三塘湖盆地牛圈湖油田西山窑组储集层特征及评价

三塘湖盆地牛圈湖油田中侏罗统西山窑组油藏储集层的骨架砂体为扇三角洲水下分流河道复合砂体。储集层岩石学总的特征为低结构、低成分成熟度，成分分类属长石岩屑砂岩和岩屑砂岩。垂向上物性非均质性很强。根据物性变化的旋回性和垂向变化特征，划分了三个物性段。整个含油层段储集层孔隙度和渗透率频率分布近于正态分布，总体表现为中孔、低渗的特点。储集空间以原生的粒间孔隙和次生的粒间溶孔为主，其孔隙结构特征以小孔、细喉和小孔、微细喉、细歪度、分选差为特征。影响储集性能的主要成岩作用为压实作用、胶结作用和溶解作用。成岩阶段属晚成岩阶段Ａ期。储集层的宏观物性参数与微观结构参数之间有良好的相关关系。经综合分类评价，上部两个层段为中—差的储集层，下部层段为非储集层，且储集层具强水敏性。

RESERVOIR CHARACTERISTIC OF XISHANYAO FORMATION OF MIDDLE JURASSIC IN NIUJUANHU OILFIELD, SANTANGHU BASIN.

Fan delta distributary channel sand body is framework one of Xishanyao reservoir(Middle Jurassic) in Niujuanhu oilfield. The petrology of reservoir is characterized by low structural and compositional maturity. The lithology is feldspar lithic sandstone and lithic sandstone. It has severe vertical heterogeneity, and can be classified into three members based on cyclic and vertical changes of petrophysical properties. Reservoir space is dominated by primary intergranular pore and secondary intergranular denudation pore, characterized by small pore and fine throat, small pore and tiny throat, fine skewness and poor sorting. Reservoir quality is controlled by compaction, cementation and dissolution in A period of Late diagenetic period. There is better correlation between macro petrophysical parameters and micro structural parameters. Comprehensive evaluation indicated that two members in upper part are medium bad reservoir, while lower member has no reservoir quality. Sensitivity analysis showed that the reservoir is strongly water sensitive.