The characteristics of nano-pore of the 3rd member shale from Dongying Formation of Paleogene in Liaozhong Sag

Abstract

The reservoirs structure and pore characteristics of shale have greatly influenced the reservoir, adsorption and migration of oil and gas, and have become one of the important contents of reservoir physical characteristics evaluation. The organic-rich shales in the 3rd member shale of the Dongying Formation in Paleogene, Liaozhong sag, Bohai bay basin were studied in this paper. Firstly, the surface of shale sample was etched by argon ion polishing technology, and then the microscopic pore morphology was observed by field emission environment scanning electron microscope. The results show that: 1) the pores of shale reservoir in 3rd member shale of the Dongying Formation from Liaozhong sag are divided into inorganic pores (including intergranular pores, intragranular pores, interstratal pores and intercrystalline pores), organic pores and microfractures; 2) the intergranular pores are largely developed, intragranular pores and interlaminar pores are relatively developed, micro-cracks are less developed, and intergranular pores and organic pores are rarely developed.