四川盆地非常规储层特征研究—以某构造须家河组致密砂岩储层为例

Study on the Characteristics of Unconventional Reservoir in Sichuan Basin:a Case Study on Tight Sandstone Reservoir in Xujiahe Formation of A Structural Zone

须家河组致密砂岩储层是四川盆地某构造区主力产气层。通过对该区多口井铸体薄片、扫描电镜、物性及压汞曲线特征分析,认为须家河组砂岩储层岩石类型复杂;孔隙度平均值为7.8%,渗透率平均值为0.435m D,孔渗相关性不强;孔隙类型由剩余原生孔隙、次生溶蚀孔隙和微裂缝组成,次生溶孔为主要孔隙类型,喉道往往是多种类型共生;结合压汞曲线和孔隙结构特征将该区储层分为三种类型。

The tight sandstone of the Xujiahe Formation is one of the main gas bearing formation of a structural zone in Siehuan Basin. Based on thin sections, scanning electron microscopy, core porosity and permeability data, and mercury injection data, it was considered that the types of reservoir rocks are complex; Tile average porosity is 7.8%, the average permeability is 0.435mD, showing that the correlation between porosity and permeability is not so strong; Types of pore are residual primary porosity, secondary dissolution porosity and micro crack, while the secondary dissolution porosity is the major one, and the throat is often a variety of symbiosis; Combing with the mercury injection data and pore structure characteristic, the reservoir of this area can be divided into three types.