Arsenal Casing Equipment v. Citadel Casing Solutions: Dismissed Without Prejudice
Arsenal Casing Equipment, LLC brought a patent infringement action against Citadel Casing Solutions, LLC in the Southern District of Texas, asserting US12091966B1 covering wet shoe casing technology. The case closed in 111 days via voluntary dismissal without prejudice under Rule 41, leaving Arsenal free to refile.
Wet shoe patent dispute ends fast — door stays open for Arsenal
Arsenal Casing Equipment, LLC filed suit against Citadel Casing Solutions, LLC on 17 April 2025 in the United States District Court for the Southern District of Texas, before Judge Alfred H. Bennett. The complaint asserted infringement of US12091966B1, a patent covering Arsenal’s wet shoe technology used in downhole casing operations — a critical component in oil and gas well completion workflows.
The action closed on 6 August 2025, just 111 days after filing, when Arsenal filed a Notice of Dismissal under Federal Rule of Civil Procedure 41(a)(1)(A)(i). Judge Bennett ordered the claims against Citadel dismissed without prejudice, meaning no merits adjudication took place and Arsenal’s patent claims remain intact and refillable at a future date.
A resolution in under four months is notably swift for patent litigation and suggests the parties may have reached a commercial accommodation, or that Arsenal elected to reassess its litigation posture before Citadel filed a responsive pleading. The public record does not disclose any settlement terms, licensing agreement, or other consideration. Because the dismissal is without prejudice, the competitive and IP risk between these parties is not fully resolved.
Filing to Dismissed without Prejudice in 111 days
111 days — resolved well under the typical 2–3 year district court patent trial timeline
Dismissed without prejudice: what the Rule 41 order means for both parties
Rule 41(a)(1)(A)(i): plaintiff’s unilateral exit before answer
Under FRCP 41(a)(1)(A)(i), a plaintiff may voluntarily dismiss an action without a court order before the defendant has served an answer or a motion for summary judgment. Arsenal exercised this right, resulting in a dismissal that carries no res judicata effect — the claims are legally as if they were never adjudicated. The court’s order formalised the dismissal but added no independent findings.
No merits rulingWithout prejudice: Arsenal can refile — but context matters
A without-prejudice dismissal preserves Arsenal’s right to bring the same infringement claims again in a future action. This is materially different from a with-prejudice dismissal, which would bar refiling. The public record does not reveal whether any settlement, licence, or covenant not to sue was exchanged. If this was a bare procedural withdrawal, the threat of litigation against Citadel persists unless a private agreement exists.
Refile right preservedCitadel escapes this round — but faces residual exposure
Citadel Casing Solutions avoids an adverse judgment and incurs no recorded cost award. However, the without-prejudice nature of the dismissal means it has not obtained any legal ruling invalidating US12091966B1 or establishing non-infringement. If no licence or settlement has been secured privately, Citadel remains exposed to a future infringement action on the same patent and potentially the same product conduct.
No invalidity ruling obtainedWet shoe patent remains a live competitive weapon in oilfield services
US12091966B1 emerges from this action unscathed and unrestricted in scope. Arsenal’s IP position in wet shoe casing technology is unchanged. For competitors or new entrants developing similar downhole casing shoe solutions, the patent remains an active risk to monitor. The speed of dismissal may suggest private resolution, but absent public confirmation, the sector should treat Arsenal’s enforcement posture as ongoing.
Patent enforceability intactFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Arsenal Casing Equipment, LLC | Company | Oilfield equipment company — holder of US12091966B1 covering wet shoe casing technologySearch in Eureka ↗ |
| Defendant | Citadel Casing Solutions, LLC | Company | Citadel Casing Solutions, LLC — oilfield casing solutions provider, named infringerSearch in Eureka ↗ |
| Plaintiff counsel | Matthew Scott Evans | Attorney | Counsel for Arsenal Casing Equipment, LLCSearch in Eureka ↗ |
| Plaintiff law firm | McCutcheon Joseph, PLLC | Law Firm | Representing Arsenal Casing Equipment, LLCSearch in Eureka ↗ |
| Presiding judge | Judge Alfred H Bennett | Judge | Texas Southern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The court’s order does not reflect any merits determination. Judge Bennett formalised Arsenal’s Rule 41(a)(1)(A)(i) notice, confirming that no answer or summary judgment motion had been filed by Citadel at the time of withdrawal. The without-prejudice qualifier is legally significant: it preserves Arsenal’s claims entirely, prevents any issue or claim preclusion, and leaves US12091966B1’s validity and scope untested. The brevity of the order is consistent with the procedural posture — this was an administrative closure, not a judicial resolution.
