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

Rehan Khan,Mohd Amin Abd Majid,Hassan Iftikhar,Tauseef Ahmed,Amir Ahmad,Hamdan H Ya,Mohammad Azad Alam,M Azeem,William Pao

doi:10.3390/ma13204601

Rehan Khan, Mohd Amin Abd Majid + Show 7 more

Open Access

https://doi.org/10.3390/ma13204601

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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.

Highlights

It is well-known that erosion-corrosion is one of the ubiquitous deterioration modes of piping components [1]
An experimental investigation was employed to evaluate the erosion-corrosion in 90◦ elbows under erosive slug flow conditions with 2, 5, and 10 wt.% sand fines concentration
The investigation was performed for the horizontally oriented AISI 1018 steel elbows installed in the multiphase flow loop where the water and air flow to simulate slug flow conditions

Summary

Introduction

It is well-known that erosion-corrosion is one of the ubiquitous deterioration modes of piping components [1]. Erosion-corrosion could cause significant degradation of pipelines in hydrocarbon production fields and result in an unpredictable failure of the piping components and operating process [2,3]. Sand particles are often transported in pipelines from reservoirs in multiphase flow configurations during the production process and induce erosive wear in piping components [4,5]. Elbow pipes are extensively used to redirect the flow in hydrocarbon and mineral processing industries, the erosive wear in a 90◦ elbow pipe configuration conceivably 50-times higher than that in straight pipe configurations under multiphase flow [6]. Multiphase flow in pipelines is characterized by the distribution of two or more phases into heterogeneous flow regimes as they flow concomitantly in a pipe [7]. In horizontal–horizontal orientation, the flow patterns are generally categorized as plug, slug, low hold up wavy, and annular flow [8]

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