Pulsed Second Order Magnetic Field Nuclear Magnetic Resonance for Real-Time Fluid Transport Measurements
Nuclear magnetic resonance (NMR) measurement techniques are able to characterise a large array of physical properties and systems, both transparent and opaque, in a nondestructive, non-invasive manner. This allows systems to be probed with minimal disturbance, and in most cases, information can be obtained with little to no experimental bias. For these reasons NMR lends itself well to many fields of research. Of particular importance to this research is NMR measurement of the characteristic function which defines fluid transport known as the average propagator. This quantity provides the probability distribution for fluid displacement, and all mobility information of the fluid matter under measurement. The average propagator is normally measured by NMR with a series of experiments which require an extended period of time. When systems are evolving on a time scale which is shorter than the total experimental time required to measure the average propagator, the measurement cannot be performed as different experiments in the series relate to different states of the system. In this thesis a method for transforming the slow, serial process of measuring the average propagator into an instantaneous, parallel process has been developed. This allows real-time characterisation of flows, diffusion, and the properties of the pore spaces in porous media containing fluid. The details of the newly developed technique are provided along with new hardware designed and built to perform the new parallel method, allowing instantaneous measurement of the average propagator. Experimental results are presented for well known model systems. These systems are used because their properties and models describing their behaviour are well understood. The experimental measurements for these model systems were compared to theoretical predictions to verify the effectiveness of the new average propagator measurement technique, providing a proof of concept, and proving the validity of this new average propagator measurement for real-time characterisation of fluid transport and porous media.