DRA Principles & Benefits to Pipeline Operation
The flow in most crude and refined products pipelines lies in turbulent range. In this flow regime, much of the energy is wasted as eddy currents and other random motions. Because of this wasted energy, the pressure required to reach higher flow rates increases rapidly. Drag reducing chemicals can reduce the frictional pressure loss, in the turbulent flow regime, as they are long chain polymers which cause the flow to be more streamlined. Traditionally it has been successfully applied to improve flow rates, thus increase export capacity of existing facilities and increase revenues, or to reduce energy costs (Pump Stations shutdown). Increasingly DRA has found an important role as a Pipeline Integrity Management instrument. When the pipeline is de-rated due to age and corrosion build-up, the operator can maintain current throughput by utilizing DRA, operating at the reduced MAOP. This allows the operator to postpone or eliminate the costly capital investment to upgrade the pipeline. Many times the need for the maximum throughput is temporary and by postponing the investment, the pipeline may be able to meet the temporary surge demand. All the mentioned benefits can be achieved by DRA users without additional capital cost, since no investment in the mechanical upgrade or modification of the pipeline design. Investment costs of new pipeline constructions can be significantly reduced by incorporating the application of DRA in the pipeline design, as a consequence of smaller diameters, thinner walls and fewer Pump Stations needed. Operation and Maintenance Safety can be improved as a consequence of lower operation pressure and lower corrosion rates.