Fundamentals of Natural Gas and Species Flows from Hydrates Dissociation - Applications to Safety & Sea Floor Stability

Fossil fuels are expected to continue to play a dominant role in production of electricity well into the 21st Century and beyond. Majority of the planned developments, however, is centered on natural gas due to its numerous environmental advantages. Methane hydrate reserves in the oceans and in permafrost, is a potentially enormous source of natural gas. Therefore, developing economical and environmentally safe technology for natural gas production from hydrate is critical to satisfying the future energy need of the nation. Despite a number of earlier studies, many fundamental aspects of hydrate dissociation process and the resulting natural gas and water flows are not fully understood. In particular, the nature of species flow after hydrate dissociation in unconsolidated sediment and the potential of sea floor instability are not known. Furthermore, the associated safety problems due to gas pressure buildup during drilling in a hydrate layer are not fully understood.

The primary goal of this project is to provide a fundamental understanding of flow conditions of hydrate dissociation products in consolidated and unconsolidated sediment. We also will develop semi-analytical computational models to be used as tools to guide the safety related issues. These include predicting the rate of natural gas pressure buildup during drilling in a hydrate reservoir, the nature of gas and water flows in the reservoir after hydrate dissociation, and the potential for sea floor instability. Availability of such an understanding, detailed experimental data and a computational tool are crucial to the future development of technology for economical and safe natural gas production from hydrate in the 21st Century.

The experimental phase of the study, is concerned with visualizing and measuring the gas and water velocities during hydrate dissociation, as well as examining the nature of slurry flows that are produced by the hydrate dissociation in unconsolidated sediments.

Funded by US Department of Energy, National Energy Technology Laboratory (NETL)