`U.S. Patent No. 8,851,162 by Rutledge for
`Sucker Rod Apparatus and Method
`
`
`
`Prepared by:
`
`Gary R. Wooley
`
`Wooley & Associates, Inc.
`
`3100 S. Gessner, Suite 325
`Houston, Texas 77063
`Phone 713.781.8974
`Email gary@wooley.com
`
`
`
`
`
`
`
`Prepared for:
`
`Morgan, Lewis & Bockius LLP
`
`1000 Louisiana St., Suite 4000
`Houston, Texas 77002-5006
`Phone 713.890.5165
`
`29 January 2016
`
`
`Wooley & Associates, Inc.
`
`
`
`Pet'rs Exhibit 1010
`John Crane v. Finalrod
`IPR2016-00521
`
`Page0000001
`
`
`
`TABLE OF CONTENTS
`
`
`I.
`
`II.
`
`Page
`Introduction ..................................................................................................... 1
`1.
`Background and Qualifications ............................................................ 1
`2.
`Engagement .......................................................................................... 2
`3. Materials Consulted .............................................................................. 3
`Basic Oil Well Sucker Rods ........................................................................... 5
`1.
`Field Use of Oil Sucker Rods ............................................................... 5
`2.
`Overview of Forces Encountered During Sucker Rod Use ................. 8
`3.
`Common Problems to Address in the Field ....................................... 16
`III. Legal Standards for Patentability ................................................................. 25
`1.
`Anticipation ........................................................................................ 25
`2.
`Obviousness ........................................................................................ 26
`IV. Overview of U.S. Patent 8,851,162 to Rutledge .......................................... 28
`1.
`Rutledge ’162 Patent Effective Filing Date ....................................... 28
`2.
`Overview of the Rutledge ’162 Patent ............................................... 29
`3.
`Prosecution History of the Rutledge ’162 Patent ............................... 30
`Relevant Field of Art .................................................................................... 32
`V.
`VI. Level of Ordinary Skill ................................................................................. 33
`VII. Claims of the Rutledge ’162 Patent .............................................................. 34
`VIII. Claim Constructions ..................................................................................... 37
`1.
`Claim Construction Standard ............................................................. 37
`2.
`Construction of The Rutledge ’162 Patent Claim Terms ................... 39
`IX. Background Invalidity Analysis ................................................................... 43
`1.
`Scope and Content of the Prior Art .................................................... 43
`2.
`The ’162 Rutledge Patent Claim Sets ................................................ 43
`3.
`Overview of the Prior Art Patents ...................................................... 48
`4. Motivation to Combine The Prior Art Patents ................................... 50
`Claims 1, 6-11, 16-20, 25-28, 30, & 31 are invalid under 35 U.S.C.
`§103 as obvious over the Rutledge ’431 Patent in view of Strandberg ....... 52
`-i-
`
`
`X.
`
`
`
`
`
`Page0000002
`
`
`
`TABLE OF CONTENTS
`(continued)
`
`Page
`
`
`
`1.
`
`2.
`
`3.
