三塘湖盆地石炭系火山岩储集空间类型及储层特征

Reservoir Space Type and Reservoir Characteristics of Carboniferous Volcanic in Santanghu Basin

利用岩石薄片、铸体薄片、扫描电镜、压汞等测井多种资料,系统研究了三塘湖盆地石炭系火山岩储层的岩性特征、储集空间特征和储层特征。研究表明,石炭系火山岩储层以中、基性火山岩为主;储集空间分为原生孔隙、次生孔隙、裂缝三大类;储层孔隙组合有孔隙型、裂缝型、孔-缝复合型,其中孔-缝复合型最为有利;储层具低孔-特低孔、低渗-特低渗和强非均质性的特征,埋藏压实作用对火山熔岩的影响有限,不整合面和喷发间歇面、断裂发育带对有利储层的分布具有控制作用。

Petrographic characteristics, reservoir porosity and characteristics of Carboniferous volcanic rocks in the Santanghu Basin are described based on hand sample, slabs, and thin section observations, SEM, mercury injection and logging data. The results show that the reservoir rock types are dominated by intermediate-basic volcanic rock;porisity is classified into primary pores, secondary pores, and fracture porosity;volcanic reservoir types are the pore, fracture and combined fractures and initial porosity, among which the last type is most favorable. The physical properties of the reservoir are characterized by low to super-low porosity, low to super-low permeability and strong heterogeneity. The mechanical compaction had limited influence on the physical properties of the volcanic lava flows. The unconformity surface, boundaries between different flows, and major faults control the distribution of favorable reservoirs.