IP Law Daily, PATENT—Fed. Cir.: Well-completion technology developer retains contributory-infringement victory but faces validity retrial, (Sep 16, 2026)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

A competing well-tool supplier could not change its claim-construction position or revive unpreserved contributory-infringement arguments on appeal, although a companion ruling required a new validity trial.

An oil-and-gas well-completion technology developer kept its contributory-infringement verdict against a supplier of competing downhole-tool components, despite a partial Federal Circuit win for the supplier. The court vacated only the finding that the asserted patent claims were not invalid and directed a new trial on that issue. It otherwise left the infringement judgment intact, holding that the supplier had forfeited central arguments it sought to make after trial (NCS Multistage Inc. v. TCO Group AS, No. 24-2379 (Fed. Cir. Sep. 14, 2026)).

Separate appeal. NCS Multistage Inc. and NCS Multistage LLC, which develop technology used in oil and gas well completions, asserted U.S. Patent No. 10,465,445 (the ’445 patent) against TCO Group AS, formerly TCO AS. The patent covers a float tool used while casing pipe is positioned in a wellbore.

The claimed tool includes a rupture-disc assembly. The disc seals part of the tool during installation but is designed to open after the casing reaches its intended position, allowing fluid to pass through the casing string.

NCS accused TCO’s TDP-PO tools of infringing claims 28 and 29. A Western District of Texas jury found in NCS’s favor on infringement and validity. Following post-trial proceedings, the district court entered an amended judgment finding that TCO induced and contributorily infringed both claims, that the claims were not invalid, and that NCS was entitled to damages.

The appeal differed from a same-day precedential decision involving the same patent and another accused supplier. The companion decision required a broader retrial because claim-construction errors affected infringement and validity. In TCO’s appeal, the court found grounds to reopen validity but not infringement.

Changed position. TCO argued that the phrase “a rupturing force” in claim 29 could include an impact force. The Federal Circuit declined to consider that interpretation because TCO had advocated a different construction in the district court.

During claim construction, TCO proposed that the relevant language meant that the rupture disc could open when exposed to hydraulic pressure equal to or greater than its burst pressure. The district court adopted a substantially similar construction referring to rupturing hydraulic pressure. At trial, however, TCO attempted to present a slide indicating that a rupturing force could be either hydraulic pressure or impact force. The district court excluded the slide as inconsistent with its construction.

Relying on TVIIM, LLC v. McAfee, Inc., 851 F.3d 1356, 1363 (Fed. Cir. 2017), the Federal Circuit held that TCO could not advocate one interpretation before the district court and pursue a materially different interpretation on appeal. The district court therefore properly confined the trial to the construction that TCO itself had proposed.

Contributory infringement. NCS’s contributory-infringement theory concerned rupture-disc assemblies used in the TDP-PO tools. National Oilwell Varco was licensed to manufacture and sell the tools but obtained glass-disc assemblies from TCO Products. NCS maintained that those assemblies constituted a material part of the patented invention and had no substantial noninfringing uses.

Citing Fujitsu Ltd. v. Netgear Inc., 620 F.3d 1321, 1326 (Fed. Cir. 2010), the court explained that contributory infringement requires direct infringement, knowledge of the patent, a material component, and the absence of substantial noninfringing uses.

TCO argued on appeal that it could not be liable because TCO Products, rather than TCO itself, manufactured the assemblies. It also contended that its belief that the TDP-PO tools did not infringe defeated the required knowledge element.

The court found that TCO had not adequately presented either argument in its post-trial briefing. Its district court submissions focused instead on whether the assemblies were material and whether they had substantial noninfringing uses. TCO therefore forfeited the argument that its subsidiary’s role prevented liability.

Its asserted belief in noninfringement was similarly missing from the relevant portion of the post-trial briefing. At most, TCO had made a cursory assertion that it lacked knowledge that the components were specially made or adapted for infringement. Even if that argument had been preserved, competing trial testimony about TCO’s knowledge supplied substantial evidence for the jury’s finding.

Citing i4i Ltd. Partnership v. Microsoft Corp., 598 F.3d 831, 851 (Fed. Cir. 2010), aff’d, 564 U.S. 91 (2011), the court declined to address TCO’s separate challenge to induced infringement. The contributory-infringement verdict independently supported the judgment, making review of the alternative infringement theory unnecessary.

Validity retrial. TCO separately challenged the construction of “casing string” and the jury instructions addressing prior art under 35 U.S.C. §102(b). The Federal Circuit had resolved substantially similar issues in the companion precedential decision concerning the same patent.

Consistent with that ruling, the court vacated the judgment that claims 28 and 29 were not invalid and remanded for a new validity trial. It did not decide whether TCO had established invalidity as a matter of law, leaving the district court to assess the record first.

The revised construction of “casing string” did not require another infringement trial. Claims 28 and 29 covered an apparatus configured for use with a casing string. Undisputed evidence showed that the accused tools could be connected in-line with such a string. NCS therefore did not have to prove that the tools had actually been used for casing flotation.

The Case is No. 24-2379.

Judge: Cunningham, T.

Attorneys: Domingo M. Llagostera (Blank Rome LLP) for NCS Multistage Inc. Jonathan R. Spivey (Polsinelli PC) for TCO Group AS.

Companies: NCS Multistage Inc.; TCO Group AS

Cases: Patent FedCirNews