Garrett Best, Steven Reedy, Calvin Stewart and Steve Gault
OXY USA, Inc.
In 2016, a recommendation was made in EOR to begin utilizing Grade “C” when replacing rods in San Andres wells or wells less than 5,000’ deep. The advantage of the Grade “C” rods believed to be better corrosion resistance, tubing leak reduction, and lower material cost. It was also recommended that “T” coupling be considered as an alternative to Spray Metal (“SM”) couplings as they are softer and should fail preferentially to the tubing. As with any technology that is new to the field in question there is concern about wide spread use until sufficient data is gathered on a smaller subset of wells to prove up the concept. As failure frequency is a key metric when evaluating artificial lift performance, and it can take several years to develop sufficient data, an analysis method needed to be utilized to track the equipment performance over a shorter duration so that use can be expanded as early as possible. This was accomplished by developing statistical data for sucker rod and coupling installations and failures over a specific time period comparing the failure rate of the “C” rods and “T” couplings versus the “KD” rods and “SM” couplings that are typically run. The analysis showed that the “C” grade rods and “SM” couplings were not showing an increased failure rate and therefore provided support to start expanding their use in EOR, which should result in significant cost savings. To further understand the corrosion differences between C-Rods and KD-Rods corrosion coupons were constructed from sections of actual rods and placed in several wells of varying characteristics. This paper will also present the findings from this corrosion test, which is currently nearing completion.