Benchmarking PET for geoscientific applications: 3D quantitative diffusion coefficient estimation in clay rock


Benchmarking PET for geoscientific applications: 3D quantitative diffusion coefficient estimation in clay rock

Lippmann-Pipke, J.; Gerasch, R.; Schikora, J.; Kulenkampff, J.

For the first time ever the diagonal anisotropic effective diffusion coefficient, Deff = (Dxx, Dyy, Dzz), was quantified in a geologic core material in one single object of investigation. That is possible due to the combination of the non-invasive observation of Na+ diffusion in Opalinus clay by means of GeoPET (PET: positron emission tomography) followed by quantitative 3D+t data evaluation by means of finite element numerical modelling (FEM). The extracted anisotropic effective diffusion coefficient parallel (||) and normal (|) to the bedding of the clay rock, Deff =(D||, D|, D||) are comparable to those of earlier experimental studies reported by (Van Loon, et al. 2004. ES&T 38, 5721-5728). They were obtained on the same type of geomaterial (Opalinus clay, Switzerland), but by invasive methods which requires sample aliquots. We consider this study as benchmark for the long-standing development of our GeoPET method. We suggest GeoPET based fluid flow transport visualization combined with computer based process simulation henceforth as gold standard for the effective transport parameter quantification in the geosciences.

Keywords: Benchmarking GeoPET; Ddiffusion; Opalinus clay; FEM simulation

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Publ.-Id: 23398