The US Court of Appeals for the Federal Circuit reversed a district court ruling that invalidated patent claims for indefiniteness, finding that the disputed language was a minor clerical error. Canatex Completion Solutions, Inc. v. Wellmatics, LLC, et al., Case No. 24-1466 (Fed. Cir. Nov. 12, 2025) (Moore, Prost, Taranto, JJ.)
Canatex sued Wellmatics and several GR Energy entities for infringing its patent directed to a releasable connection for a downhole tool string. The patent covers a two-part device used in oil and gas wells that allows operators to disconnect and retrieve the upper part of the tool string while leaving the lower part in the well if it becomes stuck.
The patent’s claims, abstract, and specification include the phrase “the connection profile of the second part.” During claim construction, the defendants argued that the phrase lacked an antecedent basis, rendering the claims indefinite. Canatex responded that the phrase should have read “the connection profile of the first part” and that a skilled artisan would immediately recognize the error. Canatex asked the district court to construe the phrase accordingly.
The district court disagreed, finding that the “pervasiveness of the error” in both the claims and the specification suggested that the error “was an intentional drafting choice and not an error at all.” The district court added that Canatex’s failure to seek correction from the United States Patent and Trademark Office suggested that the error was neither minor nor evident on the face of the patent. The district court found all asserted claims invalid for indefiniteness. Canatex appealed.
The Federal Circuit reversed. The Court found the error obvious and determined that a skilled artisan would recognize only one reasonable correction, which was changing “second” to “first.” The Court characterized the mistake as a minor clerical or typographical error and rejected arguments that alternative interpretations were plausible. The Court emphasized that its conclusion was consistent with the intrinsic evidence.
