The experimental part, regarding the calculation of the well sand granularity, is done in the following way: according to STAS 1934/4-72, the calculation of the granularity is done by the mechanical sifting of the well sands, the diagram of the sand granularity histogram is done, the cumulative curve of the granularity frequency is traced. The form and aspect of the grains of sand surfaces are determined. The forms of the grains are: round, rounded, ragged and splinter-like; and the aspects of the grains are: smooth, rough and broken. For the studio there are used 100 grams of sand from the wells in Videle, from Videle oil field. A mechanical sifting device, with horizontal and vertical vibrations, will be used. The experimental study of the well sand granularity was made in order to establish the working conditions/parameters for erosion wear research of the depth screw pumps, used for crude oil recovery [3, 4].