VALIDATION OF FRICTION COEFFICIENT AND WEAR CONCEPTS IN SUCKER ROD LIFT SYSTEMS

In some of today’s unconventional wells, sucker rod pumping systems are facing challenges related to excessive wear, affecting production and increasing operational costs. One of the reoccurring damages in a sucker rod pumped well occurs near the kick-off point in a deviated well between the coupling and the tubing or between the sucker rod and the tubing; the metal-to-metal contact causes hole-in-tubing failures and operators have been seeking solutions to mitigate or minimize excessive tubing wear in highly deviated wells. Wear caused by both metal contact and abrasive particles, as well as corrosive attack from the wellbore’s fluid also affects the metal integrity of the tubing, coupling and sucker rod. It is beneficial to develop fundamental understanding on wear and friction concepts in rod lift applications, to optimize rod lift product designs and improve Mean Time Between Failures (MTBF) in deviated wells.

In this paper, the concepts of friction and wear will be explained from applied rod lift engineering perspective. Field tested solutions to reduce tubing wear will be presented with lab and field data.