The project aims to develop new and unconventional nuclear magnetic resonance (NMR) applications to link measurements between laboratory, borehole and field scale.
The project aims to develop new and unconventional nuclear magnetic resonance (NMR) applications to link measurements between laboratory, borehole and field scale. Nuclear magnetic resonance provides a fast and non-destructive tool to estimate characteristic hydrological parameters of porous media, e.g. water content, porosity, fluid saturation, pore size distribution and hydraulic conductivity / permeability. The following applications are currently under development at our department:
Compared to borehole NMR measurements, laboratory measurements generally have a high data quality and provide high spatial resolution. The NMR Core Scanner, developed at LIAG, is based on a commercial “low field” NMR instrument (2MHz), used for rock core analyses, as well as a linear actuator for fully automated positioning. The NMR Core Scanner can characterize water-saturated samples (e.g. unconsolidated sediments in a plastic casing) with a length of up to 1m and a diameter of up to 108mm. A joint interpretation of measurements with overlapping sensitive volumes leads to a 1D-spatial resolution of few millimetres. The NMR Core Scanner targets to link in situ NMR borehole measurements with the advanced capabilities of laboratory NMR.
Conventional NMR-logs have a limited spatial resolution, dependent on the probe and logging speed, of several decimetre to meter. After a detailed survey of the sensitive volume of a probe, a joint interpretation of measurements with overlapping sensitive volume can increase the spatial resolution of NMR-logs to the range of a few centimetre to decimetre. This opens new fields of application for borehole NMR, like for example to characterize (geological) interfaces or thin layers. Possible targets located in the shallow subsurface are e.g. the vadose zone, the capillary fringe above an aquifer or hydrocarbon contaminations, which enables combining borehole NMR with near surface geophysical methods, like e.g. surface NMR or ground penetrating radar.
Preliminary studies lead to the third-party funded (DFG) project MoreSpin, where LIAG with project partners develop a mobile NMR instrument to map physical soil parameters in the near subsurface (2m).
Jan. 2018 - Dec. 2020