`
`The Rutledge ’431 & Strandberg Patents Disclose Each
`Element of Claims 1, 11, 20, & 31 ..................................................... 52
`Rutledge ’431 Patent Discloses Each Additional Element of
`Claims 6, 16, and 25 ........................................................................... 81
`Rutledge ’431 Patent Discloses Each Additional Element of
`Claim 7 ............................................................................................... 82
`Rutledge ’431 Patent Discloses Each Additional Element of
`Claims 8, 17, and 26 ........................................................................... 83
`Rutledge ’431 Patent Discloses Each Additional Element of
`Claims 9, 18, and 27 ........................................................................... 84
`Strandberg Discloses Each Additional Element of Claims 10,
`19, and 28 ........................................................................................... 85
`Strandberg and the Rutledge ’431 Patent Disclose Each
`Additional Element of Claim 30 ........................................................ 88
`XI. Claims 2-5, 12-15, 21-24, and 32-38 are invalid under 35 U.S.C. §103
`as obvious over the Rutledge ’431 and Strandberg Patents further in
`view of Morrow ............................................................................................ 93
`1. Morrow Discloses Each Additional Element of Claims 2, 12,
`21, 32, and 38 ..................................................................................... 93
`2. Morrow Discloses Each Additional Element of Claim 33 ................. 97
`3. Morrow Discloses Each Additional Element of Claims 3, 13,
`22, 34, and 35 ..................................................................................... 98
`4. Morrow Discloses Each Additional Element of Claims 4, 14,
`23, and 36 ......................................................................................... 101
`Rutledge ’431 Discloses Each Additional Element of Claims 5,
`15, 24, and 37 ................................................................................... 103
`XII. Claims 29 and 39 are invalid under 35 U.S.C. §103 as obvious over
`the Rutledge ’431 and Strandberg Patents further in view of Iwasaki ...... 106
`Iwasaki Discloses Each Additional Element of Claim 29 ............... 106
`1.
`Iwasaki Discloses Each Additional Element of Claim 39 ............... 109
`2.
`
`4.
`
`5.
`
`6.
`
`7.
`
`5.
`
`
`
`
`
`-ii-
`
`
`
`Page0000003
`
`
`
`TABLE OF CONTENTS
`(continued)
`
`Page
`
`
`XIII. Claim 40 is invalid under 35 U.S.C. §103 as obvious over the
`Rutledge ’431 and Strandberg Patents further in view of the Rutledge
`’560 Patent .................................................................................................. 110
`XIV. Conclusion .................................................................................................. 114
`XV. Appendix ..................................................................................................... 115
`1.
`Resumé for Gary R. Wooley ............................................................ 115
`2.
`List of Recent Wooley Testimony ................................................... 116
`
`
`
`
`
`-iii-
`
`
`
`Page0000004
`
`
`
`
`
`I.
`
`Introduction
`1.
`Background and Qualifications
`1. My name is Gary R. Wooley. I am currently President of Wooley &
`
`Associates, Inc., a petroleum and mechanical engineering consulting firm. A copy
`
`of my current curriculum vitae more fully setting forth my experiences and
`
`qualifications is submitted herewith in the Appendix to this Report.
`
`2.
`
`I have more than 40 years of petroleum industry experience most of
`
`which has been in the upstream sector dealing with drilling, completions,
`
`production, reservoir performance and other subjects including artificial lift such as
`
`rod pumping. I received my university training at Louisiana State University in
`
`Baton Rouge, Louisiana and was awarded a B.S. in Mechanical Engineering in
`
`1969, an M.S. in Engineering Science in 1970 and Ph.D. in Engineering Science
`
`with minors in Applied Mathematics and Mechanical Engineering in 1972.
`
`3.
`
`I was trained in the petroleum industry by four major oil companies,
`
`Shell, Chevron, Humble (Exxon) and ARCo and have been a consulting engineer
`
`since 1978 with clients that include all of the major oil companies, service
`
`contractors and supply companies and many smaller companies. I have conducted
`
`laboratory and field tests, developed computer models, and designed and evaluated
`
`downhole oilfield equipment. I have worked on multiple artificial lift projects
`
`including rod pumps.
`
`Wooley & Associates, Inc.
`
`1
`
`
`Page0000005
`
`
`
`
`
`4.
`
`This report contains facts, opinions and conclusions based on my
`
`training and experience and the information reviewed at the time of this writing.
`
`My resumé is also presented in the Appendix along with my recent testimony.
`
`5.
`
`This report contains my general opinions, but obviously not all details
`
`are included. If asked questions on these facts and opinions or other subjects, I may
`
`have opinions not specifically listed herein. There may be documents and
`
`testimony that support my opinions that are not included herein.
`
`6.
`
`As additional information is examined, these facts, opinions and
`
`conclusions may be changed and/or supplemented. Upon review of additional
`
`documents and testimony I may supplement or revise my opinions. Also, after
`
`reading reports by defendants’ experts, I may have opinions to rebut those expert
`
`opinions.
