Production drilling starts at Mariner North Sea oil field
Production drilling has started in the massive Mariner oil field in the UK North Sea, operator Statoil has announced.
Up to five wells will be drilled before hook-up and commissioning activity starts on the Mariner A platform next summer.
First oil is expected to be produced from Mariner in 2018.
The pre-drilling campaign is expected to support about 500 jobs in the UK Continental Shelf (UKCS).
Mariner, which lies about 93 miles (150km) east of Shetland, is one of the largest projects currently under development in the UKCS.
The heavy oil field has reserves estimated at more than 250 million barrels of oil, with an average plateau production of about 55,000 barrels per day.
Hedda Felin, managing director of Statoil Production UK, said: "This is an exciting period for us as a UKCS operator as we transition from the planning phase to active offshore operations.
"Pre-drilling enables production to reach plateau levels more quickly after the start of operations on Mariner A.
"It will also be an important learning period for us, in terms of understanding the reservoir and identifying potential efficiencies for future wells, with safety and the protection of the environment being our fundamental priorities."
One of the world's largest jack-up rigs, The Noble Lloyd Noble, is currently positioned over the Mariner jacket, which was installed in 2015.
The first production wells will be drilled through a well deck on the jacket.
Up to five wells will be drilled before the platform topside modules arrive in mid-2017. They are currently under construction in South Korea.
Statoil said that up to 100 reservoir targets could be drilled over the lifetime of the Mariner field, based on the current development strategy.
The operator had hoped to get production under way next year. However, in October 2015 it announced it was postponing the start, citing delays at construction yards in South Korea.
Statoil has a 65.1% stake in Mariner. It co-venturers are JX Nippon Exploration & Production (UK) Ltd (20%), Siccar Point Energy (8.9%) and Dyas Mariner Ltd (6%).