Pore structure characterization based on joint numerical and experimental study: a case study of Nanpu Sag

Abstract

Abstract Petrophysical properties such as acoustic velocity, resistivity and nuclear magnetic resonance are greatly depending on the pore structures. This is because the pore structures could control the elastic modulus, conductive path and seepage distribution of the rock. The theoretical simulation and acoustic–electrical–nuclear magnetic resonance joint experiments were used to study the pore structure control action of acoustic, electrical and nuclear magnetic characteristics by taking the sandstone samples of Nanpu Sag as an example which the pore structure of the samples was classified based on the mercury intrusion fractal curve. It is found that the control action of pore structure type on the variation law of longitudinal and transverse wave velocity is mainly affected by the aspect ratio of pores; the effect of pore structure type on resistivity change is mainly affected by pore–throat ratio and tortuosity; the influence of pore structure on nuclear magnetic changes is mainly affected by pore size factors.

Keywords

• Pore structure
• Control action
• Petrophysical characteristics
• Theoretical simulation
• Acoustic–electrical–nuclear magnetic resonance joint experiments