Enhancements in the tribological performance of environmentally friendly water-based drilling fluids using additives

Abstract

Since their introduction in the 1960s, oil-based drilling fluids or muds (OBM) have been applied as drilling fluids in oil & gas exploration activities. However, they cause potential issues, such as contaminating immediate areas of freshwater aquifers around the well site, and causing permanent damage to the environment during the disposal of cuttings. In an effort to seek promising environmentally-friendly alternative drilling fluids with competitive or even better drilling performance than OBM, this paper investigates the tribological performance of potassium chloride polymer water-based muds (WBM) and artificial sea water (KCl brine), and comparing them with a reference OBM. To improve the OBM tribological attributes, select additives are adopted and added individually into the above-mentioned muds. Test results show that the tribological performance of both WBM and KCl brine could be drastically improved to levels equal or better than the widely-used OBM with the addition of a low percentage of certain friction-modifying additives. Chemical characterization showed the formation of an effective FeCl2/Fe3O4 tribofilm, which is the main reason for the significant enhancement.