Coefficient of Friction (COF) and Wear Ranking of Water-based Muds (WBM) and Oil-based Muds (OBM)

Drilling mud is used to lubricate the drill bit as well as bore hole and tool joints. Lubrication job is a must in order to minimize the friction and wear to the drill string. No reference table of selecting the best composition of drilling mud has been made in past years to study this friction and wear activities on the bore hole and tool joints. By manipulating different kinds of compositions in water-based muds (WBM) and oil-based muds (OBM), the responding variables which are the coefficient of friction (COF) and wear can be tabulated and ranked from the highest to lowest value. In terms of drilling cost, it can reduce the cost of number of drill strings used due to abrasion wear. This study is conducted by using Multispecimen Wear Tester (MWT) which the equipment simulates the rotations of drill string to the wellbore formation. From the findings, calcium chloride is the best additive to reduce the friction and wear activities for WBM and VG Plus is the best additive for OBM. Synthetic and polymer-based muds should be included in future in order to complete the COF and wear ranking of drilling fluids.