Novel approach to improve shale stability using super-amphiphobic nanoscale materials in water-based drilling fluids and its field application

Abstract In this study, super-amphiphobic nano-silica nanoparticles (SA-NPs) were used to enhance the shale stabilization performance of water-based drilling fluids (WBDFs) by altering surface wettability, preventing capillary self-priming effect, and plugging nano-micro pores shale. The results transmission electron microscopy, particle size distribution, scanning microscopy characterization revealed that SA-NPs exhibited a nanoscale “coalesce” structure, which is composed spherical particles joined together, could form nano-papillary structure on surface. Due presence scale rough structures ultra-low energy components, treated SA-NPS property in contact angle test. Contact angles water hexadecane reached up 154.13° 151.34° after being with SA-NPs, respectively. Furthermore, addition 1% WBDFs reduce linear swelling rate from 40.5 6.0%, increase cuttings recovery percentages 82.5 95.6%, low permeability core 81.25 94.00%, raise high-temperature high-pressure uniaxial compressive strength 3.45 4.87 MPa. Compared polyether amine fumed nano-silica, produced best performance. Based excellent high-performance WBDF was developed applied Dagang Oilfield. During operation? no wellbore instability, sticking, other complex situations occurred. indicate better address issue instability formations have great application prospect well drilling.