Natural gas hydrate (NGH) has been regarded as a fossil fuel reserve for the future on account of its tremendous potential. The numerical modeling on NGH formation/dissociation mechanism contributes to better understanding its accumulation and distribution feature, and optimizing the development program. This paper aims to develop a new simulator for the NGH formation in the core-scale sandy sediments based on the computational fluids dynamic (CFD) methods. The mathematical model is established based on the kinetic reaction model of hydrate formation, the permeability reduction model by the NGH, model of heat and mass transfer in porous media. The hydrate formation model is programmed by C language, and used as a subroutine for Fluent software which is adopted to solve the governing equations of the multiphase flow. The simulator scheme is verified by comparison with the experiment and numerical simulation in literature. What's more, this study reproduces the same fluctuant tendency of temperature as the experiment during the 1.0 h–2.0 h for the first time. Different reaction surface models of NGH formation/dissociation are evaluated by the developed codes. The effects of the reaction surface of hydrate (RSH) model and the initial fluids distribution on the hydrate formation process are simulated and analyzed. The variation of the RSH in NGH formation/dissociation should be taken into consideration when modeling the hydrate re-formation in the exploitation of NGH. The initial distribution of water and gas has a great impact on the hydrate formation in the sealed reactor. The hydrate distribution is ununiform, even when assuming the water and methane are mixed uniformly in a homogeneous porous media. This study provides new insight for the parametric estimation of the RSH model in the hydrate formation and dissociation modeling.

天然气水合物（NGH）由于其巨大的潜力而被视为未来的化石燃料储备。NGH形成/离解机制的数值模拟有助于更好地了解其积累和分布特征，并优化开发程序。本文旨在基于计算流体动力学（CFD）方法，为岩心尺度砂质沉积物中的NGH形成开发一个新的模拟器。基于水合物形成的动力学反应模型，NGH的渗透率降低模型，多孔介质中的传热传质模型建立了数学模型。水合物形成模型用C语言编程，并用作Fluent软件的子程序，该软件用于求解多相流的控制方程。通过与文献中的实验和数值模拟相比较，验证了仿真器方案。此外，本研究首次再现了与实验在1.0 h–2.0 h内相同的温度波动趋势。NGH形成/解离的不同反应表面模型通过开发的代码进行评估。模拟和分析了水合物反应面（RSH）模型和初始流体分布对水合物形成过程的影响。在对NGH开采中水合物的重整进行建模时，应考虑RSH在NGH形成/解离中的变化。水和气体的初始分布对密封反应器中水合物的形成有很大影响。水合物分布不均匀，即使假设水和甲烷在均匀的多孔介质中均匀混合也是如此。这项研究为水合物形成和离解模型中RSH模型的参数估计提供了新的见识。