Experimental Investigation of Polymer-Coated Silica Nanoparticles for Enhanced Oil Recovery.

Alberto Bila,Jan Åge Stensen,Ole Torsæter

doi:10.3390/nano9060822

Alberto Bila, Jan Åge Stensen + Show 1 more

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https://doi.org/10.3390/nano9060822

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Abstract

Recently, polymer-coated nanoparticles were proposed for enhanced oil recovery (EOR) due to their improved properties such as solubility, stability, stabilization of emulsions and low particle retention on the rock surface. This work investigated the potential of various polymer-coated silica nanoparticles (PSiNPs) as additives to the injection seawater for oil recovery. Secondary and tertiary core flooding experiments were carried out with neutral-wet Berea sandstone at ambient conditions. Oil recovery parameters of nanoparticles such as interfacial tension (IFT) reduction, wettability alteration and log-jamming effect were investigated. Crude oil from the North Sea field was used. The concentrated solutions of PSiNPs were diluted to 0.1 wt % in synthetic seawater. Experimental results show that PSiNPs can improve water flood oil recovery efficiency. Secondary recoveries of nanofluid ranged from 60% to 72% of original oil in place (OOIP) compared to 56% OOIP achieved by reference water flood. In tertiary recovery mode, the incremental oil recovery varied from 2.6% to 5.2% OOIP. The IFT between oil and water was reduced in the presence of PSiNPs from 10.6 to 2.5–6.8 mN/m, which had minor effect on EOR. Permeability measurements indicated negligible particle retention within the core, consistent with the low differential pressure observed throughout nanofluid flooding. Amott–Harvey tests indicated wettability alteration from neutral- to water-wet condition. The overall findings suggest that PSiNPs have more potential as secondary EOR agents than tertiary agents, and the main recovery mechanism was found to be wettability alteration.

Highlights

The production rates of existing oil fields are declining and the frequency of new explorations has become scarce
The interfacial tension (IFT) between crude oil and each nanofluid with a concentration of 0.1 wt % was measured values were measured using pendant drop method
This work investigated the effect of polymer-coated silica (PSiNPs) nanoparticles as additives to seawater injection for enhancing oil recovery in neutral-wet Berea sandstone rocks

Summary

Introduction

The production rates of existing oil fields are declining and the frequency of new explorations has become scarce. The significance of enhanced oil recovery (EOR) techniques is highly understood by oil companies [1,2] In this regard, nanoparticles (NPs) have been researched as additives to improve water flooding oil recovery. The small size (1–100 nm) of the nanoparticles and large surface area-to-volume ratio increase the particle mobility and surface activity, at elevated temperature, which contribute to alter the fluid–rock interface properties [2,3,4]. This makes the NPs appropriate for oil production. Silica NPs are the most studied nano-materials for EOR-applications [7,8,9,10], as they are the most abundant compounds on

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