EXPERIMENTAL HYDRATE FORMATION AND GAS PRODUCTION SCENARIOS BASED ON CO2 SEQUESTRATION

A number of laboratory experiments have investigated the rates and mechanisms of hydrate formation in coarse-grain porous media. They have shown the importance of initial water saturation and salinity on forming methane hydrates in mostly excess gas systems. Many of these experiments were conducted in a sample holder fitted within a MRI instrument that allowed for a unique method of monitoring hydrate formation by the loss of signal intensity as water and free gas are converted into a solid phase. The hydrate- saturated samples were then subjected to various procedures to release the methane. Most of the experiments focused on the exchange of carbon dioxide for methane in the hydrate. The rates and efficiency of the exchange process were reproducible over a series of initial conditions, with the notable observation that no free water was observed during the exchange process. Permeability measurements on hydrate- saturated core indicate a finite level of permeability to gas, even in cores where all of the free water was converted to hydrate. .