In Canatex Completion Sols., Inc. v. Wellmatics, LLC, No. 2024-1466 (Fed. Cir. Nov. 12, 2025), the Federal Circuit reversed a district court decision invalidating claims of Canatex’s U.S. Patent No. 10,794,122 for indefiniteness due to lack of antecedent basis. The patent relates to a two-part downhole tool used in oil and gas wells, where a “first part” remains downhole and a “second part” can be decoupled and retrieved. The disputed claim language referred to “the connection profile of the second part” for lacking antecedent basis. Canatex argued this was an obvious drafting error that should read “the connection profile of the first part.”
The district court rejected this argument, finding the error was not evident. The district court reasoned that the error was carried throughout the independent claims and the specification, suggesting an intentional drafting choice and not an error. For example, the patent drafter may have intended to provide antecedent bases for the “second part.” Moreover, Canatex had not sought to correct the error at the USPTO. Thus, the district court held the claims were indefinite.
On appeal, the Federal Circuit disagreed, determining that intrinsic evidence, including the specification, figures, and claim structure, made the error obvious to a person of ordinary skill in the art. The Federal Circuit explained that the claim language, as written, was nonsensical because it described a component of the second part releasing itself, which contradicted the disclosed invention. The Federal Circuit concluded there was only one reasonable correction: replacing “second” with “first.” Because the error was evident and the correction straightforward, the Federal Circuit reversed the indefiniteness ruling, holding the claims should be judicially corrected.
Author: Matthew Korwin
Edited by April Capati and Craig Drachtman