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`UNITED STATES PATENT AND TRADEMARK OFFICE
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`———————————
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
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`———————————
`
`PETROLEUM GEO-SERVICES INC.,
`Petitioner
`
`v.
`
`WESTERNGECO LLC
`Patent Owner
`
`———————————
`
`Cases
`IPR2014-00687 (U.S. Patent No. 7,162,967)
`IPR2014-00688 (U.S. Patent No. 7,080,607)
`IPR2014-00689 (U.S. Patent No. 7,293,520)
`———————————
`
`DECLARATION OF MICHAEL S. TRIANTAFYLLOU
`
`
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 1
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`

`

`
`
`I.
`
`II.
`
`III.
`
`IV.
`
`V.
`
`VI.
`
`Table of Contents
`
`Introduction ........................................................................................................................4
`
`Legal Standards .................................................................................................................8
`A.
`Claim Construction ..................................................................................................8
`B.
`Anticipation..............................................................................................................8
`C.
`Obviousness .............................................................................................................8
`D.
`Person of Ordinary Skill in the Art ..........................................................................9
`
`Summary of Opinions ......................................................................................................10
`A.
`Summary of Opinions Regarding the ’607 Patent .................................................14
`A.
`Summary of Opinions Regarding the ’967 Patent .................................................14
`B.
`Summary of Opinions Regarding the ’520 Patent .................................................14
`
`Background of the Technology .......................................................................................15
`A.
`Background Technical Principles ..........................................................................15
`B.
`Dr. Bittleston and Mr. Hillesund’s Work...............................................................29
`C.
`The Patents At Issue...............................................................................................30
`1.
`’607 Patent .................................................................................................32
`2.
`’967 Patent .................................................................................................34
`3.
`’520 Patent .................................................................................................38
`
`Claim Construction ..........................................................................................................41
`A.
`“Streamer Positioning Device” ..............................................................................41
`B.
`“Predicting Positions” ............................................................................................42
`C.
`“Calculate Desired Changes” .................................................................................43
`D.
`“Global Control System” .......................................................................................44
`E.
`“Streamer Separation Mode” .................................................................................45
`F.
`“Feather Angle Mode” ...........................................................................................46
`
`The Alleged Prior Art ......................................................................................................47
`A. Workman................................................................................................................47
`B.
`Elholm ....................................................................................................................52
`C.
`Hedberg ..................................................................................................................56
`D.
`’636 PCT ................................................................................................................60
`
`VII. WesternGeco’s Patents Are Not Anticipated or Obvious ............................................61
`A.
`The ’607 Patent ......................................................................................................61
`1.
`Claims 1 & 15 ............................................................................................61
`2.
`Claims 1 & 15 Are Not Anticipated or Rendered Obvious Due to
`Workman....................................................................................................61
`a.
`Workman Does Not Anticipate the ’607 Patent .............................61
`i.
`Missing Elements from Workman .....................................61
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 2
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`B.
`
`C.
`
`ii.
`
`Workman Does Not Enable a Streamer Positioning
`Device ................................................................................67
`Workman Does Not Render the ’607 Patent Obvious ...................71
`b.
`Claims 1 & 15 Are Not Rendered Obvious Due to Workman in
`view of Elholm ...........................................................................................73
`a.
`Missing Elements from Elholm ......................................................73
`b.
`The Combination Does Not Make the ’607 Patent Obvious ..........73
`The ’967 Patent ......................................................................................................75
`1.
`Claims 1 & 15 ............................................................................................75
`2.
`Claims 1 & 15 Are Not Anticipated or Rendered Obvious by the
`’636 PCT ....................................................................................................75
`a.
`Missing Elements from the ’636 PCT ............................................75
`b.
`Missing Elements Would Not be Obvious ......................................77
`The ’520 Patent ......................................................................................................78
`1.
`Claims 1, 2, 18, 19 .....................................................................................78
`2.
