1. State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology(Beijing),Beijing　 100083,China;2. College of Geo-science and Surveying Engineering,China University of Mining and Technology (Beijing),Beijing　 100083,China;3. State Key Laboratory of Petroleum Re-source and Prospecting,China University of Petroleum( Beijing),Beijing　 102249,China;4. College of Geosciences,China University of Petroleum( Beijing), Beijing　 102249,China

运用普通扫描电镜、氩离子抛光—场发射扫描电镜、Image J2x软件分析、高压压汞、低温CO2和N2吸附实验方法,对川南地区下寒武统筇竹寺组和下志留统龙马溪组两套页岩气储层微观孔隙成因类型、孔隙结构特征及其对页岩含气性的影响进行了研究。结果表明,川南地区下古生界页岩微观孔隙主要发育粒间孔、粒内孔、有机质孔和微裂缝等多种成因孔隙类型;下古生界页岩微观孔隙总面孔率为3.95%7.48%,筇竹寺组页岩总面孔率和有机质孔面孔率低于龙马溪组页岩;下古生界页岩总孔容为（3.9324.96）×10-3m L/g,总比表面积为2.72729.399 m2/g,孔径为0.351.00,2.54.7和5575 nm的孔隙是总孔容的主要贡献者,孔径为0.31.0,2.55.5 nm的孔隙主要提供了总比表面积,筇竹寺组页岩总孔容和总比表面积均较龙马溪组页岩要低;页岩微观孔隙的面孔率、有机质孔、孔容、比表面积、孔径分布均会影响页岩含气性。下古生界筇竹寺组和龙马溪组页岩在微观孔隙结构特征的上述差异,为揭示川南地区筇竹寺组与龙马溪组页岩含气性的差异提供了依据。

The genetic type of microscopic pore,the characteristics of pore structure and its influence on gas content from the Lower Cambrian Qiongzhusi and Lower Silurian Longmaxi Formations shale gas reservoirs in southern Sichuan Basin were studied by using scanning electron microscope,argon ion polishing-field emission scanning electron microscope,Image J2 x software analysis,high pressure mercury injection,low temperature N2 and CO2 adsorption experi- ments. The results show that the multiple genetic types of microscopic pores,including inter-granular pore,intragranu- lar pore,organic matter pore and microcrack,are developed in the Lower Paleozoic shale in southern Sichuan Basin. The total surface porosity of microscopic pores is ranged from 3. 95% to 7. 48% . The total surface porosity and organic pore surface porosity of the Qiongzhusi Formation shale are lower than those of the Longmaxi Formation shale. The total pore volume of the Lower Paleozoic shale is (3. 93-24. 96) ×10-3 mL / g,total specific surface area is 2． 727-29． 399 m2 / g in range. These pores whose pore sizes are 0. 35-1. 00,2. 5-4. 7 and 55-75 nm in range are the main contribu- tion of total pore volume,and those pores whose pore sizes are 0. 3-1. 0 nm and 2. 5-5. 5 nm in range account for the main total specific surface area. Total pore volume and total specific surface area of the Qiongzhusi Formation shale are lower than those of the Longmaxi Formation shale. All the surface porosity,organic pore,pore volume,specific surface area and pore size distribution of microscopic pores will affect the gas content of shale. The above differences of pore structure characteristics in the Lower Paleozoic Qiongzhusi and Longmaxi Formations shale provide a basis for revea- ling the difference of gas content between the Qiongzhusi Formation shale and the Longmaxi Formation shale in south- ern Sichuan Basin.

国家重点基础研究发展计划(973)资助项目(2012CB214702)；国家自然科学基金资助项目(41572125)；国土资源部公益性行业科研专项基金资助项目(201311022)；

Wang Zhe,Li Xianqing,Zhou Baogang,et al. Characterization of microscopic pore structure and its influence on gas content of shale gas reservoirs from the Lower Paleozoic in southern Sichuan Basin [ J]. Journal of China Coal Society,2016,41 (9):2287 - 2297.