`
`2.
`7.
`
`Engagement
`
`I have been retained by John Crane, Inc. and John Crane Production
`
`Solutions, Inc. (“John Crane”) in connection with the Petition for Inter Partes
`
`Review (“IPR”) of U.S. Patent No. 8,851,162 (“the ’162 Patent”), Case No.
`
`IPR2016-00521. I submit this declaration in support of John Crane’s request for
`
`IPR of the ’162 Patent. I understand that my testimony will be submitted for the
`
`purposes of testimonial evidence in IPR2016-00521 to be considered before the
`
`Patent Trial and Appeal Board (“PTAB”).
`
`Wooley & Associates, Inc.
`
`2
`
`Page0000006
`
`
`
`
`
`8.
`
`I am not an employee of John Crane, or any affiliate or subsidiary
`
`thereof.
`
`9.
`
`I am being compensated at my normal hourly rate of $ 520 per hour.
`
`My compensation is in no way dependent upon the outcome of the IPR.
`
`10.
`
`I have been asked to provide my opinions relating to the validity of
`
`the ’162 Patent. Specifically, I have been asked to provide my opinion regarding:
`
`(i) the level of ordinary skill in the art to which the ’162 Patent pertains, and (ii)
`
`the patentability of claims 1 – 40 of the ’162 Patent.
`
`11. The opinions expressed in this declaration are not exhaustive of my
`
`opinions on the validity of claims 1 – 40 of the ’162 Patent. Therefore, the fact
`
`that I do not address a particular point should not be understood to indicate any
`
`agreement on my part that any claim otherwise complies with the validity and
`
`patentability requirements.
`
`3. Materials Consulted
`12.
`In preparing this declaration, I reviewed the following material,
`
`which, in conjunction with my personal experience in the relevant field, provide
`
`the basis of my opinions in this Report:
`
`a)
`
`b)
`
`c)
`
`John Crane’s Petition for Inter Partes Review;
`
`The ’162 Patent (Ex. 1001);
`
`The ’162 Patent file history (Ex. 1002);
`
`Wooley & Associates, Inc.
`
`3
`
`Page0000007
`
`
`
`
`
`
`
`d) U.S. Patent No. 8,113,431 (“Rutledge ’431 Patent”; Ex. 1003);
`
`e)
`
`f)
`
`g)
`
`U.S. Patent No. 4,475,839 (“Strandberg”; Ex. 1004);
`
`U.S. Patent No. 4,662,774 (“Morrow”; Ex. 1005);
`
`U.S. Patent No. 8,113,277 (“Rutledge ’277 Patent”; Ex. 1006);
`
`h) U.S. Patent No. 4,822,201 (“Iwasaki”; Ex. 1007);
`
`i)
`
`j)
`
`k)
`
`l)
`
`U.S. Patent No. 4,919,560 (“Rutledge ’560 Patent; Ex. 1008);
`
`U.S. Patent No. 5,253,946 (“Watkins”; Ex. 1009);
`
`Side-by-Side Comparison of the ’162 Patent claims (Ex. 1011);
`
`U.S. Patent No. 4,401,396 (“McKay”; Ex. 1012);
`
`m) U.S. Reissue Patent No. RE32,865 (“Rutledge ’865 Patent”; Ex.
`
`1013);
`
`n) U.S. Patent No. 7,730,938 (“Rutledge ’938 Patent”; Ex. 1014);
`
`o)
`
`Edward L. Hoffman, Finite Element Analysis of Sucker Rod
`
`Couplings with Guidelines for Improving Fatigue Life, Sandia
`
`National Laboratories, (Jul. 11, 1997) (“Hoffman Article”; Ex.
`
`1015);
`
`p) U.S. Patent No. 8,062,463 (“Rutledge ’463 Patent”; Ex. 1016);
`
`q) U.S. Patent No. 6,886,484 (“Thomas”; Ex. 1017); and
`
`r)
`
`U.S. Patent No. 4,653,953 (“Anderson”; Ex. 1018)
`
`
`
`Wooley & Associates, Inc.
