| dc.description.abstract | In comparison to vertical hole drilling, recent explorations of ERD wells and use of horizontal drilling strings has significantly increased the drag and torque as well as wear on the drill string, drill column, casings and other equipment. The friction and wear preventive properties of petroleum mud is therefore very important to keep oil extraction economical and sustainable. Addition of small concentrations of additives to petroleum mud has shown significant positive effect on these properties and is an area of interest in research studies of this industry.
In this study, the improvement in friction and wear preventive properties of mud additives on petroleum mud is analyzed using the Four-Ball machine. There is a total of 23 additives analyzed which included 4 insoluble and 19 soluble additives. The friction tests were carried out on E52100 steel balls, at a temperature of 75 degrees C and were performed at ambient pressure. The machine speed was set at 400 rotations per minutes while a force of 15kg was excreted. These conditions are similar to those of ASTM D4172 with the rpm reduced from 1200 to 400. Experiments with lubricant additives on the Four-Ball machine, at similar conditions, show extensive wear in boundary and mix lubrication (starved lubrication) regimes, signaling significant metal-metal interaction. The literature shows extensive interest in the Utralube II additive. Experiments showed only a 5-8% improvement in the friction and wear preventive properties for this additive. EDS results show that better performing additives had lower levels of salts and corrosive chemicals on the surface of the scar. | |
