Optimization of Enhanced Oil Recovery using Nano-Fluid Assisted Polymer Flooding in Heterogeneous Reservoirs

Project Abstract

The use of nano-fluid assisted polymer flooding (NFPF) is investigated as an enhanced oil recovery (EOR) strategy to optimize sweep efficiency and improve oil production in heterogenous reservoirs characterized by high permeability contrast, wettability heterogeneity, and natural fractures. This study integrates experimental characterization, reservoir-scale simulation, and optimization to quantify the incremental oil recovery, techno-economic viability, and environmental implications of NFPF compared to conventional polymer flooding and nanofluid flooding alone. Nano-fluids composed of functionalized nanoparticles dispersed in aqueous polymer solutions are designed to modify rock-fluid interactions, stabilize displacing fronts, and reduce sub-surface fingering by enhancing mobility control and interfacial properties under reservoir-relevant conditions. A comprehensive laboratory program evaluates rheology, stability, shear-thinning behavior, interfacial tension (IFT) reduction, and core-scale displacement under varying temperature, salinity, hardness, and nanoparticle concentration. The polymer phase provides viscoelasticity for improved sweep, while nanoparticles promote adsorption layer formation, pore-scale bridging, and altered capillary pressures, potentially expanding the displacing efficiency in both high- and low-permeability zones. Upscaling to a pseudo-3D reservoir model with heterogeneity controlled by statistical distributions and fracture networks enables sensitivity analyses on permeability contrast, clay content, capillary number, and injection protocol. Advanced multiphase flow simulations couple non-Newtonian polymer rheology with dynamic nanoparticle transport, adsorption, and aggregation, allowing assessment of injectivity penalties, polymer degradation, and nanoparticle retention along the flow path. The study develops a parametric optimization framework to identify optimal nanoparticle loading, polymer concentration, and injection timing (primary, polymer alone, nanofluid enhanced polymer sequences) that maximize net present value (NPV) while maintaining reservoir safety and conformance. Results indicate that NFPF can achieve higher oil recovery factors than conventional polymer flooding in reservoirs with pronounced heterogeneity by stabilizing the displacing front, reducing early breakthrough, and promoting favorable wettability shifts. The mechanism includes improved mobility ratio, enhanced interfacial rigidity, and localized alteration of pore throat wettability via nanoparticle–polymer association, which collectively suppress viscous fingering and improve conformance. However, trade-offs arise from potential nanoscale retention and increased viscosity that may impact injectivity; these are mitigated through optimized nanoparticle size, surface functionalization, and periodic slugging schemes. The economic assessment demonstrates feasibility under moderate oil price scenarios and outlines risk mitigation strategies related to long-term nanoparticle fate and environmental impact. The research contributes a validated workflow for integrating NFPF into field development plans, offering a practical pathway to unlock additional recoverable reserves in heterogeneous formations while providing guidelines for parameter selection, reservoir monitoring, and performance forecasting.

Project Overview

What This Project Is About

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The project explores ways to move more oil from reservoirs that are hard to drain. It combines tiny liquid additives (nano-fluids) with a gel-like polymer flood to improve how water pushes oil toward production wells, especially when the rock layers are varied and irregular.

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The Problem It Addresses

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Objectives of the Project

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1. Understand the basic concepts of enhanced oil recovery (EOR) and why heterogeneity matters.
2. Investigate how nano-fluid additives interact with polymers in porous rocks.
3. Assess the performance of nano-fluid assisted polymer flooding through simple simulations or lab tests.
4. Identify practical operating conditions and potential cost benefits.

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What You Will Do Step by Step

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Review relevant literature; learn basic reservoir properties; design simple experiments or models to test interactions; run simulations or analyze data; interpret results; and suggest feasible field application steps.

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Expected Outcome

A clear assessment of whether nano-fluid assisted polymer flooding can enhance oil recovery in heterogeneous reservoirs, with practical guidelines for further testing and potential cost and efficiency benefits.