Elliot Grunewald

Elliot Grunewald

PhD university	Stanford University

SEG J. Clarence Karcher Award 2014

Elliot Grunewald has published 15 papers in peer-reviewed journals on the topic of surface nuclear magnetic resonance (NMR) to explore for and characterize groundwater aquifers. He has received several best-paper awards from AGU, ASEG, and SAGEEP. He demonstrated the capability of acquiring surface NMR data using the same advanced pulse sequence that is now the standard in logging and laboratory NMR. This allows for noninvasive estimation of the properties of groundwater aquifers and marks a major breakthrough not just in surface NMR but also in near-surface geophysics.

Biography Citation for SEG J. Clarence Karcher Award 2014

Contributed by Rosemary Knight

Elliot Grunewald exemplifies what we look for in a recipient of the J. Clarence Karcher Award. His passion is the development of nuclear magnetic resonance (NMR) methods to explore for and characterize groundwater aquifers. Over the past eight years, he has shown an outstanding ability to advance both the fundamental science and the technology of NMR.

Elliot came to Stanford in September 2005 to work with me on a Ph.D. in environmental geophysics. The critical question motivating his research was how to use NMR measurements, proven for petroleum applications, to accurately estimate water content and permeability of unconsolidated groundwater aquifers. He focused on exploring the fundamental aspects of the measurement that are unique to the near-surface groundwater problem.

Elliot’s experiments were both elegant in design, and very challenging to conduct. His first set of results illuminated a critical aspect of the NMR response of heterogeneous unconsolidated materials – the coupling behavior of well-connected groups of pores. “Inter-pore coupling” had previously been studied theoretically but this work provided the first clear evidence and implications of this phenomenon in sediments. These results are published in two papers in Geophysics.

A second set of results revealed controls on the relationship between the surface NMR measurement and permeability; quantifying, for the first time, how the coupled effect of magnetic susceptibility and pore size impacts this relationship. This work, published in Near-Surface Geophysics, has enormous implications for the acquisition and interpretation of surface NMR data. A year later, we were able to explain the differences in coincident logging and surface NMR data by using these results to account for the impact of magnetic field inhomogeneity.

Elliot has made equally strong contributions to the practical advancement of NMR technologies. His commitment to working at the interface between science and technology was made very apparent when, after completing his Ph.D., he decided to continue at Stanford as a half-time postdoctoral fellow, and to work half-time at the NMR technology company Vista Clara – commuting back and forth between San Francisco and Seattle for a year. His research during that year resulted in two papers in Geophysics – one showing that magnetic susceptibility can influence the functional form of the NMR decay, and one validating a new acquisition mode useful for surface NMR surveys in regions where the magnetic susceptibility of the materials is high enough to impact the NMR response.

Since 2012 Elliot has worked full-time as Chief Geophysicist at Vista Clara where he continues research, while also playing a key role in the development of NMR instrumentation designed specifically for near-surface applications. Elliot continues to publish insightful papers that display his deep understanding of the physics underlying the NMR method and his commitment to advancing their usefulness for groundwater applications. His papers and presentations are always a stellar mix of basic and applied science. A breakthrough in NMR logging occurred three decades ago when a group of researchers implemented a sequence of pulses that allowed rapid measurement of the full relaxation response downhole. This breakthrough was responsible for establishing NMR logging as a valuable and reliable technology. A year ago, Elliot made an analogous breakthrough for surface NMR, demonstrating the capability to acquire surface data using the same advanced CPMG pulse sequence. This tremendous accomplishment means that we can rapidly acquire the surface NMR data needed to obtain accurate estimation of the properties of groundwater aquifers.

Elliot has had an enormous impact on advancing the use of NMR methods for groundwater applications, not only through his own research but also through his generous support of others. He is an outstanding recipient of the J. Clarence Karcher Award.