`
`4
`
`Page0000008
`
`
`
`
`
`II. Basic Oil Well Sucker Rods
`1.
`Field Use of Oil Sucker Rods
`13. The ’162 Patent is directed to designs for sucker rod end fittings that
`
`are used to connect one or more oil sucker rods. Ex. 1001, Abstract. By way of
`
`background, a sucker rod pump (illustrated below) operates to bring underground
`
`oil to the earth’s surface.
`
`Ex. 1015, at 9.
`
`
`
`Wooley & Associates, Inc.
`
`5
`
`Page0000009
`
`
`
`
`
`14.
`
`In the above exemplary implementation, the sucker rod pump has a
`
`primary drive motor attached to a flywheel and crank arm. Attached to the crank
`
`arm is a Pitman Arm, which links the crank arm to a walking beam. The walking
`
`beam has a horse head at its other end. During operation, the primary drive motor
`
`turns the flywheel, such that the arms interact to convert the rotary motion of the
`
`drive motor to a translational pumping motion of the horse head. It’s this pumping
`
`motion of the horse head that drives the pumping of the sucker rod string.
`
`15. At the end of the sucker rod string is one or more valves that are used
`
`to maintain the direction of the oil flow. These valves may take a number of
`
`forms, but they are often just a ball in a cage that allow the oil to flow into the
`
`valve during the down stroke, and then plug the hole in the cage and restrict the
`
`reverse flow of oil on the upstroke. Thus, the successive downward and upward
`
`stroke of the horse head causes extraction of oil by pushing it up the rod string
`
`from the underground reservoir.
`
`16.
`
`In order to recover oil from deep oil wellbores, it is well known in the
`
`art to create a “string” of sucker rods by connecting multiple sucker rods end-to-
`
`end using sucker rod end fittings. As the prior art Rutledge ’277 Patent, U.S.
`
`Patent No. 8,113,277 (Ex. 1006) explains:
`
`It is well known in the art to use sucker rods to actuate a downhole
`pump to recover oil from a wellbore. Typically, a series of sucker rods
`are connected end to end to form a sucker rod string, which extends
`from the pump drive 10 to the pump 14 (FIG. 1). It should be
`
`Wooley & Associates, Inc.
`
`6
`
`Page0000010
`
`
`
`
`
`appreciated that pump drive 10 is typically a pump jack (i.e. a beam
`pump system) or other known pump drive. Further, downhole
`pump 14 is typically a conventional pump well known in the art. It
`should be appreciated that although fiberglass or composite sucker
`rods are light weight, they are typically connected by metallic end
`fittings 30 which add to the weight of the string and can be a
`considerable factor in a very deep wellbore as the pump drive must
`overcome the weight of the sucker rod string, including the metallic
`end fittings 30 in order to acuate [sic] the downhole pump 14. It
`should be appreciated that the sucker rod string can be made up of
`many rods that are approximately thirty-seven (37) feet in length, the
`string can comprise one single continuous rod, or a few continuous
`rods which can be hundreds of feet in length or even a thousand or
`more feet in length. Regardless of the length of the sucker rod, it is
`preferably assembled, as described herein, with an end-fitting 30 as
`illustrated in FIGS. 4 or 4A.
`
`Ex 1006, 1:61 – 2:17; see also id., Fig. 1:
`
`Wooley & Associates, Inc.
`
`7
`
`
`
`Page0000011
`
`
`
`
`
`17. Thus, it was well-known in the art well before the time of the ’162
`
`Patent to create sucker rod strings by connecting hundreds, sometimes thousands
`
`of feet of fiberglass sucker rods end-to-end. Since the 1970s, these sucker rod
`
`strings have been made of fiberglass. See Rutledge ’865 Patent, Ex. 1013 (filed
`
`1979 and describing fiberglass sucker rod strings).
