We are reporting the synthesis of a novel nanofluid (NF) via encapsulating superparamagnetic iron oxide nanoparticles (SPIONs) into nanosurfactant (NS), using a low-cost and simple method. This NF is designed to enhance the oil recovery at lower concentrations and reduced cost comparing to the conventional chemical flooding. In this work, two different sizes of SPIONs were encapsulated into NS. For that, 5 and 10 nm SPIONs in toluene were mixed in variable ratios with petroleum sulfonate and further formulated into the reservoir conditions stable NF. The colloidal stability in the reservoir conditions was characterized by incubating the NF samples in an oven at 100 <sup>0</sup>C for an extended period and in the presence of 6 wt% saline brine. The NF formulations impact on the interfacial tension (IFT) was measured using spinning drop tensiometer. Encapsulation of SPIONs was confirmed by the cryo transmission electron microscopy (cryo-TEM). Notably, all the formulations exhibited remarkable colloidal stability at high temperature and high salinity aqueous conditions over a year. The IFT measurements indicated a significant reduction in the IFT (0.001-0.005 mN/m) compared to the NS sample alone (0.02 mN/m). Plausibly, the synergy between SPIONs and the NS reduces the IFT by more than two orders of magnitude comparing to NS alone. These results are encouraging and will be further studied, including encapsulation of different nanoparticles to generate a library of smart NFs to support versatile upstream applications.

Superparamagnetic iron oxide nanoparticles (SPIONs) encapsulated nanofluids for EOR applications

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.