Depressurization of hydrate-bearing sediments (HBS) is inevitably accompanied with sediment transport, not only structural host sediment itself but also fine particles, which can be a significant problem in producing gases from HBS, as demonstrated in recent field-scale hydrate production tests. Particularly, the migration of fine sediment particles can alter the hydro-mechanical properties of sediments, and reduce long-term hydrocarbon productivity by causing local-clogging around wells. However, questions as to under which circumstances and to what extent the fines migration and pore-clogging occur remain poorly resolved, particularly in association with two-phase flows. Therefore, this study explored the fines migration induced by fluid flows and the resulting pore-clogging in porous media. One-dimensional channel experiments were carried out with sandy sediments containing non-plastic silty fines to examine effects of fluid velocity and mixed fluid flows on pore-clogging occurrence. In single-phase flows, the flow velocity had a pronounced effect on determining the fines behavior, exhibiting from no or minimal fines detachment, through fines migration with no clogging, and to fines migration accompanying pore-clogging with increasing flow velocity. In two-phase flows with mixed gas–water fluids, the presence of gas–water interfaces clearly promoted pore-clogging because the fines were readily collected at gas–water interfaces, resulting in high particle concentration at the menisci. The particle-level force analysis also corroborates the experimental observations, showing that the drag force primarily determined by the flow velocity plays a significant role in the fines detachment against the particle weight in the single-phase flows. In contrast, the gas–water interfacial tension overwhelms the drag force and the particle weight, and thereby, governs pore-clogging behaviors in mixed fluid flow conditions. The presented results provide insights into pore-scale mechanisms of pore-clogging induced by fines migration, which is associated with gas production in HBS, as mixed fluids flow can accompany fines detachment, fines migration, and pore-clogging near wellbores.

含水合物沉积物（HBS）的降压不可避免地伴随着沉积物的运输，不仅是结构主体沉积物本身，而且还有细颗粒，这是从HBS生产气体的一个重大问题，如最近的现场规模水合物生产试验所证明的那样。特别是，细小的沉积物颗粒的迁移会改变沉积物的水力机械特性，并通过引起井周围的局部堵塞而降低长期的烃产量。然而，关于在什么情况下以及在多大程度上发生细粉迁移和孔堵塞的问题仍然没有得到很好的解决，特别是与两相流有关的问题。因此，本研究探讨了由流体流动引起的细粒迁移以及在多孔介质中导致的孔堵塞。用含非塑性粉质细粉的沙质沉积物进行一维通道实验，以研究流体速度和混合流体流量对孔堵塞发生的影响。在单相流中，流速对确定细粉的行为具有显着的影响，从没有或最小的细粉分离开始，通过没有阻塞的细粉迁移，到随着流速增加伴随细孔堵塞的细粉迁移。在具有混合气水流体的两相流中，气水界面的存在明显促进了孔的堵塞，因为细粒很容易在气水界面处被收集，从而导致弯液面处的颗粒浓度很高。粒子级力分析也证实了实验观察，结果表明，主要由流速决定的阻力在细粉分离中对单相流中的颗粒重量起着重要作用。相反，气水界面张力压倒了阻力和颗粒重量，从而控制了混合流体流动条件下的堵塞孔道行为。由于混合流体的流动会伴随着细粒的分离，细粒的迁移以及井筒附近的孔堵塞，因此提出的结果提供了对由细屑迁移引起的孔堵塞的孔隙尺度机制的见解，这与HBS中的天然气生产有关。控制混合流体流动条件下的孔堵塞行为。由于混合流体的流动会伴随着细粒的分离，细粒的迁移和井筒附近的堵塞，因此，本文提出的结果提供了由细屑迁移引起的孔隙堵塞的孔隙尺度机制的见解，这与HBS中的天然气生产有关。控制混合流体流动条件下的孔堵塞行为。由于混合流体的流动会伴随着细粒的分离，细粒的迁移和井筒附近的堵塞，因此，本文提出的结果提供了由细屑迁移引起的孔隙堵塞的孔隙尺度机制的见解，这与HBS中的天然气生产有关。