Thermodynamic Effects on Hydrate Formation in Deepwater Pipeline

Abstract

Hydrate formation has long been a challenge for flow assurance in deepwater natural gas pipelines. Hydrates are formed when natural gas is brought into contact with water usually at low temperature and high pressure in deepwater pipelines. The pressure is relatively high in deepwater pipelines, so it is entirely possible to meet the hydrate formation conditions and pose a significant operational and security challenge. This study provides a means to ascertain the thermodynamic properties for hydrate formation in a deepwater gas pipeline. The thermodynamic properties are to be assumed between the similarity of the hydrate formation and the isothermal adsorption in a deepwater pipeline. The study aims to develop a correlation for calculating the hydrate formation pressure, temperature and fugacity of a gas mixture. The correlation is based on the gas hydrate formation temperature and pressure with and without inhibitors. This study also provides a hydrate prediction phenomena associated with gas condensation in deepwater pipelines and it will improve the ability to predict the thermodynamic properties of hydrate formation.