A custom-built, solvent recirculating, supercritical fluid extraction (SFE) apparatus was used to study the extraction of hydrocarbons from a crude oil tank bottom sludge (COTBS) with supercritical ethane. The SFE experiments were carried out varying the pressure (10 MPa and 17.20 MPa) and temperature (35 degrees C and 65 degrees C. The yield of the extracted hydrocarbon fraction increased with increase in extraction pressure at constant temperature, and decreased with increase in extraction temperature at constant pressure. The maximum extraction yield was obtained at the pressure and temperature conditions that lead to the highest solvent density. The extracted hydrocarbon fraction was a significantly upgraded liquid relative to the original untreated COTBS.