鄂尔多斯盆地陇东地区延长组低渗透储层孔隙结构分类研究

运用铸体薄片、扫描电镜与常规压汞等资料,对陇东地区延长组低渗透储层孔隙结构分类标准进行了研究。不同孔隙结构特征参数与宏观物性参数的相关分析表明,最大连通喉道半径与渗透率的相关关系最好,为喉道分级的最优参数;运用数据构形的方法确定出了喉道分级界限,建立了储层孔隙、喉道分级标准。综合孔隙与喉道大小的组合及储层孔喉的其他特征,将延长组储层砂岩的孔隙结构划分为六种类型:大中孔粗喉型、中小孔中喉型、中小孔细喉型、小孔微细喉型、细微孔微细喉型和细微孔微喉型。不同孔隙结构类型的储层具有不同的物性特征及不同的产液能力。

Research on the pore structure classification of low permeability reservior of the Yanchang Formation in Longdong Area.Ordos Basin

Using the data such as cast thin section,scanning electron microscope and mercury-injection,the present paper investigates the pore structure classification standards of low permeability reservoir of the Yanchang Formation in Longdong Area,Ordos Basin.The correlation analysis among characteristic parameters of microscopic pore structure and macroscopic physical properties shows that the maximum connected pore-throat radius has the best correlativity with permeability and acts as the favorable parameter for throat grading;using method of data configuration,the paper determines the throat grading boundaries and establishes the grading standards of reservoir pores and throats.The reservoir pore structure of the Yanchang Formation could be classified into six types including big-mid pore coarse throat type,mid-small pore mid throat type,mid-small pore fine throat type,small pore micro-fine throat type,fine-micro pore micro-fine throat type,and fine-micro pore micro throat type.Reservoir could have different physical properties and liquid production capacity according to its pore structure type.