Inverse modeling of a multistep outflow experiment for determining hysteretic hydraulic properties
Stefan Finsterle1, Torben O. Sonnenborg2, and Boris Faybishenko1
Proceedings, TOUGH Workshop ’98, Lawrence Berkeley National Laboratory, Berkeley, CA, May 4-6, 1998, p. 250 – 256
1Lawrence Berkeley National Laboratory, Earth Sciences Division
University of California, Berkeley, CA 94720 2Department of Hydrodynamics and Water Resources (ISVA) Technical University of Denmark, 2800 Lyngby, Denmark
Abstract. A new, closed-form hysteretic model of the capillary pressure-saturation and relative permeability-saturation relationship has been implemented into iTOUGH2. The hysteretic capillary pressure function is based on the van Genuchten model, with a modified version of the dependent domain model of Mualem to describe the scanning curves. Hysteresis in the relative permeability relations is considered to be mainly a result of nonwetting fluid entrap- ment. The hysteresis model was used in combination with inverse modeling techniques to examine the potential of a simple drainage-imbibition experiment to determine hysteretic hydraulic properties.