Grane is an offshore oil field in the North Sea located 185 km west of the city of Haugesund on the western coast of Norway. It is Norway's first heavy crude oil production field and Statoil's largest heavy oil field in the Norwegian continental shelf. The oil from the field, located in Block 25/11 is transported to Sture terminal via Grane oil pipeline. The injection gas is imported to Grane oil field from the Heimdal, located just north the field.

Ownership

The Grane field is operated by Statoil, with Statoil holding 38% of the stake, Petoro – 30%, ExxonMobil – 25.60%, and ConocoPhillips – 6.40%.

Technical features

The field lies in 128 m of water at total depth of 1700 m. The reservoir is nearly 27 km2 and has an average pay thickness of 50 m with an average porosity of 33% and permeability of 5–10 Darcies. The reservoir consists of sandstones of Heimdal formation of Paleocene age, Lista Formation and has high viscosity.

Development history

Norsk Hydro and partners started development of the field in 1991. The Grane field started producing in September 2003. 31 production wells were put into operation. The facility was designed by Aker Solutions Engineering in 2000–2003.

Production

At Grane oil field, Norsk Hydro used the technology applied at its Troll and Oseberg fields to maximize production in Grane. An estimated 700 Moilbbl is expected to be produced by the field with 214 koilbbl/d. With the first horizontal well drilled, Hydro already reached a peak production by 10 March 2006 setting a record at 243 koilbbl/d which exceeded the initially established field plan by about 30 koilbbl. From then on, the field supplied the market an average 220 koilbbl/d. The company expects 55% recovery from the field. This makes Grane third of the size of Oseberg and twice the size of Brage. There is no gas cap in Grane field. The production profile of the Grane field (in million Sm3 oil equivalent) is as follows.