Liberty Energy Inc v. US Well Services LLC

1. Case Identification

• Case #: IPR2025-00105
• Patent #: 11,959,533
• Filed: November 5, 2024
• Petitioner(s): Liberty Energy Inc. and Liberty Energy Services LLC
• Patent Owner(s): U.S. Well Services Holdings, LLC
• Challenged Claims: 1-25

2. Patent Overview

• Title: Multi-plunger Pumps and Associated Drive Systems
• Brief Description: The ’533 patent relates to drive systems for multi-plunger hydraulic fracturing pumps. The disclosed system uses a plurality of motors, which can be electric, to power the pump through a planetary gear train that translates power to the pump’s crankshaft.

3. Grounds for Unpatentability

Ground 1A: Obviousness of Claims 1-4 and 10-13 over Buckley, Bergan, August, Joyner, and Morris

• Prior Art Relied Upon: Buckley (Application # 2020/0256429), Bergan (Application # 2015/0361736), August (NASA Contractor Report 3793), Morris (Application # 2016-03690609), and Joyner (Patent 6,907,667).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Buckley taught the foundational system: a multi-plunger hydraulic fracturing pump powered by a plurality of electric motors coupled via a gearbox. Bergan taught using a planetary gear system with input pinions to couple multiple electric motors to a load in the related field of oil and gas drilling. August taught a "star arrangement" variation of a planetary gear system where the ring gear serves as the output, a modification that results in a lower, more useful gear ratio. Finally, the combination of Morris and Joyner taught connecting a prime mover to a pump with a universal joint-based coupling comprising a "plurality of arms" to mitigate misalignment, which Petitioner alleged met the limitation added during prosecution to secure allowance.
  • Motivation to Combine: A POSITA would combine Bergan's known planetary gear system with Buckley's pump to implement a well-understood method for aggregating power from multiple motors. The POSITA would further modify this with August's star arrangement—a simple substitution of one known gearing configuration for another—to achieve the predictable and beneficial result of a lower gear ratio suitable for driving a high-torque pump with high-speed motors. To address predictable vibration issues, a POSITA would incorporate the universal joint taught by Morris and detailed in Joyner.
  • Expectation of Success: Petitioner asserted a POSITA would have an expectation of success because the combination involved applying known techniques (planetary gears, star arrangements, universal joints) to a known system (multi-motor fracturing pump) to achieve predictable results (power transmission, favorable gear ratios, and vibration mitigation).

Ground 1B: Obviousness of Claims 1, 3, 4, 10, 12, and 13 over Yi, Bergan, August, Joyner, and Morris

• Prior Art Relied Upon: Yi (Chinese Publication No. CN103742382A), Bergan (Application # 2015/0361736), August (NASA Contractor Report 3793), Morris (Application # 2016-03690609), and Joyner (Patent 6,907,667).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented an argument analogous to Ground 1A but substituted Yi as the base reference. Petitioner asserted Yi disclosed a "fracturing pump transmission system" using multiple motors to drive a crankshaft-type plunger pump. While Yi did not detail the specific gearing, Petitioner argued a POSITA would look to the other references to supply these known components. Bergan, August, Morris, and Joyner were alleged to teach the same planetary gear, star arrangement, and universal joint coupling limitations as in Ground 1A.
  • Motivation to Combine: The motivation was similar to Ground 1A. A POSITA starting with Yi’s general system would be motivated to look for specific, known gearing configurations to implement the multi-motor drive. Bergan offered a known solution, which could be predictably improved for the application by using August’s star arrangement. The Morris/Joyner coupling would be added for its known benefits in a practical system.
  • Expectation of Success: Success was expected because it involved implementing Yi's system using conventional and well-understood mechanical components and configurations from the secondary references.

Ground 3A: Obviousness of Claims 7 and 16 over Buckley, Bergan, August, Joyner, Morris, and Payne

• Prior Art Relied Upon: The combination from Ground 1A, plus Payne (Application # 2016/0533267).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground added Payne to the combination of Ground 1A to address claims requiring a variable frequency drive (VFD). Payne taught a hydraulic fracturing system with electric motors controlled by a VFD to vary the pump's rotational speed.
  • Motivation to Combine: Petitioner argued there was an express motivation, as Buckley disclosed that its motors "may permit the motors [] to run at various speeds or power outputs." A POSITA would be motivated to look to references like Payne for known techniques to achieve this control. Furthermore, market incentives would motivate using AC motors with VFDs, as taught by Payne, due to their known advantages in reliability, cost, and size over DC motors.
  • Expectation of Success: A POSITA would have a high expectation of success, as adding a VFD to control AC motors was a well-known, established technology with predictable results (variable speed control) long before the patent's priority date.

• Additional Grounds: Petitioner asserted numerous additional obviousness grounds. These included combinations using Karassik to teach pumps with seven or nine plungers (Claims 5, 6, 14, 15), Rosman to teach alternative gear configurations (Claims 8, 9, 17, 18), and Jelaska or Tutterow to supplement combinations with general knowledge regarding gear ratios and avoiding pump cavitation (Claims 19-21).

4. Arguments Regarding Discretionary Denial

• §314(a) (Fintiv Factors): Petitioner argued that discretionary denial under Fintiv would be improper. It asserted that the parallel district court litigation was in its infancy and that the petition was filed diligently within four months of receiving infringement contentions. Petitioner contended that the strong merits of the petition also weighed in favor of institution.
• §325(d): Petitioner argued that institution was proper because the grounds relied upon prior art and arguments not previously considered by the USPTO. Specifically, key references like August, Morris, Joyner, and Yi were not before the examiner during prosecution. Petitioner emphasized that these new references taught the very limitation—a final drive gear connected to the crankshaft by a "plurality of arms"—that was added to the claims to overcome the examiner's rejections and achieve allowance.

5. Relief Requested

• Petitioner requests institution of inter partes review and cancellation of claims 1-25 of Patent 11,959,533 as unpatentable.