High content of mechanical impurities in well production at Samotlor field has been noted for more than twenty years. Lately, this problem has grown in importance due to the changes in production wells structure and transfer of production to hard-to-produce reservoirs with discontinuous and highly discontinuous beds. The results of field studies on the causes of wells sanding-up are analyzed. It is noted, that the largest content of mechanical impurities in well production is observed during start-up operations after workovers and at unstable production conditions. The procedures for elimination of negative influence of such impurities on the work of well equipment are proposed.