Interfacial Friction Evolution in an Oil-Based Drilling Fluid Environment: An Atomic Understanding from ReaxFF Simulations

This paper investigates the evolutionary behavior of interfacial friction in the oil-based drilling fluid environment using ReaxFF molecular dynamics simulations. The analysis of friction and wear at the contact interface shows that the essence of friction and wear is the change of atomic crystal structure caused by mechanical forces. The lubricating effect of oil-based drilling fluid prevents shear deformation between the contact interfaces, thus keeping the friction stable. The analysis of the motion of the molecules of the oil-based drilling fluid and the friction chemistry further shows that the reduction of friction is attributed to hydrodynamic lubrication of the oil-based drilling fluid molecules and passivation of a large number of H-2 and a small number of H atoms generated by the friction chemistry. In addition, the study of temperature changes during sliding shows that oil-based drilling fluids can absorb high temperatures at the friction interface, reducing the risk of high temperature damage to the friction pair during sliding. The related research results provide a theoretical basis for the friction and wear behavior in oil-based drilling fluid environments at the molecular level.