More demanding operating conditions, sueh as deeper wells and higher production, are pushing rod pumping artificial lift systems to dieir limits. This trend was demonstrated at Cerro Dragon Field in southern Argentina (Fig. 1), where the operator had increased utilization of secondary recovery and, with it, the total production flow per well. This increase was pushing the fields rod pumping systems to their limits. Rod pin and coupling failures had become common problems in the field, demonstrating that the rod connection is the weakest link in a rod pumping system when working at very high loads, Fig. 2. This means that the fatigue resistance of the connection is inferior to the fatigue resistance of the rod body.
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