Influence of additives on the friction and wear reduction of oil-based drilling fluid

Abstract

Abstract In comparison to conventional vertical hole drilling, extended reach drilling wells with long horizontal section require higher driving torque due to the increased drag on the drill string, drill column, casing and other equipment. This has led to higher friction and wear on the drilling equipment. Friction and wear preventive properties of oil-based drilling fluid is therefore important to keep oil extraction economical and sustainable. The addition of small concentrations of hydrocarbon additives to drilling fluid has shown significant positive effects on these properties. In this study, improvements in friction and wear properties of drilling fluid with the use of friction reduction additives was analyzed using a four-ball experimental configuration. Experiments resulted in wear in boundary and mixed lubrication regimes due to significant metal-metal interaction. The results showed that liquid friction reduction additives with long hydrocarbon tails and high metal affinity polar heads achieved better performance than additives that contained molybdenum dialkyldithiocarbamate. Energy dispersive spectroscopy results indicated lower levels of salts and corrosive chemicals on the surface of the wear scars for the best preforming additives.