潜江凹陷盐间页岩油藏开发难度大,基质流体动用困难。为了提高其开发效率,必须深入研究盐间页岩油储层储集空间及微观孔隙结构特征。以潜江凹陷盐间页岩油储层岩心为研究对象,利用扫描电镜、高压压汞及低温氮气吸附对其微观孔隙结构进行综合定量表征,明确了盐间页岩油储层微观孔隙结构特征。研究结果表明:潜江凹陷盐间页岩油储层孔隙总体上是以纳米级孔隙为主,并伴随着少量微米级溶蚀孔及微裂缝;盐间页岩储层孔喉发育类型单一且分布较为集中连续,微孔含量低,介孔和大孔占比高,最可几孔径峰值范围在40~60 nm,主要孔隙控制区间为10~200 nm。定量表征盐间页岩储层微观孔隙结构特征对研究认识页岩储层流体流动机理具有重要意义。

In Qianjiang depression, it is difficult to develop the intersalt shale oil reservoir and percolate the crude oil in the matrix. To enhance the efficiency of reservoir development, the reservoir space and the microscopic pore structure of the shale oil reservoir shall be analyzed in depth. Aiming at the intersalt shale oil reservoir in Qianjiang depression, this study carries out quantitative analysis and determines the full-scale pore structure through the high pressure Hg injection, cryogenic nitrogen adsorption and scanning electron microscopy. Result indicates that the pore structures of the shale oil reservoir in Qianjiang depression mainly consists of the nanometer pores in general, with a small number of micron-corrosion pores and microfractures. The pore-throat type of the intersalt shale oil reservoir is single with concentrated distribution. Few number of micro-pore structures is found in the intersalt shale oil, while there is high percentage of mesoporous and macropore. The range of the maximum aperture peak is 40~60 nm, and the range of the main pore is 10~200 nm. Quantitative characterization of microscopic pore structures of intersalt shale oil reservoirs in Qianjiang depression plays an important role in studying the flow mechanism of the shale oil reservoir.