`
`18. Since the time that sucker rod strings were first used, a key
`
`consideration has been sucker rod fatigue at the end fitting. In material sciences,
`
`fatigue refers generally to the weakening of a material caused by repeatedly
`
`applied loads. When dealing with sucker rod strings, fatigue results from the
`
`progressive and localized structural damage that occurs when the sucker rods are
`
`subjected to cyclic loading of the reciprocating environment of pumping oil wells,
`
`i.e., up stroke and down stroke of the sucker rod string. A brief introduction to the
`
`forces that interplay to result in failure due to sucker rod fatigue are described
`
`below. However, it is should be noted that this discussion is merely exemplary and
`
`a POSITA would understand that fatigue failure of a fiberglass sucker rod is
`
`caused by changing forces on the rod, environmental considerations such as
`
`temperature, and the material properties of the fiberglass sucker rod.
`
`2. Overview of Forces Encountered During Sucker Rod Use
`19.
`In some of the fiberglass sucker rod and end fitting prior and current
`
`art the forces acting on and the stresses in the sucker rod and the end fitting are
`
`Wooley & Associates, Inc.
`
`8
`
`Page0000012
`
`
`
`
`
`described in an imprecise manner. I provide an overview of several of the forces
`
`commonly encountered during use of sucker rod strings in this section in effort to
`
`clarify some of these concepts. It is important to keep clear that forces are vector
`
`quantities that have a magnitude and direction, and stress is a tensor that has
`
`principal and shear components. Discussing one component of force or stress, for
`
`example, when discussing end fitting designs, is of value, but not sufficient to
`
`make decisions about deformation and failure of material. A POSITA would
`
`understand that there are additional forces and considerations interacting with the
`
`end fitting and sucker rod that would also affect the force distribution at any
`
`particular point.
`
`20.
`
`In the cylindrical coordinate system that is commonly used for
`
`discussion of sucker rods and end fittings, generally the principal directions used
`
`are axial (along the axis of the rod, vertical in vertical wells), radial (perpendicular
`
`to the rod axis, horizontal in vertical wells) and circumferential or tangential
`
`(perpendicular to radial direction and along the circumference of the rod or fitting,
`
`horizontal in a vertical well). I note that not all of the prior art that I have reviewed
`
`utilize these terms consistently. Where possible, I have endeavored to identify
`
`these inconsistencies in use in the prior at, and to use the foregoing terminology
`
`consistently throughout my opinions.
`
`Wooley & Associates, Inc.
`
`9
`
`Page0000013
`
`
`
`
`
`21. Another issue that requires careful discussion is material behavior.
`
`Steels such as those used to manufacture end fittings can often be characterized
`
`with a bilinear stress-strain curve that changes slope at the yield point. Except in
`
`extreme circumstances the steel stress-stain curve is reasonably assumed to be
`
`independent of temperature, pressure and environment. In most steels the
`
`mechanical properties described by the stress-strain curve are isotropic. Of course
`
`introduction of hydrogen sulfide can significantly affect the performance of steel,
`
`and extremely high temperatures can alter the stress-strain curve for steel. In
`
`contrast, the material properties for fiberglass like that used to manufacture sucker
`
`rods are significantly different that steel. A stress-strain curve for fiberglass may
`
`have a linear portion at low stress or may not, depending on temperature and time.
`
`Elevated temperature reduces the stiffness of fiberglass, and the effects of creep
`
`make the response of fiberglass dependent on the rate of loading. Another issue is
`
`the properties of fiberglass are usually anisotropic, i.e. different in axial, radial and
`
`circumferential directions, depending on the method of manufacture and materials
`
`used. Thus, in discussing the forces encountered during operation of the pumping
`
`unit, it is important to keep in mind that the steel end fitting respond differently to
`
`the reciprocating forces of pumping than the fiberglass sucker rod itself.
`
`22. Among the prior art the terminology for forces encountered during
`
`operation of a pumping unit using a sucker rod string to extract oil include
`
`Wooley & Associates, Inc.
