Permeability and anisotropy of IODP core samples by mobile NMR

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The main objectives are (1) to refine and extend the NMR techniques developed so far for in¿situ core analysis at the drilling site with a Halbach scanner, and (2) to design mobile NMR equipment for routine nondestructive on-line measurements of porosity and pore size distributions of water saturated drill core sections within the ODP and the IODP program directly after drilling. The equipment produced in the previous project is suitable to demonstrate the principles in laboratory studies and to use in basic investigations near to the laboratory. For routine investigations it needs to be improved with a sliding table and comfortable operating software. The methodical study aims at providing experimental data with details beyond the pore-size distribution function. The NMR techniques applied to this purpose are multi-pulse relaxometry, conventional pulse gradient NMR, NMR imaging, and novel two-dimensional NMR experiments which correlate distributions of relaxation-times and diffusion-coefficients. By combining the image information, the integral pore-size distribution function from relaxation or diffusion maps, and the integral information about pore anisotropy from diffusion-diffusion correlation maps, a set of detailed data is available, which eventually can be used to model the pore structure and pore connectivity to finally obtain estimates of permeability more accurate than currently available.