`Claims 1, 2, 18, and 19 Are Not Anticipated or Rendered Obvious
`Due to Workman ........................................................................................78
`a.
`Workman Does Not Anticipate the ’520 Patent .............................79
`b.
`Workman Does Not Render the ’520 Patent Obvious ...................82
`Claims 1, 2, 18, and 19 Are Not Anticipated by or Obvious Over
`Hedberg ......................................................................................................84
`
`3.
`
`3.
`
`VIII. Conclusion ........................................................................................................................87
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`
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`3
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 3
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`I, Dr. Michael S. Triantafyllou, hereby state the following:
`
`I.
`
`INTRODUCTION
`
`1. I have over 40 years of research and development experience in the dynamics and control of
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`marine vehicles and structures. I specialize in two fields: (1) control theory; and (2) the
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`interactions between fluids and structures, including fluid mechanics and structural
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`dynamics. A copy of my curriculum vitae, including a list of the publications I have
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`authored within the last 10 years, is attached hereto as Exhibit A. I have provided testimony
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`at a deposition and at trial in the past 4 years. These engagements are listed in Exhibit B. I
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`am being compensated at a rate of $350 per hour for the time I devote to this matter. I have
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`no financial interest in the outcome of this litigation. The information I considered in
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`forming my opinions is attached hereto as Exhibit C.
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`2. I earned a bachelor’s degree in Naval Architecture and Marine Engineering in 1974 from the
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`National Technical University of Athens in Athens, Greece. I have also earned the degrees
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`of Masters of Science in Mechanical Engineering, and Masters of Science in Ocean
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`Engineering, both awarded in 1977 from the Massachusetts Institute of Technology (“MIT”).
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`In 1979, I earned a Doctorate of Science in Ocean Engineering from MIT. During the course
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`of my doctorate studies, I conducted research on the dynamics and control of ships and
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`positioning structures for the oil industry.
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`3. Since 1979, I have been a faculty member first in MIT’s Ocean Engineering department and
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`then in MIT’s Mechanical Engineering department. I was an Assistant Professor from 1979
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`to 1983, and Associate Professor without tenure from 1983 to 1986. Much of my research
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`during this time focused on cable mechanics, and specifically on the design of marine cable
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 4
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`lines subject to large forces, such as ocean currents. Many of the principles of cable
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`mechanics are equally applicable to streamers used in marine seismic surveys. In addition to
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`my research, I taught courses in the design of floating structures and the dynamics of ocean
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`structures.
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`4. I earned permanent tenure status in 1986. I continued my research on cable mechanics,
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`focusing specifically on towed cables, including streamers and towed arrays. In conjunction
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`with the United States Navy, I studied the fluid mechanics of towed arrays for use behind
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`submarines for the detection of other vessels. Though the precise nature of my work for the
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`Navy remains confidential, it involved the development of the boundary layer theory around
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`towed cables, as well as their hydrodynamics and maneuverability.
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`5. In 1990, I earned the title of Professor. I continued to work on the development of cables and
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`towed arrays for the United States Navy, specifically focusing on conducting modeling
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`studies for the hydrodynamics of marine cables.
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`6. Since 2004, I have served as the Director of the Center for Ocean Engineering at MIT. In
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`2008, I was named Associate Department Head of the Mechanical Engineering Department,
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`and I currently serve as the William I. Koch Chair in Marine Technology. During 2007-
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`2014, I conducted research focused on developing steering capabilities for the Navy’s
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`acoustic towed arrays. The technology is similar to the steerable streamer concepts
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`employed by the oil exploration industry. Part of my research focused on simulating the
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`overall performance of underwater arrays towed by helicopter at high speed for underwater
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`detection. Arrays towed by helicopter present many of the same challenges as arrays towed
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`by marine seismic vessels, but also present many additional challenges. For example,
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`5
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 5
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`helicopters tow arrays at much faster speeds, up to twenty miles per hour, than seismic
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`vessels, adding to the complexity of the system.
