ABSTRACT
Wax deposition can be both a downhole and topside problem, blocking the ow of hydrocarbons uids as they are cooled.1-3,157 The term “parafn” is used in the United States to describe oileld wax, although “parafn wax” is a better terminology. Waxes are solids made up of long-chain (>C18), normal or branched alkane compounds that are naturally present in crude oils and some condensates.4 Some cyclic alkanes and aromatic hydrocarbons may also be present. It has been established conclusively that normal alkanes (n-parafn waxes) are predominantly responsible for pipeline wax deposition. Waxes in crudes are usually harder to control than those in condensates as they are of longer-chain alkanes. When the molecular size is 16-25 carbon atoms, soft mushy waxes are observed. Hard crystalline waxes have 25-50 or more carbons in the chain. The melting point of the parafn waxes increases as the size of the molecule increases. Generally, the higher the melting point, the more difcult it is to keep the parafn wax from forming deposits.
