高邮凹陷阜三段砂岩储层控制因素分析

Controlling Factors of Sandstone Reservoir in the Third Member of Funing Formation in Gaoyou Sag

根据大量的岩性、物性、岩石薄片等资料,从沉积微相、成岩作用、含油气性3个方面分析了储层发育的控制因素。研究认为,高邮凹陷阜三段发育三角洲-湖泊沉积体系,储层以长石岩屑砂岩为主,储集空间主要为粒间溶孔、粒内溶孔,受成岩作用影响储层主要具有中-低孔、低-特低渗的特征;沉积微相控制砂体的形成与演化,水下分流河道和河口砂坝分布区是物性条件相对较好的有利砂体分布区;有利砂体储层受油气早期充注影响,孔隙在深层得以较好保存。

Based on large amount of data of lithologics,physical property and thin section,the controlling factors of the reservoir development were analyzed from the aspects of sedimentary microfacies,diagenesis and oil-bearing property.Study shows that the third member of Funing Formation sandstone belongs to delta-lacustrine depositional system in Gaoyou Sag composed of feldspathic lithic sandstone,the reservoir space is consisted of the intergranular dissolved pores and the intergranular pores,the reservoirs influenced by diagenesis are characterized by medium-low porosity,low and ultra-low permeability.The sedimentary microfacies control the formation and distribution of sandbodies.The area of underwater distributary channel and river-mouth bar is the area of favorable sandbodies with relative good physical property,the reservoirs with favorable sandbodies are influenced by early oil accumulation,thus pores could be preserved.