DIGITAL IMAGE ANALYSIS OF DISTRIBUTION OF IMMISCIBLE FLUIDS IN NATURAL POROUS MEDIA

MONTORO, MARCOS ALEXIS; FRANCISCA, FRANCO M.

ASTM GEOTECHNICAL TESTING JOURNAL

AMER SOC TESTING MATERIALS

Lugar: West Conshohocken; Año: 2013 vol. 36 p. 1 - 14

0149-6115

This article proposes a method of digital image analysis to monitor immiscible displacement in soil samples. Four different natural soil samples were studied: coarse, medium, fine and silty sand. Paraffin oil and a sodium fluorescein solution were used as the displaced and displacing phase, respectively. Immiscible displacement tests were performed in a plexiglass cell and monitored by means of digital image analysis and direct volumetric measurement. The images were processed to obtain gray levels at different stages during the tests. Saturation of paraffin oil was then computed from the gray level and a linear regression equation was developed for each soil tested. The proposed method enabled valuable information to be obtained of the processes that take place at the face of the samples during displacement and in the middle of the samples at the end of the tests. This procedure was very effective for analyzing different flow patterns, isolating areas with trapped paraffin oil, and to determining the ganglia size distribution at different stages of the immiscible displacement tests. The results indicated that particle size and microstructure heterogeneities determine the flow pattern features observed during the immiscible displacement of paraffin oil by water.