Uneven wear behavior of downhole tool clearance material under slurry erosion

Abstract

Slurry erosion of clearance fits is one of the primary reasons for the decline in the performance of downhole tools. In this study, slurry erosion experiments and computational fluid dynamics simulations were performed to understand the effect of particle impact velocity as well as the erosion mechanisms on the surface of 38CrMoAlA steel. The results indicated that uneven erosive wear occurred along the flow direction on the surface of clearance material. The uneven erosive wear can be attributed to the variation of particle impact angle affected by fluid streamlines. The site and the area of the most severe erosion changed arising from the particle impact velocity. The failure of the clearance material was mainly due to the aggravation of localized erosion wear. To extend the service life of downhole tools, the region downstream of the clearance inlet (10 mm from the inlet) should be prioritized.