ABSTRACT The Draugen oil field lies in block 6407/9 in the Haltenbanken oil and gas province. The field is located 150 km off the coast of Norway and 200 km south of the Arctic Circle, in water depths of 240 to 280 m. The Draugen field was discovered in 1984 by well 6407/9-1. Five additional exploration/appraisal wells and 2D seismic assisted in delineating the reservoir The field is hosted by a low-relief north-south-trending anticline measuring some 20 by 6 km. The reservoir lies at a depth of 1600 m subsea and has an oil column of 40 m. The main reservoir is the Late Jurassic Rogn Formation sands, interpreted as a shallow marine sand bar. A separate, smaller accumulation has also been proved in Middle Jurassic Garn Formation sands in the western part of the field. The estimated STOOIP is 180 million standard m 3 . Recoverable reserves are estimated at 67 million standard m 3 of oil and some 3 billion standard m 3 of associated gas. The field will be developed with a concrete gravity base structure and offshore loading. The initial development plan calls for six oil producers and six subsea water injectors. The platform will be installed in the summer of 1993, with first oil shortly thereafter. The planned plateau production rate is 14,300 standard m 3 of dry oil per day.

Abstract Before we get into details and think how to improve 4D monitoring, let us look at some results of 4D surveys in action and get a feel for what they can do for us.