PTAB

IPR2015-00310

WesternGeco LLC v. PGS Geophysical As

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Seismic Surveying
  • Brief Description: The ’981 patent discloses a marine seismic surveying system that uses multiple seismic energy sources fired in successive sequences. The core concept involves varying the time delay between the firing of a first and second source in each successive sequence to enable separate identification of the seismic signals originating from each source.

3. Grounds for Unpatentability

Ground 1: Anticipation by De Kok - Claims 23, 24, and 30 are anticipated by De Kok.

  • Prior Art Relied Upon: De Kok (Patent 6,545,944).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that De Kok discloses all elements of independent claim 23 and dependent claims 24 and 30. De Kok teaches a method for acquiring seismic data using "simultaneously activated seismic energy sources." Petitioner asserted that Figure 5A of De Kok explicitly shows sequential series of shots (Source TD1 and Source TD2) that have "different delay codes for successive shots." This varying time delay between the activation of corresponding sources in successive shots (e.g., shot 1 vs. shot 2) was argued to meet the central limitation of the ’981 patent’s claims, which require a time delay that "varies between successive firing sequences." De Kok's teaching of programmed time delays was asserted to meet the "systematically" varied limitation of claim 24, and its disclosure of using three or more sources meets the limitations of claim 30.

Ground 2: Obviousness over Beasley in view of Timoshin - Claims 23-30 are obvious over Beasley in view of Timoshin.

  • Prior Art Relied Upon: Beasley (Patent 5,924,049) and Timoshin (Soviet Union Patent No. 1,543,357).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Beasley discloses a marine seismic survey system with the fundamental components of claim 23: multiple seismic sources fired simultaneously or near-simultaneously, towed by vessels with sensor arrays. Beasley broadly teaches that the sources may be arranged to emit "encoded wavefields using any desired type of coding" but does not explicitly disclose varying time delays. Petitioner contended that Timoshin, which relates to land-based seismic surveying, supplies this missing element by teaching the use of random numbers as "launch delays" for overlapping source activations to enable subsequent signal separation. The combination, therefore, discloses a system where the time delay varies between successive firing sequences, as required by claim 23.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) reading Beasley’s suggestion to use "any desired type of coding" would have been motivated to look at known encoding techniques. Petitioner argued it was commonplace to adapt known land-based solutions, like the time-delay encoding taught in Timoshin, to marine applications. Combining Timoshin’s established method with Beasley’s system was a simple substitution of one known element for another to obtain the predictable result of improved signal separation.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination merely applies a known signal separation technique (Timoshin) to a conventional seismic survey system (Beasley) to achieve a predictable outcome.

Ground 3: Obviousness over Beasley in view of Edington - Claims 23-30 are obvious over Beasley in view of Edington.

  • Prior Art Relied Upon: Beasley (Patent 5,924,049) and Edington (Patent 4,953,657).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground presents an alternative to Ground 2, using Edington as the source for the time-encoding technique. As before, Beasley provides the foundational marine survey system. Edington was asserted to explicitly teach the core inventive concept: "shooting the sources at least a second time substantially simultaneously with a different determinable time delay between the activation of each source from the determinable time delay used in at least one previous shooting." Petitioner argued this directly teaches varying the time delay between successive shots to allow for signal separation, thus rendering the limitations of claim 23 obvious when applied to Beasley's system. The dependent claims were argued to be obvious variants, such as systematic or random variation of the time delays.
    • Motivation to Combine: The motivation is identical to that in Ground 2. Edington provided another well-known, off-the-shelf time-encoding technique that a POSITA would have been motivated to implement in Beasley's system to achieve the predictable result of distinguishing signals from simultaneously fired sources.
    • Expectation of Success: Success was predictable because the combination involved implementing a known method for its intended purpose in a known system.

4. Key Claim Construction Positions

  • "wavelet time" (Claim 28): Petitioner proposed that the broadest reasonable interpretation of this term is "the duration of the source signature."
    • Argument: Petitioner argued that although the term is not explicitly defined, the specification states the time delay between sources should be at least as long as the "wavelet time" to "avoid interference between the first and second sources." A POSITA would understand that to avoid interference between the direct source signals, the delay must be at least the duration of the source signal's signature. This construction was central to Petitioner's obviousness argument for claim 28, contending it would be obvious to wait for this duration to prevent source signature interference, a primary challenge in signal separation.

5. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 23-30 of the ’981 patent as unpatentable.