Wellboss Co LLC v. Lonestar Completion Tools LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: The WellBoss Company, LLC (Texas)
  • Defendant: Lonestar Completion Tools, LLC; Michael J. Harris; Kenneth J. Anton (Texas)
  • Plaintiff’s Counsel: KEARNEY, MCWILLIAMS & DAVIS
• Case Identification: 4:26-cv-00821, TXSD, 02/03/2026
• Venue Allegations: Venue is alleged to be proper in the Southern District of Texas because Defendants are Texas residents and/or entities with an established place of business in the District, and have allegedly committed acts of infringement within the District.
• Core Dispute: Plaintiff alleges that Defendant’s "ONEPlug" line of frac plugs infringes a patent related to the design and construction of downhole tools used in hydraulic fracturing.
• Technical Context: The technology concerns frac plugs, which are tools used to temporarily isolate zones within an oil or gas wellbore during hydraulic fracturing operations, a critical process for extracting hydrocarbons from low-permeability rock formations.
• Key Procedural History: The complaint alleges that Plaintiff provides notice of its patent portfolio through virtual marking on its product packaging. It also alleges Defendants have advertised the accused product as "patent pending," while Plaintiff asserts the product incorporates features covered by the asserted patent. The complaint further alleges that Plaintiff sent a notice of infringement letter to Defendants prior to filing suit.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

• Patent Identification: U.S. Patent No. 11,634,965, “Downhole Tool and Method of Use,” issued April 25, 2023.

The Invention Explained

• Problem Addressed: The patent's background describes several problems with conventional downhole plugs used in fracturing operations. These include the difficulty, time, and expense of removing plugs after use, particularly those made of durable metals like cast iron Patent, col. 2:56-65 Other issues include the risk of plugs setting prematurely in the wellbore and the potential for poor sealing performance under extreme downhole pressures and temperatures Patent, col. 3:10-18
• The Patented Solution: The invention is a downhole tool featuring a central component called a "double cone," which has a dual-frustoconical outer surface Patent, abstract; Patent, col. 4:26-31 A carrier ring, which holds a seal element, is positioned at the proximate end of the cone, while a slip assembly, for gripping the wellbore casing, is positioned at the distal end Patent, col. 5:6-15 This specific geometric arrangement of components is intended to provide a reliable seal while using less material, resulting in a shorter, more easily deployable, and faster-to-remove tool Patent, col. 4:1-9
• Technical Importance: This design aims to improve the operational efficiency and reduce the cost of hydraulic fracturing by creating a more compact and easily drillable frac plug, a key consideration in a competitive and cost-sensitive industry Patent, col. 4:1-9

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶41
• The essential elements of independent claim 1 include:
  • A "double cone" with a specific structure including an inner flowbore and a ball seat.
  • A "carrier ring" that slidingly engages the proximate end of the double cone and has a groove for a seal element.
  • A "slip" engaged with the distal end of the double cone.
  • A "guide assembly" proximate the slip.
  • Specific geometry wherein the double cone's outer surface has a "first angled surface" and a "second angled surface," with the second angle being "negative to that of the first angle."
  • A functional requirement that in a "set configuration," the carrier ring's underside surface is "entirely in contact with the outer surface" of the double cone, and a ball is engaged against the ball seat.
• The complaint seeks a declaratory judgment that Defendants infringe one or more claims of the patent, suggesting the potential assertion of additional claims Compl. ¶69

III. The Accused Instrumentality

Product Identification

• The accused products are identified as the "ONEPlug," which is also referred to as "ONEPlug Ultralite," "Ultralite," or "composite frac plug" Compl. ¶26

Functionality and Market Context

• The ONEPlug is a downhole frac plug sold for use in oil and gas hydraulic fracturing operations Compl. ¶24 The complaint alleges that it is a direct competitor to Plaintiff's products Compl. ¶25
• The complaint includes an advertisement for the ONEPlug, which is promoted as having "Reliable deployment," "Efficient drill-up," and being "The first and only composite frac plug manufactured from ONE continuous piece of material" Compl. p. 6
• To describe the ONEPlug’s functionality, the complaint references diagrams from U.S. Patent No. 11,434,715, which is assigned to Defendant Lonestar, alleging that these diagrams depict the infringing configuration of the ONEPlug Compl. ¶29; Compl. ¶43
• The complaint presents an image from Defendant's marketing materials comparing the ONEPlug to a diagram from the '715 Patent, suggesting a close correspondence between the two Compl. p. 7

