Paraffin deposits in pipelines, tanks and other equipment are quite common in the oil industry. This deleterious phenomenon results from physical and chemical conditions that allow the deposit of straight chain high molecular weight contents of the oil, such as alkanes. In deep sea pipelines through cold waters, low temperatures and high pressures favor the paraffin deposit, which may completely block the oil flow, thus stopping the production, and incurring on large financial losses. The Nitrogen Generating System (acronym SGN) was developed to remove paraffin deposits with an exothermic reaction that increases the temperature and, therefore, raises the solubility of the paraffin deposited. SGN has been successfully applied to several real-life cases in the oil industry, but care must be exercised when paraffin blockages occur in nowadays risers. The walls of risers are commonly formed by several layers of different materials, including steel and polymers. Hence, if not properly devised, the use of SGN may result on temperature increases that cause thermal decomposition of the wall layers and structural damage to the riser. This work deals with the numerical thermal analysis of the application of SGN to the removal of a paraffin blockage in a riser.