Abstract
Methane hydrate is one of the potential resources of natural gas in the near future, because a large amount of reservoir exists in marine sediments and permafrost regions worldwide. It is very important to investigate physical phenomena in hydrate reservoirs, especially for developing an extraction system for gas hydrates, and in considering the environmental impacts by the development.In this study, we carried out an experimental research on hot water injection process as one of the thermal stimulation methods, using a special-type apparatus designed for simulating hydrate reservoir. As a result of the experiments, it was found that the dissociation process by hot water injection consisted of the following four stages, such as (1) displacement of free methane gas due to water injection, (2) additional hydrate formation at downstream zone due to migration of dissociated gas and water, (3) actual dissociation, (4) completion of dissociation. In addition, the permeability of the hydrate reservoir was observed as a function of time that, tended to decrease during the additional hydrate formation period and increase during the actual hydrate dissociation period. Based on experimental data of temperature distribution during dissociation, the reservoir could be divided into three zones from upstream edge, and dissociation zone was extremely narrow area depending on the dissociation rate. Furthermore, we discussed the effect of injected water temperature, reservoir pressure and hydrate saturation on the movement of dissociation front and gas production behavior.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
