10. NMR Imaging of Fluids and Flow in Porous Media

Abstract

This chapter discusses the application of the techniques of nuclear magnetic resonance (NMR) and nuclear magnetic resonance imaging (MRI) to probe fluids and flow in porous media, for which the imaging methods and interpretations of image data are often complicated because of the effects that the solid matrix has on the fluid. Although the fundamental imaging principles used in biomedical imaging are generally applicable to imaging fluid flow in porous media, obtaining quantitative images sensitive to only one of the desired NMR parameters in porous solids requires special considerations. The challenges and experimental techniques developed to probe fluids and flow in porous media are discussed in the chapter, along with some applications of MRI to processes in porous media. NMR provides many exciting new opportunities for probing fluid states and flow within porous media. It is a noninvasive method that is sensitive to molecular-level events within fluids, and with imaging, fluid states and properties can be resolved spatially. While other techniques, such as optical, ultrasonic, and x-ray methods, can be used to visualize fluid saturations and flow patterns, nuclear MRI provides unique and effective methods for obtaining quantitative information on the distribution and flow of fluids within porous media. MRI can image nuclear spin density, NMR relaxation processes, chemical compositions, and the fluid transport processes of diffusion and flow.