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.

A significant quantity of hydrocarbons remains in the reservoir after production using primary and secondary techniques. Traditional recovery techniques produce about 33 % of the original oil in place. However, the utilization of chemicals such as surfactants and polymers facilitate the additional recovery of one‐third of this oil. Researchers are currently aiming at mixing surfactant and nanoparticles for their potential applications in petroleum industry. In this work, authors claimed to be the first to study usage of synthesized Mesoporous Silica Nanoparticles (MSN) with Sodium Dodecyl Sulphate (SDS) surfactant to understand its applicability in Chemical Enhanced Oil Recovery through evaluation of the surface tension & Interfacial tension, surfactant adsorption, contact angle, and core flooding experiments. Surface tension studies revealed a synergistic interaction between MSN and anionic surfactant molecules. With the introduction of 2500 ppm of anionic surfactant, the surface tension of deionized water reduces to 34.5 mN/m from 72.4 mN/m. The surface tension of the mixture was further lowered by ∼9.8 % with the addition of 300 ppm MSN. The Interfacial Tension results also showed the same trend. When 300 ppm of MSN was introduced, then IFT values decreases from 8.13 mN/m to 3.91 mN/m at 2500 ppm of anionic surfactant. Contact angle measurements after MSN injection went from 77.98° for SDS (2500 ppm) to 73.36°, 66.54°, and 41.95° for 100, 200, and 300 ppm of MSN, respectively. This demonstrates that the shift toward water‐wet behavior increased along with the MSN concentration. Additionally, adding 300 ppm of MSN lowered surfactant adsorption by ∼80 % at a surfactant concentration of 2500 ppm. Up to 72.27 % of the OOIP could be recovered using the chemical slug made of SDS surfactant, polymer, and MSN. The research data suggests that the MSN can increase the effectiveness of the chemical injection approach, which can be used to recover more oil.