Joint inversion of nuclear magnetic resonance data from partially saturated rocks using a triangular pore model

• DOI: 10.1190/geo2017-0697.1
• Publication Date: 2018-04-26T08:05:19Z
• Authors: Thomas Hiller; Norbert Klitzsch
• Keywords: Porosimetry; Imbibition

Measurement of nuclear magnetic resonance (NMR) relaxation is a well-established laboratory/borehole method to characterize the storage and transport properties rocks due its direct sensitivity corresponding pore-fluid content (water/oil) pore sizes. Using NMR, correct estimation of, e.g., permeability strongly depends on underlying model. Usually, one assumes spherical or cylindrical pores for interpreting NMR data. To obtain surface relaxivity thus, pore-size distribution, calibration procedure by, mercury intrusion porosimetry gas adsorption has be used. Recently, joint inversion approach was introduced that used measurements at different capillary pressures/saturations (CPS) derive distribution (PSD) simultaneously. We further extend this from bundle parallel capillaries with triangular cross sections. With approach, it possible account residual trapped water within corners/crevices partially saturated pores. In addition, we have developed allows determining shape these by using levels drainage imbibition. show applicability our synthetic measured data sets determine how combination CPS significantly improves interpretation fully porous media.