Abstract The Huntington discoveries are an unusual exploration success in that two oil accumulations were tested in separate syn- and post-rift reservoirs with a single well. The discoveries are located 205 km east of Aberdeen in the East Central Graben some 35 km east of Forties Field in 300 ft of water. The 22/14-5 discovery well, drilled in May 2007, encountered a 122 ft oil column in the Paleocene Forties Sandstone and also a 136 ft oil column in the Upper Jurassic Fulmar Sandstone. Both the Forties and the Fulmar contain high-quality oil, 41 and 39° api gravity, respectively. Aggregate flow rates from the two zones exceeded 11 000 boepd on test. Appraisal drilling of the Forties was completed in late 2007 with first oil targeted for 2011. The Fulmar appraisal programme is currently in progress. The Forties reservoir is a high net to gross sandstone containing stacked channel sequences deposited in a submarine fan system. The Fulmar reservoir also contains a thick sand package deposited in a shallow marine shelf setting. Pre-drill mapping based on reprocessed 3D seismic indicated a structural closure on both horizons at the location tested by the well. At both the Forties and Fulmar targets, however, the oil column height exceeded the pre-drill prognosis. This overview will focus on pre-drill perceptions of the prospect relative to actual drilling results.

Abstract The Jasmine Field is located in blocks 30/06 and 30/07a on the J Ridge, the southeastern extension of the Forties–Montrose High, which separates the eastern and western basins of the UK Central North Sea. The field was discovered in 2006 and is close to two ConocoPhillips producing fields, Jade and Judy, which serve as useful local analogues. The main West Limb structure is a turtle-back faulted anticline NW of the Joanne salt pillow. The primary reservoir is Triassic in age and consists of stacked fluvial sandstones of the Joanne Member of the Skagerrak Formation. The HPHT exploration wells 30/06-6 and geological sidetrack 30/06-6Z discovered a rich gas condensate column of 2300 ft, some 1100 ft deeper than the mapped independent structural closure of the prospect, and achieved good flow rates on test. To appraise the discovery and assess the potential for significant additional volumes in an adjacent downfaulted terrace, a programme comprising a main well and two sidetrack wells was initiated in 2007. Appraisal well 30/06-7 discovered a 550 ft hydrocarbon column in the Northern Terrace with a hydrocarbon–water contact shallower than that observed in the West Limb, thereby proving structural compartmentalization between the two fault blocks. Good flow rates were achieved from a drill stem test in mechanical sidetrack well 30/06-7Z. Sidetracks 30/06-7Y and 30/06-7X were drilled to confirm the northwestern extension of the West Limb discovery and to test the northern extent of the Northern Terrace accumulation, respectively. This programme has reduced volumetric uncertainty but the trapping mechanism and the ultimate extent of the Jasmine accumulation remain unknown. Comprehensive data acquisition throughout the exploration and appraisal phases, including drill stem testing, core recovery and seismic data reprocessing, has facilitated a detailed reservoir characterization programme. Jasmine represents a significant new high pressure/high temperature resource in the mature Central North Sea and is currently undergoing development planning.