Enhanced Oil Recovery (EOR) Using Nanoparticle Dispersions: Underlying Mechanism and Imbibition Experiments

TLDR

The study demonstrates that IIT nanofluid displaces crude oil via structural disjoining pressure in high‑salinity brine, providing direct visual evidence of the mechanism. Imbibition tests show that IIT nanofluid achieves 50 % oil displacement efficiency in Berea sandstone at 55 °C, compared to 17 % with brine alone, and similar performance is observed with a silica‑nanoparticle nanofluid, underscoring its effectiveness in high‑salinity, Ca²⁺/Mg²⁺‑rich reservoirs.

Abstract

This paper presents the results of imbibition tests using a reservoir crude oil and a reservoir brine solution with a high salinity and a suitable nanofluid that displaces crude oil from Berea sandstone (water-wet) and single-glass capillaries. The Illinois Institute of Technology (IIT) nanofluid is specially formulated to survive in a high-salinity environment and is found to result in an efficiency of 50% for Berea sandstone, compared to 17% using the brine alone at a reservoir temperature of 55 °C. We also present a direct visual evidence of the underlying mechanism based on the structural disjoining pressure for the crude oil displacement using IIT nanofluid from the solid substrate in high-salinity brine. These results aid our understanding of the role of the nanofluid in displacing crude oil from the rock, especially in a high-salinity environment containing Ca2+ and Mg2+ ions. Results are also reported using Berea sandstone and a nanofluid containing silica nanoparticles.