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`7. In 2013, I became Chairman of the Board of the National Technical University of Athens.
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`8. For approximately twenty years, my research at MIT has also included the development of
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`marine robots with flexible hulls that propel themselves through water, or “swim,” much like
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`fish. In its initial stages, the project involved the design and control of robot bodies that
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`swim like marine creatures, such as dolphins and tuna. These robots are capable of sensing
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`their surrounding environmental conditions in order to achieve optimal propulsion and
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`maneuverability. The robots are capable of adjusting their motion to account for ocean
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`currents and turbulence from structures in the water. They can be controlled remotely, but
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`are also capable of autonomous control. More recently, my research efforts have been
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`focused on the development of specialized pressure and velocity sensors distributed
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`throughout the robot bodies, which allow the robots to detect flow patterns and other objects
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`in the water. This research has been featured several times in industry and academic
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`publications, including Physics of Fluids, Discovery Magazine, and The Scientific American.
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`Ultimately, the practical application of this project will be to apply these principles to larger
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`marine vessels for faster turning and more precise control of, for example, marine cables. In
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`2014 I was elected fellow of the American Physical Society for “pioneering the use of
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`biomimetic robots.”
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`9. In addition to my responsibilities at MIT, since 1979 I have been a visiting research scientist
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`at the Woods Hole Oceanographic Institute (“WHOI”) in Woods Hole, Massachusetts.
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`WHOI is one of the world’s largest ocean research and engineering organizations. Its work
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`6
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 6
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`focuses on all aspects of ocean research, including the development of technology for natural
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`resource exploration beneath the ocean subsurface. As part of my research at WHOI, I was
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`part of the team that developed the WHOI-Cable, a simulation program that simulates the
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`fluid mechanics and dynamics for moorings and towed marine cables and arrays.
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`10. I routinely consult on issues related to marine exploration for the petroleum industry,
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`including projects on behalf of ExxonMobil, Mobil, Conoco Philips, Chevron, and Technip.
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`I am also a frequent presenter at several professional society conventions, including the
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`International Society of Offshore Mechanics and Polar Engineers and the Society of Naval
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`Architects and Naval Engineers. My research has been published in a variety of industry and
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`scientific journals, including the Journal of Fluid Mechanics and the Journal of Fluids and
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`Structures.
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`11. In my career I was involved in the design and implementation of advanced filtering and
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`control systems. My doctoral thesis (1976-1979) was on the dynamic positioning control
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`system used for ships drilling for oil and gas (funded by NSF). From 1979 through 1984 I
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`studied the problem of landing VTOL aircraft on smaller Navy ships using Kalman filtering
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`techniques to estimate and predict ship motions (funded by NASA). In 1986 through 1991 I
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`studied with a colleague at WHOI the dynamic positioning for ships that tow remotely
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`operated vehicles such as the ARGO and JASON vehicles of WHOI (funded by the Navy).
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`From 1991 through 1999 I directed the effort for designing the control systems for the
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`laboratory robot RoboTuna and the autonomous robot RoboPike (funded by ONR, DARPA,
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`and NOAA). From 1996 through 2006 I directed the development of hybrid control systems
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`that combine in real time simulation and experimentation, a methodology that is now used by
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`several groups worldwide (funded by ONR). From 2000 through 2006 I directed the
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`7
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 7
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`development of the autonomous robot RoboTurtle (funded by DARPA-CEROS and NOAA).
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`Since 2007, I have been involved with the development of pressure sensor arrays for real
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`time estimation of the flow around moving robots and structures, as well as with the design
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`of advanced biomimetic robots.
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`II.
`
`LEGAL STANDARDS
`
`A.
`
`Claim Construction
`
`12. I understand that in an inter partes review proceeding, the terms in the claims of the patent
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`are given their broadest reasonable interpretation in light of the specification, as understood
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`by one having ordinary skill in the relevant art as of the priority date of the patent at issue. I
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`have been informed that the priority date of the patents at issue is October 1, 1998.1
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`B.
