Dm. Tuck et al., SYNCHROTRON-RADIATION MEASUREMENT OF MULTIPHASE FLUID SATURATIONS IN POROUS-MEDIA - EXPERIMENTAL-TECHNIQUE AND ERROR ANALYSIS, Journal of contaminant hydrology, 31(3-4), 1998, pp. 231-256
Citations number
43
Categorie Soggetti
Water Resources","Environmental Sciences","Geosciences, Interdisciplinary
Multiphase flow in porous media is an important research topic. In sit
u, nondestructive experimental methods for studying multiphase flow ar
e important for improving our understanding and the theory. Rapid chan
ges in fluid saturation, characteristic of immiscible displacement, ar
e difficult to measure accurately using gamma rays due to practical re
strictions on source strength. Our objective is to describe a synchrot
ron radiation technique for rapid, nondestructive saturation measureme
nts of multiple fluids in porous media, and to present a precision and
accuracy analysis of the technique. Synchrotron radiation provides a
high intensity, inherently collimated photon beam of tunable energy wh
ich can yield accurate measurements of fluid saturation in just one se
cond. Measurements were obtained with precision of +/-0.01 or better f
or tetrachloroethylene (PCE) in a 2.5 cm thick glass-bead porous mediu
m using a counting time of 1 s. The normal distribution was shown to p
rovide acceptable confidence limits for PCE saturation changes. Source
s of error include heat load on the monochromator, periodic movement o
f the source beam, and errors in stepping-motor positioning system. Hy
podermic needles pushed into the medium to inject PCE changed porosity
in a region approximately +/-1 mm of the injection point. Improved ma
ss balance between the known and measured PCE injection volumes was ob
tained when appropriate corrections were applied to calibration values
near the injection point. (C) 1998 Elsevier Science B.V.