High-Resolution Direct Push NMR Tools for Groundwater Investigations

A small-diameter nuclear magnetic resonance (NMR) technology optimized for use with direct push (DP) and cone penetrometer test (CPT) drilling has been developed. The DP NMR tool can be deployed through 2.25-in. diameter DP and CPT drilling rods allowing high-resolution NMR logging measurements to be acquired during retraction of drill rods. DP NMR technology runs from a person-portable battery-powered control unit and provides significantly higher resolution in both the spatial (vertical) dimension and in the time domain of the NMR measurement than previously available NMR technology. In this study, we summarize the development of two different DP NMR tools and demonstrate their application at different sites within the United States. We believe that this technology can provide a leap forward in adoption of NMR technology for high-resolution hydrological and geophysical investigations in groundwater resources and environmental remediation applications.