Secondary Oil Recovery Using Graphene-Based Amphiphilic Janus Nanosheet Fluid at an Ultralow Concentration

Abstract

Nanofluid of graphene-based amphiphilic Janus nanosheets produced high-efficiency tertiary oil recovery at a very low concentration (0.01 wt %). The more attractive way is to use nanofluid during the secondary oil recovery stage, which can eliminate the tertiary stage and save huge amounts of water, especially at times when the price of oil is low. Here, we continue to report our findings on the application of the same nanosheets in secondary oil recovery, which increased oil recovery efficiency by ≤7.5% at an ultralow concentration (0.005 wt %). Compared with nanofluids of homogeneous nanoparticles, our nanofluid achieved a higher efficiency at a much lower concentration. The nanosize dimension of this two-dimensional carbon material improves transport in rock pores. After single-side surface hydrophobization of oxidized graphene with alkylamine, the partial restoration of the graphitic sp2 network was detected by Raman, ultraviolet–visible, etc. The amphiphilic Janus nature of nanosheets led to their unique behavior at toluene–brine interface. Oil immersion testing clearly showed the change in the shape of the droplet. The three-phase contact angle decreased from 150° to 79°, indicating the change in the wettability of the solid surface from oleophilic to oleophobic. On the basis of the measured three-phase contact angles, the interfacial tension in the presence of the nanosheets was further calculated and was lower than the interfacial tension without the nanosheets. These interfacial phenomena can help residual oil detach from the solid surface, which contributes to the improved oil recovery performance.

Review on the recent progress in the preparation and stability of graphene-based nanofluids

“…Baby and Sundara [97] presented a technique for preparing the copper oxidedecorated graphene-dispersed nanofluids. Firstly, carboxyl Silicone oil Functionalized GNS MHM, then synthesized 0.0-0.07 mass% [130] EG DI NDG-MNT HM, then CVD 0.005-0.03 vol% 0.005-0.02 vol% [131] DW + SUR GNSs SBM 0.05 mass% [132] Kerosene + SUR GNPs SBM 0.005-0.2 mass% [133] DW GNSs SBM 0.003-0.009 mass% [134] DW + SUR GR SBM 0.05-0.15 mass% [192] EG GO MHM 0.1-5 vol% [193] DW Phenyl-sulfonic-functionalized GR SBM 0.02-1 vol% [194] DI GO MHM 0.005-0.01 mass% [195] EG GO MHM 0.01-0.05 mass% [196] DW GNSs SBM 0.003-0.006 mass% [197] DI GNPs SBM 0.025-0.1 mass% [198] DW GNPs SBM 1 mass% [199] DW + SUR GNPs SBM 0.05-0.15 vol% [200] DW GNSs SBM 0.001-0.01 mass% GR graphene, GI graphite, NP nanoparticle, SUR surfactant Then, the functionalized graphene was utilized to decorate the CuO nanoparticles with the help of CuCl 2 and NaBH 4 and NaOH. Baby and Ramaprabhu [98] and Kole and Dey [105] utilized dried GO to produce hydrogen exfoliated graphene in hydrogen at 200 °C.…”

Janus particles: from concepts to environmentally friendly materials and sustainable applications

“…Such sheet-like Janus structures benefit from their rotation restriction, leading to more stable emulsions, and a higher surface-to-volume ratio compared to spherical counterparts. In a following contribution by the same group, the graphene-based amphiphilic Janus nanosheets were applied for secondary oil recovery to eliminate the tertiary stage and save large amounts of water [110]. The Janus nanosheets provided an increased oil recovery by up to 7.5% in a saline environment [110].…”

“…In a following contribution by the same group, the graphene-based amphiphilic Janus nanosheets were applied for secondary oil recovery to eliminate the tertiary stage and save large amounts of water [110]. The Janus nanosheets provided an increased oil recovery by up to 7.5% in a saline environment [110]. Although the efficiency is lower compared to the former publication, this approach benefits from lower concentrations of nanosheets, huge amounts of saved water, and higher oil production rates for fast cost recovery [110].…”

Electrochemical Performance of Free‐Standing and Flexible Graphene and TiO2 Composites with Different Conductive Polymers as Electrodes for Supercapacitors

“…Grapheneo xide (GO) wass ynthesized by using am odified Hummer'sm ethod, the details of whichh ave been reported previously. [18,19] The free-standing andf lexible graphene films were prepared by the reduction process using direct drying and hydriodic acid (HI, 57 %) reduction. The final rGO films were namedG .…”

“…Conductive polymers (CPs) such as polyaniline (PANi), polypyrrole (PPy), and polythiophene( PTh) are quite often chosen in the productiono ff unctionals upercapacitors for their pseudocapacitance and inherently elastic polymericn ature. [17] Wan et al [18] used af acile scale-up process to fabricate ar GO-PPycellulose hybrid paper electrode for as upercapacitor.T he results provedt hat PPy could significantly improve the capacitance and flexibility of the as-prepared composite electrodes. However,t he low chemical stabilityo fC Ps could lead to poor cycling performance during the electrochemical process.…”