Gas relative permeability characterization is of key significance to model the behavior of gas flow in gas hydrate-bearing sediments. The present study proposes a novel model to relate gas relative permeability to gas hydrate saturation based on X-ray micro-CT imaging information of xenon hydrate pore-scale distribution in sand sediments. Lattice Boltzmann method (LBM) was used to obtain permeability values of xenon hydrate-bearing sediments via micro-CT data. The results showed that gas relative permeability (K_r) versus gas hydrate saturation (S_h) data are consistent with the new model and the imitative effect is relatively better than that of the simple Corey model. Besides, we calculated gas relative permeability versus gas hydrate saturation curves for various pore habits via idealized models. Experimental measurements and simulation results showed that the grain-coating gas hydrate exhibits the highest gas relative permeability, while pore-filling gas hydrate exhibits the lowest values of gas relative permeability, and the cementing gas hydrate ranges in between. We validated the new gas relative permeability calculation model by applying it to the well logging data of gas hydrate reservoirs. Our results showed that the novel model is beneficial for permeability characterization of gas hydrate reservoirs and gas relative permeability calculations.

气体相对渗透率表征对于模拟含天然气水合物沉积物中的气体流动行为具有关键意义。本研究基于砂质沉积物中氙水合物孔隙尺度分布的 X 射线显微 CT 成像信息，提出了一种将气体相对渗透率与天然气水合物饱和度联系起来的新模型。使用格子 Boltzmann 方法 (LBM) 通过显微 CT 数据获取含氙水合物沉积物的渗透率值。结果表明，天然气相对渗透率（K _r）与天然气水合物饱和度（S _h) 数据与新模型一致，模仿效果相对优于简单的 Corey 模型。此外，我们通过理想化模型计算了各种孔隙习性的气体相对渗透率与天然气水合物饱和度曲线。实验测量和模拟结果表明，颗粒包覆型天然气水合物的相对渗透率最高，孔隙填充型天然气水合物的相对渗透率最低，胶结型天然气水合物介于两者之间。我们通过将新的气体相对渗透率计算模型应用于天然气水合物储层的测井数据进行验证。结果表明，该模型有利于天然气水合物储层渗透率表征和气体相对渗透率计算。