西湖凹陷Y构造带花港组储层特征及物性影响因素分析

Reservoir Characteristics and Influence Factors of Huagang Formation in Y Structure, Xihu Sag

Y构造带花港组储层整体属于特低孔、中-特低渗储层,在储层整体致密的背景下发育3个次生孔隙发育带。作者通过物性分析、显微镜观察、阴极发光分析以及扫描电镜分析认为,研究区花港组储层溶蚀孔隙发育。沉积环境是研究区储层物性最重要的影响因素,沉积粒度一定程度上影响了研究区砂岩储层物性,富岩屑、富长石的沉积环境为后期溶蚀孔隙的发育提供了物质基础;成岩作用是研究区储层物性重要的影响因素,压实及压溶作用是研究区储层物性变差的主要因素,而溶蚀作用则是深部储层物性变好的主要因素;断裂带热事件也是研究区深部储层次生高孔带发育的重要原因之一。

The reservoirs of Huagang Formation in Y structure generally belong to the scope of ultra-low porosity, medium to ultra-low permeability. The presence of three secondary pore zones, however, improves the reservoir properties. Based on the study of analytic data including physical property test, microscopic observation, cathode luminescence and scanning electron microscopy （SEM）, it can be concluded that the dissolution pores are well developed in the reservoir of Huagang formation. Sedimentary environment is the most important factor affecting the physical properties of reservoirs in the study area. Particle size influences the physical property to some extent, and the sediments rich in debris and feldspar are advantageous to the development of dissolution pores. Another significant factor affecting reservoir physical property is diagenesis. The compaction and pressure solution are the main factors that deteriorate the physical properties of reservoirs. However, the dissolution makes the deep reservoir better in physical properties in local areas. The third important factor for forming the secondary pore in the study area is fault thermal event.