Estimation of Wax Deposition in Subsea Pipelines

Developed is a multi-physics low dimensional model forecasting wax deposition rate within subsea production pipelines. This research employs experiments from 1-D and 2-D multiphase flow that have been successfully matched by a combined physics model on a closed-loop structure where the measuring length was 2.5m and the pipe inside diameter 0.0144m. The wax precipitation factor correlations used in 1-D and 2-D wax deposition models are valid only for 1-phase flows. Thus, to apply the 2-phase flow along these models the import of a coefficient is applied, directly related to the Gas Volume Fraction. Finally, there is a simulation that validates the model for 1-D, 1-phase closed loop system and a simulation for 1-D, 2-phase closed loop system. Then, the model is applied on a subsea pipeline for 1-D, 1-phase for a pipe of 0.305m ID, 80km long and for 2-D, 2-phase separately for a pipeline of same ID, 100m and 1000m long.