Schiehallion field was discovered in 1993 by the semi-submersible drilling vessel Ocean Alliance while drilling the third exploration well in block 204 (well 204-3). The field is located in blocks 204/20 and 204/25 of the United Kingdom Continental Shelf in a water depth of . Recoverable oil reserves of Schiehallion are estimated to be between . Schiehallion is named after a mountain in the highlands.