Subject Number : S-20-KU-0022
Support Type : Technical support (except the training)
Proposal Title (English) : Potential of Alumina-based Nanofluids for Oil Production
Username (English) : R. Nguele
Affiliation (English) : Kyushu University

1. Summary
The deposition of polyaromatic hydrocarbon (PAH) is one of the main challenges in oil production specifically if the fossil resource is produced by carbon dioxide (CO2) injection. Mitigating the deposition of PAHs not only could enhance the production, but more importantly could ensure the sequestration of CO2. Thus, the primary objective of the research is the prevention of PAH precipitation, with a main focus given to asphaltene. The research uses the versatile properties of nanoparticles to inhibit the aggregation of macromolecules in the oil.
2. Experimental
Asphaltene was extracted from Japanese Heavy crude oil (API 160o) as per the standard procedures. Extracted asphaltene was then dissolved into toluene to prepare an asphaltenic solution of 1000 ppm. Both Zeta-potential and the particle size of the different nanofluids as well as those of the asphaltene solution were measured using a device based on electrophoresis light scatter method using He–Ne laser as the light source (ELS-8000, Otsuka Electronics, Japan)
3. Results and Discussion
Defining the porosity impairment as the different of porosity of sandstone before and after CO2 injection, it was found that neither water or polymer (PVOH) could inhibit the deposition in asphaltene despite the low particle size (Fig. 1). However, adding alumina nanoparticles (Al-NP), the impairment was much lower, which leads to the thought that there is a possibility of using Al-NP as inhibitor.

Fig. 1 Porosity impairment as function of nanofluid average size
4. Others
N/A“.
5. Publication/Presentation
(1) I. Hiroki, R. Nguele, K.N. Nchimi, K. Sasaki (Journal of Petroleum Exploration and Production) Vol. 11 (2021) p.p. 1415-1427.
(2) R. Nguele, K. Sasaki (Colloids and Surfaces A: Physicochemicaland Engineering Aspects) https://doi.org/10.1016/j.colsurfa.2021.126630
6. Patent
N/A”