高邮凹陷阜宁组一段致密砂岩储层特征及其物性控制因素

Reservoir Characteristics and Controlling Factors on Physical Properties of Tight Sandstone in 1st Member of Funing Formation in Gaoyou Sag

摘要: 针对高邮凹陷阜一段致密储层物性差异大，物性控制因素认识不清的问题，综合利用薄片观察、扫描电镜观察、高压压汞、恒速压汞和微米CT扫描等技术方法，对研究区致密储层特征开展了研究。结果表明，研究区致密储层具有高石英含量，低岩屑、长石含量，主要发育有压实作用、胶结作用、溶蚀作用和交代作用等成岩作用类型，储集空间以粒间、粒内溶蚀孔隙为主，其次为原生孔隙和晶间孔隙。通过对比研究区南部断阶带与北部斜坡内带致密储层特征，认为沉积作用、构造作用、成岩作用和孔隙结构四个因素综合作用导致了两个地区储层物性的差异，沉积作用宏观上控制不同相带储层的物性分布，构造作用通过控制不同地区储层的埋藏方式进而影响成岩作用，在不同成岩作用类型和成岩作用强度下储层形成了不同的孔隙结构类型，并最终导致了储层物性的差异。

Abstract: Reservoir characteristics are researched on the problem of great difference in physical properties and confusion of physical properties control factors that in the first member of Funing formation in Gaoyou Sag. Thin section observation, scanning electron microscope observation, high-pressure mercury injection, rate-controlled mercury injection and micron CT scanning were used in this study. Research indicates that the reservoirs mainly consist of high quartz content, low feldspar and lithic content, the main diagenesis of which includes compaction, cementation, dissolution, and replacement. The reservoir space is dominated by intergranular and intragranular dissolution pores, followed by primary pores and intercrystalline pores. Sedimentation, tectonics, diagenesis and pore structure lead to the differences of physical properties between the Southern step-fault zone and the Northern Slope zone. Sedimentation controls the distribution of physical properties of reservoirs in different facies zones, tectonics influences diagenesis by controlling the burial modes of reservoirs in different regions. Under the different diagenetic types and diagenetic intensity, different types of pore structure are formed in reservoirs, which finally lead to the differences of reservoir physical properties.