PTAB

IPR2016-00624

Pason Systems USA Corp. v. Auto-Dril. Inc.

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1. Case Identification

2. Patent Overview

  • Title: WELL DRILLING CONTROL SYSTEM
  • Brief Description: The ’172 patent discloses an automatic drilling system for controlling the weight-on-bit (WOB) during the drilling of a borehole. The system uses a sensor to measure the weight of the drill string, an electronic comparison means to compare the measured WOB to a user-selected value, and a programmable control means to operate a motor-driven brake, thereby regulating the feed of the drill string.

3. Grounds for Unpatentability

Ground 1: Obviousness over Bowden and Guggari - Claims 1-3 are obvious over Bowden in view of Guggari under 35 U.S.C. §103.

  • Prior Art Relied Upon: Bowden (Patent 3,265,359) and Guggari (Patent 6,029,951).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of Bowden and Guggari taught all limitations of the challenged claims. Bowden, a foundational patent from 1966, disclosed an automatic drilling control system that used a diaphragm tension sensor on the drill line to maintain a constant WOB by controlling a brake-lifting motor. Petitioner contended Bowden taught the core system of claim 1: an automatic driller, drawworks, prime mover, a sensor on the bit support means (the cable), and a means to compare weight values and control a brake. However, Bowden's system was largely electro-mechanical and hydraulic.
    • Guggari, filed in 1998, disclosed a modern, fully electronic drawworks control system using a Programmable Logic Controller (PLC) and a strain gauge affixed directly to the deadline to produce a direct electrical signal representing WOB. Petitioner asserted that Guggari taught the specific electronic and digital limitations of the ’172 patent, including the "programmable control means" (claim 1), the use of a PLC (claim 2), and the various electronic "means" elements of claim 3 (e.g., memory, user input, signal processing). Guggari's strain gauge was argued to be the very type of "directly interfaced" sensor that the Applicant used to overcome prior art during prosecution of the ’172 patent.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) at the time of the invention (2002) would have been motivated to upgrade the older, analog system of Bowden with the modern, digital electronic components taught by Guggari. The motivations cited were numerous and compelling:
      • Improved Performance and Reliability: Replacing Bowden's hydraulic and analog components with Guggari's digital system (PLC, direct electronic sensor) would eliminate signal loss over long hydraulic lines, increase accuracy, and enable advanced control strategies like PID loops, which are superior to Bowden's simple proportional control.
      • Cost, Safety, and Versatility: By 2002, digital electronics were cheaper, more reliable, and easier to use than the older systems. Guggari's system allowed control electronics to be located safely away from the hazardous rig floor, a significant advantage over Bowden's design. A digital system is also more versatile, capable of controlling multiple brake types and providing system redundancy, which Bowden’s analog system could not do.
    • Expectation of Success: The combination was portrayed as a predictable substitution of known, modern electronic components (strain gauges, PLCs) for their older analog counterparts to achieve the same goal of automatic WOB control. A POSITA would have reasonably expected this upgrade to result in a more efficient, accurate, and reliable system without requiring any undue experimentation.
    • Key Aspects: Petitioner's central argument was that the Examiner allowed the ’172 patent based on an allegedly novel "direct interface" of the WOB sensor, but was not aware of prior art like Guggari, which explicitly disclosed such a direct electronic interface (a strain gauge on the deadline). The combination of Bowden and Guggari rendered the claimed invention obvious.

4. Key Claim Construction Positions

  • "bit weight sensor ... directly interfaced with bit support means" (Claims 1 & 3): Based on the prosecution history, Petitioner argued this term was added to distinguish over a prior art patent (Ball ’608) that used a hydraulic sensor to create a pressure signal, which was then remotely converted to an electrical signal. Therefore, Petitioner contended the term must be construed to mean a sensor, like a strain gauge, that is physically located on the bit support means (the cable) and generates an electrical signal at that location, rather than transmitting a non-electrical signal for later conversion. Guggari's strain gauge met this construction.
  • Means-Plus-Function Terms (Claims 1 & 3): Petitioner provided constructions for several means-plus-function terms, identifying corresponding structures in the ’172 patent's specification that were also taught by the prior art.
    • "electronic bit weight comparison means" (Claim 1): Construed as a computer unit or PLC programmed to compare measured WOB with a set point. This structure was taught by Guggari's PLC-based system.
    • "programmable control means" (Claim 1): Construed as a Variable Frequency Drive (VFD) that receives a signal from the PLC to control the brake motor. VFDs were known components, and Guggari taught a PLC controlling a motor drive.
    • "braking means" (Claims 1 & 3): Construed as the physical brake band and lever assembly. This was a conventional component taught by both Bowden and Guggari.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and cancellation of claims 1, 2, and 3 of Patent 6,994,172 as unpatentable.