`
`Anticipation
`
`13. I understand that a claim is unpatentable if it is anticipated. Anticipation of a claim requires
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`that every element of a claim be disclosed expressly or inherently in a single prior art
`
`reference, arranged in the prior reference as arranged in the claim. I understand that for a
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`feature to be “inherent” in a reference, the feature must necessarily be present based on the
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`details that are disclosed. I also understand that in order to anticipate, a reference must
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`enable one of skill in the art to practice an embodiment of the claimed invention without
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`undue experimentation.
`
`C.
`Obviousness
`
`1 My opinions would not change if the U.S. PCT filing date of September 28, 1999 were used
`as the priority date.
`
`
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`8
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 8
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`14. I understand that a claim is unpatentable if it is obvious. Obviousness of a claim requires that
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`the claim would have been obvious from the perspective of a person having ordinary skill in
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`the relevant art at the time the invention was made. I understand that a claim may be obvious
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`from a combination of two or more prior art references.
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`15. I understand that an obviousness analysis requires an understanding of the scope and content
`
`of the prior art, any differences between the claims of the patent in question and the prior art,
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`and the level of ordinary skill in the pertinent art.
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`16. I also understand that objective evidence of nonobviousness should be considered when
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`evaluating the obviousness of a claim. I understand that this objective evidence may include
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`the commercial success of the patented invention, any long-felt but unsolved need in the art
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`that was satisfied by the invention, the failure of others to make the invention, skepticism of
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`those having ordinary skill in the art at the time of the invention, unexpected results of the
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`invention, praise of the invention by those having ordinary skill in the art, and copying of the
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`invention by others in the field.
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`D.
`
`Person of Ordinary Skill in the Art
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`17. I understand that a person of ordinary skill in the art (“POSA”) is a hypothetical person that
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`is presumed to have the level of skill of a typical practitioner of the art at issue and is also
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`presumed to be aware of all relevant prior art. I also understand that multiple factors are
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`relevant in determining the level of ordinary skill in the art including, among other things, the
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`educational level of the inventor, the sophistication of the technology, the type of problems
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`encountered in the art, and prior art solutions to those problems.
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`9
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 9
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`18. Based on my consideration of those factors and my own experience in the field, it is my
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`opinion that one of ordinary skill in the art at the time of the ’520 patent, ’607 patent, and
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`’967 patent would have a Bachelor of Science in ocean engineering or control systems; or
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`five years of experience in the field of ocean engineering or marine seismic surveys.
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`III.
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`SUMMARY OF OPINIONS
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`19. I have been asked to give an opinion on whether certain claims of the ’520 patent (Ex. 1001),
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`’607 patent (Ex. 2043), and the ’967 (Ex. 2044) patent are anticipated or obvious based on
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`certain references. This section contains a summary of my opinions in this matter, which I
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`explain in further detail below.
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`20. I have included a table below listing the patents and claims I was asked to consider:
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`WesternGeco’s Patents At Issue
`
`Patent Number
`
`Claims at Issue
`
`U.S. Pat. No. 7,080,607
`(the ’607 patent)
`
`1. A method comprising:
`(a) towing an a array of streamers each having a plurality of streamer
`positioning devices there along;
`(b) predicting positions of at least some of the streamer positioning
`devices;
`(c) using the predicted positions to calculate desired changes in
`position of one or more of the streamer positioning devices; and
`(d) implementing at least some of the desired changes.
`
`15. An array of seismic streamers towed by a towing vessel
`comprising:
`(a) a plurality of streamer positioning devices on or inline with each
`streamer;
`(b) a prediction unit adapted to predict positions of at least some of the
`streamer positioning devices; and
`(c) a control unit adapted to use the predicted positions to calculate
`
`
`
`
`10
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 10
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`

`

`
`
`WesternGeco’s Patents At Issue
`
`Patent Number
`
`Claims at Issue
`
`U.S. Pat. No. 7,162,967
`(the ’967 patent)
`
`U.S. Pat. No. 7,293,520
`(the ’520 patent)
`
`desired changes in positions of one or more of the streamer
`positioning devices.
