PTAB

IPR2016-01901

Baker Hughes Inc v. Lubrizol Specialty Products Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Drag Reduction of Asphaltenic Crude Oils
  • Brief Description: The ’249 patent discloses methods of reducing frictional pressure loss during the pipeline transport of heavy crude oils. The methods involve introducing a high molecular weight drag reducing polymer into a liquid hydrocarbon characterized by high asphaltene content (at least 3% by weight) and low API gravity (less than 26°).

3. Grounds for Unpatentability

Ground 1: Claims 1-5 are obvious over the Holtmyer Publication in view of the Holtmyer Patent and Carnahan.

  • Prior Art Relied Upon: Holtmyer Publication ("Study of Oil Soluble Polymers as Drag Reducers," 1980), Holtmyer Patent (Patent 3,758,406), and Carnahan ("Precipitation of Asphaltenes in Heavy Oil and Tar Sands," 2000).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the Holtmyer Publication taught most limitations of claim 1. It disclosed using a poly(isodecyl methacrylate) homopolymer (iDMA), which contains oxygen heteroatoms, to achieve significant drag reduction in various hydrocarbons, including a crude oil and an aromatic hydrocarbon with an API gravity of 22.5° (less than the claimed 26°). Petitioner asserted a POSITA would have understood that this drag reduction occurs by suppressing turbulent eddies and that adding the polymer would inherently not decrease the hydrocarbon's viscosity. The Holtmyer Publication also suggested polymer concentrations that overlap with the claimed range. The primary limitation not explicitly disclosed was applying this polymer to a hydrocarbon with an asphaltene content of at least 3 weight percent.
    • Motivation to Combine: Petitioner contended a POSITA would combine these references to apply a known drag-reducing polymer to a well-known type of fluid. The Holtmyer Publication demonstrated the economic benefits of using iDMA to reduce friction in pipelines. The Holtmyer Patent taught that higher concentrations of drag reducers might be needed when suspended solids (like asphaltenes) are present. Since heavy, asphaltenic crude oils were known to exist and cause transport inefficiencies, a POSITA would have been motivated to try the effective iDMA polymer from the Holtmyer Publication in such oils to achieve the known economic benefits of improved flow. Carnahan provided the necessary technical data on the properties of such heavy oils.
    • Expectation of Success: Petitioner's core argument for success rested on solubility parameters. A POSITA would have known that a polymer’s effectiveness depends on its solubility in the target fluid. Using standard methods, a POSITA could calculate the solubility parameter of the Holtmyer Publication’s iDMA polymer. The Carnahan reference provided the expected range of solubility parameters for heavy, asphaltenic crude oils. Because the calculated value for iDMA (17.84 MPa¹/²) fell squarely within the range provided by Carnahan (16.4 to 20.5 MPa¹/²), a POSITA would have had a reasonable expectation that the iDMA polymer would be soluble and therefore effective in the claimed heavy crude oil.

Ground 2: Claims 1-5 are obvious over Inaoka in view of Carnahan.

  • Prior Art Relied Upon: Inaoka (European Patent Application No. EP 0,882,739 A2) and Carnahan (a 2000 book chapter).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Inaoka disclosed a 2-ethylhexylmethacrylate (2EHMA) homopolymer, identical to "Polymer A" in the ’249 patent, as a drag reducer suitable for crude oil. Inaoka taught that the polymer has a high molecular weight, a straight-chain structure, and contains heteroatoms (oxygen). A POSITA would have understood the drag reduction mechanism and inherent viscosity effects, as in Ground 1. Inaoka also disclosed a preferred concentration range (0.1 to 100 ppm) that overlaps with the range claimed in the ’249 patent. Similar to the Holtmyer Publication, Inaoka did not explicitly disclose using the 2EHMA polymer in a crude oil with the specific combination of low API gravity and high asphaltene content.
    • Motivation to Combine: The motivation was analogous to Ground 1. A POSITA, aware of the 2EHMA polymer from Inaoka and its suitability for crude oil, would have been motivated by the significant economic advantages of drag reduction to apply it to all types of crude oil, including the known heavy, asphaltenic crudes described by the patent’s claims.
    • Expectation of Success: The rationale for expecting success paralleled the argument in Ground 1. A POSITA would have sought to confirm the solubility of Inaoka’s 2EHMA polymer in the target heavy crude. The solubility parameter of 2EHMA was known or easily calculable (18.04 MPa¹/²), a value that corresponds exactly with that provided in the ’249 patent for its "Polymer A." This value falls directly within the solubility parameter range for heavy crude oils disclosed by Carnahan, providing a strong and reasonable expectation that the 2EHMA polymer would be soluble and effective.

  • Arguments for Dependent Claims 2-5: Petitioner argued that the additional limitations in dependent claims 2, 3, and 5 (at least 25,000 repeating units; molecular weight of at least 1x10⁶ g/mol) were expressly taught or inherently present in the high molecular weight polymers disclosed in both the Holtmyer Publication and Inaoka. Claim 4, which specified the heteroatom type, was met because the polymers in both primary references contain oxygen atoms.

4. Key Technical Contentions (Beyond Claim Construction)

  • Solubility Parameter as a Predictor of Success: A central technical contention underpinning both grounds was that a POSITA would have used solubility parameters as a routine and predictable tool to assess the viability of a drag-reducing polymer in a specific hydrocarbon. Petitioner argued that by comparing the calculated solubility parameter of a known polymer (from Holtmyer or Inaoka) with the known range for a target fluid (from Carnahan), a POSITA could reliably predict solubility and, by extension, the effectiveness of the polymer as a drag reducer, rendering the application obvious.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-5 of the ’249 patent as unpatentable under 35 U.S.C. §103.