Dutch firm Heerema Marine Contractors has mated the topsides of the Repsol Sinopec-operated Montrose platform the UK North Sea, with the pre-installed jacket, some 200 kilometers east of Aberdeen.

In a statement on Wednesday, the operator said this was a “major milestone” for the the Montrose Area Redevelopment (MAR). The Montrose Bridge Linked Platform (BLP) topside was built by Heerema Fabrication Group’s Zwijndrecht yard in the Netherlands.

The 10,500 tonnes topsides was placed on the jacket by Heerema’s SSCV Thialf crane vessel. Repsol Sinopec says that the milestone marks the next phase of a project that will unlock an additional 100 million boe of reserves and extend the life of the Montrose Area to beyond 2030.

Installation of the topsides was followed by installation of the bridge linking it to the Montrose Alpha platform, and of the flare boom. Work will now on the commissioning of the plant and integration of the wells, with first production from the Shaw field expected during the first quarter of 2017, the operator said.

Bill Dunnett, Managing Director of Repsol Sinopec Resources UK (expected to rebrand imminently from Talisman Sinopec Energy UK) said: “We’re very pleased to be able to report a safe and efficient installation of the new bridge-linked platform. This is a major step forward for this project and a tangible demonstration of the long term commitment of our shareholders – Repsol and Sinopec – and partner, Marubeni, to the UKCS. This is a completely new facility in our core infrastructure and will be a game-changer for this business. MAR adds significant production and maximises economic recovery from these historic assets.”

Andy Samuel, chief executive of the Oil and Gas Authority in the UK said: “The Oil and Gas Authority is very pleased to see this important milestone in the redevelopment of the Montrose Area, which adds new fields and significant reserves, and also maximises economic recovery and extends the life of the existing fields.”