In this study, for the first time an effort is made to examine the effect of surfactant hydrophobicity on the synthesis of lanthanideseries nanoparticles inside the core of reverse micelles.Tween...

Improving water-based drilling fluid properties to mitigate instability issues at elevated temperatures is the need of the hour. In this study, industrially prepared silica nanoparticles (NPs) coated with AEAPTS ([3-(2-Aminoethylamino) propyl] trimethoxy silane) was used as an additive to enhance the rheology and control filtration of the water-based mud. Silica nanoparticles were coated separately in a two-step process, which involved the addition of a hydroxyl group first and then coating with AEAPTS. To check its applicability in water-based drilling fluids rheological and filtration tests were done with varying NP concentrations of 0.2, 0.3, and 0.4 w/v %. The rheology values of the mud samples were recorded both before and after the thermal aging of mud in the roller oven at 105°C for 16 hours. The filtration test was carried out according to API standards with 100 psi differential pressure for 30 minutes. The silane coating over the silica NPs was confirmed with the shifting in the peaks of the FTIR (Fourier Transform Infrared) spectra of the sample. Both the plastic viscosity (PV) and the apparent viscosity (AV) of the drilling fluid were found to be increasing with silane-coated silica nanoparticles’ inclusion when tested at 30°C and 60°C. The degradation in the rheology of the base mud without nanoparticles after thermal aging was found to be around 60 % which was reduced to around 20 % with the addition of the coated silica nanoparticle. Also, a remarkable reduction in the filtrate volume, when compared with base mud, was achieved with the addition of the silane coated NP in the mud. The results show that the novel AEAPT silane-coated silica NPs can be used as a rheology modifier and filtration control additive in water-based drilling fluid for high-temperature drilling applications.

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Graphene as surfactant carrier material for EOR/IOR is used. Its performance is evaluated through adsorption, desorption, interfacial tension and emulsification studies. Moreover, the kinetic and thermodynamic parameters are identified in order to understand the physicochemical behavior pertaining to its applicability in surfactant flooding. The surfactant carrier, graphene is acquired and its physicochemical behavior is characterized by X-Ray diffraction, Fourier transform infrared spectroscopy, surface area analysis, etc. The uptake capacity of the surfactant is investigated by adsorption and desorption studies at different subsurface conditions. The kinetics of the process are identified to understand the rate and order of the reaction, whereas thermodynamic behavior of the surfactant carrier is evaluated to find its Gibbs free energy, enthalpy, entropy, activation energy, etc. Further, a reduction in interfacial tension and stability of emulsion between crude oil and brine is inspected. The uptake capacity of the surfactant obtained from the adsorption and desorption study confirmed that adequate quantities of surfactant can be transported into the deep subsurface with minimal loss. This infers the requirement of surfactant in lesser quantity when compared to surfactants without any nanocarrier. Similarly, a reduction in interfacial tension and increase in emulsion stability is expected to be increased. Furthermore, graphene shows a remarkable change in hydrophobicity with a change in pH and salinity which indicates that the properties can be suitably tailored as per requirement, making it a good candidate for surfactant EOR/IOR. Also, the obtained thermodynamic data suggest endothermic and spontaneous adsorption behavior, which may be a favorable phenomenon when subjected to the higher subsurface temperature. Graphene as a surfactant carrier and its performance is investigated for the first time rendering it unique for EOR/IOR applicability studies.