1. n. 
A hydrocarbon compound that often precipitates on production components as a result of the changing temperatures and pressures within the production system. Heavy paraffins occur as wax-like substances that may build up on the completion components and may, if severe, restrict production. Paraffin is normally found in the tubing close to surface. Nevertheless, it can form at the perforations, or even inside the formation, especially in depleted reservoirs or reservoirs under gas-cycling conditions.