Axial symmetrical thermal conduction and phase transformations in THF hydrate-bearing sediments

Thermal conduction and phase transformation are physical-chemical processes during the dissociation of gas hydrate-bearing sediments. Heat transfer leads to the expansion of hydrate dissociation front and the weakening of soils accompanied by the seepage of fluids and the deformation of sediments. As a consequence, ground failure may occur which can damage engineering structures and lead to environmental disasters. Hydrate dissociation in sediments is investigated using tetrahydrofuran (THF) hydrate sediments under various thermal strengths, and the time-dependent development of a hydrate-dissociation front is elucidated. An axial-symmetrical theoretical model and a numerical method are proposed based on experimental observations and analysis of the physical processes. Numerical and experimental results for evolution of the hydrate-dissociation front are in good agreement. Copyright © 2013 by The International Society of Offshore and Polar Engineers (ISOPE).