Carbon Nanotubes as a Multifunctional additive and its Impact in Oil Based Mud System drilling Hydraulics

Abstract

The drilling fluids should exhibit shear thinning characteristics to have less resistance at high shear rates. Nanoparticles can enhance the rheological properties of drilling fluids using different mechanisms. Nanomaterials are engineered materials with at least one dimension in the range of 1–100 nm. Carbon nanotubes were chosen in this study due to their unique physio-chemical properties, thus, a good candidate for smart oil based mud formulation. This study investigates the multifunctional ability of carbon nanotubes in oil based mud system and its impact on the drilling hydraulics. Application of carbon nanoparticles in literature have mostly been on water based mud systems and mostly at weight less than 2 g. Effect of carbon nanotubes on flow properties of oil based mud systems within the range of 1 to 3 g weight was analysed. The result shows that the carbon nanotubes improved the flow properties of the formulated oil based mud systems into an acceptable and desirable range required for optimal hole cleaning. The flow behaviour index (n) for the oil based mud systems for drilling hydraulics calculations were between zero and one, thus, they behaved like pseudo plastic fluids (Non-Newtonian fluids) both in the drill pipe and the annulus. It was also observed that, there was increase in the ratio of flow behaviour index to consistency index (n/K) and this will help reduce cuttings bed height in the wellbore.