Francisco Diaz Telli, Daniel Muse, Ezequiel Fernandez and Matias Pereyra, Tenaris Sucker Rods Rita Toscano, Simyteck
Sucker rods connection-related failures represent today one of the main limitations of beam pumping applications. More demanding field operative conditions are pushing connections to their limits, which become thus the weakest link of the system. API Sucker Rods Specifications (11B) haven"t changed much since the 70"s. The fact that stress distribution is poor in current connection together with their tendency to get loose due to the lack of thread interference, are the main causes of stress concentration points which finally lead to failures. After several attempts to come out with a solution to address this problem, a new premium connection was developed. Lab and field tests have shown it is capable of working way over the sucker rod body capacity. Through this revolutionary change we"ve been able to expand the current beam pumping application limits. This paper will show field experience of sucker rods working under very high loads.