Gas Production from Methane-Hydrate-Bearing Sands by Ethylene Glycol Injection Using a Three-Dimensional Reactor

Abstract

The gas production from methane-hydrate-bearing sediment by injecting ethylene glycol (EG) solution was investigated using a three-dimensional experimental apparatus. Eight experimental runs were performed to examine the influence of operation conditions on hydrate dissociation by EG injection. The variations of pressure and temperature distribution in the reactor stimulated by the injected EG were obtained for the gas production process of the hydrate. The variation trend of temperature in the injection stage shows a shape of a "well" because of heat transfer and hydrate dissociation. The appearance sequence of temperature "well" and "well" depth is different for every port at different depths and radii. The effects of the concentration and quantity of EG and soaking time on the gas production ratio are examined. It shows that there exists an optimal value of the mass ratio of injected EG solution to initial water, where a maximum gas production ratio appears. When other conditions are similar, the gas amount produced by hydrate dissociation increases with the increase of the inhibitor concentration. The gas production efficiency increases with the decrease of the EG quantity and the increase of the EG concentration.