Measurement of electrical resistivity of saturated loose sandpack has been conducted using four-electrode technique and direct current method. Nine samples with three different grain sizes were prepared for the measurement. The water saturation level was increased by physically injecting brine to the samples in three different vertical positions, i.e. bottom, middle and top. Digital image analysis of the sample is also carried out to analyze the microstructure and to estimate several physical properties. The results show that spatial fluid distribution significantly affects the electrical resistivity of the sample. There is an area that has significant contribution for reducing resistivity, which is the area between two potential electrodes. In addition, it is also revealed that samples with large grains have higher resistivity than samples with small grains. This result can be explained by the physical properties of the permeability of the sample and the surface tension phenomena.

Keywords  

Electrical resistivity ,   Distribution spatial of fluid  , Grain size , Loose sand , Digital image of sandpack