Experimental Determination of Relative Permeability of Sand

In order to measure the water-retention and relative permeability of a sandy soil, an experimental device, initially designed in our laboratory for sandstone, was adapted. The method of measurement used is based upon the steady state method which is regarded as an efficient method to produce an accurate measurement of relative permeability. Liquid and gas are simultaneously injected, and measurements of pressure drop and saturation are made when steady state is reached. These measurements are generally conducted under small pressure gradients and over reasonable time periods. The main objective of this paper explains the special difficulties which had to be overcome as a result of the cohesionless nature of sand. The most important steps will be presented and analyzed. Once the final device had been fabricated, experiments conducted on fine sand were carried out and led to the determination of the water-retention and relative permeability curves of the sandy soil. The experimental results obtained showed a very good consistency of curve measurements.