`
`10
`
`Page0000014
`
`
`
`
`
`compressive forces on the end fitting, tensive forces, shear forces, negative load
`
`forces, radial forces, back pressure forces, and shock load. As mentioned, the prior
`
`art often uses these terms in an imprecise manner, including by misidentifying the
`
`primary force at play or by neglecting to give a more complete picture of the force
`
`components that are interacting with each other at any given moment. In an effort
`
`to promote consistency in terminology throughout my discussion of the prior art, I
`
`provide the following non-exhaustive explanation of force terms as they are used
`
`in the prior art and the ’162 Patent.
`
`23. Compressive Forces: Compression is the application of forces at
`
`different points on a material or structure that tend to compact or reduce the
`
`volume of the material or structure. In the context of sucker rod strings,
`
`compressive forces may be axial, radial, or circumferential in direction.
`
`24. Because the pump must work against the weight of the rod string and
`
`the hydraulic head of the fluid in the production tubing string, which head
`
`pressures can be extremely high dependent upon the depth of the well, high axial
`
`loads or forces are present during both the upstroke and down stroke parts of the
`
`cycle, resulting in varying stresses at each point in the sucker rods and end fitting
`
`in this reciprocating environment.
`
`25. Radial Compressive Forces: Radial compressive forces are
`
`compressive forces acting in the radial direction. In the context of sucker rod
`
`Wooley & Associates, Inc.
`
`11
`
`Page0000015
`
`
`
`
`
`strings, radial compressive forces are applied to the sucker rod by the wedges from
`
`the end fitting being squeezed inward by the application of axial tensile load to the
`
`sucker rod during pumping.
`
`26. Axial Compressive Forces: Axial compressive forces are
`
`compressive forces acting in the axial direction. In the context of sucker rod
`
`strings, axial compressive forces are applied to the sucker rod on the downstroke
`
`during pumping. In the upper portion of the sucker rod string, the downstroke may
`
`reduce tension but not achieve compression
`
`27. Circumferential or Tangential Compressive Forces:
`
`Circumferential or tangential compressive forces are compressive forces acting in
`
`the circumferential direction. In the context of sucker rod strings, circumferential
`
`compressive forces are applied to the sucker rod by the wedges from the end fitting
`
`28. Tensile Forces: Tensile forces are forces that tend to expand or
`
`increase the volume of a material or structure. Similar to compressive forces,
`
`tensile forces may be axial, radial, or circumferential.
`
`29. Shear Forces: Shear forces or shearing refers generally to the forces
`
`that are applied to the wedge shaped formations and which tends to separate the
`
`wedge shaped portions from the body of the sucker rod.
`
`30. Negative Load Forces: Several of the prior art Rutledge patents refer
`
`to “negative load forces.” Based on my reading of the prior art Rutledge patents,
`
`Wooley & Associates, Inc.
`
`12
`
`Page0000016
`
`
`
`
`
`these references appear to associate negative load forces with axial compressive or
`
`reduced tensile forces imparted during the down stroke of the pump. During up
`
`stroke, the pump must work against the weight of the rod string as well as the
`
`weight of the fluid within the rod string. This weight places a tensile load on each
`
`respective sucker rod that equals the weight of the number of rods that the sucker
`
`rod is supporting below.
`
`31. During down stroke, however, the axial load and forces decrease as
`
`the pump moves downward often to near zero and not uncommonly to a negative
`
`tensile load, i.e. into compression. Thus, negative load forces could also refer to
`
`the compressive axial forces imparted on the end fitting during down stroke in the
`
`lower part of the sucker rod string if the pump moves downward quickly enough.
`
`32. These negative load forces can also be exacerbated when using fiber
`
`sucker rod, which have been commonly used in the industry for decades. As
`
`another prior art Rutledge Patent, U.S. Reissue Patent No. RE32,865 (“Rutledge
`
`’865 Patent”; Ex. 1013), explains “fiberglass sucker rod construction[s] . . .
