Determination of the single- and multi- phase ...

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XVI International Conference on Computational Methods in Water Resources (CMWR-XVI) Ingeniørhuset

Determination of the single- and multi- phase transport properties of a layered soil by combining laboratory experiments with numerical calculations
Paper
Author:Christos Tsakiroglou <ctsakir@iceht.forth.gr> (FORTH / ICE-HT, Stadiou street, Platani, P.O.Box 1414, GR-26504 Patras, Greece)
Christos Aggelopoulos <caggelop@iceht.forth.gr> (FORTH / ICE-HT, Stadiou street, Platani, P.O.Box 1414, GR-26504 Patras, Greece)
Presenter:Christos Tsakiroglou <ctsakir@iceht.forth.gr> (FORTH / ICE-HT, Stadiou street, Platani, P.O.Box 1414, GR-26504 Patras, Greece)
Date: 2006-06-18     Track: General Sessions     Session: General
DOI:10.4122/1.1000000622
DOI:10.4122/1.1000000623

A military airport situated in Northern Poland has highly been contaminated by jet- fuel since 2nd world war. Geological characterization revealed that the unsaturated zone is a highly heterogeneous soil consisting of three main layers dominated by massive clay with desiccation fractures, homogeneous sand, and fractured sandy till. In order to proceed in the implementation of an in situ stimulation- remediation program, information concerning the transport properties of the various layers and their interfacial zones is required. Depending on the texture of the (non-fractured) soil matrix, its single- and multi- phase transport properties are either estimated with history matching of displacement experiments or calculated from microscopic properties of the pore structure. For the permeable sandy layers, immiscible and miscible displacement experiments are performed on disturbed and undisturbed soil columns, and the electrical resistance along the columns is monitored. The electrical measurements are employed to calculate the transient response of the water saturation profile along the column, as well as the solute concentration breakthrough curve at various axial positions of the column. The experimental datasets are introduced into numerical codes of inverse modeling of the two-phase flow and advection-dispersion equations to estimate the relative permeability curves, the capillary pressure curve, and the longitudinal dispersion coefficient. For the low permeability massive clay and sandy till layers, the pore- and throat-size distributions along with the network accessibility functions of the matrix are estimated by processing the autocorrelation function of 2-D BSEM images of polished cross-sections of porecasts, and inversing experimental data of Hg intrusion / retraction curves. Then, critical path analysis is used to calculate the absolute permeability, and formation factor, whereas a quasi-static pore network approach is employed to calculate the relative permeability and capillary pressure curves.