US12091966B1 — wet shoe downhole casing technology
US12091966B1, filed under application number US17/959719, covers Arsenal’s wet shoe technology — a component used in downhole casing strings during oil and gas well completion. Wet shoe tools typically allow fluid circulation through the casing shoe during run-in, enabling operators to manage wellbore conditions more effectively than with conventional float equipment. The patent’s issuance as a B1 publication indicates it proceeded to grant without reissue, suggesting a relatively clean prosecution history.
For the oilfield services and well completion sector, a granted patent on wet shoe technology from an active equipment supplier represents a meaningful IP boundary. Competitors offering similar float equipment, casing shoe, or circulation-enabling downhole tools should evaluate their product designs against the claims of US12091966B1. Arsenal’s decision to immediately assert the patent following issuance signals an intent to protect market position aggressively in a sector where differentiated completion tooling carries significant commercial value.
Should you run an FTO against US12091966B1?
Any company designing, manufacturing, or supplying wet shoe tools, float equipment, or circulation-enabling casing shoe technology for US oil and gas well completions should treat US12091966B1 as a priority FTO target. Arsenal has already demonstrated enforcement intent by filing suit. The patent is recently issued, its claims have not been tested in litigation, and no invalidity ruling exists on the public record. This makes it an active and undiminished risk for competing product lines.
PatSnap Eureka’s FTO Search Agent can map your product’s technical features against the claim language of US12091966B1, surface prior art that could support an IPR petition if needed, and identify design-around pathways. For in-house teams at oilfield services companies, running this analysis now — before Arsenal refiles or expands its enforcement programme — is significantly lower cost than defending a full infringement action in the Southern District of Texas.
Run a freedom-to-operate analysis on US12091966B1 to assess your product’s exposure
Run FTO in Eureka →Similar patent cases in downhole oilfield casing technology
Explore comparable patent infringement actions involving downhole completion tools and casing equipment filed in Texas federal district courts.
What this case signals for the downhole casing technology IP landscape
A fast Rule 41 exit in a wet shoe patent dispute leaves key questions unanswered — and the risk unresolved.
Early dismissals in oilfield patent cases often precede private licensing deals
When a plaintiff dismisses under Rule 41(a)(1)(A)(i) before any answer is filed, it typically signals that either a commercial resolution was reached or that the plaintiff is repositioning. In oilfield equipment disputes, this pattern is consistent with confidential cross-licence or supply arrangements. Competitors should consider whether a quiet licence has de-risked Citadel’s position.
US12091966B1 is unscathed — FTO exposure remains real for wet shoe competitors
No invalidity finding, no claim construction, and no estoppel resulted from this case. Any company operating in the wet shoe or float equipment space in US oil and gas should treat US12091966B1 as an active enforcement risk. Arsenal’s willingness to file suit demonstrates it is prepared to litigate, and a without-prejudice dismissal preserves every future option.
Arsenal v Citadel — key questions answered
The case was dismissed without prejudice on 6 August 2025. Arsenal filed a voluntary notice of dismissal under FRCP 41(a)(1)(A)(i), and Judge Bennett ordered Citadel dismissed with no merits ruling. Arsenal retains the right to refile the same infringement claims against Citadel in the future.
The case asserts US12091966B1, filed under application US17/959719, covering Arsenal’s wet shoe technology used in downhole oil and gas casing operations. The patent is recently issued and has not been subjected to any validity challenge or claim construction in litigation.
Dismissed without prejudice means the case ended with no determination on the merits. Arsenal’s infringement claims are preserved in full — the company can refile the same claims based on US12091966B1 at any time, subject to the applicable statute of limitations. No estoppel or preclusion attaches to Citadel from this dismissal.
The public record does not disclose why Arsenal withdrew. A pre-answer Rule 41(a)(1)(A)(i) dismissal within 111 days is consistent with a private settlement, licence negotiation, or a decision to reassess litigation strategy. Because no answer was filed by Citadel, Arsenal could exit without court approval and without any cost exposure to Citadel.
Wet shoe technology refers to a downhole tool at the base of a casing string that allows fluid to flow through during run-in operations, helping operators manage wellbore pressure and circulation conditions. It is used during oil and gas well completion. US12091966B1 protects Arsenal’s implementation of this technology, which it alleged Citadel’s products infringed.
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