`
`impart[] an elasticity to the sucker rod string not found in conventional all-steel
`
`sucker rods. In a reciprocating environment, this elasticity inherent in pre-stressed
`
`fiberglass, results in an increased effective stroke length, and an increased stroking
`
`force over that of a steel rod having a comparable surface stroke.” Ex. 1013, 4:64
`
`– 5:2. The Rutledge ’865 Patent explains that this effect is similar to stretching a
`
`Wooley & Associates, Inc.
`
`13
`
`Page0000017
`
`
`
`
`
`rubber band, where the lower rods in the sucker rod string experience a stroke
`
`length greater than those of the upper end of the sucker rod string. Id. at 5:2-9.
`
`Thus, the elastic nature of the sucker rod string can increase the potential for
`
`negative load forces depending on the rate of reciprocation and sucker rod
`
`properties and dimension.
`
`33. Many of the prior art Rutledge patents appear to also refer to the
`
`compressive force applied by the end fitting to the sucker rod during upstroke as
`
`“negative” load. For example, prior art Rutledge Patent, U.S. Patent No. 8,113,277
`
`(“Rutledge ’431 Patent,” Ex. 1003) states that “Negative load refers to forces
`
`acting on the side of the wedge opposite from the gripping side of the wedge
`
`describes a wedge shaped design.” Ex. 1003, 2:29-31. The Rutledge ’431 Patent
`
`also explains that “Negative load is very destructive to the wedges of prior art
`
`designs, causing catastrophic shear failure of the wedge.” Id.at 2:31-33 (emphasis
`
`added).
`
`34. Back Pressure Forces: The ’162 Patent makes reference to “back
`
`pressure” forces. Back pressure typically refers to a pressure that opposes the flow
`
`of a fluid in a confined place, such as a pipe. However, the ’162 Patent does not
`
`appear to use back pressure in this sense. The ’162 Patent refers to a back pressure
`
`exerted on the sucker rod end fittings and the wedge system formed therein. In
`
`particular, the ’162 Patent describes “the wedge system 110 of the present
`
`Wooley & Associates, Inc.
`
`14
`
`Page0000018
`
`
`
`
`
`disclosure greatly enhances the stability of the sucker rod 10 and ability of the fiber
`
`composite rod 200 and end fitting 100 combination to accept enhanced
`
`compressive and back pressure forces associated with the reciprocating
`
`environment in which the sucker rods 10 are used.” Ex. 1001, 5:35-40 (emphasis
`
`added). A POSITA would understand “reciprocating environment” to refer to the
`
`cyclic upward and downward stroke of the pump and string of sucker rods. Thus,
`
`as used in the context of the ’162 Patent, a POSITA would understand “back
`
`pressure forces” to encompass the compressive forces imparted by the axial tensile
`
`load during reciprocation, similar to the “negative” forces described by the
`
`Rutledge ’431 Patent. See Ex. 1003, 3:5-14 (“Wedges transmit the compressive
`
`and tensing forces of pumping from the steel connector to the fiberglass rod and
`
`vice-versa. . . . Essentially, the metal end fitting squeezes the deformations in the
`
`adhesive when compressive and back travel forces are applied to the
`
`construction.”) (emphases added).
`
`35. Shock Load Forces: A shock load refers generally to the force that
`
`results when an object suddenly accelerates or decelerates. As one prior art
`
`Rutledge patent explains, “when a shock load occurs that creates a negative load,
`
`the wedge has the ability to absorb the negative load forces and to thereby resist
`
`failure of the rod connection.” Ex. 1003, 2:31-37. Thus, generally speaking, shock
`
`loads are one factor that can contribute to negative load forces.
`
`Wooley & Associates, Inc.
`
`15
`
`Page0000019
`
`
`
`
`
`3.
