At current production, Grane field supply the market with more than 220,000 barrels of oil per day. Innovative solutions were needed to produce the heavy oil from the field.

The Grane field started production on September 23, 2003. It is the first heavy oil field on the Norwegian continental shelf. Close cooperation between Hydro,s operations, project development team, contractors and partners forms the basis for completing the Grane facilities. The project was delivered on schedule, below budget and without high-potential incidents.

A pre-drilling campaign comprising 12 wells allowed production start-up shortly after completion of the offshore commissioning phase. The drainage strategy of the reservoir is based on gas injection with gas imported through the North Sea gas transportation system. Reserves of more than 700 million barrels will be drained by 31 production wells. The strategy is to reach the expected 60% recovery factor by drilling multilateral wells.

The 22,000-tonne process, drilling and accommodation installation exports Grane,s crude to the Sture Oil Terminal on Norway,s west coast, via a 212 kilometer long, 28, pipeline. Hydro,s high-pressure, multiphase flow loop located at the research center in Porsgrunn has been used to design the topside process and topside process equipment in cooperation with contractors. The operations comply with Hydro,s ‘zero discharge’ philosophy.


This paper presents the challenges Hydro as an operator faced during the field development and production ramp-up period.

It will briefly describe Grane,s solutions and experiences into plateau production.

At peak production, Grane is one of the top-producers in the Norwegian offshore sector. It is estimated that the field will account for 7 percent of all Norwegian output. This ensures many good years for the Sture terminal, which is one of Norway,s most important ports for exporting oil to the market.

Hydro Oil and Energy

Hydro has been the second-largest producer of oil and gas in the Norwegian offshore sector since Norway's petroleum industry started in the early 1970s. Hydro has steadily built up its experience and expertise to become one of today's leading offshore companies in the world. Hydro also leads in the development of new technology and aspires to be the safest company operating and creating high value in Norwegian waters.

Hydro is currently the operator of 13 oil and gas fields in the Norwegian offshore sector. They are the Oseberg Field Center, Oseberg �st (East), Oseberg Sør (South), Oseberg C, Brage, Njord, Troll B and Troll C, Heimdal, Grane, Tune, Vale and Fram. The last three are sub-sea installations. The Oseberg Field Center is Hydro,s largest installation.

For a long time, Oseberg was Norway,s highest-producing oil field and will soon become one of the country,s largest gas fields. Troll Oil is currently Norway,s most productive oil field, despite the fact many once thought its oil could not be recovered. In 1999, Hydro installed Troll Pilot, the world,s first sub-sea wellstream separation unit.

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