An Analysis of Carcass Layer Erosion in Un-Bonded Flexible Offshore Pipework

In this paper, a simplified model for erosion in un-bonded flexible pipes caused by the sand entrained in the produced fluid is established. Flow field analysis is performed based on the governing equations of the continuous fluid and the discrete particles. A two-way coupled Eulerian-Lagrangian approach is employed to solve the gas-solid flow in the pipe bend. To eliminate the influence of the length of the straight pipe section on the stability of the flow field in the pipe, the flow field distribution under different lengths is analyzed to determine the optimal straight pipe length. Six commonly used erosion models are adopted to predict the erosion rate. After comparing the prediction results with experimental data, the most accurate Oka model is selected to calculate the effect of the fluid and structure parameters on erosion. Effects of particle parameters and pipe structural parameters on the erosion rate of curved flexible pipes are numerically fitted, and the quantitative description is given.