Schlumberger Holdings Ltd v Electromagnetic Geoservices AS

For inventive step, the person skilled in the art is not necessarily an invariant individual or team. The relevant art depends on the question being asked. In an art-changing invention, the post-patent team able to perform the invention may differ from the pre-patent team confronting the problem.

Obviousness requires asking whether either relevant skilled person would recognise the other field’s problem, solution or useful expertise. A long-standing and valuable solution that no one adopted, coupled with contemporaneous expert reaction, may strongly rebut hindsight-based technical obviousness. Prior art anticipates only where, read as a whole, it gives clear and enabling directions that necessarily fall within the claim.

EMGS appealed from Mann J’s decision in the Patents Court, [2009] EWHC 58 (Pat), holding its European patents invalid. The appeal ultimately concerned EP 1,256,019, directed to using marine controlled-source electromagnetic surveying to determine whether a known submarine reservoir contained hydrocarbons rather than water or brine.

The judge had held the patent obvious over the Chave, MacGregor and Srnka prior-art documents. He had rejected novelty attacks based on Srnka and Yuan. Schlumberger’s respondent’s notice challenged the latter conclusions.

The central issues were the identity of the person skilled in the art for inventive step where the invention joined different technical disciplines, the weight of secondary evidence of inventiveness, and whether the prior disclosures anticipated or made the claimed method obvious.

1. Appeal allowed. The court set aside the findings that the patent was obvious over Chave, MacGregor and Srnka. It dismissed Schlumberger’s cross-appeal on anticipation by Srnka and Yuan.
2. For claim construction and sufficiency under the European Patent Convention, the skilled person has the patent in hand. Under Article 56, however, the inquiry is pre-patent. The relevant skilled person or team is identified by the actual technical problem and the art in which it arose. An invention may itself change the relevant art by bringing together previously separate skills. It is not enough to deem the new specialist part of the pre-existing team merely because that specialist is needed to perform the disclosed invention.
3. The correct inquiry was whether an exploration geophysicist would see that CSEM offered a real prospect of solving the identified problem, or would have reason to consult a CSEM expert; and whether a CSEM expert would know of that problem and appreciate that CSEM offered such a prospect. If neither route, nor the formation of a combined team, was obvious, the marriage of the arts was not obvious.
4. Secondary evidence was material. The claimed use was a significant and useful advance which could apparently have been made for years. There was no satisfactory alternative explanation for its absence. Contemporaneous reactions from leading CSEM experts also showed that the idea had not previously occurred to them. Those matters rebutted the hindsight assertion that the method was technically obvious.
5. Chave and MacGregor described CSEM for general mapping and, in particular, thick resistive layers. They did not identify the exploration problem or teach the use of CSEM to distinguish thin hydrocarbon-bearing reservoirs from water-bearing reservoirs. Srnka was obscure, had led to no useful development, and did not make that step obvious when combined with common general knowledge.
6. A novelty attack requires a clear, unambiguous and enabling disclosure, read as a whole. It is impermissible to excise difficult parts of Srnka to create an anticipation. Yuan did not concern the claimed extractable hydrocarbon reservoir or the claimed search or discrimination. It did not clearly exploit a refracted-wave component as claimed or necessarily teach the required relationship between wavelength and transmitter-receiver offset.

• Court of Appeal (Civil Division): Allowed EMGS’s appeal and set aside the findings of obviousness: [2010] EWCA Civ 819.
• High Court, Chancery Division, Patents Court: Mann J had held EP 1,256,019 invalid for obviousness over Chave, MacGregor and Srnka, while rejecting the pleaded novelty attacks based on Srnka and Yuan: [2009] EWHC 58 (Pat).