`Common Problems to Address in the Field
`36. The above discussion of forces encountered during sucker rod use
`
`provides a brief overview of the forces encountered during design of sucker rod
`
`end fittings. It is should be noted, however, that this discussion is merely
`
`exemplary and a POSITA would understand that failure due to sucker rod fatigue
`
`is a factor of many these forces and environmental considerations, such as by
`
`changing forces on the rod, environmental considerations such as temperature, and
`
`the material properties of the fiberglass sucker rod. Accordingly, a POSITA would
`
`understand that these forces may interact in various end fitting designs in varying
`
`ways, which makes sucker rod fatigue difficult to predict without conducting
`
`expensive fine element analysis tests. Thus, a POSITA would generally be
`
`motivated to test end fitting designs having even slight modifications to their
`
`design to determine whether they impact failure due to sucker rod fatigue. That
`
`said, a number of predominant views with respect to sucker rod fatigue and end
`
`fitting design have emerged within the industry and would have been well-known
`
`to a POSITA at the time of the ’162 Patent’s filing.
`
`37.
`
`In particular, it is readily apparent and widely known to those working
`
`in the petroleum industry that failure due to sucker rod fatigue most often occurs in
`
`the portion of the sucker rod that is encased in the end fittings connecting the ends
`
`of two adjacent rods. It has also been widely known since at least the 1970s, as
`
`Wooley & Associates, Inc.
`
`16
`
`Page0000020
`
`
`
`
`
`illustrated by the prior art Rutledge ’865 Patent (Ex. 1013), that using epoxy wedge
`
`systems within the interior wall of the end fitting, as opposed to using a linear
`
`surface, greatly reduce failure due to sucker rod fatigue in the end fitting. Wedge
`
`systems, akin to that described by the prior art Rutledge ’865 Patent, have been a
`
`dominant design for decades. Since this time, many of those skilled in the art have
`
`sought to reduce failure due to sucker rod fatigue by varying various parameters of
`
`the wedge system, including length of the wedge, the slope of the wedge’s incline,
`
`both on the trailing edge and leading edge, number of wedges, configuration of the
`
`wedges, and their respective sizes and shape.
`
`38. An article published by Edward L. Hoffman, entitled Finite Element
`
`Analysis of Sucker Rod Couplings with Guidelines for Improving Fatigue Life,
`
`Sandia National Laboratories, published in 1997 (“Hoffman Article; Ex. 1015”),1
`
`identified three approaches to improving the fatigue resistance of threaded sucker
`
`rod couplings: (1) decrease the nominal alternating stress amplitude by increasing
`
`the box stiffness relative to the pin stiffness, (2) optimize the preload generated
`
`during the make-up process to minimize the local mean hydrostatic stress in the
`
`coupling, and (3) decrease the severity of the stress concentrations which provide
`
`
`1 I note that the Hoffman Article discusses threaded connections used in sucker rod
`string designs. However, many of the design principles (for example, minimizing
`stress concentrations) are equally applicable to wedge end fittings and are
`confirmed as a central consideration in many of the prior art patents identified
`herein.
`
`Wooley & Associates, Inc.
`
`17
`
`Page0000021
`
`
`
`
`
`preferred sites for fatigue damage. Ex. 1015, at 64-65. Each of these approaches
`
`would be well-known to a POSITA in the industry prior to the filing of the ’162
`
`Patent. The Hoffman Article also recognizes that “Any combination of the above
`
`design approaches could be used to extend the service lives of existing sucker rod
`
`couplings, or to design a coupling which would meet the desired requirement of
`
`indefinite service life.” Ex. 1015, at 65. Further, the Hoffman article describes a
`
`valuable analysis tool for design of sucker rod end fittings.
`
`39. Thus, a POSITA at the time of the ’162 Patent’s filing would
`
`understand these three factors are examples of the motives for designing sucker rod
`
`end fittings. Many of the prior art end fitting designs described herein discuss
`
`these same considerations. In particular, many of the prior art discuss the third
`
`consideration from the Hoffman Article, designs that help minimize “the severity
`
`of the stress concentrations which provide preferred sites for fatigue damage.” Ex.
`
`1015, at 65. Several more specific considerations for designing wedge systems
`
`that were well-known at the time of