LAUSR

The microstructure characteristics of the reservoir are closely related to the seepage capacity of the reservoir. Compared with conventional reservoirs and low permeability reservoirs, the tight oil is stored in a smaller nanoporous space. The microscopic pore structure of reservoir is the geometrical shape, size, distribution, and interconnected relationship of porosity and throat. The experiment was conducted on several tight rock samples taken from the Chang 7 formation in Xunyi county of Ordos Basin, China. Based on nano-CT scanning and advanced image processing technology Avizo, we build a three-dimensional comprehensive pore and throat network model. In the result of our study, reservoir space types are dissolution pores with mineral particles inside in the pore network model. Then, the pore throat morphology in the forms of small globular and tubular with SEM was explained. There is a big difference in quantity distribution at different locations, which is limited to the permeability of samples. Pore types are mostly round tubular and long tubular, while isolated pores account for a significant proportion. Through making and analyzing the three-dimensional structure of interconnected pores, obtained their specific forms and the division of connectivity types.