Sulfonated Polystyrene Nanoparticles as Oleic Acid Diethanolamide Surfactant Nanocarriers for Enhanced Oil Recovery Processes

Abstract

The aim of this study is the evaluation of partially sulfonated polystyrene nanoparticles (SPSNP) efficiency as nanocarriers for a non-ionic surfactant, oleic acid diethanolamide (OADA), in the reduction of the surfactant losses and the increase of oil recovery. The synthesized oleic acid diethanolamide was characterized by FTIR, 1H NMR, 13C NMR, surface tension (γ = 36.6 mN·m−1, CMC = 3.13 × 10−4 M) and interfacial tension of mineral oil/OADA aqueous solutions (IFTeq = 0.07 mN·m−1). The nanoparticles (SPSNP) were obtained by emulsion polymerization of styrene, DVB and sodium 4-styrenesulfonate (St-S) in the presence of OADA aqueous solution and were characterized by FTIR and PCS. The results show that the presence of ionic groups in the polymer structure promoted a better nanoparticles suspensions′ stability, smaller particles production and more pronounced IFT reduction. The SPSNP obtained with an OADA concentration twenty times its CMC and 0.012 mol % of St-S presented a particle size around 66 nm and can act as efficient nanocarriers decreasing the water/oil interfacial tension to low values (0.07 mN·m−1) along the time, when in contact with the oil. Transport and oil recovery tests of the nanocarriers systems in an unconsolidated sand porous medium test show that the SPSNP do inhibit surfactant adsorption onto sand particles surface and induced an increase of oil recovery of up to about 13% relative to the water flooding oil recovery, probably due to a synergistic effect between the nanoparticles and surfactant action at the water/oil interface.

Surface functionalized Fe3O4‐polyacrylamide dispersion for improved oil recovery at harsh conditions

“…Their potentiality has been proved in MRI and is also considered applicable in oilfield applications for reservoir imaging 23 and chemical EOR purposes 17,43 . However, the harsh conditions, i.e., reservoir temperature up to 120°C and pressure up to a few hundred bars with high salinity content, could significantly reduce NPs potentials, in addition to their strong tendency to be adsorbed onto mineral surfaces 43‐45 . Under such harsh conditions, the stability of NPs is reduced with the formation of aggregations and agglomerations, which may pose possible formation damage due to pore obstruction 25,46,47 .…”

“…Khalil et al used different polymers and organic acids as surface modifiers for different NPs types 15 . Depending on the particle nature, these modifications can occur by forming coordination interactions in various functional groups such as phospholic acid, carboxiclic acid, thiols, phosphonic acid, alcohols, silanes, and amines 45,49‐51 . However, these studies have not investigated the stability of the prepared fluids under harsh conditions such as high temperature and high salinity (HT‐HS), which are considered the most significant contributors to NPs aggregation and agglomeration during EOR.…”

“…17,43 However, the harsh conditions, i.e., reservoir temperature up to 120 C and pressure up to a few hundred bars with high salinity content, could significantly reduce NPs potentials, in addition to their strong tendency to be adsorbed onto mineral surfaces. [43][44][45] Under such harsh conditions, the stability of NPs is reduced with the formation of aggregations and agglomerations, which may pose possible formation damage due to pore obstruction. 25,46,47 For instance, Izadi and coworkers observed an increased pressure gradient for core flooding analysis with Fe 3 O 4 because of the pore blockage by particle precipitation and aggregation.…”

Fe3O4 Nanoparticles as Surfactant Carriers for Enhanced Oil Recovery and Scale Prevention

“…In general, the use of surfactant-coated nanoparticles can bring better results in EOR application when compared with the use of surfactants itself. They are responsible for performing specific tasks such as surfactant controlled delivery at the oil–water interface changing the interfacial tension (IFT) and the rock wettability, optimizing the oil recovery process. − Nanoparticles efficiency as EOR agent is directly related to their flow through the porous reservoir media, determined by the nanoparticle size/pore size ratio. Thus, the size of pore throats must be significant, or the nanoparticles must be small enough to ensure the nanofluid flow inside the reservoir.…”