日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

セッション記号 H (地球人間圏科学) » H-SC 社会地球科学・社会都市システム

[H-SC07] 地球温暖化防止と地学(CO2地中貯留・有効利用、地球工学)

2019年5月29日(水) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:徂徠 正夫(国立研究開発法人産業技術総合研究所地圏資源環境研究部門)、薛 自求(公益財団法人 地球環境産業技術研究機構)、愛知 正温(東京大学大学院新領域創成科学研究科)

[HSC07-P07] CO2 注入試料の光ファイバーによるひずみ検出

*朴 赫1孫 艶坤1薛 自求1 (1.公益財団法人 地球環境産業技術研究機構)

キーワード:光ファイバー、CO2フラッド、ひずみ検出、ひずみプロファイル、X線CT

In order to detect strain of rock specimen during CO2 injection using optical fiber, a laboratory experiment was carried out using porous sandstone. Spiral direction strain of core specimen was detected by optical fiber. We compared the strain profiles in the case of one-phase flow (water only) and the case of two-phase flow (CO2 in water saturated specimen). CT image analysis was also used to determine the internal state of the specimen. Sarukawa sandstone (diameter: 34.83mm, length: 179.50mm) was used in this study. Porosity of the specimen determined by X-ray CT imaging is 23.38%. This specimen is homogeneous overall, but there are some gravels in some places. The permeability is about 7 mDarcy. The experiment was conducted under the pressure and temperature conditions that simulate underground environments; pore pressure: 10MPa, temperature: 40 degrees Celsius. The confining pressure selected in this study is 12MPa. The specimen was first saturated with KI aqueous solution (11.5 wt%). The permeability was confirmed using the KI aqueous solution. The upstream pump was prepared at 10.5 MPa for differential pressure of 0.5MPa. The CO2 flooding was carried out until the total fluid injection reaches about 7.6PV (pore volume). Optical fiber measurement and X-ray CT imaging were performed in all experimental steps. In the case of one-phase flow (water only), as soon as the water injection started, the strain profile was completed. And the strain profile was almost constant until the test ended. In the case of two-phase flow (CO2 flooding in water saturated specimen), there was a small strain increase up to CO2 breakthrough and there was a sudden strain increase after the breakthrough. In this study, it was possible to measure the spiral direction strain of 180mm long core specimen. At the same time, we could visualize the process of CO2 flooding by X-ray CT image analysis. It has become possible to measure distortion of a long distance under the ground with a single optical fiber. It reveals that the optical fiber sensing is a potential tool for future CO2 storage industries.