PTAB

IPR2019-01582

Enercorp Sand Solutions Inc. v. Specialized Desanders Inc.

Title: Desanding Apparatus and a Method of Using Same
Brief Description: The ’921 patent discloses an apparatus and method for removing particulates, such as sand, from multiphase fluid streams produced from oil or gas wells. The core of the invention is a vessel that uses an internal, "generally upright spiral plate baffle" to create an elongated, horizontal flow path, which facilitates the separation of gas from liquids and solids via gravity and changes in momentum.

Prior Art Relied Upon: Al-Alusi (Application # 2009/0314161).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that Al-Alusi, which discloses a cyclone separator for removing contaminants from an aircraft’s anti-ice system, teaches every element of the challenged claims. Al-Alusi’s separator vessel (102) includes a tangential inlet (204) for multiphase fluid, a central gas outlet conduit (200), and a drain (208). Crucially, Petitioner argued Al-Alusi’s spiral plate (212) is a “generally upright spiral plate baffle” that creates an elongated, generally horizontal flow path, has an open top and bottom, and is positioned below the top of the vessel, thereby meeting the key limitations of independent claim 1. Petitioner further contended that the claimed "freeboard interface" is met by Al-Alusi, as accumulated liquid or solids would necessarily form an interface at the level of the gas outlet intake.
- Key Aspects: The argument hinges on interpreting Al-Alusi's cyclone separator components as directly corresponding to the specific baffle and interface limitations added during prosecution of the ’921 patent.

Prior Art Relied Upon: Al-Alusi (Application # 2009/0314161).
Core Argument for this Ground:
- Prior Art Mapping: This ground relied on the same mapping of Al-Alusi as Ground 1. Petitioner argued that even if Al-Alusi does not explicitly anticipate every limitation, any differences would have been obvious modifications.
- Motivation to Combine (or Modify): Petitioner presented two motivations. First, a POSITA would have been motivated to adapt Al-Alusi for oilfield desanding applications, as Al-Alusi itself suggests its technology can be applied to other systems. This would involve routine scaling and modification using known principles like computational fluid dynamics. Second, in adapting Al-Alusi to handle valuable hydrocarbons (unlike the air in Al-Alusi), a POSITA would have been motivated to use a batch-draining system instead of a continuous one to prevent product loss. This modification would directly result in the formation of the claimed "freeboard interface" as liquids accumulate.
- Expectation of Success: Petitioner argued a POSITA would have had a high expectation of success because cyclone separation is a well-understood, predictable technology. The petition also asserted an "obvious to try" rationale, stating that cyclone separators were one of a finite number of predictable solutions for the known problem of sand removal.

Prior Art Relied Upon: Al-Alusi (Application # 2009/0314161) and Cauley (Patent 7,641,770).
Core Argument for this Ground:
- Prior Art Mapping: This ground addressed claim 11, which adds a specific drain structure comprising an inlet valve, a discharge valve, and a "particulate accumulation chamber" between them. Petitioner argued that Al-Alusi teaches the base separator vessel, while Cauley teaches the specific drain configuration. Cauley discloses a standard double-dump valve for handling bulk solids (tar sands), which inherently includes two spaced gates (valves) with an intermediate chamber.
- Motivation to Combine: A POSITA would have been motivated to combine Cauley's well-known double-dump valve with the drain of Al-Alusi's separator. The purpose would be to solve the known problem of removing collected particulates from a pressurized vessel on a batch basis without depressurizing the system or losing valuable hydrocarbons.
- Expectation of Success: Success would be highly predictable, as this involves the simple and common practice of attaching a standard, off-the-shelf component (a double-dump valve) to the outlet of a separation vessel.

"freeboard interface": Petitioner contended this term, which appears in claims 1 and 13, is not a standard term of art and must be construed based on the specification. Petitioner argued it has two distinct meanings: 1) when liquids are present, it is the gas/liquid interface (liquid level); 2) when no liquids are present, it is the highest elevation to which particulates can accumulate before the desanding process fails. This dual construction was critical to arguing that Al-Alusi, which can operate with or without liquids, meets the limitation.
"generally upright spiral plate baffle": Based on the prosecution history, Petitioner argued this term must be construed as a plate-like structure oriented to "check, impede, or obstruct" the incoming, generally horizontal fluid stream. This construction was used to distinguish the claimed invention from prior art rejected by the examiner (Greve), which taught a horizontal "raceway" that was parallel to, rather than obstructive of, the flow. Petitioner argued Al-Alusi’s spiral plate meets this obstructive requirement.

Petitioner argued that discretionary denial under §325(d) would be inappropriate because the asserted prior art and arguments were not the same or substantially similar to those previously presented to the USPTO.
The primary reference, Al-Alusi, was never cited or considered during examination. Petitioner contended that Al-Alusi is materially different from the references the examiner reviewed (Milia and Greve). Specifically, Petitioner argued that Al-Alusi teaches the very elements the applicant used to overcome the examiner's rejections, such as a spiral baffle with an open top and an outlet conduit intake located below the top of the baffle. Therefore, Petitioner asserted the petition raised new issues and presented persuasive, new evidence of unpatentability.

Petitioner requested that the Board institute an inter partes review and cancel claims 1-16 of the ’921 patent as unpatentable.