陕北斜坡上古生界山_2—盒_8段沉积-成岩与储层孔隙特征  

THE POROSITY CHARACTERISTICS OF SEDIMENTARY AND DIAGENETIC ENVIRONMENT FOR SHAN-2 MEMBER TO HE-8 MEMBER AT THE UPPER PALEOZOIC IN NORTHERN SHAANXI SLOPE

作　　者：王奕萱 张晓东 孙勇[1] 安星宇 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中国河南国际合作集团有限公司,郑州450004 [3]中国冶金地质总局山东局蒙古正元有限责任公司,济南250100

出　　处：《地质力学学报》2014年第3期230-242,共13页Journal of Geomechanics

基　　金：国家自然科学基金重点项目(编号:90814007)

摘　　要：鄂尔多斯盆地陕北斜坡上古生界山2段—盒8段发育典型的低渗致密岩性气藏,储层物性控制着区内气藏的富集,在致密储层中孔隙发育特征与储层沉积环境及后期成岩作用密切相关。通过沉积物粒度分析、储层孔隙特征扫描电镜观察,探讨了研究区储层在压实成岩作用后期孔隙的破坏作用,建立了黏土矿物转化序列。研究结果显示,研究区山2—盒8段砂岩储层在压实成岩作用后对储层孔隙的破坏作用主要包括黏土矿物转化及胶结作用;黏土矿物转化模式为"蒙脱石-伊蒙混层-伊利石"型,后期伴有高岭石和绿泥石的伊利石化;发育于碎屑颗粒表面的绿泥石黏土膜在降低储层原生孔隙的同时,抑制了后期发生的硅质胶结作用,为残余粒间孔的保存和次生溶孔的形成提供了物质基础,绿泥石套膜的发育成为气藏勘探评价中储层优选的关键参数之一。The typical low permeability lithological reservoir is the main reservoir which has been developed from Shan-2 member to He-8 member at the upper Paleozoic in Northern Shaanxi slope, Ordos Basin. The reservoir properties dominate the enrichment of oils and gas. The merits of tight reservoir porosity are associated with their sedimentary and diagenetic environment. In this paper, the influence of the late-diagenetic on reservoir porosity was discussed according to the sedimentary particle size analysis and scanning electron microscopy observation. From the result of this study, we can draw the conclusion that the chief destructions of reservoir-quality which is in the transform sequence of ＂ Montmorillonite-Andreattite-Illite＂ are the cementation and the evolution of clay cementation. Furthermore, the clay membrane of chlorite which is developed in the surface of clastic particles can protect the reservoir porosity from the late-cementation while block the primary porosity. Therefore the clay membrane of chlorite can be one of the criteria to judge the reservoirquality in gas reservoir exploration.

关 键 词：陕北斜坡 山西组 石盒子组 成岩作用 孔隙特征 

分 类 号：P618.130.2[天文地球—矿床学]