`
`———————————
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`———————————
`
`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
`
`
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 1
`
`
`
`
`
`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
`
`
`
`
`
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 2
`
`
`
`
`
`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
`
`
`
`
`
`3
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 3
`
`
`
`
`
`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
`
`marine vehicles and structures. I specialize in two fields: (1) control theory; and (2) the
`
`interactions between fluids and structures, including fluid mechanics and structural
`
`dynamics. A copy of my curriculum vitae, including a list of the publications I have
`
`authored within the last 10 years, is attached hereto as Exhibit A. I have provided testimony
`
`at a deposition and at trial in the past 4 years. These engagements are listed in Exhibit B. I
`
`am being compensated at a rate of $350 per hour for the time I devote to this matter. I have
`
`no financial interest in the outcome of this litigation. The information I considered in
`
`forming my opinions is attached hereto as Exhibit C.
`
`2. I earned a bachelor’s degree in Naval Architecture and Marine Engineering in 1974 from the
`
`National Technical University of Athens in Athens, Greece. I have also earned the degrees
`
`of Masters of Science in Mechanical Engineering, and Masters of Science in Ocean
`
`Engineering, both awarded in 1977 from the Massachusetts Institute of Technology (“MIT”).
`
`In 1979, I earned a Doctorate of Science in Ocean Engineering from MIT. During the course
`
`of my doctorate studies, I conducted research on the dynamics and control of ships and
`
`positioning structures for the oil industry.
`
`3. Since 1979, I have been a faculty member first in MIT’s Ocean Engineering department and
`
`then in MIT’s Mechanical Engineering department. I was an Assistant Professor from 1979
`
`to 1983, and Associate Professor without tenure from 1983 to 1986. Much of my research
`
`during this time focused on cable mechanics, and specifically on the design of marine cable
`
`
`
`
`
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 4
`
`
`
`
`
`lines subject to large forces, such as ocean currents. Many of the principles of cable
`
`mechanics are equally applicable to streamers used in marine seismic surveys. In addition to
`
`my research, I taught courses in the design of floating structures and the dynamics of ocean
`
`structures.
`
`4. I earned permanent tenure status in 1986. I continued my research on cable mechanics,
`
`focusing specifically on towed cables, including streamers and towed arrays. In conjunction
`
`with the United States Navy, I studied the fluid mechanics of towed arrays for use behind
`
`submarines for the detection of other vessels. Though the precise nature of my work for the
`
`Navy remains confidential, it involved the development of the boundary layer theory around
`
`towed cables, as well as their hydrodynamics and maneuverability.
`
`5. In 1990, I earned the title of Professor. I continued to work on the development of cables and
`
`towed arrays for the United States Navy, specifically focusing on conducting modeling
`
`studies for the hydrodynamics of marine cables.
`
`6. Since 2004, I have served as the Director of the Center for Ocean Engineering at MIT. In
`
`2008, I was named Associate Department Head of the Mechanical Engineering Department,
`
`and I currently serve as the William I. Koch Chair in Marine Technology. During 2007-
`
`2014, I conducted research focused on developing steering capabilities for the Navy’s
`
`acoustic towed arrays. The technology is similar to the steerable streamer concepts
`
`employed by the oil exploration industry. Part of my research focused on simulating the
`
`overall performance of underwater arrays towed by helicopter at high speed for underwater
`
`detection. Arrays towed by helicopter present many of the same challenges as arrays towed
`
`by marine seismic vessels, but also present many additional challenges. For example,
`
`
`
`
`5
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 5
`
`
`
`
`
`helicopters tow arrays at much faster speeds, up to twenty miles per hour, than seismic
`
`vessels, adding to the complexity of the system.
`
`7. In 2013, I became Chairman of the Board of the National Technical University of Athens.
`
`8. For approximately twenty years, my research at MIT has also included the development of
`
`marine robots with flexible hulls that propel themselves through water, or “swim,” much like
`
`fish. In its initial stages, the project involved the design and control of robot bodies that
`
`swim like marine creatures, such as dolphins and tuna. These robots are capable of sensing
`
`their surrounding environmental conditions in order to achieve optimal propulsion and
`
`maneuverability. The robots are capable of adjusting their motion to account for ocean
`
`currents and turbulence from structures in the water. They can be controlled remotely, but
`
`are also capable of autonomous control. More recently, my research efforts have been
`
`focused on the development of specialized pressure and velocity sensors distributed
`
`throughout the robot bodies, which allow the robots to detect flow patterns and other objects
`
`in the water. This research has been featured several times in industry and academic
`
`publications, including Physics of Fluids, Discovery Magazine, and The Scientific American.
