Premium Sucker Rods Improve Performance In Demanding Environments By Martín Bühler, Edgardo Lopez, Esteban Oliva and Federico Camara Guillet HOUSTON-Downhole failures in artificial lift systems using sucker rods usually are related to three main component systems: the sucker rod string, the subsurface pump or the production tubing string. Failure can involve one of more of these systems, such as rod-tubing abrasive wear, but the good news is that readily available solutions exist to help producers overcome sucker rod string-related failures in challenging downhole environments. Operating conditions for sucker rods are becoming more aggressive as water and the presence of carbon dioxide and hydrogen sulfide grow. In addition, increased bending loads and tensile stresses require robust mechanical properties. Under the combined effect of those conditions, sucker rod failures can occur mainly because of corrosion fatigue under multiaxial loads. Severe corrosion issues also are observed because of wear corrosion or erosion corrosion phenomena, again as a consequence of those demanding conditions. Shale operations and high volumes of injected water for mature fields have shown increased risk of failures related to corrosion processes. Corrosion fatigue of carbon and low-alloy steels is a complex type of failure and the behavior of the materials is very hard to predict. JUNE 2021 59