Trondheim, Norway-based Electromagnetic Geoservices ASA (EMGS) reports that three of its patents are disputed by Schlumberger Holdings, a subsidiary of Schlumberger, Houston (NYSE: SLB). The Dutch patent court stayed the proceedings until a decision by the European Patent Office, which is expected within three to four years. The court also upheld EMGS’s assertion that it is the inventor of sea-bed logging and that EMGS was the first company to use electromagnetism to directly detect oil and gas reservoirs.