`
`Ultimately, the practical application of this project will be to apply these principles to larger
`
`marine vessels for faster turning and more precise control of, for example, marine cables. In
`
`2014 I was elected fellow of the American Physical Society for “pioneering the use of
`
`biomimetic robots.”
`
`9. In addition to my responsibilities at MIT, since 1979 I have been a visiting research scientist
`
`at the Woods Hole Oceanographic Institute (“WHOI”) in Woods Hole, Massachusetts.
`
`WHOI is one of the world’s largest ocean research and engineering organizations. Its work
`
`
`
`
`6
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 6
`
`
`
`
`
`focuses on all aspects of ocean research, including the development of technology for natural
`
`resource exploration beneath the ocean subsurface. As part of my research at WHOI, I was
`
`part of the team that developed the WHOI-Cable, a simulation program that simulates the
`
`fluid mechanics and dynamics for moorings and towed marine cables and arrays.
`
`10. I routinely consult on issues related to marine exploration for the petroleum industry,
`
`including projects on behalf of ExxonMobil, Mobil, Conoco Philips, Chevron, and Technip.
`
`I am also a frequent presenter at several professional society conventions, including the
`
`International Society of Offshore Mechanics and Polar Engineers and the Society of Naval
`
`Architects and Naval Engineers. My research has been published in a variety of industry and
`
`scientific journals, including the Journal of Fluid Mechanics and the Journal of Fluids and
`
`Structures.
`
`11. In my career I was involved in the design and implementation of advanced filtering and
`
`control systems. My doctoral thesis (1976-1979) was on the dynamic positioning control
`
`system used for ships drilling for oil and gas (funded by NSF). From 1979 through 1984 I
`
`studied the problem of landing VTOL aircraft on smaller Navy ships using Kalman filtering
`
`techniques to estimate and predict ship motions (funded by NASA). In 1986 through 1991 I
`
`studied with a colleague at WHOI the dynamic positioning for ships that tow remotely
`
`operated vehicles such as the ARGO and JASON vehicles of WHOI (funded by the Navy).
`
`From 1991 through 1999 I directed the effort for designing the control systems for the
`
`laboratory robot RoboTuna and the autonomous robot RoboPike (funded by ONR, DARPA,
`
`and NOAA). From 1996 through 2006 I directed the development of hybrid control systems
`
`that combine in real time simulation and experimentation, a methodology that is now used by
`
`several groups worldwide (funded by ONR). From 2000 through 2006 I directed the
`
`
`
`
`7
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 7
`
`
`
`
`
`development of the autonomous robot RoboTurtle (funded by DARPA-CEROS and NOAA).
`
`Since 2007, I have been involved with the development of pressure sensor arrays for real
`
`time estimation of the flow around moving robots and structures, as well as with the design
`
`of advanced biomimetic robots.
`
`II.
`
`LEGAL STANDARDS
`
`A.
`
`Claim Construction
`
`12. I understand that in an inter partes review proceeding, the terms in the claims of the patent
`
`are given their broadest reasonable interpretation in light of the specification, as understood
`
`by one having ordinary skill in the relevant art as of the priority date of the patent at issue. I
`
`have been informed that the priority date of the patents at issue is October 1, 1998.1
`
`B.
`
`Anticipation
`
`13. I understand that a claim is unpatentable if it is anticipated. Anticipation of a claim requires
`
`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
`
`feature to be “inherent” in a reference, the feature must necessarily be present based on the
`
`details that are disclosed. I also understand that in order to anticipate, a reference must
`
`enable one of skill in the art to practice an embodiment of the claimed invention without
`
`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.
`
`
`
`
`8
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 8
`
`
`
`
`
`14. I understand that a claim is unpatentable if it is obvious. Obviousness of a claim requires that
`
`the claim would have been obvious from the perspective of a person having ordinary skill in
`
`the relevant art at the time the invention was made. I understand that a claim may be obvious
`
`from a combination of two or more prior art references.
`
`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,
`
`and the level of ordinary skill in the pertinent art.
`
`16. I also understand that objective evidence of nonobviousness should be considered when
`
`evaluating the obviousness of a claim. I understand that this objective evidence may include
`
`the commercial success of the patented invention, any long-felt but unsolved need in the art
`
`that was satisfied by the invention, the failure of others to make the invention, skepticism of
`
`those having ordinary skill in the art at the time of the invention, unexpected results of the
`
`invention, praise of the invention by those having ordinary skill in the art, and copying of the
`
`invention by others in the field.
