Phase Equilibria Studies in Water-Methane System: Structural Memory-Effect of Water On Hydrate Re-Formation

Abstract

Naturally-occurring hydrates are promising resources. The potential value of gas accumulation in naturally-occurring gas hydrates can exceed 16 equivalent trillion tons of oil. There are many accurate findings on properties of gas hydrates. This is especially true for laboratory formed gas hydrates, but many of definite physical properties are not completely understood. More importantly, in terms of production point of view, the conditions of formation as well as stable existence of naturally occurring gas hydrate deposits are still not well known. These difficulties are further complicated by the structural memory-effect of water on hydrate re-formation, a phenomenon in which previously hydrate-formed liquid re-forms hydrate more readily. This research mainly focused on the stability of hydrate existence in various condition to determine how the water-gas system with previous hydrate history affects the re-formation of hydrates, both experimentally and numerically using the molecular dynamic simulation.