Increase of injection efficiency in geological CO2 sequestration using SDS and SDBS

Carbon dioxide in the atmosphere causes global warming as a greenhouse gas. Therefore, countries around the world are considering underground storage to reduce carbon dioxide. Carbon dioxide underground storage means injection before waste gas filed, oil field, deep saline aquifer and so on. The temperature and pressure conditions of carbon dioxide for underground storage are supercritical, and a reduction in injection efficiency is expected due to high capillary pressure during injection. In this study, considering the high capillary pressure, utilizing anionic surfactants (SDS, SDBS). Thus, the enhancement of carbon dioxide efficiency with surfactant type and concentration was evaluated. In addition, quantitative injection characteristics according to the injection rate of carbon dioxide were analyzed using a micro model.

Experimental results look like follow. Surfactant exhibits higher injection efficiency than water at low carbon dioxide injection rates, and the difference in injection efficiency between water and surfactant decreases as the injection rate increases. However, the differences between the types of surfactants (SDS, SDBS) and concentrations used in this study are relatively modest.

To solve the experimental technology limitations in field use, the pore network model is used. The pore network model has the advantage of effective prediction of carbon dioxide injection efficiency in the future. To validate the Pore network model, constructed network is like the micromodel. As a result, the analysis derived the same tendency as the experiment. In the future expected, the pore network model developed in this study will be able to predict carbon dioxide injection.