`
`D.
`
`Person of Ordinary Skill in the Art
`
`17. I understand that a person of ordinary skill in the art (“POSA”) is a hypothetical person that
`
`is presumed to have the level of skill of a typical practitioner of the art at issue and is also
`
`presumed to be aware of all relevant prior art. I also understand that multiple factors are
`
`relevant in determining the level of ordinary skill in the art including, among other things, the
`
`educational level of the inventor, the sophistication of the technology, the type of problems
`
`encountered in the art, and prior art solutions to those problems.
`
`
`
`
`9
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 9
`
`
`
`
`
`18. Based on my consideration of those factors and my own experience in the field, it is my
`
`opinion that one of ordinary skill in the art at the time of the ’520 patent, ’607 patent, and
`
`’967 patent would have a Bachelor of Science in ocean engineering or control systems; or
`
`five years of experience in the field of ocean engineering or marine seismic surveys.
`
`III.
`
`SUMMARY OF OPINIONS
`
`19. I have been asked to give an opinion on whether certain claims of the ’520 patent (Ex. 2063),
`
`’607 patent (Ex. 1001), and the ’967 (Ex. 2044) patent are anticipated or obvious based on
`
`certain references. This section contains a summary of my opinions in this matter, which I
`
`explain in further detail below.
`
`20. I have included a table below listing the patents and claims I was asked to consider:
`
`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
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 10
`
`
`
`
`
`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
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 11
`
`
`
`
`
`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.
`
`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
`
`
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 12
`
`
`
`
`
`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
`
`
`
`
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 13
`
`
`
`
`
`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.
`
`
`
`
`14
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 14
`
`
`
`
`
`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
`
`bottom of the ocean. A seismic vessel typically tows a portion of this equipment through the
`
`water, and there is also equipment located on the seismic vessel itself. Devices in the water
`
`are usually called “wet” devices because they are in the water, while devices on the boat are
`
`typically called “dry” devices. A piece of equipment, usually called an “air gun,” is towed in
`
`the water behind the seismic vessel and causes a small, controlled explosion underwater.
`
`This explosion generates sound waves that travel through the water and penetrate the surface
`
`of the earth; the waves travel through the layers of the earth that lie beneath the ocean floor,
`
`each layer in a different way based on the geological formations found within the earth, and
`
`some of the energy is reflected at the interfaces between layers. Underwater sensors known
`
`as hydrophones pick up these reflections — many sensors are needed to measure the
`
`reflections at several locations, in order to be able to determine the shape of the earth layers
`
`that cause the reflections. Based on these reflected signals, special computer programs are
`
`used to reconstruct the shape of the earth layers based on the hydrophone measurements as
`
`well as to provide information regarding the contents of those layers to reveal whether oil or
`
`another natural resource is present. In order for the measurements to cover a large area, yet
`
`
`
`
`15
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 15
`
`
`
`
`
`still be accurate, many hydrophones are towed behind the vessel and spread over a large area,
`
`like a large antenna. The hydrophones are contained inside several very long cables called
`
`streamers, which are typically several miles long, and are connected through wires to a
`
`computer system on the towing vessel.
`
`32. Environmental factors, such as current speed and direction, can significantly influence the
`
`path of the towed array. Currents often contain turbulent eddies and therefore exert a non-
`
`uniform force on the streamers. The irregular force of the current changes the shape of the
`
`highly flexible streamers, causing inaccuracies in the hydrophone measurements. Changes in
`
`streamer shape can also result in streamer entanglement, causing significant damage to
`
`equipment and delay of the exploration.
`
`
`
`Figure 1 - Example of the effect of currents on a streamer.
`
`33. In 2D surveys, one streamer cable (containing within it many hydrophones) is towed behind
`
`the vessel. That allows for an image of a flat slice through the earth. In order to get a 3D
`
`image, one needs to combine multiple slices next to each other. For that reason, in a 3D
`
`
`
`
`16
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 16
`
`
`
`
`
`
`
`
`survey, typically multiple streamers are towed next to each other, in what is typically known
`
`as a streamer array.
`
`Figure 2 - An idealized single seismic streamer in a 2D survey.
`
`Figure 3 - An idealized seismic streamer array in a 3D survey.
