Hysteresis of the NMR response and the complex relative permittivity of the quartz granules powders and solid sandstones during the water imbibition and drainage

Abstract

This work provides the results of the complex relative dielectric permittivity ε = ε′ − iε″ (CRP) measurement and nuclear magnetic resonance (NMR) response of the quartz powders and cores of different porosity at stepped moistening and drainage. It is shown that CRP and NMR responses are ambiguous functions on water. The character of the CRP hysteresis depends on the electromagnetic field frequency, on the particle size and water salinity. The analysis of the NMR data shows that firstly the larger pores are filled with water at moistening and they are also drained first. Thus at the same water content, which is obtained in both the processes of moistening and drainage, pores of different sizes are filled. Herewith the water droplets have different curvature radiuses and different wetting contact angles which is the main cause of the hysteresis in the CRP and NMR response.