A review of numerical research on gas production from natural gas hydrates in China

Since the success of recovering natural gas from hydrate-bearing reservoirs (HBRs) in Shenhu Area of the northern South China Sea in 2017, China has successfully produced natural gas from hydrates in permafrost and ocean environments. It certainly will be required to achieve further research quality and scientific contribution for the natural gas hydrates exploitations in China. This paper is primarily to summarize and review the excellent numerical achievements contributed by Chinese research groups on natural gas production from HBRs up to now, and to put forward some suggestions for future directions in numerical studies of natural gas hydrates in China from our own point of view. In this paper, general concept of hydrate exploitation and the assistance of understanding the numerical simulation process were first introduced. Then according to the fundamental principle of numerical simulation for gas production from HBR, the developed theoretical models describing the specific physical processes of hydrate exploitation, hydrate decomposition kinetic and thermophysical properties of multiphase and multicomponent were discussed in detail. Finally, the comprehensive comments were presented to evaluate the technical feasibility of various production schemes and well configurations for experimental and field gas production, and analyze the potential of special HBRs in Shenhu area of South China Sea and Qilian Mountain Permafrost