A thermal fouling study was undertaken using three sour Canadian crude oils. Experiments were carried out in a recirculation fouling loop, equipped with an annular (HTRI) electrically heated probe. Fluids at pressures of about 10001340 kPa under a nitrogen atmosphere were re-circulated at a velocity of 0.75 m/s for periods of 48 hours, and the decline in heat transfer coefficient followed under...