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Longest producing well from an offshore platform-world
record set by Gulltopp
[April
15] STAVANGER, Norway--The Gulltopp well on the Gullfaks field
has been completed, setting a world record for the longest
producing well from an offshore platform, according to StatoilHydro.
Hydrocarbons were flowing up through the well at 9,910 m (32,513
ft).
The 10-km (6.2-mi) drill pipe was controlled
from the drilling rig at the sea surface.
It was run 150 m (492 ft) down to the seabed,
and then sequentially down through various types of rock strata.
(enlarge
photo)
"This is a day of rejoicing both for Gullfaks
and StatoilHydro," says Arne Sigve Nylund, the head of Operations
West in StatoilHydro.
"We were aware of the risk that Gulltopp drilling from the
platform might fail. This makes it extra great that we today
have successfully completed the company's most demanding drilling
operation."
The experience gained by StatoilHydro
is very valuable to the further development of both remote
prospects at Gullfaks and on other fields in the company's
portfolio.
"The increased range that we now envisage for
platform drilling opens up new perspectives for effective
exploitation of existing infrastructure, and thus increased
producing life," Nylund says.
An extensive plan for how to extend the life
of the field, which came on stream back in 1986, has been
developed.
The 10-kilometre drill pipe was controlled
from the drilling rig at the sea surface. It was run 150 metres
down to the seabed, and then kilometre after kilometre through
various types of rock strata.
The longer the drill pipe is, the more difficult
it is to control the forces that are transferred to the drill
bit down in the deep, thousands of metres away. This requires
great attention and skills by personnel in charge of drilling.
"The Gulltopp well has been a great technological
challenge, and was possible thanks to high professional skills
among our own drilling and well personnel, in addition to
crucial contribution by the involved suppliers," says Geir
Slora, head of drilling and wells in StatoilHydro.
"There have been project delays due to subsurface
conditions and demanding technical and operational challenges
related to the well, brake system in the drilling rig and
platform's power supply. It has therefore been necessary to
upgrade the brake system and power supply," Slora says.
Why drill such a long well?
The record-long Gulltopp well is a result of the distance
from the nearest platform. It is 10 kilometres from Gullfaks
to the oil discovery.
The alternative to drilling this distance would
be to locate a subsea template on the seabed. This, however,
would be far more expensive than drilling from an existing
platform.
Facts about Gulltopp:
# StatoilHydro's longest well on stream on the Norwegian
continental shelf
# 9 910 metres long down to 2 430 metres below
the sea surface
# Gulltopp was drilled from the Gullfaks A platform
in the North Sea outside Florø
# The oil and gas discovery was proven in 2002, and
drilling started in April 2005
# The recoverable resources are 4 million standard
cubic metres of oil and 500 million standard cubic metres
of gas
# The expected production plateau: 16 000 barrels of
oil per day # Licensees: StatoilHydro
70 percent, Petoro 30 percent
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