Ganglion Dynamics and Its Implications to Geologic Carbon Dioxide Storage

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• 作者：Yifeng Wang ; Charles Bryan ; Thomas Dewers ; Jason E. Heath ; Carlos Jove-Colon
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：January 2, 2013
• 年：2013
• 卷：47
• 期：1
• 页码：219-226
• 全文大小：424K
• 年卷期：v.47,no.1(January 2, 2013)
• ISSN：1520-5851

文摘

Capillary trapping of a nonwetting fluid phase in the subsurface has been considered as an important mechanism for geologic storage of carbon dioxide (CO₂). This mechanism can potentially relax stringent requirements for the integrity of cap rocks for CO₂ storage and therefore can significantly enhance storage capacity and security. We here apply ganglion dynamics to understand the capillary trapping of supercritical CO₂ (scCO₂) under relevant reservoir conditions. We show that, by breaking the injected scCO₂ into small disconnected ganglia, the efficiency of capillary trapping can be greatly enhanced, because the mobility of a ganglion is inversely dependent on its size. Supercritical CO₂ ganglia can be engineered by promoting CO₂鈥搘ater interface instability during immiscible displacement, and their size distribution can be controlled by injection mode (e.g., water-alternating-gas) and rate. We also show that a large mobile ganglion can potentially break into smaller ganglia due to CO₂鈥揵rine interface instability during buoyant rise, thus becoming less mobile. The mobility of scCO₂ in the subsurface is therefore self-limited. Vertical structural heterogeneity within a reservoir can inhibit the buoyant rise of scCO₂ ganglia. The dynamics of scCO₂ ganglia described here provides a new perspective for the security and monitoring of subsurface CO₂ storage.