The presence of CO2, sand, and water in oil and gas reservoirs causes erosion–corrosion leading to material degradation in pipelines and fluid handling equipment that results in increasing maintenance and repair costs and a decrease in production. While the weight loss caused by erosion–corrosion is known to depend on flow velocity, angle of impact, sand loading and size and target material properties, field operators often limit the flow rate based on a critical corrosion velocity to protect the equipment. This study investigates the effects of sand loading and flow velocity on weight loss associated with erosion–corrosion in a mild steel sample using a submerged impingement jet. The weight loss by erosion, corrosion and their interaction for a flow velocity range of 10 m/s to 20 m/s and sand loading range of 300 mg/L to 600 mg/L, in a seawater environment, are presented. The results showed that the weight loss by pure erosion and erosion–corrosion interaction increases linearly with jet velocity and sand loading, and that erosion is dominant in all cases except at low velocity and sand loading. The scanning electron microscope (SEM) images after impingement tests were analyzed. In addition, correlations for the velocity and sand loading were derived using the design of experiment method (DOE).

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Liquid-solid flow erosion in curved pipes of gradually varying cross section is investigated. The model consists of three components integrated: Fluid Transport to describe the flowing fluid via Reynolds-Averaged Navier-Stokes equations with standard k-ε turbulence model, Particle Transport to describe the trajectories of the solid particles using Discrete Particle Modeling (DPM) and Particle Erosion to describe the erosion rate using Oka erosion model. The model is validated against experimental data for erosion in curved pipe of constant cross section. This study focuses at the geometrical effect of curved pipes, i.e. converging, constant cross section and diverging, on erosion. Both maximum erosion and locations where it occurs are identified. Results show that curved converging pipes suffer from high erosion rate concentrated especially in the outer wall of the curved section. Curved diverging pipes on the other hand has much lower erosion of erosion rate at least one order of magnitude lower compared against that of diverging pipes and concentrated on the side wall of the curved section. This very different erosion behavior is highlighted in the study.

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