煤层气井排采中断将导致大量煤粉滞留于支撑裂缝内，造成支撑裂缝渗透率伤害。围绕固−液两相流和气−液−固三相流2种流型，开展了排采中断后恢复模式对支撑裂缝内煤粉运移的影响实验，对比了一级和逐级恢复模式下支撑裂缝渗透率演化规律，揭示了排采恢复模式对支撑裂缝内煤粉运移的作用机制。结果表明：在固−液两相流条件下，一级恢复模式可使支撑裂缝渗透率提升至中断前水平之上，而逐级恢复模式却难以使渗透率恢复至中断前水平；在气−固−液三相流条件下，一级和逐级恢复模式均能使支撑裂缝气、液相渗透率提升至中断前水平之上，且一级恢复模式的提升效果更好；在固−液两相流和气−液−固三相流条件下，煤粉滞留形式主要为固−液界面和气−液界面黏附，其差异性是导致相同恢复模式下渗透率改善效果不同的主要原因，一级恢复模式的流速增幅较逐级恢复模式更大，其诱发的壁面剪应力和气−液界面扰动效应更强，故对煤粉促排效应就越强，渗透率改善效果就越好；在单相流排水阶段和气−水合采阶段，为抑制排采中断对支撑裂缝渗透率的影响，排采中断后均应采用一级恢复模式进行生产。

In the drainage process of coalbed methane well, the interruption of drainage will induce a large amount of coal fines to stay in propped fractures, causing damage to the permeability of propped fractures. Based on the solid-liquid two-phase flow and gas-liquid-solid three-phase flow two patterns, experiments were carried out to investigate the effect of recovery mode after drainage interruption on coal fines migration in propped fractures. The permeability evolution law of propped fractures under the one-stage recovery mode and step-by-step recovery mode was compared, and the mechanism of coal fines migration under different recovery modes was revealed. The results show that the one-stage recovery mode can increase the permeability of propped fractures above the pre-interruption level under the condition of solid-liquid two-phase flow, but the step-by-step recovery mode is difficult to restore the permeability of propped fractures to the pre-interruption level. Under the condition of gas-solid-liquid three-phase flow, both the one-stage recovery mode and the step-by-step recovery mode can increase the permeability of gas phase and liquid phase beyond the pre-interruption levels, and the one-stage recovery mode presents a better improvement effect than the step-by-step recovery mode. Under the conditions of solid-liquid two-phase flow and gas-liquid-solid three-phase flow, the retention forms of coal fines in propped fractures are mainly solid-liquid interface and gas-liquid interface adhesion, which is the main reason for the different improvement effects of the permeability of propped fracture under a same recovery mode. The flow rate amplification of the first-stage recovery mode is much greater than that of the step-by-step recovery mode, resulting in greater wall shear stress and stronger gas-liquid interface disturbance effects. As a result, the promotion and discharge effect on retained coal fines is stronger, and the improvement effect on permeability is better. During the stages of single-phase water drainage and gas-water joint drainage, in order to suppress the impact of drainage interruption on the permeability of propped fractures, the first-stage recovery mode should be adopted after the interruption of drainage.