`
`1. A method comprising:
`(a) towing an array of streamers each having a plurality of streamer
`positioning devices there along, at least one of the streamer
`positioning devices having a wing;
`(b) transmitting from a global control system location information to
`at least one local control system on the at least one streamer
`positioning devices having a wing; and
`(c) adjusting the wing using the local control system.
`
`15. An array of seismic streamers towed by a towing vessel
`comprising:
`(a) a plurality of streamer positioning devices on or inline with each
`streamer, at least one of the streamer positioning devices having a
`wing;
`(b) a global control system transmitting location information to at least
`one local control system on the at least one streamer positioning
`device having a wing, the local control system adjusting the wing.
`
`1. A method comprising:
`(a) towing an array of streamers each having a plurality of streamer
`positioning devices there along contributing to steering the streamers;
`(b) controlling the streamer positioning devices with a control system
`configured to operate in one or more control modes selected from a
`feather angle mode, a turn control mode, and a streamer separation
`mode.
`
`2. The method of claim 1 wherein the control mode is the feather
`angle mode, and the controlling comprises the control system
`attempting to keep each streamer in a straight line offset from a
`towing direction by a feather angle.
`
`18. An apparatus comprising:
`(a) an array of streamers each having a plurality of streamer
`positioning devices there along;
`
`
`
`
`11
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 11
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`

`

`
`
`WesternGeco’s Patents At Issue
`
`Patent Number
`
`Claims at Issue
`
`(b) a control system configured to use a control mode selected from a
`feather angle mode, a turn control mode, a streamer separation mode,
`and two or more of these modes.
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`19. The apparatus of claim 18 wherein the control mode is the feather
`angle mode, and the controlling comprises the control system
`attempting to keep each streamer in a straight line offset from a
`towing direction by a feather angle.
`
`21. The following table lists the references the Board granted institution on:
`
`Alleged Prior Art
`
`Reference Title
`
`Exemplary Figure
`
`U.S. Pat. No. 5,790,472
`
`Inventors:
`Ricky L. Workman and
`Ronald Edward Chambers
`(the Workman patent or
`Workman)
`
`Title:
`Adaptive Control of Marine
`Seismic Streamers
`
`
`
`
`12
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`
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 12
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`

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`
`
`Alleged Prior Art
`
`Reference Title
`
`Exemplary Figure
`
`U.S. Pat. No. 5,532,975
`
`Inventor:
`Tor Elholm
`(the Elholm patent or
`Elholm)
`
`Title:
`for
`Device and Method
`Positioning
`of
`Towing
`Systems for Use in Marine
`Seismic Surveys
`
`U.S. Pat. No. 3,581,273
`
`Inventor:
`Ronald M. Hedberg
`(the Hedberg patent or
`Hedberg)
`
`Title:
`Marine Seismic Exploration
`
`
`
`
`13
`
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`
`
`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 13
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`

`

`
`
`Alleged Prior Art
`
`Reference Title
`
`Exemplary Figure
`
`Application
`International
`WO 98/28636 PCT
`(the ’636 PCT)
`
`Inventor:
`Simon Bittleston
`
`Title:
`for
`Devices
`Control
`Controlling the Position of a
`Marine Seismic Streamer
`
`
`
`A.
`
`Summary of Opinions Regarding the ’607 Patent
`
`22. Claims 1 and 15 of the ’607 patent are not anticipated by Workman.
`
`23. Claims 1 and 15 of the ’607 patent are not obvious over Workman.
`
`24. Claims 1 and 15 of the ’607 patent are not obvious over Workman and Elholm.
`
`A.
