砂岩在西湖凹陷花港组交互式盖层中的作用初探

西湖凹陷花港组盖层具有砂泥岩交互式发育特征，而与泥岩伴生的砂岩类盖层的油气封闭作用研究较少。采用岩芯、镜下观察及压汞等分析方法，对砂泥岩交互式盖层中的砂岩特征进行了分析。结果表明，盖层中的砂岩可作为有效盖层，砂岩类盖层早期受沉积环境控制，含有较多的泥质而导致早期压实作用较强，加之晚期的黏土矿物转换及胶结物的发育，具备形成良好盖层的条件。在不同地区进行砂岩盖层有效性研究时应以沉积环境为基础，针对不同类型的砂岩进行成岩作用研究，并针对不同类型的砂岩样品进行实验分析以明确砂岩盖层的有效性。

Preliminary Investigation on the Role of Sandstones in Interacting Caprocks of the Huagang Formation in the Xihu Depression

Interactions between sandstone and mudstone are present in the developmental characteristics of caprocks of the Huagang Formation in the Xihu Depression, but studies on the role of mudstone-associated sandstone-type caprocks in the sealing of petroleum are relatively scarce. The characteristics of sandstones within interactive sandstone-mudstone caprocks were analyzed using rock cores, microscopic observations, and mercury intrusion porosimetry. The results show that sandstones within the caprock are able to act as an effective seal (caprock). Sandstone-type caprocks are controlled by their sedimentary environment during early periods, and their high argillaceous mineral content led to strong compaction during these periods. The addition of clay mineral transformation and cement development in later periods imbued these rocks with the conditions necessary for the formation of a highly effective caprock. The sedimentary environment of caprocks should be the foundation for studies on the effectiveness of sandstone caprocks in different regions, and diagenetic studies should be performed on the various sandstones present. In addition, experimental analyses should be conducted on different types of sandstone samples to determine the effectiveness of sandstone caprocks.