Safety and economy evaluation of PPD-added oil pipeline in the 3/7 Block of Sudan

The crude oil produced in Sudan 3/7 Block is a high set point crude, and if the heated transportation process is used separately, the energy consumption will be higher. However, if the comprehensive process with PPD/heating treatment is adopted, the energy consumption of pipeline will be effectively reduced. Running parameters of pipeline with PPD added at shutdown and restart conditions were numerically simulated. Results showed that when the shutdown duration for the Pipeline Section PS4- PS5 which was more prone to gel in winter enlarges to 50 hr, the mean temperature of oil of the whole line with or without PPD was higher than the set point of oil, the max allowable shutdown duration was increased from 2.8 d to 3.5 d in winter in the case of accident, which increased the operation safety of pipeline. Simulated calculation on the parameters produced in the temperature drop duration of closed Pipeline Section PS2-PS6 with or without PPD was carried out. Results indicated that for the oil pipeline with PPD, 3 heaters currently operated could be cut down to 1 heater, and especially, constant temperature transportation could be realized in summer, which saved the fuel cost up to 1 244×10⁴ USD/yr. It is considered that the research conclusions can provide the technical support to the constitution of a reasonable operation program for the pipeline with PPD.