Effects of Gas-Injection Well Configurations on Hydrate-Based CO2 Sequestration

Abstract

As CO2 emissions from anthropogenic activities continue to increase, hydrate-based CO2 sequestration has attracted considerable attention. This study systematically investigated the formation behavior and the coupled heat and mass processes of CO2 hydrates under different injection well configurations. Experiments were conducted under single-well, dual-well, and triple-well gas injection conditions in a high-pressure crystallizer. The results indicate that the effect of well number on CO2 hydrate formation is nonmonotonic, while injection configuration plays a decisive role in governing hydrate formation behavior. The linear triple-well gas injection configuration reduced the induction time by 31.7% relative to the other triple-well configurations and achieved the highest final hydrate saturation of 23.45% among the configurations tested in this study. In addition, multiwell injection promoted a more uniform temperature distribution within the crystallizer. These results show that well-configuration optimization enhances hydrate formation efficiency and provides guidance for the design of multiwell CO2 injection strategies in heterogeneous porous media.