With increasing emphasis on low-carbon environmental protection, CO₂ enhanced coalbed methane production and methane reuse in abandoned mines (rich in N₂) have gradually become one of the future development directions. These scenarios involve the coordinated migration of different gases such as CO₂, CH₄, and N₂, and the differences in properties of different gases that affect the flow process. Previous studies often focused on the adsorption differences between gases, neglecting the differences during desorption process. In view of this, the current work conducted experiments and finite element numerical analysis on the desorption process of CO₂, CH₄, and N₂, clarified the differences and influencing factors of desorption among the gases, and analyzed the flow change rules under different permeability and diffusion capabilities. The results indicated that the main differences among CO₂, CH₄, and N₂ during desorption are reflected in the parameters of Langmuir volume, permeability, and diffusion coefficient. These parameters showed that CO₂ has the highest value during desorption, while N₂ has the lowest. The factors affecting the magnitude of differences between CO₂, CH₄, and N₂ are mainly their compositions. Specifically, ash content significantly affects the difference in adsorption capacity, while moisture content influences permeability and diffusion coefficient. During desorption, permeability plays a continuous role throughout the whole process, while diffusion coefficient is exhibited mainly in the initial stage of desorption. Different gases have varying sensitivities to permeability and diffusion coefficients during desorption. Changes in permeability and diffusion coefficient significantly affect the CO₂ desorption process. N₂, on the other hand, is the least sensitive, especially to changes in diffusion coefficient. During gas flow, when reservoir permeability is less than 0.01 mD (= 9.869233 × 10⁻¹⁸ m²), permeability becomes the main factor that affects flow. When the diffusion coefficient is less than 5 × 10⁻⁹ m²/s, increasing the diffusion coefficient is necessary to effectively promote gas outflow. To effectively increase gas production, it is necessary to comprehensively consider the magnitudes of permeability and diffusion coefficient.

随着人们对低碳环保的日益重视，CO ₂ 强化煤层气增产以及废弃矿山（富含 N ₂ ）的甲烷回用逐渐成为未来的发展方向之一。这些场景涉及不同气体（如 CO ₂ 、 CH ₄ 和 N ₂ ）的协调迁移，以及影响不同气体性质的差异。流水作业。以往的研究往往关注气体之间吸附的差异，而忽略了解吸过程中的差异。鉴于此，本工作对CO ₂ 、CH ₄ 、N ₂ 的解吸过程进行了实验和有限元数值分析，阐明了气体解吸的差异及影响因素，分析了不同渗透率和扩散能力下的流量变化规律。结果表明，解吸过程中CO ₂ 、CH ₄ 和N ₂ 三者的主要差异体现在Langmuir体积、渗透率和扩散参数上。系数。这些参数表明，解吸过程中CO ₂ 的值最高，而 N ₂ 的值最低。影响CO ₂ 、CH ₄ 和N ₂ 差异大小的因素主要是它们的组成。具体而言，灰分含量显着影响吸附能力的差异，而含水量则影响渗透性和扩散系数。在解吸过程中，渗透率在整个过程中持续发挥作用，而扩散系数主要表现在解吸初期。 不同的气体在解吸过程中对渗透率和扩散系数具有不同的敏感性。渗透率和扩散系数的变化显着影响CO ₂ 解吸过程。另一方面，N ₂ 是最不敏感的，尤其是对扩散系数的变化。气体流动过程中，当储层渗透率小于0.01 mD（= 9.869233 × 10 ⁻¹⁸ m ² ）时，渗透率成为影响流动的主要因素。当扩散系数小于5×10 ⁻⁹ m ² /s时，需要增大扩散系数才能有效促进气体流出。为了有效提高产气量，需要综合考虑渗透率和扩散系数的大小。