10.4122/1.1000000622
Tsakiroglou, Christos
Christos
Tsakiroglou
ctsakir@iceht.forth.gr
Aggelopoulos, Christos
Christos
Aggelopoulos
caggelop@iceht.forth.gr
Tsakiroglou, Christos
Christos
Tsakiroglou
ctsakir@iceht.forth.gr
Determination of the single- and multi- phase transport properties of a layered soil by combining laboratory experiments with numerical calculations
XVI International Conference on Computational Methods in Water Resources
2006
2006
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.