Effect of Boron nitride (BN) and surface modified BN on the properties of laboratory water-based drilling fluid formulated in Duovis/XG polymers: Experimental and Simulation studies.

Abstract

Properly designed drilling fluid is one of the key factors for efficient and safe drilling operations. Oil-based muds (OBMs) are more extensively used to drill in deeper and harsher environments, where the fluid stability and properties are of major importance. However, economic and environmental considerations limit competitiveness of OBMs. Consequently, there is a current demand to customize the properties of water-based mud by introducing innovative additives. Due to unique mechanical, chemical, thermal and tribological features, nanoparticles revolutionized the number of conventional technologies of energy industries including Petroleum industry. Among other contributions to the upstream domain, the nano-sized particles can enhance drilling fluid properties and hence reduce problems associated with excessive torque and drag, insufficient hole cleaning, borehole instability and fluid loss. The thesis evaluates the performance of micro-sized (150-300nm) Boron nitride (BN) particles in the laboratory formulated WBM. The effect of mentioned additives on the drilling fluid was examined in the dry state as well as in oil grafted condition and coupled with oil lubricant. Results obtained from the experimental and simulation investigation are highlighted as:  0.03 wt.% of dry BN reduced the coefficient of friction (CoF) of Duovis-based fluid by 24%.  0.2 wt.% of grafted BN reduced CoF of Xanthan Gum (XG)-based fluid by 44%.  0.3 wt. % of BN along with a lubricant reduced the CoF of XG-based fluid by 54%.  0.3 wt.% of BN along with a lubricant improved the lubricity of the Duovis-based fluid containing 0.02 wt.% of MWCNT-OH by 53%.  Grafted BN and BN along with a lubricant increased the plastic viscosity.  BN along with a lubricant at the concentration of 0.3 wt.% reduced filtrate volume by 12%.  Sonication had an adverse effect on the lubricating properties of nanofluids.  High pH yielded lower coefficient of friction of the nanofluids.  The addition of 0.3 wt.% of dry BN in the Duovis-based fluid reduced the pressure loss in circulating loop by average 32%.  The addition of 0.3 wt.% of BN along with a lubricant in XG-based fluid allowed to extend the well length by 18%.  The addition of 0.2 wt.% of grafted BN Duovis-based fluid decreased the flow rate required for cuttings carriage in the horizontal section by 31%.