NORSK HYDRO TO DEVELOP TROLL FIELD OIL ZONE

July 10, 1995
Norsk Hydro AS plans to develop a thin oil zone in the gas sector of Troll field in the Norwegian North Sea, effectively doubling estimated oil recovery from the field. The company is completing a 19.5 billion kroner ($3 billion) development of the West Troll oil reservoir, where estimated reserves are 420 million bbl of oil. Now, Hydro plans to drill as many as 54 wells in the field's central 13 in thick oil zone, which lies below the giant gas cap. The program is expected to boost

Norsk Hydro AS plans to develop a thin oil zone in the gas sector of Troll field in the Norwegian North Sea, effectively doubling estimated oil recovery from the field.

The company is completing a 19.5 billion kroner ($3 billion) development of the West Troll oil reservoir, where estimated reserves are 420 million bbl of oil.

Now, Hydro plans to drill as many as 54 wells in the field's central 13 in thick oil zone, which lies below the giant gas cap. The program is expected to boost Troll's total oil recovery to more than 1 billion bbl.

Rolf Prydz, director of Hydro exploration and production, said the company intends to complete by spring 1996 a development an to place Troll's gas province oil on production in 1999. This plan will be submitted to Norway's Ministry of Industry & Energy by yearend 1996.

Oil wells in the southern sector of the gas province will be tied back via subsea manifolds to Hydro's West Troll oil platform, due to be installed in the field this month.

Prydz said oil wells in the northern sector of the gas province likely will require a new platform installed in the gas province to handle extra production via new subsea manifolds.

A production semisubmersible is the most likely platform choice, possibly a converted drilling rig. Water depth in the probable installation area is more than 300 in.

Prydz said the big hike in oil reserves stemmed from use of things such as 3D seismic technology' horizontal drilling, and improved development techniques.

Troll is the sixth largest oil field off Norway, Prydz said, "which is very interesting when you think that the oil reserves were said to be noncommercial at first."

Hydro's West Troll platform, the world's largest concrete semisubmersible production unit, was to undergo tow-out to its mooring site in the field early this month. Oil production is due by Oct. 1.

Norske Shell AS recently installed a giant concrete platform in the eastern gas province of Troll field. The field's gas reserves are an estimated 45 tcf.

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