The pore structure of Longmaxi shale in Fuling area of the Sichuan Basin is so complicated that con-ventional single test technology fails to accurately characterize the microscopic shale pores. The multi-scale micro-cosmic pore structure of Longmaxi shale in Fuling area was studied using SEM of an argon ion polished surface, pressure mercury-nitrogen adsorption, and nuclear magnetic resonance ( NMR) analyses. The shale reservoirs in Jiaoshiba mainly contain gray black to black argillaceous siltstones and silty mudstones with three pore types:organic and inorganic pores, and micro-cracks. The pore size distribution of shale is of multiple-scales, most of which are micro pores and meso pores. Pore diameter < 20 nm accounts for over 80％ of the total. Quantitative NMR analysis showed that the main layer pore radius of Longmaxi Formation shale is significantly greater than the non-main layer. The pore size distribution increased with well depth. On the plane, the areas where the pore diameter peak value of the main layer shale is> 2 nm, the porosity is> 3％, and the water saturation of < 40％showed favorable reservoir preservation conditions.%四川盆地涪陵地区龙马溪组页岩的孔隙结构复杂,常规单一测试技术已不能准确表征页岩的微观孔隙.运用氩离子抛光扫描电镜、压汞—吸附联测、核磁共振分析等多种方法,研究了涪陵地区龙马溪组页岩多尺度微观孔隙结构.结果表明,焦石坝页岩以灰黑色—黑色泥质粉砂岩及粉砂质泥岩为主,页岩发育有机质孔隙、无机孔隙和微裂缝3种孔隙类型;页岩孔隙大小分布是多尺度的,主要是微孔和中孔,孔隙直径小于20 nm的占总孔隙80％以上.核磁共振分析定量研究表明,龙马溪组页岩主力层孔隙半径明显大于非主力层,纵向上随井深增加,孔隙分布峰值向右偏移,页岩孔隙半径增大;平面上,主力层页岩孔隙直径峰值大于2 nm、孔隙度大于3％、含水饱和度低于40％的区块,储层保存条件好.
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