Laboratory analyses identified copious precipitation of waxes in the pipeline, induced by cooling of the fluid in the sub-sea segment. Levels of wax deposits had the potential to jeopardize the profitability of the whole project and the frequency of pigging operations was potentially so high as to make the plant almost inoperable.
Based on an initial laboratory analysis, KBC conducted a full fluid re-characterization of the pipeline as well as pressure, volume and temperature (PVT) modeling with Multiflash. The utilization of the wax thermodynamic model in Multiflash concluded that the expected precipitation of solid waxes, although quite visible, was significantly lower than in previous estimates, which were based on less-accurate modeling techniques. A full wax deposition study was conducted using FloWax, which concluded that wax deposits, although present, were in fact not sufficient to render the plant unprofitable.
KBC demonstrated that wax deposits, while a definite risk, were manageable for the pipeline in questions. Specifically, KBC showed that precipitated wax was up to 100 times lower than had been previously predicted and a pigging frequency of between 6 and 14 days was required, which was compatible with the profitability of the plant.