A small group of fields account for the bulk of Norway's total Natural Gas production. The single largest field is Troll, which produced 930 Bcf in 2004 and represents about one-third of Norway's total natural gas production. Other important fields include Sleipner Ost (450 Bcf), Asgard (360 Bcf), and Oseberg (250 Bcf). These four fields compose over 70 percent of Norway's total gas production (see chart).

Despite the maturation of its major natural gas fields in the North Sea, Norway has been able to sustain annual increases in total natural gas production by incorporating new fields. In October 2004, the Kvitebjorn field came onstream with an expected production level of 710 million cubic feet per day (Mmcf/d).
 
Statoil expects to bring the Halten Bank West project onstream in October 2005, which includes estimated reserves of 1.2 Tcf spread among five fields (Kristin, Lavrans, Erlend, Morvin, and Ragnfrid).

Over the long term, Norway is counting on non-North Sea projects to provide significant natural gas production. In the Norwegian Sea, Norsk Hydro is currently developing the Ormen Lange field. The project consists of an offshore production facility and a subsea Pipeline linking the field to the gas processing terminal in Nyhamma.
 
In addition, the Ormen Lange project includes a pipeline linking Nyhamma to Easington, England (see below). Ormen Lange holds an estimated 14 Tcf of recoverable reserve and will have a full production capacity of 710 Bcf per year. Shell will take over as Operator of the project from Norsk Hydro in the production phase, which is scheduled to begin in 2007.
 
Also in the Norwegian Sea, Shell announced in 2005 that it had made a major discovery in the Onyx prospect, west of the company's existing Draugen field. According to the Norwegian Petroleum Directorate (NPD), the find could contain as much as 2.1 Tcf of recoverable gas reserves.