Performance Evaluation of Novel Silane Coated Nanoparticles as an Additive for High-Performance Drilling Fluid Applications

Abstract

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.