Norwegian survey outfit EMGS has lost a patent decision to Schlumberger in a London court which decided the Oslo-based company could not make money in U.K. waters on "certain activities".

EMGS, or Electromagnetic Geoservices, produces reservoir images for "pinprick" accuracy in exploration. The rights to some of its key technology has been contested by others, including France-based oilfield services giant Schlumberger.

"Following proceedings launched by Schlumberger, three of its patents were not upheld in a first instance decision at the High Court in London," the company warned shareholders, before adding, "EMGS retains over 115 patents in 32 jurisdictions and in excess of 130 applications in 26 jurisdictions around the world.

EMGs management then announced a "strategic review" in light of the development, for which Goldman Sachs were retained.

Past battles over intellectual rights to electromagnetic technology, a god send to those forking out millions for chancy wells, have involved Statoil and Scottish engineers.

Tags: EMGS, Schlumberger