Schlumberger Logelco Incorporated v Coflexip SA

Schlumberger Logelco Incorporated installed an apparatus at the Soekor Field Development Project near Mossel Bay to transfer oil from a subsea wellhead to a surface production platform. Coflexip SA was the holder of South African Patent 89/1418, relating to an apparatus using flexible hose risers with an intermediate buoyancy element and holding means connected to a deadman on the seabed to impart a predetermined curvature. Coflexip alleged that Schlumberger’s apparatus infringed claims 1, 8 and 9 of the patent. Schlumberger denied infringement and counterclaimed for revocation of the patent on grounds including lack of novelty, obviousness and lack of clarity.

The appeal was dismissed. The finding of infringement was upheld, the counterclaim for revocation of the patent was dismissed, and the interdict granted by the Commissioner of Patents remained in force.

The case is an important South African authority on patent infringement and validity, particularly in relation to novelty and obviousness. It clarifies the interpretation of patent claims, the assessment of prior art, and the role of expert evidence in determining inventive step. The judgment is frequently cited for its analysis of obviousness under the Patents Act 57 of 1978 and for its careful distinction between what imparts a technical effect and what determines its extent.