Fervo Energy Co v. Ormat Technologies Inc

1. Case Identification

• Case #: IPR2024-00665
• Patent #: 7,320,221
• Filed: March 8, 2024
• Petitioner(s): Fervo Energy Co.
• Patent Owner(s): Ormat Technologies Inc.
• Challenged Claims: 1-38

2. Patent Overview

• Title: Method and Apparatus for Enhancing Geothermal Energy Extraction
• Brief Description: The ’221 patent discloses a method and apparatus for enhancing geothermal fluid recovery for power generation. The system uses a deeper horizontal injection well and a shallower, spaced-apart horizontal production well, leveraging pressure and temperature-induced water density differences to improve fluid flow.

3. Grounds for Unpatentability

Ground 1: Obviousness over Rinaldi and General Knowledge - Claims 1-3, 6-11, 24-31, and 34-37 are obvious over Rinaldi in view of the general knowledge of a POSITA.

• Prior Art Relied Upon: Rinaldi (Patent 4,676,313) and the general knowledge of a Person of Ordinary Skill in the Art (POSITA).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Rinaldi, which teaches enhanced oil recovery, discloses the core configuration of the challenged claims: a deeper horizontal injection well and a shallower, vertically and horizontally spaced horizontal production well. Rinaldi's method for recovering oil by injecting fluids to create pressure and density differences was alleged to map directly onto the limitations of independent claims 1, 9, and 34 for recovering geothermal fluid. Dependent claims relating to pumps, monitoring, and well perforations were asserted to be disclosed by Rinaldi or considered well-known techniques within the general knowledge of a POSITA.
  • Motivation to Combine: A POSITA would combine Rinaldi’s teachings with geothermal applications because the ’221 patent itself acknowledged that many geothermal drilling techniques were derived from the oil and gas industry. Petitioner asserted it would have been obvious to apply Rinaldi's proven fluid recovery methods to the analogous problem of improving geothermal fluid extraction to achieve predictable results.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success, as the underlying principles of fluid dynamics, pressure differentials, and buoyancy are fundamental and apply equally to both oil and geothermal reservoirs.

Ground 3: Obviousness over Rinaldi, Grassiani, and Brannan - Claims 1-38 are obvious over Rinaldi in view of Grassiani and Brannan.

• Prior Art Relied Upon: Rinaldi (Patent 4,676,313), Grassiani (a 2000 geothermal conference proceeding), and Brannan (Patent 5,273,111).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground used Rinaldi for the basic well configuration, as in Ground 1. Grassiani was introduced to teach specific power plant components required by dependent claims, such as using a binary power plant with an organic Rankine cycle (claim 18), an air-cooled condenser (claim 19), and specific working fluids like pentane (claim 20). Brannan, another oil recovery patent, was cited to teach specific well dimensions, such as horizontal well lengths up to 1.25 miles (claims 12-13) and horizontal/vertical spacing up to 2000/150 feet (claims 14-15), which Petitioner argued were conventional design choices.
  • Motivation to Combine: A POSITA, starting with Rinaldi's fluid extraction system, would be motivated to incorporate Grassiani's power plant designs to efficiently convert the recovered geothermal heat into electricity. Similarly, a POSITA would consult a reference like Brannan for conventional and exemplary well spacing and dimensions to optimize the reservoir layout for a specific formation, a standard engineering practice.
  • Expectation of Success: The combination involved applying known power generation systems (Grassiani) and conventional well design parameters (Brannan) to a known fluid recovery architecture (Rinaldi), representing a predictable assembly of known elements.

Ground 5: Obviousness over Mims, Kruger, and Swenson - Claims 1, 2, 4-7, 9-11, and 25-37 are obvious over Mims in view of Kruger and in further view of Swenson.

• Prior Art Relied Upon: Mims (Patent 4,850,429), Kruger (a 1975 geothermal energy report), and Swenson (a 1995 geothermal reservoir modeling paper).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground used Mims as the primary reference, which, like Rinaldi, taught a method for hydrocarbon recovery using parallel horizontal injection and production wells. Kruger was introduced to teach methods for stimulating geothermal production and increasing extraction efficiency. Swenson was cited for its disclosure of modeling geothermal reservoirs (using its GEOCRACK program) to determine optimal well spacing based on factors including rock temperature and flow rates, directly addressing the "dependent on the elevated temperature" limitation.
  • Motivation to Combine: A POSITA would combine Mims’s well layout with Kruger’s efficiency-enhancing techniques to improve geothermal fluid recovery. Furthermore, it would have been obvious to use the advanced modeling techniques taught by Swenson to optimize the well spacing and flow rates in the Mims/Kruger system to ensure longevity and maximize thermal productivity, which are predictable goals in system design.
  • Expectation of Success: A POSITA would expect success in applying modeling (Swenson) and efficiency principles (Kruger) to a known well configuration (Mims), as this represents a standard engineering approach to system optimization.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including Rinaldi over Swenson; Mims over general knowledge; Mims over Grassiani and Brannan; and Rinaldi over Swenson and Alkhasov. These grounds relied on similar theories of adapting oil recovery techniques and combining them with known geothermal system components and optimization methods.

4. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under §325(d), asserting that Grounds 1-7 were based on prior art references and arguments never considered during the original prosecution.
• Petitioner also argued against discretionary denial under Fintiv, contending that institution was favored because the related district court case was in its earliest stages. Key factors cited included: no trial date had been set, no substantial investments had been made by the parties beyond initial filings, and there was no overlap in invalidity contentions, as none had been filed in the court proceeding. Petitioner concluded that the petition presented a compelling case on the merits that warranted institution.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-38 of the ’221 patent as unpatentable under 35 U.S.C. §103.