IV. Analysis of Infringement Allegations

’965 Patent Infringement Allegations

• Identified Points of Contention:
  • Evidentiary Question: The infringement allegations rely on mapping the claims of the ’965 Patent onto technical drawings from Defendant's own '715 Patent, rather than on a direct analysis of the physical ONEPlug product Compl. ¶29 This raises the threshold question of whether the accused ONEPlug, as sold, is a faithful and complete embodiment of the '715 patent's figures and, if so, whether that embodiment meets every limitation of the asserted claim.
  • Scope Question: The claim requires that in a "set configuration," the carrier ring's underside surface is "entirely in contact with the outer surface" of the double cone Compl. ¶41 This "entirely" limitation suggests a demanding standard of contact. The infringement analysis may hinge on what degree of contact is required and whether the accused product actually achieves it in operation.
  • Technical Question: The claim recites a specific geometry where a "second angled surface" has a "second angle negative to that of the first angle" Compl. ¶41 While the complaint provides one interpretation of this language Compl. ¶49, the precise technical meaning of this geometric relationship and whether the accused product's structure meets it will be a subject for claim construction and factual determination.

V. Key Claim Terms for Construction

• The Term: "entirely in contact"

  • Context and Importance: This term defines the required state of the carrier ring relative to the double cone when the tool is set. Practitioners may focus on this term because absolute language like "entirely" often becomes a central point of dispute. If the accused device has any gap or incomplete contact between these surfaces in its set state, it may support a non-infringement argument.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent does not appear to provide language that explicitly broadens the ordinary meaning of "entirely." A party might argue for a functional interpretation, where "entirely" means sufficient contact to perform the intended function, but this is not directly supported by the specification.
    • Evidence for a Narrower Interpretation: The claim language itself is unambiguous. The specification reinforces a literal interpretation by stating, "in the set or unset position, an underside surface 223b of the carrier ring 223 may be entirely engaged with the outer surface 219" ’965 Patent, col. 13:45-48 This use of "entirely engaged" in the detailed description could be used to argue for a strict, literal interpretation requiring complete surface-to-surface contact.

• The Term: "double cone"

  • Context and Importance: This is the core structural element of the invention, and its definition dictates the overall architecture of the claimed tool. The dispute will likely involve whether the defendant's central component, as designed and manufactured, falls within the scope of this term.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides a general definition: "The term 'double cone' as used herein may refer to a tubular component having an at least one generally frusto-conical surface" ’965 Patent, col. 9:5-8 This could support an argument that the term covers a range of similar structures.
    • Evidence for a Narrower Interpretation: The abstract and specific embodiments describe the double cone as having a "dual-cone outer surface" ’965 Patent, abstract The specification further clarifies that it "may be dual-frustoconical in shape" and include "a first angled surface and a second angled surface" with a specific negative angular relationship ’965 Patent, col. 4:26-31 This language, combined with the limitations in Claim 1, could be used to argue that the term is limited to this specific dual-angled geometry.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that Defendants induced infringement by encouraging "customers, users, distributors, affiliates, employees, and/or service providers" to use the Infringing Plug in an infringing manner Compl. ¶53; Compl. ¶62 Contributory infringement is alleged on the basis that the Infringing Plug is "especially made or adapted for use in infringing the Asserted Patent" and is not a "staple article of commerce suitable for substantial non-infringing uses" Compl. ¶54; Compl. ¶63
• Willful Infringement: The willfulness allegation is based on both constructive and actual notice. The complaint alleges constructive notice through Plaintiff's virtual patent marking Compl. ¶51 and actual notice via a written notice of infringement sent on January 5, 2026 Compl. ¶52; Compl. ¶64 The complaint alleges that Defendants' continued infringement after receiving this notice is willful and deliberate Compl. ¶56

VII. Analyst’s Conclusion: Key Questions for the Case

• A central evidentiary question will be one of product-to-patent mapping: does the accused ONEPlug product, as actually manufactured and sold, embody the specific design shown in the defendant's '715 patent diagrams, and more critically, does its physical structure and operation satisfy every limitation of Claim 1 of the ’965 Patent?
• A key legal issue will be one of claim construction: how will the court construe the term "entirely in contact"? The case may turn on whether this requires absolute, literal surface contact between the carrier ring and the double cone, or if a lesser, functionally sufficient contact is enough to meet the claim limitation.
• A third core issue will combine claim construction and factual analysis: can the geometric limitation requiring a "second angle negative to that of the first angle" be construed to read on the physical design of the accused ONEPlug? This will require the court to first define the technical scope of the term and then determine if the accused product falls within it.