Oil-based compositions for dispersing asphaltenes and paraffins in ducts and equipment employed in the field of oil production, transporting, processing and storing are provided. The compositions are easy to formulate and they further are environmentally friendly as they are biodegradable and “green” products. The compositions comprise a non-polar solvent and bismuth nanoparticles, and can optionally further comprise a compound in the terpenes or terpenoids family and an organic acid.