The multi-billion dollar development of Norway's Johan Sverdrup oilfield, the largest North Sea discovery in decades, is proceeding ahead of plan and below budget, operator Statoil said today. 

The construction of platforms and other equipment needed to start crude production from the field, which holds an estimated 2-3 billion barrels of oil equivalent, is nearly 60% complete, it added.

Development of the first of two independent phases is now estimated to cost 92 billion Norwegian crowns ($11.82 billion).

This is down from a previous estimate of 97 billion and more than 30 billion less than the company had initially anticipated. 

"We are seeing high quality in project planning and execution across the entire project," Statoil's chief executive Eldar Saetre said in a statement. 

"The project continues to benefit from good drilling and well efficiency, which together has enabled us to further reduce our forecast for the first phase," he added. 

Statoil reiterated the first phase was expected to start production in late 2019. Partners in the field are Lundin Petroleum, Aker BP, AP Moller-Maersk and Petoro.