Statfjord, largest single oil field in the North Sea, is located on the U.K.-Norwegian boundary between 61° and 61°30^prime N lat. Initial estimates are that about 11% of the field lies in U.K. waters. Its discovery, in March 1974, was based on interpretation of seismic reflection surveys and extrapolation of a productive regional trend. Two principle sandstone reservoirs, Middle Jurassic Brent and Lower Jurassic-Upper Triassic Statfjord, contain reserves in the order of 3 billion bbl within a productive area of approximately 20,000 acres (580 sq km). Reservoir properties are excellent, with permeabilities in darcies. The field extends northeasterly 15.5 mi (24.8 km) and averages 2.5 mi in width (4 km).

Tilted Jurassic fault blocks form the primary hydrocarbon trap at Statfjord as throughout the East Shetland basin. Statfjord field is a structural-stratigraphic trap formed by westward tilting and erosion of a major fault block. Brent deltaic sands and underlying Statfjord continental (fluvial) sands are truncated by middle to late Kimmerian unconformities on the crest and east flank of the structure which is marked by a major fault system. Overlying and onlapping Jurassic and Cretaceous shales seal the trap. Organically rich Upper Jurassic shales provide an excellent oil source. Reservoirs have separate oil-water contacts. Normal faulting separates Statfjord field from Brent field to the southwest.

Joint development by Norway and the U.K. utilizes "condeep" type gravity platforms and initial offshore loading. Development drilling from Statfjord 'A' platform (towed to location in May 1977) began in late 1978. First production is expected late in 1979.