Nano-enhanced Oil Recovery using Hybrid Surfactant-Polymer Flooding in Ultra-Low Permeability Carbonate Formations

Project Abstract

Nano-enhanced Oil Recovery (EOR) through a hybrid surfactant-polymer flooding system is investigated to address the challenge of recovering hydrocarbons from ultra-low permeability carbonate formations. The study integrates nanotechnology with conventional chemical EOR techniques to enhance sweep efficiency, reduce interfacial tension, and improve mobility control in tight reservoirs. A multidisciplinary approach combines experimental measurements, pore-scale visualization, core flooding, and numerical simulation to quantify the impact of nano-additives on key parameters such as rock wettability, surface charging, and pore-scale fluid distribution. The nano-enhanced formulation comprises surface-modified nanoparticles designed to stabilize emulsions, alter wettability toward a more water-wet state, and promote favorable dispersion within polymer-viscoelastic networks. The surfactant component targets a reduced interfacial tension (IFT) between oil and aqueous phases, facilitating easier mobilization of trapped oil, while the polymer provides plume shaping and viscosity contrast to mitigate fingering and radial channeling in heterogeneous carbonate rocks. Laboratory investigations evaluate the synergy between nanoparticles, surfactants, and polymers under reservoir-relevant conditions, including high salinity brines, elevated temperature, and brine salinity control challenges. Coreflood experiments are conducted on representative ultra-low permeability carbonate plugs to determine recovery improvements, optimal NP concentration, and the interaction effects among salinity, pH, and rough mineral surfaces. Interfacial rheology and zeta-potential analyses elucidate the mechanisms by which nanomaterials modulate interfacial film stability, adsorption, and colloidal stability, thereby influencing disjoining pressures and film rupture dynamics during oil displacement. High-resolution imaging techniques, such as micro-CT and nuclear magnetic resonance, provide insights into pore-scale displacement patterns, wettability alteration, and oil ganglia mobilization in the presence of hybrid chemistries. A coupled mathematical framework is developed to predict oil recovery performance, incorporating NP-enhanced IFT reduction, altered wettability, polymer-viscosity effects, and relative permeability modifiers. Sensitivity analyses identify critical parameters controlling efficiency, including NP size, surface modification, surfactant structure, and polymer molecular weight. The results demonstrate that nano-enhanced hybrid flooding yields meaningful improvements in ultimate recoverable reserves by expanding wettability alteration windows, stabilizing emulsions to facilitate oil layer detachment, and increasing sweep efficiency through viscosity-mediated flow control. Economic viability is assessed through a techno-economic analysis, considering chemical costs, nanoparticle synthesis, and lifecycle environmental implications. The study also addresses practical deployment challenges such as dispersion stability under reservoir heterogeneity, potential formation damage, and compatibility with existing production infrastructure. The findings contribute to a deeper understanding of synergistic interactions in nano-enabled EOR and offer a scalable framework for translating laboratory successes into field-applicable strategies for carbonate reservoirs with ultra-low permeability, potentially unlocking substantial additional hydrocarbon production while reducing energy intensity and emissions associated with conventional recovery methods.

Project Overview

What This Project Is About

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A straightforward look at using tiny particles and tailored chemicals to push more oil out of very tight carbonate rocks. The project mixes safe, small-scale “nano” particles with a mix of surface-active substances (surfactants) and long-lasting polymers to reduce water’s grip on rock surfaces and lower the pressure needed to move oil. The goal is to improve oil recovery where the rock pores are especially small or complex.

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The Problem It Addresses

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In ultra-tight carbonate rocks, traditional water flooding struggles because oil sticks to the rock and the pathways are tiny. This makes oil recovery low and leaves a lot of oil behind. The project aims to find a practical mix that can mobilize trapped oil and work in these challenging rocks, potentially boosting output and extending field life.

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Objectives of the Project

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1. Explore how nano-particles interact with surfactants and polymers in tight rocks.
2. Test a hybrid formulation that can lower interfacial tension and improve displacement of oil.
3. Evaluate the stability of the formulation under reservoir-like conditions.
4. Assess the potential increase in oil recovery using simple lab models.
5. Identify practical constraints for field application (cost, safety, scalability).

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What You Will Do Step by Step

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1) Review simple literature to understand current methods. 2) Design small lab experiments with tight rock samples. 3) Prepare nano-surfactant-polymer mixtures. 4) Run tests that mimic reservoir conditions (pressure, temperature). 5) Measure how much oil is recovered and how fluids behave. 6) Analyze results with basic statistics. 7) Compare different formulations. 8) Discuss what works best and what needs more work.

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Expected Outcome

A clear, practical formulation concept that shows potential for higher oil recovery in ultra-tight rocks, plus an understanding of how nano-particles help in combination with surfactants and polymers. The work should highlight steps toward field testing and outline any major hurdles to scale up.