Wear of couplings with oilfield tubing

Sucker rod couplings and tubings in a non-vertical oil well are subjected to severe wear as they interact during the cyclic pumping operation. This wear can become excessive in sand environments. Worn couplings and rods can be relatively easily replaced during shutdowns, but tubing is very costly to replace. Therefore, it is important to minimize the wear of these components by choosing a suitable coupling/tubing sliding combination.;A wear testing apparatus was designed in the laboratory to evaluate the wear of couplings and tubing under simulated operating conditions. With this apparatus it was found that the ceramic coated coupling (TiO...