Concentration and velocity field measurements by magnetic resonance imaging in aperiodic heterogeneous porous media.

Magnetic resonance imaging (MRI) techniques were investigated as a means to obtain concentration and velocity field measurements for the verification of a stochastic model for conservative chemical transport. MRI techniques were successfully applied to obtain one-dimensional breakthrough images and two-dimensional velocity images along the length of an aperiodic heterogeneous porous medium. Experimental moment data showed the concentration field in the experimental model to be slightly positively skewed. Velocity images showed the velocity field to be relatively uniform with no channeling or preferential flow behavior. Measured covariance functions showed evidence of negative correlation in the velocity field. The detailed spatial information provided by these imaging experiments has demonstrated that MRI is a valuable tool for obtaining experimental data for the verification of existing theoretical models.

NMR imaging experiments for the verification of stochastic transport theory.

Nuclear magnetic resonance (NMR) imaging techniques were investigated as a means to obtain velocity field measurements for the verification of a stochastic transport theory. A modified stimulated-echo pulse sequence was used to make velocity images in an aperiodic heterogeneous porous medium. Construction of the velocity covariance from measurements of the fluctuating velocity has demonstrated that nuclear magnetic resonance imaging is a valuable tool for obtaining experimental data for the examination of existing stochastic transport theory.