<p>This article presents the results of selecting extractants for the extraction process of oil sludge from contaminated areas of the Absheron Peninsula, such as Surakhany, Ramana, Bibigeybat, and Balakhany. Used motor oils of well-known brands were tested as potential extractants. Based on an analysis of their technological and chemical properties, the most suitable oil for sludge treatment was identified, depending on the sludge composition. The use of spent motor oils as extractants ensures high extraction efficiency due to the optimal interaction of their surfactants, dispersants, and detergents with sludge components, as well as their favorable molecular structure and oxidative and thermal stability. These oils facilitate the effective separation of various chemical and fractional components of oil sludge, thereby improving both the overall environmental and economic performance of sludge treatment technologies.</p>