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Experimental Study on the Distribution Characteristics of $CO_{2}$ in Methane Hydrate-Bearing Sediment during $CH_{4}/CO_{2}$ Replacement
Content Provider | MDPI |
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Author | Sun, Jianye Hao, Xiluo Li, Chengfeng Wu, Nengyou Chen, Qiang Liu, Changling Li, Yanlong Meng, Qingguo Huang, Li Bu, Qingtao |
Copyright Year | 2022 |
Description | $CH_{4}/CO_{2}$ replacement is of great significance for the exploitation of natural gas hydrate resources and $CO_{2}$ storage. The feasibility of this method relies on our understanding of the $CH_{4}/CO_{2}$ replacement efficiency and mechanism. In this study, $CH_{4}/CO_{2}$ replacement experiments were carried out to study the distribution characteristics of $CH_{4}$ and $CO_{2}$ in hydrate-bearing sediments during and after replacement. Similar to previously reported data, our experiments also implied that the $CH_{4}/CO_{2}$ replacement process could be divided into two stages: fast reaction and slow reaction, representing $CH_{4}/CO_{2}$ replacement in the hydrate-gas interface and bidirectional $CH_{4}/CO_{2}$ diffusion caused replacement, respectively. After replacement, the $CO_{2}$ content gradually decreased, and the methane content gradually increased with the increase of sediment depth. Higher replacement percentage can be achieved with higher replacement temperature and lower initial saturation of methane hydrate. Based on the calculation of $CO_{2}$ consumption amounts, it was found that the replacement mainly took place in the fast reaction stage while the formation of $CO_{2}$ hydrate by gaseous $CO_{2}$ and water almost runs through the whole experimental process. Thus, the pore scale $CH_{4}/CO_{2}$ replacement process in sediments can be summarized in the following steps: $CO_{2}$ injection, $CO_{2}$ diffusing into sedimentary layer, occurrence of $CH_{4}/CO_{2}$ replacement and $CO_{2}$ hydrate formation, wrapping of methane hydrate by mixed $CH_{4}-CO_{2}$ hydrate, continuous $CO_{2}$ hydrate formation, and almost stagnant $CH_{4}/CO_{2}$ replacement. |
Starting Page | 5634 |
e-ISSN | 19961073 |
DOI | 10.3390/en15155634 |
Journal | Energies |
Issue Number | 15 |
Volume Number | 15 |
Language | English |
Publisher | MDPI |
Publisher Date | 2022-08-03 |
Access Restriction | Open |
Subject Keyword | Energies Petroleum Engineering Ch4/co2 Replacement Gas Hydrate Distribution Characteristics |
Content Type | Text |
Resource Type | Article |