On 1 September, there was no longer oil production from the oldest permanent production platform on the Norwegian shelf. After more than 39 years in active service, it is being prepared for cold phase. 

The Ekofisk field represents a solid piece of Norwegian oil history. Ekofisk 2/4 A (picture taken at Ekofisk in 1973) has been at the field from the early days. It started producing in the spring of 1974, and has over nearly four decades provided a considerable contribution to Norwegian oil production – and income.

These are big numbers. The total production was 872 million barrels of oil equivalent – mostly oil and some gas. At most, daily production reached 70,000 barrels. One well in particular, A-20, has been a very good contributor for a long time. This well has also contributed to production of more than 87 million barrels and was the last well to be shut down.

Major resources

“This is truly a milestone, for ConocoPhillips and the entire offshore industry. It is very impressive to look back on what skilled employees have achieved at Ekofisk 2/4 A,” says President Europe Steinar Våge. Ekofisk was Norway’s first oil field, but significant resources still remain in the reservoir. “So this is in not the end,” says Våge. The platform is one of the true pioneers. The steel jacket was constructed in France. Due to the rapid progress plan, construction of the first platforms was distributed across multiple locations and countries. The model which was used as a basis for construction was developed for oil production in the Gulf of Mexico, where the conditions are very different from the North Sea.

Traditional solutions weren’t always the best, and this resulted in many challenges. The tragic incident with a fire on Ekofisk 2/4 A in 1975, in which three people died when a rescue capsule fell down after being lowered incorrectly, particularly bears mentioning. The fire occurred in the splash zone – where a riser had rusted. It later emerged that corrosion was created in this area when the hot oil rose up through the risers. Co-cooperation with the Norwegian Petroleum Directorate and Veritas resulted in the risers being replaced with a more robust and safer patent in the splash zone.

Monitored from shore

Over the years, many people have worked and been trained on board the platform. Up to 1996, the platform had a crew of about 35 people, but has been remotely monitored since. This first took place from the control room on Ekofisk 2/4 K, while in recent years production has been monitored from the onshore operations centre in Tananger. A roving crew of eight people have been responsible for maintenance and have visited the platform daily. The months ahead will be hectic on board, through production has stopped. The preparations for plugging wells have started. A total of 23 wells will be plugged and abandoned permanently. The Rowan Gorilla 6 drilling rig will start this work at the beginning of 2014 and the work is scheduled to be completed over the course of 2016.

Though the oldest platform has been shut down, the Ekofisk field still has several exciting and productive years ahead. “We are looking forward and planning to be a key player on the Norwegian shelf in 2050 as well,” says Steinar Våge. A new well, Z 17, has already been drilled and is ready to start producing from the same reservoir zone as 2/4 A when the newly installed platform Ekofisk 2/4 Z is ready towards the end of 2013. Fully developed, the 2/4 Z platform will have 35 production wells.