川中营山构造须家河组第二段致密砂岩储层特征

四川盆地营山构造须家河组第二段是一套以长石石英砂岩、岩屑长石砂岩为主的地层.通过对须二段储层岩心、薄片观察及物性资料分析,确定须二段属于三角洲前缘亚相,储集砂体由水下分流河道和河口砂坝砂体组成；储集空间类型主要为粒间孔、粒内溶孔；属低孔低渗的裂缝-孔隙型储层.储层发育受沉积、成岩作用双重影响,沉积相是储层形成的基础,成...

Geological features of tight sandstone reservoir of Member 2 of Xujiahe Formation in Yingshan structure, Central Sichuan, China

Member 2 of Upper Triassic Xujiahe Formation(T3x2) is a set of debris-feldspar and feldspar-quartz sandstone in the Yingshan structure.Based on the cores,the flake observation and physical properties data of the reservoir in the T3x2,this study indicates that the 2nd member belongs to the front-delta deposition.The main reservoir sandy bodies have deposited in subaqueous distributary channel and distributary mouth bar with intergranular pore and intragranular pores as reservoir space.The reservoir is a cracked-porous type with low porosity and low permeability.The reservoir’s development is influenced by both sedimentary facies and diagenesis.The sedimentary facies is the basis of the development of the reservoir and the diagenesis process controls the reservoir’s ability.Cementation and compaction are the major diagenesis to destroy the pores,and dissolution is the major diagenesis to form the secondary pores.