Flow Assurance Assessment for Arctic Conditions

The flow assurance of produced reservoir fluids from the wellhead to the processing facility is important to the success and cost-effective operation of production systems, especially under Arctic conditions. The technical challenges and huge developmental/operational cost of Arctic field operations necessitated a flow assurance assessment to investigate the Arctic specific flow assurance concerns such as gas hydrates, long tiebacks and low temperature in order to find a best-suit solution approach. In this study, PIPESIM simulator was used to model the thermal-hydraulic properties of the fluid along a 120 km Arctic subsea to onshore Ormen Lange pipeline. Three techniques for gas hydrate and low-temperature management were assessed, these include thermal insulation, direct electric heating (DEH) and thermodynamic inhibitors (methanol and mono-ethylene glycol (MEG)). The hydrate formation temperature (HFT) was determined from the model as 21ºC and the thermal insulation thickness that gave a steady state operating temperature outside the HFT was 180mm.