Experimental study on stress-dependent multiphase flow in ultra-low permeability sandstone during CO2 flooding based on LF-NMR

Oil production performance in the unconventional reservoirs is significantly affected by the flooding agent and occurrence environment. In this study, the in-situ stress and displacement pressure effects are considered, the response of CO2/Oil and pore structure was monitored by online low field nuclear magnetic resonance (LF-NMR). The results show that the pore structure was composed of adsorption pore (AP<3 m s), percolation pore (3 m s< PP<30 m s), and migration pore (30 m s

Automated summary

The study monitors the response of CO2/Oil and pore structure using online low field nuclear magnetic resonance (LF-NMR), considering the effects of in-situ stress and displacement pressure. The results indicate that the pore structure consists of adsorption pore, percolation pore, and migration pore.