著者

當舎利行

出版者

東京地学協会

雑誌

地学雑誌

巻号頁・発行日

vol.117, no.4, 2008

著者

藤井 孝志 菅井 裕一 佐々木 久郎 橋田 俊之 當舎 利行 中尾 信典

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.129, no.12, pp.701-706, 2013-12-01 (Released:2014-12-01)

参考文献数

17

被引用文献数

1 1

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Understanding of interfacial interactions among supercritical CO2 (scCO2), water, and mineral phase is necessary for a precisely prediction of CO2 migration into aquifers. The purpose of this study is to assess the impact of scCO2 on flow property of Kimachi sandstone and Iidate granite in a CO2 rich dense phase i.e., the condition of which scCO2 is expected to displace formation water in the course of CO2 injection. In this experiment, the permeability test for CO2 gas was conducted before and after a CO2 saturation procedure that is filled with scCO2 in pores of rocks. To investigate a mechanical property of rock specimen in the presence of scCO2, the axial strain was also measured using a laser displacement sensor during scCO2 saturation processes. Our results showed that both Kimachi sandstone and Iidate granite samples tested have a more or less decreasing trend of gas permeability with increasing exposure time to scCO2. It was further shown that the axial strain of Kimachi sandstone and Iidate granite increased as scCO2-exposure time increased. Additionally, increases in masses and dimensions of test samples before and after scCO2 saturation processes were clearly observed under atmospheric pressure conditions. It can, therefore be said that Kimachi sandstone and Iidate granite could be capable of swelling and permeability change accompanied by CO2 sorption into their internal structures in the presence of scCO2. Furthermore, the observed significant reduction in permeability cannot fully be explained by two model predictions based on Kozeney-Carman equation and Hagen-Poiseuille law, considering CO2 sorption onto mineral phases. The present results pointed out that CO2 sorption on rocks under geological CO2 storage conditions could have a significantly impact on flow property of rocks during CO2 injection and storage processes.