ABSTRACT
Wax (or paraffin) deposition can be both a downhole and topside problem, blocking the flow of hydrocarbons fluids as they are cooled.1-3 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 (nparaffins) are predominantly responsible for pipeline wax deposition. Waxes in crudes are usually harder to control than those in condensates as they are of longerchain 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 paraffins increases as the size of the molecule increases. Generally, the higher the melting point, the more difficult it is to keep the paraffin from forming deposits.
