Black powder in Saudi Aramco's pas pipelines consist mainly of magnetite (Fe3O4) particles. They are hard and sharp edged, making them potentially erosive to pipeline bends and control valves. The paper deals with the black powder flow under scraping conditions in gas pipelines with varying diameters and gas flow rates. A mathematical model was developed to describe the particle flow behavior. A CFD software allowed building and solving the model. The Eulerian approach modeled the continuous phase, while the disperse phase was modeled using a Lagrangian approach. The model uses methods based on the Finnie model along with The Reynolds Averaged Navier-Stokes equations to calculate the erosion rate. The pipe diameter seems to have no influence on black powder particle's velocity distribution in pipelines operating at 10 m/sec and 20 m/sec. There will be little particle-size agglomeration.. A pipeline bend with longer radius of curvature e.g. 3.0 will have a more uniformly distributed erosion over the outer wall of the bend. The simulation showed that erosion in bend of smaller ratios is negligible. In an elbow of A-53B carbon steel alloy and radius/diameter ratio of 1.5 at a maximum bulk gas velocity of 20 m/sec, the loss of material thickness due to erosion is about 71.2 µm/year (7.12 mm/100 years).
Pipe diameter does not affect black powder distribution, erosion
Oil and Gas Journal ; 110 , 7 ; 104-109
2012
5 Seiten, 7 Bilder, 3 Tabellen, 10 Quellen
Aufsatz (Zeitschrift)
Englisch
Unternehmen , Gasfernleitung , Magnetit , Härte , Partikelmorphologie , Erosion , Rohrkrümmer , Regelventil , Durchmesser , Strömungsgeschwindigkeit , numerische Strömungssimulation , Euler-Gleichung , Lagrange-Funktion , disperse Phase , Navier-Stokes-Gleichung , Reynolds-Zahl , Geschwindigkeitsverteilung , Agglomerisation , Biegeradius , Kohlenstoffstahl , Materialabtragung
Affect of black powder on inline inspection accuracy
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