建南地区上二叠统长兴组储层储集空间类型及孔隙结构特征

Types of Pore Space and Characteristics of Pore Structure in Changxing Formation of Upper Permian in Jiannan Region

基于多井岩心、薄片、铸体薄片、孔渗及压汞分析资料,结合成像测井资料,对建南地区长兴组生屑滩相储层的主要储集岩类型、储集空间类型及孔隙结构特征进行了研究,研究认为:台地边缘滩相白云岩及白云质灰岩,以及台内滩相的生屑灰岩为长兴组的主要储集岩类型。二者均归属为特低孔特低渗储层类型。台地边缘滩白云岩及白云质灰岩中可见白云石原生晶间孔及晶间溶孔,台内滩相生屑灰岩中孔隙发育程度低,但可见多类构造裂缝的产出。综合压汞曲线形态、孔喉参数特征及物性特征,划分出了以台地边缘滩相白云岩及白云质灰岩为代表的细孔小喉型孔隙结构以及以台内滩相生屑灰岩为代表的微孔微喉型孔隙结构。

Based on data of core,thin section,cast thin section,porosity and permeability,mercury intrusion analysis,and imaging logs,the main reservoir rock types,reservoir space types,and pore structure characteristics of the bioclastic beach facies reservoirs of the Changxing Formation in Jiannan area are summarized and characterized.The findings indicate that the main reservoir rock types of the Changxing Formation are dolomite and dolomitic limestone in the platform margin and the bioclastic limestone in the platform interior,both of which are categorized as the ultra-low porosity and ultra-low permeability reservoirs.The primary intergranular pores and intergranular vugs can be seen in the dolomite and dolomitic limestone in the platform margin.The pore is scanty in bioclastic limestone in the platform interior,but multiple structural fractures can be observed.Based on the mercury intrusion curve,pore throat parameters,and physical properties,the pore structure of small pore and small throat type and micropore and micro-throat type can be divided,which are represented by the platform margin beach facies dolomite and dolomitic limestone and the platform interior beach facies bioclastic limestone.