四川盆地震旦系灯影组丘滩体储层沉积模式与物性特征

研究丘滩复合体沉积模式有助于预测四川盆地灯影组优质储层.基于钻井和露头资料，通过微观薄片鉴定，发现丘滩体主要的岩石结构为藻白云岩，并可进一步细分为5种微相:丘基、丘核、丘坪、丘盖和丘翼.识别出3种典型的微相组合类型，包括反映加积的"丘基-丘核-丘坪"序列，反映迁移的"丘基-丘核-丘翼"序列，反映终止的"丘基-丘核-丘盖"序列.结合沉积相带分布，将灯影组丘滩分为加积型台缘丘滩、迁移型台缘丘滩、台内丘滩、台内台坪4种类型.其中加积型台缘丘滩体主要沉积"丘基-丘核-丘坪"序列，旋回性明显，丘核多发育格架残留孔、洞，并在反映储集性能的储层总厚度、孔隙度、渗透率等方面均有优势，是四川盆地灯影组最有利的丘滩储集体. 

Sedimentary Models and Physical Properties of Mound-Shoal Complex Reservoirs in Sinian Dengying Formation,Sichuan Basin

Mound-shoal complex sedimentary models are important for the high-quality reservoir exploration of the Dengying Formation in the Sichuan basin. Based on core and outcrop profile and thin section observation, it is found that the main rock type of the mound-shoal complex is cyanobacteria dolostone. The mound-shoal complex consists of five microfacies including mound base, mound core, mound flat, mound cap and mound flank. There are three types of vertical combination rules of these microfacies, namely, the mound base-core-flat sequence reflecting aggradation, the mound base-core-flank sequence reflecting migration and the mound base-core-cap reflecting termination. According to the distribution of sedimentary facies, the mound-shoal complex of the Dengying Formation is divided into four types including aggradation platform margin mound-shoal complex, migration platform margin mound-shoal complex, platform interior mound-shoal complex and platform interior flat. The study shows that the aggradation platform margin mound-shoal complex mainly deposits the mound base-core-flat sequence, with obvious cyclicity. Its mound core develops a large number of framework residual pores and holes. Due to its advantages in total reservoir thickness, porosity and permeability, it is concluded that the aggradation platform margin mound-shoal complex is the high-quality reservoir of the Dengying Formation in the Sichuan basin.