`
`Summary of Opinions Regarding the ’967 Patent
`
`25. Claims 1 and 15 of the ’967 patent are not anticipated by the ’636 PCT.
`
`26. Claims 1 and 15 of the ’967 patent are not obvious over the ’636 PCT.
`
`B.
`
`Summary of Opinions Regarding the ’520 Patent
`
`27. Claims 1 and 18 of the ’520 patent are not anticipated by Workman.
`
`
`
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`14
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 14
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`28. Claims 1, 2, 18, and 19 of the ’520 patent are not obvious over Workman.
`
`29. Claims 1, 2, 18, and 19 of the ’520 patent are not anticipated by Hedberg.
`
`30. Claims 1, 2, 18, and 19 of the ’520 patent are not obvious over Hedberg.
`
`IV.
`
`BACKGROUND OF THE TECHNOLOGY
`
`A.
`
`Background Technical Principles
`
`31. Marine seismic surveys use specialized equipment to discover oil and gas deposits below the
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`bottom of the ocean. A seismic vessel typically tows a portion of this equipment through the
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`water, and there is also equipment located on the seismic vessel itself. Devices in the water
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`are usually called “wet” devices because they are in the water, while devices on the boat are
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`typically called “dry” devices. A piece of equipment, usually called an “air gun,” is towed in
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`the water behind the seismic vessel and causes a small, controlled explosion underwater.
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`This explosion generates sound waves that travel through the water and penetrate the surface
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`of the earth; the waves travel through the layers of the earth that lie beneath the ocean floor,
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`each layer in a different way based on the geological formations found within the earth, and
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`some of the energy is reflected at the interfaces between layers. Underwater sensors known
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`as hydrophones pick up these reflections — many sensors are needed to measure the
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`reflections at several locations, in order to be able to determine the shape of the earth layers
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`that cause the reflections. Based on these reflected signals, special computer programs are
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`used to reconstruct the shape of the earth layers based on the hydrophone measurements as
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`well as to provide information regarding the contents of those layers to reveal whether oil or
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`another natural resource is present. In order for the measurements to cover a large area, yet
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`15
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 15
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`still be accurate, many hydrophones are towed behind the vessel and spread over a large area,
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`like a large antenna. The hydrophones are contained inside several very long cables called
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`streamers, which are typically several miles long, and are connected through wires to a
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`computer system on the towing vessel.
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`32. Environmental factors, such as current speed and direction, can significantly influence the
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`path of the towed array. Currents often contain turbulent eddies and therefore exert a non-
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`uniform force on the streamers. The irregular force of the current changes the shape of the
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`highly flexible streamers, causing inaccuracies in the hydrophone measurements. Changes in
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`streamer shape can also result in streamer entanglement, causing significant damage to
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`equipment and delay of the exploration.
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`
`
`Figure 1 - Example of the effect of currents on a streamer.
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`33. In 2D surveys, one streamer cable (containing within it many hydrophones) is towed behind
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`the vessel. That allows for an image of a flat slice through the earth. In order to get a 3D
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`image, one needs to combine multiple slices next to each other. For that reason, in a 3D
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`
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`16
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`PGS v. WESTERNGECO (IPR2014-00689)
`WESTERNGECO Exhibit 2042, pg. 16
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`survey, typically multiple streamers are towed next to each other, in what is typically known
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`as a streamer array.
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`Figure 2 - An idealized single seismic streamer in a 2D survey.
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`Figure 3 - An idealized seismic streamer array in a 3D survey.
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`PGS v. WESTERNGECO (IPR2014-00689)
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`34. These surveys typically consist of a series of “lines” where seismic data is gathered
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`(sometimes known as “shooting”) along a specified path. At the end of each line, a vessel
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`completes a “line change.” A line change is a turn a ship completes between shooting lines.
