Investigation of chia based copper oxide nanofluid for water based drilling fluid: An experimental approach

Drilling operations in oil and gas industry are associated with issues such as pipe sticking, poor wellbore cleaning and high fluid loss. Mitigation of such problems in water-based drilling mud (WBM) necessitates the application of nanotechnology in improving their filtration and rheological characteristics. In the present work, an attempt has been made to analyze the effect of nanofluid prepared using copper oxide (CuO) nanoparticles (NPs) dispersed in chia seed solution on WBM characteristics. Therefore, three samples of chia seed based nanofluids are synthesized using two-step method by varying the concentration of CuO nanoparticle from 0.2 wt% to 0.6 wt%. The resulting nanofluids are then mixed with WBM to prepare Nanofluid enhanced Water based Drilling Mud (NFWBM). The synthesized nanofluids are then characterized for their stability and thermal decomposition respectively using Scanning Electron Microscope (SEM) and Thermo-Gravimetric Analyzer (TGA). The NFWBMs are then analyzed for rheological and filtrate-loss properties at different temperatures of 30 °C, 50 °C, 70 °C and 90 °C. The hot roll aging process is carried out at 90 °C for 16 h maintaining the pressure at 0.1 MPa. The analysis projected a significant enhancement in the thermal stability of the WBM, with a reduction in viscosity of about 61.7% at 90 °C, which is critically observed to recover back to a significant extent of about 14% for chia based 0.4 wt% CuO nanofluid enhanced WBM and 19% for chia based 0.6 wt% CuO nanofluid enhanced WBM. Such improvement is observed in the rheological properties post hot rolling too. Further, the API fluid loss is observed to reduce from 7.2 ml to 6.8 ml, 6 ml, and 4.8 ml, respectively, before hot rolling, while the same reduced from 12.4 ml 11.4 ml, 10.2 ml, and 9.4 ml, respectively, for chia based 0.2 wt%, 0.4 wt%, and 0.6 wt% of CuO nanofluid enhanced water based drilling muds (NFWBMs). The present study aids in the development of novel and green additives for water-based muds to enhance their properties.