Moray Firth / Witch Ground Graben
1 April 2003

The 13/21a-3 and 13/21a-4 wells ere drilled back to back to appraise the West Captain prospect, which was first drilled by Amoco well 13/21a-1A in 1990. This well proved a thick Lower Cretaceous sequence (2,878 to 4,242 ft), including approximately 800 ft of high porosity sandstones in several blocky units of fi ne to medium grained sands up to 130 ft thick. Logs and RFT pressures showed, however, that hydrocarbon saturation was restricted to a 69 ft column (2,905-2,974 ft) within a relatively poorly developed Captain Sandstone, with only 45 ft of net sand.