靖边东南部长2储层特征及储层质量评价

利用岩心观察、薄片鉴定、孔渗分析、扫描电镜及压汞实验等资料,在对研究区储层特征进行研究的基础上,采用了多个因素综合评价的方法对储层质量进行了更为有效的分类评价。研究表明,靖边东南部长2油层组储层以中细粒长石砂岩为主;填隙物主要为铁方解石,胶结类型以薄膜-孔隙式为主;储层孔隙类型以原生孔隙为主,最主要的为残余粒间孔,储层砂岩孔喉连通性较好,且分选性较好;属中低孔、中低渗储层。利用存储系数、地层系数和流动带指数对储层质量进行关键单因素评价,再结合实验分析的微观因素建立储层分类标准,对储层质量进行多因素综合评价,将该区长2储层分为4类。结果表明,长2油层组Ⅲ类储层所占比例最大,其次为Ⅳ类储层,Ⅱ类和Ⅰ类储层比例相对较小。

Characteristics and quality assessment of Chang 2 reservoir in Southeastern Jingbian

Based on cole observation, thin section analysis, physical testing, scanning electron microscopy and mercury intrusion curve data, the reservoir characteristics are studied and the effective reservoir quality is classified and evaluated using a multi-factor comprehensive evaluation method. The result shows that Chang 2 reservoir in Southeastern Jinghian is mainly fine-grained fehtspathic sandstone： fillings are nminly iron calcite cementation type to fihn-pore type primarily; pore type are primary porosity, mainly the residual intergranular pores. Pore connectivity of reservoir sandstones is good anti sorting is good. Reservoir is low pornsity and low permeatfility reservoir. Using storage coefficient, formation factor and the index on flow zone, the key factor of reservoir is evaluated. Combined with the experimental analysis of micro factors, the reservoir classification criteria is established and multivariate reservoir quality is evaluated. Chang 2 reservoirs ean be divided into four types. The resuhs show that Type m reservoir oil gronps take the largest share, followed by Type Ⅳ reservoir and the scale of Type Ⅱ and Type Ⅰ reservuir is relatively small.