PTAB

IPR2015-00309

WesternGeco LLC v. PGS Geophysical As

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Seismic Surveying
  • Brief Description: The ’981 patent relates to a method for marine seismic surveying that uses at least two seismic energy sources. The method involves actuating the sources in multiple firing sequences and varying the time interval between the firing of the first and second sources in successive sequences to enable separate identification of the resulting seismic events from each source.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 2, 7, and 10-21 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 every limitation of the challenged claims. De Kok teaches a method for acquiring seismic data using simultaneously activated sources, including towing multiple sources and sensors from a vessel. Petitioner asserted that De Kok’s disclosure of sequential series of simultaneous shots having "different delay codes for successive shots" directly teaches the core inventive concept of varying the time interval between firing sources across successive firing sequences to enable signal separation.
    • Key Aspects: Petitioner contended that while De Kok’s disclosed technique is more sophisticated, as it relies on both programmed time delays and polarity decoding in the processing center, the claims of the ’981 patent do not exclude such an additional processing step. Therefore, under the broadest reasonable interpretation standard, De Kok’s more advanced method still anticipates the claimed invention.

Ground 2: Obviousness of Claims 1-22 over Beasley in view of Timoshin

  • Prior Art Relied Upon: Beasley (Patent 5,924,049) and Timoshin (Soviet Union Patent 1,543,357).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Beasley provides the basic framework for a marine seismic survey using two or more simultaneously or near-simultaneously fired sources. Beasley generally discloses that the sources may be arranged to emit "encoded wavefields using any desired type of coding" but does not explicitly teach the specific time-variation encoding of the ’981 patent. Timoshin, an earlier reference directed to land-based seismic surveying, was alleged to supply this missing element by teaching the use of random numbers as launch delays for overlapping sources to allow for subsequent separation of the wave fields during data processing.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine the known time-encoding technique from Timoshin with the marine survey system of Beasley. Petitioner argued it was common practice in the art to adapt solutions from land-based seismic surveying to marine applications. Applying Timoshin’s encoding method to Beasley’s system would have been a straightforward combination of known elements to achieve the predictable result of distinguishing signals from multiple sources.
    • Expectation of Success: The combination would predictably yield a method for separating the wave fields from different sources, as both references dealt with simultaneous shooting, encoding, and decoding.

Ground 3: Obviousness of Claims 1-22 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: Similar to the previous ground, Petitioner used Beasley as the primary reference for a multi-source marine survey system that generally allows for signal encoding. Petitioner asserted that Edington provides the specific teaching of time-delay encoding. Edington discloses a method of shooting at least two seismic sources substantially simultaneously with a determinable time delay, and then shooting the sources a second time with a different determinable time delay, explaining that the difference enables the signal from each source to be distinguished.
    • Motivation to Combine: A POSITA would have been motivated to apply the known and explicit time-encoding technique disclosed in Edington to the general multi-source marine survey framework of Beasley. This combination would solve the known problem of separating interfering signals from simultaneously fired sources in a predictable manner.
    • Expectation of Success: A POSITA would have had a high expectation of success in implementing Edington’s proven time-delay variation method within Beasley’s system to achieve the desired and predictable outcome of improved signal separation.
    • Key Aspects: Petitioner argued this ground was distinct from the grounds based on De Kok or Timoshin because Edington provides a more explicit discussion of varying the firing timing across multiple, successive sequences of shots, which closely mirrors the language of the challenged claims.

4. Key Claim Construction Positions

  • "wavelet time" (claim 6): Petitioner proposed that the broadest reasonable interpretation of this term is "the duration of the source signature."
    • This construction was central to the obviousness argument for claim 6. Petitioner argued that a POSITA would have understood the advantage of waiting at least the duration of the source signature before firing a second source. This would prevent direct interference between the source signatures themselves, which greatly hinders data separation, and thus it would have been obvious to implement such a delay.

5. Relief Requested

  • Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-22 of Patent 6,906,981 as unpatentable under 35 U.S.C. § 102 and § 103.