Norway's Den norkse stats oljeselskap AS has laid claim to the world record for the longest extended reach well.
Statoil's Statfjord C10 well in Block 33/09 of the Norwegian North Sea, now on stream, had a horizontal displacement of 16,410 ft. It was drilled to 20,336 ft measured depth from Statfjord field's concrete gravity based platform.
With minor changes it will be possible to drill as much as 6,560 ft farther than C10, Statoil said.
It is the first of three extended reach wells planned for the northern part of the Statfjord reservoir. They will replace three planned subsea completions that would have been tied back to Statfjord Platform C.
Statoil said C10 was planned and executed as a normal job. The original target had a horizontal displacement of 15,249 ft and a measured depth of 19,303 ft, where a "geological anomaly" was found.
Statoil went back to 16,924 ft measured depth and sidetracked to the new target with its horizontal displacement of 1 6,410 ft.
Statoil said the whole operation was completed without technical problems.
The drilling contractor, Smedvig Drilling, Stavanger, drilled 9,692 ft continuously at a rate of 89.5 ft/hr, using a Norwegian Lyng M121 bit. The bit was 20% worn after use.
FURTHER WELLS
Statoil will drill Statfjord's second extended reach well, also scheduled as a producer, in September-December. It will have a horizontal displacement of 20,664 ft and a measured depth of 23,944 ft.
A third extended reach hole, a water injection well, is planned for early next year with a horizontal displacement like C10's.
Statoil said the minor adjustments needed to achieve additional extended reach include a new top drive motor with increased torque on the Statfjord C rig. The company also will buy a 6 5/8 and 5 1/2 in. combination drillpipe to improve cuttings return.
Substantial cost savings will accrue from the success of the C10 well. The cost of the three high angle wells will be 240 million kroner ($155 million), compared with 1 billion kroner ($645 million) for the three subsea wells, which would have taken 1-2 years to drill and tie back to the platform.
Statoil plans additional high angle wells, including two water injectors in the East Statfjord satellite field from Statfjord Platform C. The wells will have horizontal reaches of 14,760 ft and 18,040 ft.
However, the 120 million bbl East Statfjord reservoir will still be produced through a subsea complex.
Statoil also plans high angle, extended reach wells in nearby Gullfaks field. Details are to be disclosed later.
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