On Monday afternoon, production started from production well number 100 on the Troll oil field in the North Sea. Altogether Troll oil produced around 350,000 barrels of oil per day in October, which makes it the highest producing field on the Norwegian continental shelf.
The well which came onstream was the 11,250 metre long three-branch well K11, which will produce oil for the Troll B platform. K11 was drilled from the semi-submersible drilling rig West Venture.
“As with the other production wells in the Troll oil field, this is a question of precision drilling,” says Johan Mikkelsen, senior vice president for the Troll field in Hydro Operations and Production Norway (OPN). “The three branches in K11 pass in a horizontal line through a total of 9150 metres in the reservoir, and the long producing sections are drilled to within a height of one metre,” he adds.
Oil production from the thin oil zone in Troll Oil has been made possible through technology to drill long, horizontal wells with great precision, which was developed in close collaboration with Halliburton and Baker Hughes. In order to reach additional areas of the reservoir, technology has been developed to drill several branches from a main well. This makes it possible for Hydro to produce oil from parts of the field that would not otherwise have been profitable.
At the end of October, a total of 6000 kilometres of wells had been drilled in the Troll oil field. Smedvig and Transocean are the present contractors for production drilling on the field, which will encompass a total of 113 wells. Of the 100 wells that are in production, 22 have horizontal production branches and five are three-branch wells. Later this week another three-branch well will be completed, I-13, which is being drilled by the semi-submersible rig Polar Pioneer.
“This was the rig that first started production drilling for the platforms Troll B and Troll C on 18 March 1994. It wasn’t involved in the drilling of well number 100, but the well it will complete this week is pretty impressive with a total length of 13,800 metres and three production branches that add up to a total of 11,700 metres,” concludes senior vice president Johan Mikkelsen.