`
`17
`
`
`
`
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 17
`
`
`
`
`
`34. These surveys typically consist of a series of “lines” where seismic data is gathered
`
`(sometimes known as “shooting”) along a specified path. At the end of each line, a vessel
`
`completes a “line change.” A line change is a turn a ship completes between shooting lines.
`
`35. It is crucial for the accuracy of oil and gas detection in all types of surveys that the
`
`hydrophones are spread out and that by the time for data processing their locations are known
`
`with high accuracy. Because the hydrophones are inside the streamers, the position of the
`
`streamers must be known very accurately. Indeed, the processing of the collected data is
`
`dependent on knowing the locations of the hydrophones. Another important concern is that
`
`adjacent streamers do not become entangled. However, when towing the streamers in the
`
`ocean, currents and waves cause them to move away from their ideal configuration. Also,
`
`when the towing ship is maneuvering, as she turns, for example, to reach a position that must
`
`be investigated, the streamers become highly curved. It takes a long time for a curved
`
`streamer to return to a straight shape, because of the large drag forces acting over a streamer
`
`that can be several miles long.
`
`36. A streamer has significant dynamics, which were understood only starting in the 1970s and
`
`through the 1990s, because of the complexity of the interaction between the structure (the
`
`streamer) and the flow. If at any point along the streamer an unsteady force is applied, the
`
`streamer will bend and will create “waves”; in other words, a lateral local motion of the
`
`streamer does not stay in the location where the force is applied, but propagates along the
`
`streamer, mainly towards the tail. The speed of travel decreases as the wave propagates
`
`towards the tail end of the streamer, but is relatively slow, 5 m/s to 2 m/s, typically. On a
`
`typical seismic streamer of several miles, a disturbance wave might take 10 minutes or more
`
`to travel the length of the streamer. If multiple forces are applied simultaneously, e.g., by
`
`
`
`
`18
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 18
`
`
`
`
`
`lateral steering devices along the streamer, they will create several such traveling
`
`disturbances that will reach the downstream birds in several seconds or minutes. Applying
`
`such forces without an appreciation of or accounting for these traveling disturbances could
`
`lead to unexpected and uncontrolled results and likely cause more harm than good.
`
`
`
`Figure 4 - Force applied by one device will affect others downstream.
`
`
`37. As shown in Dowling’s 1988 study in the Journal of Fluid Mechanics (the premier journal in
`
`fluid mechanics), there were several issues with the proper understanding of the dynamics of
`
`streamers, even when towed under steady conditions. (Ex. 2045, A. Dowling, The Dynamics
`
`of Towed Flexible Cylinders, Part I: Neutrally Buoyant Elements, 187 J. Fluid Mech., at 507-
`
`532 (1988).) The difficulty in modeling the fluid forces is outlined in the paper by Dowling
`
`and in the definitive book on the topic by Paidoussis. (Ex. 2046, M.P. Paidoussis, Fluid-
`
`Structure Interactions: Slender Structures and Axial Flow (1998).) In 1991, I was asked to
`
`
`
`
`19
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2042, pg. 19
`
`
`
`
`
`review the literature on this and related topics, where I outlined the problems with the various
`
`efforts to model and simulate the dynamics of streamers. (Ex. 2047, M.S. Triantafyllou,
`
`Dynamics of Cables, Towing Cables and Mooring Systems, 23 Shock & Vibration Dig., No.
`
`7, at 3-8 (1991).)
`
`38. The mechanics of cables and hawsers in the ocean are very complex and the capability to
`
`properly model and simulate these dynamics is a relatively recent development. Concepts
`
`such as effective tension, and complex phenomena such as the “worm-in-hole” effect of
`
`lateral drag, are some examples of recent developments that are critical to the proper
`
`simulation of underwater systems. I have published on the topic extensively, and also have
`
`co-developed with Dr. Mark Grosenbaugh of Woods Hole Oceanographic Institution the
`
`theory and algorithms that led to WHOI-CABLE, a program supported by the US Navy, that
`
`is in the public domain and can be used to simulate, among other things, the cable dynamics
`
`of towed systems. (Ex. 2048, Jason I. Gobat, Mark A. Grosenbaugh, & Michael S.
`
`Triantafyllou, Woods Hole Oceanographic Inst., WHOI Cable: Time Domain Numerical
`
`Simulation of Moored and Towed Oceanographic Systems, (November 1997); Ex. 2049,
`
`Jason I. Gobat, Mark A. Grosenbaugh, & Michael S. Triantafyllou, Generalized-α Time
`
`Integration Solutions for Hanging Chain Dynamics,