Experimental and Numerical Investigation of the Effect of Viscosity and Particle Size on the Erosion Damage Caused by Solid Particles

Oil and gas produced from wells usually contain impurities such as sand particles transported by fluid flowing through pipelines. The particles impinge on the pipe walls and fittings removing material from the wall and causes erosion damage. The effect of viscosity and particle size on the local thickness loss and total erosion ratio was investigated by conducting a comprehensive experimental study on the erosion of stainless steel 316 specimens caused by sand entrained in a submerged liquid jet. Two types of sand with sizes of 150 μm and 300 μm were used and added to liquids with 1, 14 and 55 cP viscosities. The tests were carried out for three different nozzle angles: 90° (normal to target), 75° and 45°. The results show that for the 90° orientation, the total erosion ratio does not change significantly with increase in viscosity. The measurements also show that the erosion ratio for 300 μm sand is approximately two times higher than for 150 μm sand; where the erosion ratio is the mass loss of the target divided by the mass throughput of sand. The local thickness losses on the specimens were measured using a 3D profilometer, and the results show, maximum erosion depth is increasing as viscosity increases. Comparing the Scanning Electron Microscopy (SEM) images of the specimens after the test revealed that the crater sizes do not change very much with increases in viscosity. SEM images for both viscosities of 1 and 55 cP showed that the craters become longer moving radially outward from the the center of the impact zone. Computational Fluid Dynamics (CFD) simulations of erosion patterns are compared with data and they tend to under predict the total erosion ratio and local thickness loss for slurry flows as viscosity increases.