Effect of Sand Fines Concentration on the Erosion-Corrosion Mechanism of Carbon Steel 90° Elbow Pipe in Slug Flow

Abstract

Erosion-corrosion of elbow configurations has recently been a momentous concern in hydrocarbon processing and transportation industries. The carbon steel 90° elbows are susceptible to the erosion-corrosion during the multiphase flow, peculiarly for erosive slug flows. This paper studies the erosion-corrosion performance of 90° elbows at slug flow conditions for impact with 2, 5, and 10 wt.% sand fines concentrations on AISI 1018 carbon steel exploiting quantitative and qualitative analyses. The worn surface analyses were effectuated by using laser confocal and scanning electron microscopy. The experiment was conducted under air and water slug flow containing sand fines of 50 µm average size circulated in the closed flow loop. The results manifest that with the increase of concentration level, the erosion-corrosion magnitude increases remarkably. Sand fines instigate the development of perforation sites in the form of circular, elongated, and coalescence pits at the elbow downstream and the corrosion attack is much more obvious with the increase of sand fines concentration. Another congruent finding is that cutting and pitting corrosion as the primitive causes of material degradation, the 10 wt.% sand fines concentration in carrier phase increases the erosion-corrosion rate of carbon steel up to 93% relative to the 2 wt.% sand fines concentration in slug flow.

Influence of Elbow Angle on Erosion-Corrosion of 1018 Steel for Gas–Liquid–Solid Three Phase Flow

“…The maximum Ra value was observed between 45° and 90° axial angles at the upper and bottom half of the 90° elbows. Hence, it was concluded that carbon steel 90° elbow showed maximum erosion behavior near the outlet, as mentioned in the literature [ 17 ]. On the other hand, the Ra of the samples was maximum in the outer wall in both the top and bottom of the elbow pipe.…”

“…The device used to acquire surface roughness parameters was Mitutoyo SURFTEST SJ-210. Details about the testing procedure were published in our previous work [ 17 , 18 ].…”

Erosion-Corrosion of Gathering Pipeline Steel in Oil-Water-Sand Multiphase Flow

“…The investigation results suggest that the cause of failure is electrochemical corrosion combined with the mechanical process, known as flow-induced corrosion [11]. Gathering pipelines in oilfields are seriously damaged by erosion-corrosion, which results from media including oil, gas, water and sand grains in the brine [12], so it is multiphase flow erosion-corrosion [13,14]. Because of the various compositions of oilfield brines, the mechanism of multiphase flow corrosion-erosion on the inner wall of gathering pipelines is very complex and not clear [15,16].…”

Numerical Simulation of Viscosity Effects on Carbon Steel 90° Elbow Erosion due to Sand-Liquid Flow

“…Erosive wear is generally undesirable because it can cause significant material disintegr ation, which further leads to the malfunction of piping components i.e. elbows and tee junctions [1][2][3]. There are numerous kinds of erodent amenable for erosive wear in hydrocarbon, chemical, and minerals processing industries.…”