Molecular Dynamics Simulation of the Effects of Different Initial Water Content on Methane Hydrate Decomposition
Download PDF


Water content
Decomposition rate
Gas migration
Molecular dynamics simulation



Submitted : 2023-11-27
Accepted : 2023-12-12
Published : 2023-12-27


Gas hydrate is mainly distributed in deep sea-floor sediments and permafrost regions. The water content of these sediments varies with the type of reservoir and affects the rate of hydrate decomposition. In this work, the decomposition process of methane hydrate under four different initial water contents was investigated by molecular dynamics simulation. The results were analyzed by the system conformation, radial distribution function (RDF), and mean square displacement (MSD), which revealed the microscopic mechanism of the effect of the initial water content on the decomposition rate of hydrate. The results demonstrate that the hydrate decomposition starts from the boundary to the middle, and the cage structure is destroyed layer by layer. Methane molecules continue to escape from the hydrate cages as the hydrate decomposes, and subsequent decomposition of the hydrate is inhibited when its solubility in water reaches saturation. The higher the initial water content is, the faster the decomposition rate of hydrate is. The movement distance of methane gas is affected by the initial water content. The higher the initial water content, the smaller the MSD of methane molecules.


Ersland G, Husebo J, Graue A, et al., 2010, Measuring Gas Hydrate Formation And Exchange with CO2 in Bentheim Sandstone Using MRI Tomography. Chemical Engineering Journal, 158(01): 25–31.

Moridis GJ, Collett TS, Dallimore SR, et al. 2004, Weatherill, Numerical Studies of Gas Production From Several CH4 Hydrate Zones at the Mallik site, Mackenzie Delta, Canada. Journal of Petroleum Science and Engineering, 43(3–4): 219–238.

Moridis GJ, Collett TS, Pooladi-Darvish M, et al. 2011, Challenges, Uncertainties, and Issues Facing Gas Production From Gas-Hydrate Deposits, SPE Reservoir Evaluation & Engineering, 14(01): 76–112.

Hu Y, Chen Z, Jiang Q, et al., 2023, Probing the Mechanism of Salts Destroying the Cage Structure of Methane Hydrate by Molecular Dynamics Simulation, Geoenergy Science and Engineering, 223: 211523.

Sun XL, Zhou GG, Liu ZL, et al., 2021, Effect of Ethanol Concentration on Methane Hydrate Decomposition: MD Simulation Insights. Journal of Materials Research and Technology, 13: 1722–1731.

Myshakin EM, Jiang H, Warzinski RP, et al., 2009, Molecular Dynamics Simulations of Methane Hydrate Decomposition, The Journal of Physical Chemistry A, 113(10): 1913–1921.

Takeuchi F, Hiratsuka M, Ohmura R, et al. 2013, Water Proton Configurations in Structures I, II, and H Clathrate Hydrate Unit Cells. The Journal of Chemical Physics, 138(12): 12.