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`35. It is crucial for the accuracy of oil and gas detection in all types of surveys that the
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`hydrophones are spread out and that by the time for data processing their locations are known
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`with high accuracy. Because the hydrophones are inside the streamers, the position of the
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`streamers must be known very accurately. Indeed, the processing of the collected data is
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`dependent on knowing the locations of the hydrophones. Another important concern is that
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`adjacent streamers do not become entangled. However, when towing the streamers in the
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`ocean, currents and waves cause them to move away from their ideal configuration. Also,
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`when the towing ship is maneuvering, as she turns, for example, to reach a position that must
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`be investigated, the streamers become highly curved. It takes a long time for a curved
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`streamer to return to a straight shape, because of the large drag forces acting over a streamer
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`that can be several miles long.
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`36. A streamer has significant dynamics, which were understood only starting in the 1970s and
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`through the 1990s, because of the complexity of the interaction between the structure (the
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`streamer) and the flow. If at any point along the streamer an unsteady force is applied, the
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`streamer will bend and will create “waves”; in other words, a lateral local motion of the
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`streamer does not stay in the location where the force is applied, but propagates along the
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`streamer, mainly towards the tail. The speed of travel decreases as the wave propagates
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`towards the tail end of the streamer, but is relatively slow, 5 m/s to 2 m/s, typically. On a
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`typical seismic streamer of several miles, a disturbance wave might take 10 minutes or more
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`to travel the length of the streamer. If multiple forces are applied simultaneously, e.g., by
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`PGS v. WESTERNGECO (IPR2014-00689)
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`lateral steering devices along the streamer, they will create several such traveling
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`disturbances that will reach the downstream birds in several seconds or minutes. Applying
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`such forces without an appreciation of or accounting for these traveling disturbances could
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`lead to unexpected and uncontrolled results and likely cause more harm than good.
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`Figure 4 - Force applied by one device will affect others downstream.
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`37. As shown in Dowling’s 1988 study in the Journal of Fluid Mechanics (the premier journal in
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`fluid mechanics), there were several issues with the proper understanding of the dynamics of
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`streamers, even when towed under steady conditions. (Ex. 2045, A. Dowling, The Dynamics
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`of Towed Flexible Cylinders, Part I: Neutrally Buoyant Elements, 187 J. Fluid Mech., at 507-
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`532 (1988).) The difficulty in modeling the fluid forces is outlined in the paper by Dowling
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`and in the definitive book on the topic by Paidoussis. (Ex. 2046, M.P. Paidoussis, Fluid-
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`Structure Interactions: Slender Structures and Axial Flow (1998).) In 1991, I was asked to
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`PGS v. WESTERNGECO (IPR2014-00689)
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`review the literature on this and related topics, where I outlined the problems with the various
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`efforts to model and simulate the dynamics of streamers. (Ex. 2047, M.S. Triantafyllou,
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`Dynamics of Cables, Towing Cables and Mooring Systems, 23 Shock & Vibration Dig., No.
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`7, at 3-8 (1991).)
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`38. The mechanics of cables and hawsers in the ocean are very complex and the capability to
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`properly model and simulate these dynamics is a relatively recent development. Concepts
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`such as effective tension, and complex phenomena such as the “worm-in-hole” effect of
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`lateral drag, are some examples of recent developments that are critical to the proper
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`simulation of underwater systems. I have published on the topic extensively, and also have
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`co-developed with Dr. Mark Grosenbaugh of Woods Hole Oceanographic Institution the
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`theory and algorithms that led to WHOI-CABLE, a program supported by the US Navy, that
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`is in the public domain and can be used to simulate, among other things, the cable dynamics
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`of towed systems. (Ex. 2048, Jason I. Gobat, Mark A. Grosenbaugh, & Michael S.
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`Triantafyllou, Woods Hole Oceanographic Inst., WHOI Cable: Time Domain Numerical
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`Simulation of Moored and Towed Oceanographic Systems, (November 1997); Ex. 2049,
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`Jason I. Gobat, Mark A. Grosenbaugh, & Michael S. Triantafyllou, Generalized-α Time
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`Integration Solutio