We use synchrotron X-ray micro-tomography to investigate the displacement dynamics during three-phase—oil, water and gas—flow in a hydrophobic porous medium. We observe a distinct gas invasion pattern, where gas progresses through the pore space in the form of disconnected clusters mediated by double and multiple displacement events. Gas advances in a process we name three-phase Haines jumps, during which gas re-arranges its configuration in the pore space, retracting from some regions to enable the rapid filling of multiple pores. The gas retraction leads to a permanent disconnection of gas ganglia, which do not reconnect as gas injection proceeds. We observe, in situ, the direct displacement of oil and water by gas as well as gas–oil–water double displacement. The use of local in situ measurements and an energy balance approach to determine fluid–fluid contact angles alongside the quantification of capillary pressures and pore occupancy indicate that the wettability order is oil–gas–water from most to least wetting. Furthermore, quantifying the evolution of Minkowski functionals implied well-connected oil and water, while the gas connectivity decreased as gas was broken up into discrete clusters during injection. This work can be used to design CO2 storage, improved oil recovery and microfluidic devices.

中文翻译：

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疏水多孔介质中的三相流置换动力学和海恩斯跳跃

我们使用同步加速器 X 射线显微断层扫描来研究疏水多孔介质中油、水和气三相流动过程中的置换动力学。我们观察到一种独特的气体侵入模式，其中气体以由双重和多次置换事件介导的不连续簇的形式穿过孔隙空间。气体在我们称之为三相海恩斯跳跃的过程中前进，在此期间气体重新排列其在孔隙空间中的配置，从某些区域回缩以实现多个孔隙的快速填充。气体收缩导致气节永久断开，气节在注气过程中不会重新连接。我们在原位观察到气直接驱油和水以及气-油-水双重驱替。使用局部原位测量和能量平衡方法来确定流体 - 流体接触角以及毛细管压力和孔隙占有率的量化表明润湿性顺序是油 - 气 - 水从最润湿到最不润湿。此外，量化 Minkowski 泛函的演变意味着油和水的连接良好，而气体连通性随着注入过程中气体分解成离散簇而降低。这项工作可用于设计 CO2 储存、改进的石油回收和微流体装置。而气体连通性随着气体在注入过程中分解成离散的簇而降低。这项工作可用于设计 CO2 储存、改进的石油回收和微流体装置。而气体连通性随着气体在注入过程中分解成离散的簇而降低。这项工作可用于设计 CO2 储存、改进的石油回收和微流体装置。