NCS Multistage Inc. v. Nine Energy Service, Inc. — Claim-Construction Error and Prior Art Require a New Patent Trial

Background

NCS Multistage asserted U.S. Patent No. 10,465,445, which covers a flotation tool that helps operators move a long casing string into an oil or gas well. A Western District of Texas jury found that Nine Energy’s BreakThru device infringed, rejected Nine’s invalidity defenses, and awarded damages.

The appeal centered on the meaning of claim language describing a tool used with a “casing string,” as well as an earlier TCO device sold to and used by Apache. Nine argued that the district court’s construction improperly inserted a size limitation and prevented the jury from evaluating material prior art under the correct claim scope.

The Court’s Holding

The Federal Circuit vacated the infringement judgment. It concluded that the district court’s treatment of “casing string” improperly narrowed the claims by tying the term to a particular internal-diameter requirement. The intrinsic evidence did not justify using that limitation to define the casing string itself, and the error affected the infringement presentation at trial.

The court separately held that the TDP-PO tool sold to Apache in August 2012, and Apache’s use of it, qualified as prior art. Disclosure to a commercial customer was not the sort of private communication that keeps an invention from the public for patent-law purposes. With both the claim construction and the prior-art framework corrected, the existing no-invalidity verdict could not stand.

Because NCS had additional invalidity responses that were not shown legally insufficient, the court did not enter judgment of invalidity. It ordered a new trial instead. The damages award fell with the infringement judgment. The panel did, however, uphold the district court’s exclusion of separate Maersk-related documents disclosed only two days before fact discovery closed, finding no abuse of discretion given Nine’s lack of diligence.

Key Takeaways

• Courts may not import a dimensional limitation into a familiar claim term unless the patent’s intrinsic evidence supports doing so.
• A pre-critical-date sale and customer use can create prior art even when the transaction does not broadly disclose every detail to the public.
• Correcting one invalidity issue does not automatically justify judgment as a matter of law when other fact-dependent defenses remain for a jury.
• Late-produced evidence can still be excluded even if it arrives before the formal discovery cutoff.

Why It Matters

The ruling resets a patent verdict covering specialized well-completion equipment and illustrates how claim construction can reshape both infringement and validity at once. Patent litigants should test proposed constructions against every asserted theory early, because a narrowing instruction may hide prior art as well as alter the infringement comparison.

The decision also underscores the practical importance of third-party discovery. A potentially valuable prior-art trail does not excuse waiting until the end of discovery to pursue documents from a known source.