Polymer-functionalized silica nanoparticles for improving water flood sweep efficiency in Berea sandstones

Abstract

Extraction of oil trapped after primary and secondary oil production stages still poses many challenges in the oil industry. Therefore, innovative enhanced oil recovery (EOR) technologies are required to run the production more economically. Recent advances suggest renewed application of surfacefunctionalized nanoparticles (NPs) for oil recovery due to improved stability and solubility, stabilization of emulsions, and low retention on porous media. The improved surface properties make the NPs more appropriate to improve microscopic sweep efficiency of water flood compared to bare nanoparticles, especially in challenging reservoirs. However, the EOR mechanisms of NPs are not well understood. This work evaluates the effect of four types of polymer-functionalized silica NPs as additives to the injection water for EOR. The NPs were examined as tertiary recovery agents in water-wet Berea sandstone rocks at 60 °C. The NPs were diluted to 0.1 wt. % in seawater before injection. Crude oil was obtained from North Sea field. The transport of NPs though porous media, as well as nanoparticles interactions with the rock system, were investigated to reveal possible EOR mechanisms. The experimental results showed that functionalized-silica NPs can effectively increase oil recovery in water-flooded reservoirs. The incremental oil recovery was up to 14% of original oil in place (OOIP). Displacement studies suggested that oil recovery was affected by both interfacial tension reduction and wettability modification, however, the microscopic flow diversion due to pore plugging (log-jamming) and the formation of nanoparticle-stabilized emulsions were likely the relevant explanations for the mobilization of residual oil.

Experimental Investigation of Polymer-Coated Silica Nanoparticles for EOR under Harsh Reservoir Conditions of High Temperature and Salinity

“…The authors associated the EOR effect to the NPs’ ability to decrease the injection pressure; the authors argued that displacement pressure decrease is related to the formation of a wedge film between the oil and the rock surface. More recently, Bila et al [ 15 , 16 ], Bila and Torsæter [ 17 ] carried out a series of flooding experiments with polymer-coated SiO NPs in Berea sandstone core plugs. Their studies revealed an incremental recovery ranging from 2.6% to 14% of the OOIP.…”

“…This work aims to expand our previous works [ 15 , 16 ] and attempts to investigate the recovery mechanisms of polymer-coated silica NPs under harsh reservoir conditions of high temperature and salinity. The goal is to provide additional experimental results to the data bank on the nanoparticles for enhanced oil recovery projects, while paving the way to improve our understanding of the underlying EOR mechanisms associated with silica nanoparticles.…”

Enhancing Oil Recovery with Hydrophilic Polymer-Coated Silica Nanoparticles

“…Hendraningrat and Torsaeter [13] used a water-soluble polymer, polyvinylpyrrolidone (PVP), to stabilize silica-based nanofluids and attained an increment of 2% of the OOIP. More recently, a series of flooding experiments using polymer-coated silica NPs dispersed in seawater to 0.1 wt.% was carried out by Bila et al [16] and Bila et al [17]. The authors reported an increase in oil recovery of about 14% of the OOIP in water-wet Berea core plugs and 5% of the OOIP in neutral-wet cores, respectively.…”

Enhancing Oil Recovery with Hydrophilic Polymer-Coated Silica Nanoparticles

“…Their flooding experiments revealed an increment of 2% of the OOIP. A series of flooding experiments for EOR by means of polymer-coated silica NPs dispersed in seawater to 0.1wt.% were recently carried out by Bila, et al [16] and Bila, et al [17]. They reported an increase in oil recovery of about 14% of the OOIP in water-wet Berea core plugs and 5% of the OOIP in neutral-wet cores, respectively.…”