四川盆地上二叠统大隆组页岩储层特征及其控制因素

Characteristics and determinants of shale reservoirs in the Upper Permian Dalong Formation， Sichuan Basin

叶玥豪 陈伟 汪华 宋金民 明盈 戴鑫 李智武 孙豪飞 马小刚 刘婷婷 唐辉 刘树根

Yuehao YE Wei CHEN Hua WANG Jinmin SONG Ying MING Xin DAI Zhiwu LI Haofei SUN Xiaogang MA Tingting LIU Hui TANG Shugen LIU

四川盆地开江-梁平海槽内上二叠统大隆组发育海相黑色页岩。近期LY1，DY1和HY1井在大隆组勘探发现高产页岩气，显示川北大隆组海相页岩气勘探潜力巨大，研究其页岩储层特征与控制因素具有非常重要的意义。以DY1井为研究对象，开展了大隆组页岩有机地球化学、脆性矿物含量、孔隙类型和孔隙结构等方面研究，探讨其储层特征与控制因素。结果表明：①大隆组黑色页岩为深水陆棚沉积，主要发育硅质页岩和混合质页岩岩相，脆性矿物含量高；②黑色页岩有机质丰度高，总有机碳含量（）平均可达7.84 %，有机质类型为Ⅱ-Ⅱ型，孔隙度较高，平均可达5.78 %，储集空间以有机质孔为主，微孔峰值高；③热演化程度、有机质类型和丰度控制黑色页岩孔隙发育程度，碳酸盐矿物对孔隙发育起破坏作用。

Marine black shales are found in the Upper Permian Dalong Formation within the Kaijiang-Liangping trough in the Sichuan Basin. Recently drilling of wells LY1， DY1， and HY1 has revealed high-yield shale gas in this formation， suggesting considerable potential for marine shale gas exploration in the Dalong Formation of the northern Sichuan Basin. Hence， it is highly significant to investigate the characteristics and determinants of shale reservoirs in this formation. In this study， we investigate the organic geochemistry， brittle mineral content， pore types， and pore structures of shales in the Dalong Formation in well DY1， aiming to elucidate the characteristics and determinants of the shale reservoir within. The findings show that the black shales in the Dalong Formation are of deep-water shelf deposits， exhibiting major facies of siliceous and mixed shale， high in brittle mineral contents. The organic matter of these shales exhibits a high abundance， with content averaging at 7.84 %， type Ⅱ-Ⅱ kerogens， and high porosities， averaging at 5.78 %， and the organic pores act as main storage space with the micro-pores’ peak value the highest. The development of pores in the shales is governed by the abundance， type， and thermal maturity of organic matter， while carbonate minerals are detrimental to their growth.

10.11743/ogg20240406