Journal of Earth & Environmental Waste Management
- ISSN: 3065-8799
Viktor I Smirnov, Sudad H Al-Obaidi and Alexander P Galkin
The primary objective of this study is to analyse the impact of dissolving carbon dioxide in oil on the aggregation of asphaltene and the reduction of oil permeability in sandstones. The study considers various options for oil›s interaction with carbon dioxide, both in free volume before injection into a porous medium and directly in the porous medium. Moreover, the study examines the influence of oil composition on the aggregation of asphaltene. This study delves deeper into the impact of dissolved carbon dioxide on the dispersion of the asphaltene in oil by examining how the oil flows in sandstones. Aggregation of asphaltenes in a porous medium can lead to serious problems such as the obstruction of pores and reduction in rock permeability. This can present a challenge when developing wells for carbon dioxide injection, making it difficult to achieve the desired production and oil recovery rates. It has been established that when oil interacts with carbon dioxide in a free volume before injection into a porous medium, there is a decrease in the relative mobility of oil with dissolved carbon dioxide. This is due to an increase in the volume of flowed oil, the concentration of carbon dioxide dissolved in the oil, as well as a decrease in the permeability of sandstone. The experimental results
demonstrate a significant correlation between sandstone permeability and asphaltene aggregate size, indicating that the sizes of these aggregates are comparable to those of small pores. Moreover, it is worth noting that complete flow blockage in sandstones was not observed, even after exposure to oil with dissolved carbon dioxide. It has been proven that the interaction between oil and carbon dioxide within a porous medium leads to the aggregation of asphaltene due to changes in the composition and properties of oil. This phenomenon has been observed during laboratory experiments that involved oil displacement by carbon dioxide rims. As the asphaltene content in the oil composition increases, the formation oil permeability decreases significantly. Moreover, low-permeable formations exhibit a greater decrease in permeability.