Avoiding Hydrates in the Petroleum Industry: Kinetics of Formation

Natural gas hydrates significantly impact the economics of development of offshore hydrocarbon resources in deep water. Methods for avoiding hydrates that depend on kinetics of hydrate formation may replace thermodynamic methods. Hydrate growth rates measured on a quiescent drop of water were found to agree qualitatively with rates measured in a vigorously stirred reactor when normalized with respect to the area of contact between the gas and the liquid, or liquid suspension of hydrates. The Gibbs free energy change for hydrate formation is shown to be a good estimate of driving force for hydrate growth. Hydrate growth rates per unit area correlate with the driving force.Driving force calculations suggest that hydrate structures other than the thermodynamically favored structures may form.