetic stage,it is dominated by pore water crystallization,and the cores are mostly dense. Heulandite,analcite,clinoptilolite and pyroxene are mainly caused by tuffaceous alteration,while turbidites are caused by tuffaceous alteration and pore water crystallization.(3)On the plane,the type and content distribution of zeolites are controlled by the sedimentary facies,while the dissolution difference is controlled by the supply of organic acids. Most of the laumontite are developed in the thick coarse-grained glutenite of the fan delta front,and most of the heulandite is developed in the tuffaceous conglomerate in the front of the fan delta plain. In the glutenite reservoir in delta front or near fracture development zone near the deep-water source rock development area,the turbidite has high dissolution degree and high-quality reservoir development. The research results can be used to guide the study of zeolites bearing reservoirs and the exploration of oil and gas in the Lower Urhe Formation of Permian in Mahu Depression.更多还原