Experimental Studies of Natural Gas Hydrate Dissociation in Porous Media by Inhibitor Injection with the 2D Experimental System

摘要

In this study, an artificial methane hydrate sediment sample isexperimentally made based on a two-dimensional vessel with320mm×320mm in cross section and 28mm in height. a sequence ofexperiments on MH dissociation behaviors by addition of ethyleneglycol (EG) aqueous solution under varying concentration andinjection flux and as well different production mode(Single-well orMulti-mode) are carried out. Special pressure behavior at the earlystage of injection is attributable to the high MH saturation aftercompletion of the formation. It suggests that higher solutionconcentration and the injection rate can facilitate cumulative gasproduction. However, gas production cannot sufficiently benefit frominhibitor injection with higher concentration as far as the input energyis concerned according to the energy-efficiency analysis. Multi-wellmode shows its superiority over Single-well mode in terms of total gasproduction and Productivity as well. The variations of temperature fieldwith the time elapsing reflected directly the advancement of hydratedissociation front. It is difficult to produce all the MH in a reservoirsimply with thermodynamic inhibitor injection because it gets harderfor inhibitor solution to reach to remaining hydrate effectively.