The United States Court of Appeals for the Federal Circuit recently vacated a lower court's ruling in the patent infringement case of NCS Multistage Inc. v. Nine Energy Service, Inc. This decision, filed on September 14, 2026, affects the patent rights of NCS Multistage and the operations of Nine Energy Service, particularly in the oil and gas industry. The ruling highlights the complexities of patent law and the importance of precise language in patent claims.
The case centers around U.S. Patent No. 10,465,445 (the '445 patent'), which relates to a tool used in the oil and gas industry for inserting casing into wellbores. NCS Multistage, the plaintiff, accused Nine Energy Service of infringing on several claims of this patent. The Federal Circuit's decision to vacate the lower court's judgment means that the case will return to the district court for further proceedings, potentially altering the outcome for both parties.
Background
NCS Multistage Inc. and its subsidiary, NCS Multistage LLC, filed a lawsuit against Nine Energy Service, Inc. in the United States District Court for the Western District of Texas. The dispute arose when NCS claimed that Nine had infringed on its patent related to a flotation device designed to assist in the installation of casing strings in wellbores.
The '445 patent, which NCS asserts was filed in 2013, describes a tool that addresses the challenges of inserting casing into deep wellbores, particularly in horizontal or deviated wells. NCS argued that Nine's BreakThru Casing Flotation Device infringed on multiple claims of the patent. The case was tried in the Western District of Texas, where a jury ruled in favor of NCS, finding that Nine had directly infringed the patent and that the patent claims were valid.
The Ruling
The Federal Circuit's ruling addressed several key issues raised by Nine Energy Service in its appeal. The court found that the district court erred in its construction of certain patent terms, particularly the phrases “internal diameter” and “casing string.” The court stated, “We conclude that the plain meaning of 'internal diameter' is a 'measured diameter' across the width of the casing string.” This clarification is significant as it directly impacts the interpretation of the patent claims.
The court also ruled that the district court had incorrectly limited the definition of “casing string” to a specific size, stating that there is no intrinsic record requiring such a limitation. The Federal Circuit's decision to vacate the lower court's judgment means that the case will return to the district court for a new trial under the corrected claim constructions.
Impact
This ruling has substantial implications for both NCS Multistage and Nine Energy Service. For NCS, the vacating of the judgment means that the company must prepare for a new trial, potentially affecting its financial recovery and market position. For Nine, the decision opens up the possibility of successfully challenging the validity of the patent claims, which could significantly impact its operations and product offerings in the oil and gas sector.
The case also sets a precedent regarding the interpretation of patent claims, particularly in the context of technology used in the oil and gas industry. The Federal Circuit's clarification on the meanings of “internal diameter” and “casing string” may influence future patent litigation and how patents are drafted and interpreted in similar cases.
What's Next
The case will return to the district court for further proceedings consistent with the Federal Circuit's opinion. It is unclear whether Nine Energy Service will seek further appeal after the new trial, depending on the outcome of the proceedings in the lower court.