西湖凹陷Y构造花港组致密砂岩储层孔隙演化模式

The Porosity Evolution of Tight Sandstone Reservoir of Huagang Formation in the Y Geological Structure in Xihu Depression

李倩 张萍 闫洁 杨鹏程

LI Qian ZHANG Ping YAN Jie YANG Pengcheng

中国石化股份公司上海海洋油气分公司勘探开发研究院, 上海 200120; 中国石油化工股份有限公司上海海洋油气分公司, 上海 200120

Institute of Exploration and Development, SINOPEC Shanghai Offshore Oil & Gas Company, Shanghai 200120, China; SINOPEC Shanghai Offshore Oil & Gas Company, Shanghai 200120, China

应用铸体薄片、阴极发光、扫描电镜、流体包裹体和X衍射等手段，对西湖凹陷Y构造花港组致密砂岩储层孔隙演化过程进行定量分析。认为研究区花港组低孔渗的致密砂岩储层主要的孔隙类型是次生孔隙。压实作用使孔隙度减小平均值为34.6%，是孔隙度降低的主导因素，且在早成岩阶段压实最强；胶结作用伴随着整个成岩作用阶段，使孔隙度减小平均值达3.3%，主要以碳酸盐岩胶结为主，其次为硅质和粘土矿物胶结；成岩作用过程中的溶蚀作用使孔隙度增加平均值为7.1%。

Based on the study of thin section, cathodoluminescence, scanning electron microscope, fluid inclusion and X-ray diffraction data, the authors quantitatively analyzed the porosity evolution of tight sandstone reservoir in Huagang Formation in Structure Y, Xihu sag. It reveals that secondary pores are the primary. Compaction effect is the dominant factor that decreased the original porosity by 34.6%, and makes the most contribution in the early diagenetic stage. Cementation occurs in the whole diagenetic stage, and decreased the original porosity by 3.3%. Carbonate cementation is the main cementation, followed are silica cementation and clay mineral cementation. The dissolution which occurred in the late diagenetic period increased the porosity by 7.1%.

https://doi.org/10.3969/j.issn.1008-2336.2017.04.029