If You Build a Better Sucker Rod, Will Buyers Be Willing To Change?

Abstract

When the pump breaks down and the oil stops flowing, it’s mostly likely due to a failed sucker rod. “The statistics are pretty strong. While you would think the rod pump or the progressing cavity pump is the component with the most problems, it is the rod string” that is most often to blame, said Lonnie Dunn, vice president for technology at Lifting Solutions. That’s a critical fact for Dunn who works for the biggest maker of what are known as continuous sucker rods. Rather than connecting individual rods into a string long enough to run from the surface to the pump, a single long rod is run into the well like coiled tubing. While he was talking up coiled sucker rods at the SPE Artificial Lift Conference and Exhibition, a competitor at the conference, ChampionX, was announcing a first: a protective anodic coating for its continuous sucker rods that prevents corrosion and reduces the drag when a rod rubs against the surrounding tubing (SPE 209751). Unlike competitors that have relied on coatings that provide a physical barrier, ChampionX’s defense relies on a powdered metal coating that short-circuits electrochemical reactions that can cause rapid corrosion. This is an emerging technology where the key components are long-proven. Continuous rod was patented nearly 50 years ago, and methods using anodic corrosion protection methods have been around even longer with uses ranging from protecting subsea risers to galvanized nails. Still both ideas are new in this slow-changing service sector, where there has been little change in the dimensions of the rods, and key design elements are usually based on API specifications. These companies are among a handful of innovators working to convince operators that a continuous rod is a better choice at a time when wells present more challenges, from wellbores that curve by design or by accident to reservoirs producing increasingly corrosive fluids. It has been a slow change because “sucker rods have been around a long time and the product and servicing practices are well established whereas continuous rod, especially on the servicing side, represents a significant change,” Dunn said. While there are advantages, from faster running times to reduced failures, when it comes to this long-established oilfield commodity, he suspects some customers assume “everything that can be done is done.” Continuous rods eliminate the time required to make the hundreds of connections needed to make up a rod string. The risk of connection failures is reduced by replacing multiple rods with a long rod requiring connections only at the pumping unit on the surface and the pump downhole. To back up the promise of more-durable rods, the companies in this sector are adding corrosion-resistant coatings. “The general consensus is that the wells are going to get more and more corrosive, and the industry will be going after oil and gas in harsher conditions,” said Alex Perri, product line director for ChampionX.