PTAB

IPR2014-00814

Churchill Drilling Tools US Inc v. Schoeller BleckMann Oilfield Equipment AG

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Down-Hole Activating Mechanism
  • Brief Description: The ’397 patent discloses a downhole tool, specifically a circulation sub-assembly used in oil and gas drilling. The tool uses a deformable activator (e.g., a ball or dart) dropped down the drill string to engage a seat on a sliding sleeve, shifting the tool from a normal through-flow mode to a bypass mode to divert drilling fluid.

3. Grounds for Unpatentability

Ground 1: Anticipation over the ’650 Publication - Claims 13-15, 17, and 18 are anticipated by WO 02/14650.

  • Prior Art Relied Upon: The ’650 publication (WO 02/14650).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the ’650 publication, which is substantially identical to Patent 6,923,255, disclosed every limitation of the challenged claims. It described a bypass sub with a sliding sleeve biased by a spring (biasing means) that is activated by a "ball dart assembly." This assembly was asserted to be a "deformable activator" that engages a seat, increases upstream pressure, and moves the sleeve to a bypass mode. The ’650 publication also explicitly taught including a narrow passage through the activator to permit a "limited proportion of the fluid to continue to flow," meeting the "restricted flow" limitation of claim 13. Petitioner further contended that the named inventor and the Patent Owner's own expert had admitted during litigation that the ’650 publication's disclosure met all limitations of claim 13 if "deformable activator" was construed broadly enough to cover the ball-dart assembly.

Ground 2: Anticipation over Bourgoyne - Claims 13-15, 17, and 18 are anticipated by Bourgoyne.

  • Prior Art Relied Upon: Bourgoyne (Patent 4,310,050).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Bourgoyne taught a "flow diverting device" for a drill string with all elements of the challenged claims. Bourgoyne's device included a sliding sleeve moved by an "actuator" dropped from the surface. This actuator was argued to be deformable because it comprised a main body and a "catching sleeve" attached by shear pins; upon deactivation, increased pressure caused the pins to fail and the catching sleeve to shear away, changing the actuator's shape. This shearing action at a predetermined pressure (the shear strength of the pins) met the "deformable activator" limitation. Bourgoyne also disclosed that when the device was in bypass mode, a "constant flow rate" was maintained through an orifice in the actuator, satisfying the "restricted flow" limitation.

Ground 3: Obviousness over the ’650 Publication and Baker - Claims 13-15, 17, and 18 are obvious over the ’650 publication in view of Baker.

  • Prior Art Relied Upon: The ’650 publication (WO 02/14650) and Baker (Patent 2,633,916).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that if the Board were to find the "deformable activator" of the ’650 publication did not fully meet the claim limitations, it would have been obvious to modify it using the teachings of Baker. The ’650 publication disclosed all elements of the claims except, for the sake of argument, a sufficiently robust deformable activator. Baker disclosed a "trip device" for a downhole valve, comprising a deformable, rubber-sealed spherical head (a ball-like portion) and a weighted, depending extension (a dart-like portion), which functioned as an activator.
    • Motivation to Combine: Petitioner contended a POSITA would combine these references as a simple substitution of one known element for another. Both references are from the same field of endeavor (downhole circulation tools) and address similar problems. If the ball-dart assembly in the ’650 publication was perceived as having a design weakness (as the Patent Owner allegedly argued), a POSITA would have looked to other known activators like Baker's trip device. A POSITA would have been motivated to substitute the well-known trip device from Baker for the ball-dart assembly in the ’650 publication's circulation sub.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success because the combination involved familiar elements combined according to known methods to achieve a predictable result—activating a bypass sub while maintaining restricted flow.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of the ’650 publication, Baker, and a 2004 Office Action from a related patent prosecution, as well as a combination of Bourgoyne in view of the ’650 publication.

4. Key Claim Construction Positions

  • "deformable activator": Petitioner argued for a broad construction: "an activating device which changes shape at a predetermined pressure." This construction was asserted to be consistent with the specification, which disclosed deformable balls and ball-dart combinations. Critically, Petitioner argued that "deformable" must include shear deformation, as the specification stated that a resilient ring on the activator can "shear under load." Petitioner contended that the Patent Owner's proposed narrower constructions, which required a "unitary device," were improperly imported from the embodiments and not supported by the claims.
  • "restricted flow of fluid through the sleeve is maintained": Petitioner argued this term required that some positive fluid flow must continue through the sleeve's passage after the activator engages the seat and the tool is in bypass mode. Petitioner pointed to specification language stating the restricted flow is to lubricate the drilling tool, which would be impossible with zero flow. The patentee’s use of the separate term "blocked" for zero-flow situations was cited as further support for this construction.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 13-15, 17, and 18 of the ’397 patent as unpatentable.