Relaxation and relaxation exchange NMR to characterise asphaltene adsorption and wettability dynamics in siliceous systems

Results show that the kinetics of asphaltene deposition and wettability alteration processes are strongly dependent on chemical composition of synthetic oils, asphaltene origin (light oil or bitumen) and solid phase morphology. Elements of the resulting deposition pattern and wetting state of the cores were inferred using the proposed approach, utilising low-field NMR T2 relaxation and T2-store-T2 relaxation exchange experiments combined with numerical simulation of relaxation responses. The knowledge of deposition pattern and dynamics obtained mainly by the mean of combination of NMR relaxation techniques contributes to the improved design of core wettability alteration steps and potentially to enhanced petrophysical application of low-field NMR technology.