Crude oil is a naturally occurring complex fluid with interesting flow characteristics. For example, crystallisation of high molecular weight hydrocarbons (waxes) occurs at low temperatures. When this happens, and if the particles are large enough in number, they deposit on the walls, slowly blocking the pipeline. This may sometimes also happen suddenly during shut-downs and if not managed properly, the pipeline may need to be abandoned. Prevention and management of blockage is thus a crucial problem for the petroleum industry.