Pore structure characteristics of lignite coal and oil shale reservoir of Youganwo Formation in Maoming Basin

摘要

Takingsamples of Youganwo Formation in Maoming Basin for instance, this study explores the pore characteristics of lignite coal and oil shale reservoir with various experimental techniques, such as highpowered petrographic microscopy, field emission scanning electron microscopy and mercury intrusion,on the basis of the research techniques of shale reservoir pores.The samples are processed by argon ion polishing and etching, then a variety of pores were identified under field emission scanning electron microscopy, including intergranular pores, intragranular pores, primary remaining pores ect..The results of mercury injection experiments show that lignite coal and oil shale porosity is far higher than that of shale gas reservoirs; the permeability is good but varies greatly; micro-pore(＜100nm) is the main pore type and occupies the main space and specific surface area.The observation by high-powered petrographic microscopy shows that the distribution of the organic matter in oil shale has a strong heterogeneity.Study on pores in nano-scale is helpful to improve the depth of lignite coal and oil shale reservoir research.