Speaker
Description
Gas hydrates are crystalline solids in which guest molecules are trapped within cages formed by water molecules under high-pressure and low-temperature conditions. They show great potential for submarine CO₂ storage in shallow seabed sediments. This approach involves injecting liquid CO₂ beneath the hydrate stability zone (HSZ). As the CO₂ migrates upward into the HSZ, a hydrate layer forms and acts as a seal, confining the mobile liquid CO₂ beneath it. Studying the formation and propagation dynamics of CO₂ hydrates in porous media is essential for understanding the time-dependent evolution of hydrate saturation in host sediments. This knowledge is critical for predicting the mechanical strength of hydrate-bearing sediments and for designing safe and effective CO₂ injection strategies. Microfluidics is an effective approach for visualizing the phase-transition behavior associated with hydrate formation and has been widely used in hydrate research. However, for dense hydrate formers such as liquid CO₂, the initial hydrate film formation stage is difficult to capture using traditional acid-etched glass micromodels with smooth inner surfaces. In contrast, laser-etched glass micromodels introduce controlled surface roughness, which facilitates the visualization of fine hydrate nuclei and enables direct observation of rapid hydrate film propagation during the early stages of formation. In this study, we employ a laser-etched glass micromodel to investigate hydrate formation processes involving both light phases (gaseous CH₄ and gaseous CO₂) and a dense phase (liquid CO₂). Two distinct stages of hydrate formation are identified: rapid hydrate film growth occurring within seconds, followed by hydrate thickening. In particular, we compare liquid CO₂ hydrate formation in laser-etched and acid-etched glass micromodels, confirming the superior capability of the laser-etched micromodel in capturing early-stage hydrate dynamics. Finally, the effects of subcooling, temperature, additives, and gas saturation on hydrate formation behavior are systematically examined. This work advances microfluidic hydrate research and supports the development of hydrate-based CO₂ storage technologies.
| Country | Saudi Arabia |
|---|---|
| Acceptance of the Terms & Conditions | Click here to agree |
