Insight into evolution of invasive patterns on fingering phenomenon during immiscible two-phase flow through pore structure  

作　　者：Yu Li Hui-Qing Liu Chao Peng Peng Jiao Wai Lam Loh Qing Wang 

机构地区：[1]State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum,Beijing,102249,China [2]Department of Mechanical Engineering,National University of Singapore,117575,Singapore [3]Oil and gas production Business Department,Kunlun Shuzhi Technology Co.,LTD,Beijing,100040,China

出　　处：《Petroleum Science》2024年第5期3307-3325,共19页石油科学（英文版）

基　　金：supported by the National Natural Science Foundation of China Joint Fund Project (Grant/Award Number: U20B6003);National Natural Science Foundation of China (Grant/Award Number: 52304054)。

摘　　要：Understanding fingering, as a challenge to stable displacement during the immiscible flow, has become a crucial phenomenon for geological carbon sequestration, enhanced oil recovery, and groundwater protection. Typically governed by gravity, viscous and capillary forces, these factors lead invasive fluids to occupy pore space irregularly and incompletely. Previous studies have demonstrated capillary numbers,describing the viscous and capillary forces, to quantificationally induce evolution of invasion patterns.While the evolution mechanisms of invasive patterns have not been deeply elucidated under the constant capillary number and three variable parameters including velocity, viscosity, and interfacial tension.Our research employs two horizontal visualization systems and a two-phase laminar flow simulation to investigate the tendency of invasive pattern transition by various parameters at the pore scale. We showed that increasing invasive viscosity or reducing interfacial tension in a homogeneous pore space significantly enhanced sweep efficiency, under constant capillary number. Additionally, in the fingering crossover pattern, the region near the inlet was prone to capillary fingering with multi-directional invasion, while the viscous fingering with unidirectional invasion was more susceptible occurred in the region near the outlet. Furthermore, increasing invasive viscosity or decreasing invasive velocity and interfacial tension promoted the extension of viscous fingering from the outlet to the inlet, presenting that the subsequent invasive fluid flows toward the outlet. In the case of invasive trunk along a unidirectional path, the invasive flow increased exponentially closer to the outlet, resulting in a significant decrease in the width of the invasive interface. Our work holds promising applications for optimizing invasive patterns in heterogeneous porous media.

关 键 词：Immiscible two-phase flow Fingering phenomenon Invasive pattern Capillary number Parameters optimization 

分 类 号：TE311[石油与天然气工程—油气田开发工程]