A new hydrate deposition prediction model for gas-dominated systems with free water

Abstract

Hydrate deposition is an important issue for flow assurance in subsea pipelines. Current models for hydrate deposition in gas-dominated systems with free water mainly consider hydrate formation in liquid films on pipe walls. However, hydrate particles formed from water droplets in the gas phase may also play a significant role in hydrate deposition. In this work, a new model for predicting hydrate deposition is proposed. This model considers hydrate formation from both liquid film and liquid droplets. In the model, an effective deposition ratio is introduced to calculate the deposition of hydrate particles from the gas phase by considering the influence of liquid film atomization. The simulation results agree well with the experimental data. It is indicated that the deposition of hydrate particles formed by liquid droplets in the gas phase has a significant influence on the reduction of the flow passage in the pipeline. By using the new model, the non-uniform distribution of the flow passage at different times and locations can be obtained, and the most vulnerable position for hydrate deposition can be predicted. The model predicts the risk of hydrate deposition more reliably than current methods and provides helpful advice for the prevention of hydrate deposition in the field.