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_ A privately held exploration and production (E&P) company operating in the Denver-Julesburg (DJ) Basin was facing difficulties boosting production from its mature wells as the basin’s gas-to-oil ratio (GOR) trended higher. Part of the E&P company’s challenge was inherent in the economics of maximizing the efficiency of mature wells on artificial lift. Once a well reaches a stage of steep production declines, investing in expensive stimulation techniques or equipment rarely makes financial sense. More modest investments, such as installing a simple gas separator, can also be largely futile if the well also uses a standard tubing anchor catcher (TAC) above the pump, as many of the region’s wells do. For more than a decade, it has been recognized that traditional B2-style TACs can create a chokepoint within the well because the annular space between the anchor’s outside diameter (OD) and the internal diameter (ID) of the casing is so small (URTeC 1918491). In many cases, the chokepoint invites plugging, traps formation gas, and creates a significant pressure drop within the well, accelerating the formation of scale. Possible Solutions, Unique Circumstances While slim-style TACs have proven very effective at allowing formation gas to flow around the anchor and up the annulus of a well without disrupting production, situations may arise where a TAC with a reduced ID is not compatible with a company’s preferred well design. For example, factors such as excess sand or regional preferences can influence the specific downhole placement of a tubing anchor. In the case of these mature wells with 5.5-in. OD, the operator chose 2⅞-in. tubing to accommodate a large pump and required that the TAC be placed above the seat nipple with the pump running through it. With a 2-in. ID, a 5.5-in. “slim” TAC can be set above or below the pump with 2⅜-in. tubing, but only below the pump when 2⅞-in. tubing is used. That meant this operator had to use a standard B2-style TAC in its wells, which in turn led to struggles with gas interference and plugging. The E&P company wanted to find a solution that could meet the design requirements of its wells while also promoting better flow-by to minimize the risk of gas locking. A Slim Anchor With a Fullbore ID Working with the technology developer, the production company chose to test a new TAC system. The anchor leverages a novel design that allows it to provide significantly more flow-by area around the anchor while still maintaining an ID large enough to allow rod pumps designed for 2⅞-in. tubing to pass through it. If successful, the new TAC would help to mitigate gas interference and increase production across three mature wells while meeting the requirement to be placed above the seat nipple. Three prototype anchors were manufactured and shipped to the production company via an oilfield equipment supplier in September 2024. By mid-November, all three TACs were downhole and in production. Each was set above the seat nipple with the pump running through it.