Nanofluids as Novel Alternative Smart Fluids for Reservoir Wettability Alteration

Abstract

This chapter presents an account of two metal oxide nanoparticles (zirconium and nickel oxide) on basis of their structure, morphology, crystallinity phases, and their wetting effect on solid-liquid interface. As a preliminary step to sound understanding of process mechanisms; wettability, nanoparticles, and their relations thereof were scrutinized. To investigate the nanofluids wetting inclinations, complex mixtures of the nanoparticles and NaCl brine (ZrO 2 /NaCl; NiO/NaCl) were formulated and their technical feasibility as wetting agents tested via contact angle measurement. The result shows that the nanoparticles exhibit different structural and morphological features and capable of addressing reservoir wettability challenges owing to favorable adsorption behavior on the surface of the calcite which facilitated the wetting changes quantified by contact angle. We believe this study will significantly impact the understanding of wetting at solid-liquid interface which is crucial for recovery process optimization.

Low-Salinity Surfactant Nanofluid Formulations for Wettability Alteration of Sandstone: Role of the SiO2 Nanoparticle Concentration and Divalent Cation/SO42– Ratio

“…Because the pH of the solutions (using NaOH) is high, we observe that the ratio of divalent/monovalent cations for all of the solutions is negligible. Surfactant-augmented nanofluids proved to be a strong wettability modifier for reservoir rock representative samples − ,,− as a result of co-adsorption of nanoaggregates over the surface of the rock; thus, this work is of further interest to low-salinity cases in sandstone core plugs. Therefore, in the present work, the aqueous solution [high-pH, low-salinity surfactant solutions (LSS)], which showed the maximum average surfactant adsorption on the clay, was chosen for the imbibition process with varying SNP concentrations (wt %), i.e., LSS1 + 0% SNP, LSS1 + 0.1% SNP, and LSS1 + 0.2% SNP.…”