CCS Technologies for low carbon society

[1601-04-02] Visualization of flow behavior by X-ray CT and strain measurement by optical fiber in supercritical CO₂ injection experiment using formation boundary core.

○KIYAMA TAMOTSU¹, Hyuck Park¹, Yi Zhang¹, Xue Ziqiu¹, Jiang Lanlan¹ (1. Research Institute of Innovative Technology for the Earth)

Chairman: Tetsuya Suekane (Tokyo Institute of Technology)

Keywords:X-ray C, optical fiber sensor, threshold pressure, Tago sandstone, supercritical CO2

The examination of supercritical CO₂ injection using a specimen of Tago sandstone with a clear boundary between coarse grain part and fine grain part test was carried out observing the visualized pore fluid behavior by X-ray CT and the circumferential strain behavior by optical fiber sensor. Supercritical CO₂ was injected from the coarse grain side and the threshold pressure was estimated by dynamic flow method with the flow rate change until supercritical CO₂ passed through the boundary. The results of the X-ray CT observation showed as follow: supercritical CO₂ gradually filled the pore of coarse grain part at first, but did not go beyond the boundary between coarse grain part and fine grain part. After the coarse grain part was sufficiently filled with supercritical CO₂, the infiltration into the fine grain portion started. On the other hand, it was confirmed from the strain measurement by optical fiber sensor that distinct inflatable strain was observed in advance from the stage where the saturation ratio of supercritical CO₂ is low. The observation of the apparent strain at a low saturation ratio of supercritical CO₂ suggests that the strain monitoring of formations will be effective for the monitoring of supercritical CO₂ at CCS.