Schlumberger Holdings Ltd v Electromagnetic Geoservices AS

A patent is addressed to the notional person or team capable of performing the invention, identified from the patent specification and its practical subject matter. The same skilled addressee applies to obviousness, construction and sufficiency. A technical specialist cannot be excluded merely because the alleged invention involves introducing that specialist’s technology into another field.

Anticipation requires clear and unmistakable directions to perform the claimed invention. A general disclosure of physical principles, or a result that follows from those principles, is insufficient without a clear link to the claimed application. Applying established electromagnetic surveying techniques to detecting hydrocarbon-bearing layers was obvious. Combining known electromagnetic and seismic techniques, including simultaneous deployment where logistically sensible, was likewise obvious.

Schlumberger sought revocation of three patents owned by EMGS concerning controlled-source electromagnetic techniques for identifying hydrocarbon-bearing strata beneath the seabed. The attack alleged anticipation, obviousness and, in relation to the 019 patent, insufficiency. EMGS applied to amend the claims.

The principal issues were the identity of the skilled addressee; the construction and operation of the claimed electromagnetic methods; whether the cited prior art clearly disclosed the inventions; whether the claimed applications were obvious; and whether combining electromagnetic and refraction-seismic surveys involved an inventive step.

1. Skilled addressee. The skilled addressee was a team comprising a geophysicist and a CSEM specialist. The specification itself showed that CSEM expertise was needed to perform the invention. The same notional addressee applied for construction, obviousness and sufficiency. There was no legal basis for using different skilled addressees for different validity issues. The 019 patent was therefore not insufficient on this ground, although it would have been insufficient if a CSEM specialist were excluded.
2. 019 patent. The Chave paper did not anticipate because it did not clearly and sufficiently immediately link its general CSEM teaching to the direct identification of hydrocarbon-bearing layers or to the claimed wavelength relationship. Applying its modelling and surveying techniques to hydrocarbon layers was nevertheless obvious. The MacGregor paper likewise did not anticipate but rendered the claims obvious. Srnka did not anticipate because its teaching concerning an “anomaly” was unclear and pointed in two directions; it nevertheless supplied the missing hydrocarbon-detection element when read against the common general knowledge embodied in Chave. Yuan neither anticipated nor rendered the claims obvious because it concerned quantifying known methane-hydrate deposits and gave inconclusive results.
3. 887 patent. The Ramesses and Sinha papers disclosed the in-line/broadside split but addressed conductive structures, not the claimed detection of relatively resistive hydrocarbon layers. They therefore did not anticipate. Applying the known split technique to identify resistive hydrocarbon-bearing layers was, however, obvious.
4. 640 patent. Combining CSEM and seismic information was common general knowledge. It was obvious to deploy the two techniques simultaneously or closely sequentially where that made practical and logistical sense. Under the principle in Sabaf SPA v MFI Furniture Centres Ltd [2005] RPC 209, the combination produced no synergistic technical effect; its benefits were merely the aggregate benefits of the separate techniques.
5. Disposition. All three patents fell to be revoked, subject in the case of the 887 patent to any further argument concerning subsidiary claims. The proposed amendments were formally disallowed.