Fe₃O₄ Nanoparticles as Surfactant Carriers for Enhanced Oil Recovery and Scale Prevention

Abstract

The growing demand for petroleum products and the natural decline of well’s pressure during oil production turned the oil industry’s focus onto the development and improvement of enhanced oil recovery (EOR) techniques. Nanotechnology and nanomaterials may increase oil recovery rates through nanofluid flooding applications. In this scenario, a nanofluid containing Fe3O4 nanoparticles (NPs) with the ability to carry surfactants such as cetyltrimethylammonium bromide (CTAB) was synthesized; a synergistic effect was observed when used for wettability modification of calcite fragments, reaching 80% of contact angle reduction. Raman and XPS analysis revealed that Fe3O4 NPs were able to selectively remove smaller and more disordered asphaltene molecules that present a less planar aromatic core, as indicated by the D/G Raman peaks intensity ratio and consequently weaker adsorption on the calcite surface. The presence of CTAB improved nanoparticle mobility in limestone porous medium during flooding experiments and its stability in saline solutions with high concentrations of divalent cations, while the presence of nanoparticles improved the wettability modification. Furthermore, the nanofluid can slow down CaCO3 scale formation, contributing to the flow assurance during the nanoflooding process. These combined effects improve nanofluid efficiency in tertiary oil recovery as observed during the flooding tests in an unconsolidated porous medium, giving a recovery factor up to 60%.

Hyperbranched polyglycerols derivatives as cetyltrimethylammonium bromide nanocarriers on enhanced oil recovery processes

“…Caplan et al 11 have achieved a recovery factor around 46% when used a polymeric nanoparticle as a non‐ionic surfactant carrier in sand reservoirs. On the other hand, when CTAB was carried out with Fe 3 O 4 nanoparticles in limestone unconsolidated porous media, the recovery factor after EOR was about 60% 12 . Thus, the hyperbranched polymer has shown to be a more efficient carrier than the other ones.…”

“…Other strategies such as alkalis, ammonia, ionic liquids, and sacrificial agents have also been used to reduce surfactant retention 5 . Another approach is to employ surfactant carriers to reduce surfactant losses by adsorption on rock surfaces 6–12 …”

“…Pereira et al studied the ability of Fe 3 O 4 nanoparticles (NPs) to carry CTAB and observed a synergistic effect when the system was used for the wettability modification of calcite fragments. This system promoted an increase of oil recovery of 12.8% when compared to the secondary recovery and the total oil recovery of approximately 60% 12 . Although some nanoparticles can act as surfactant carriers, reduce W/O IFT, and promote changes in the rock wettability, turning them water wet, they can present low stability in a high saline environment, which could lead to particle aggregation, causing pore obstruction and possibly formation damage 13 …”

“…Our experience with previous systems 7–12 allows us to describe the necessary qualities for a specific material to perform as a surfactant carrier. The material must be or present the following characteristics: The carrier must be able to interact with the surfactant molecule; These interactions must be stronger than the interactions of the surfactant molecule with the transport medium, the water; The complexes formed must be small enough to permeate through the rock's pores; These interactions must be weaker than the interaction of the surfactant with the delivery site, the water/oil interface; The carrier must be able to release the surfactant only at the site of interest. …”

Carbon-coated Fe3O4core–shell super-paramagnetic nanoparticle-based ferrofluid for heat transfer applications

“…Vol.% of NPs. The results suggest coagulation/agglomeration behavior for Fe 3 O 4 NPs based ferrofluids (zeta potential < ±5) leading to network formation, whereas, Fe 3 O 4 @C NPs based ferrofluids show moderate stability (±10 < zeta potential < ±30) [56,57]. The increase in stability of NPs or good dispersibility into base fluid is generally observed for core-shell NPs [58,59].…”