Capillary water determination in core plugs: a combined study based on imaging techniques and relaxation analysis.

NMR Spectroscopy and Imaging (MRI) have been used in determining the presence and the distribution of residual water inside a dolomite core saturated with oil. 1H relaxation analysis revealed the presence of different "classes" of water within the core as a function of drying temperature. The results appear to be consistent with the peculiar porosity distribution of the rock, as shown by MRI and X-ray CT analysis. The latter technique provided details of the rock matrix complementary to the information acquired by the NMR method. This kind of approach, based on the application of different techniques, was found to be very useful for an accurate evaluation of petrophysical properties of rocks, a task of relevant interest for an oil company.