川西南周公山及邻区下二叠统碳酸盐岩储层的孔隙演化史

Evolution of porosity in Lower Permian carbonatite reservoir of Zhougongshan and its adjacent areas in southwestern Sichuan

研究区地层深部的下二叠统碳酸盐岩储层孔隙的演化是在沉积作用、各种建设性和破坏性成岩作用、构造作用下的漫长地质历史构建过程。根据薄片鉴定、地化特征、成岩序列和储层孔隙发育程度分析，提出二叠统储层的孔隙演化模式，共经历了4个阶段：①原生孔隙形成．首次缩减期（沉积-同生阶段）；②次生溶孔、洞大量发育期（同生-准同生阶段和表生阶段）；③孔洞再次缩减期（浅埋藏阶段）；④埋藏溶蚀-充填-构造裂缝期（中-深埋藏阶段和构造阶段）。孔隙的演化具有溶蚀→充填→再溶蚀的多旋回性特征，一般具3～6期旋回演化。

The evolution of porosity in Lower Permian earbonatite reservoir in deep deposits of the studied area is an long forming process under the actions of deposition, constructive and destructive diagenesis and tectonization. According to the analyses on identification of thin section, geochemistry, diagenetic sequence and reservoir porosity, the authors proposed a model of py diminished stage （deposit-syngenesis phase）, development stage of induced porosity in quantity （syngenesis-penecontemporaneous and hypergene phases）, porosity re-diminished stage （shallow embedding phase）, burial corrosion-filling-tectoclase stage （mid-deep burial and structure phrase）. The evolution of porosity is in multicycle feature usually for 3 - 6 times from corrosion toward filling to corrosion.