As many as 85 discoveries remain in the pipeline for development off Norway with an estimated total investment value of about Nkr400 billion ($44 billion), with most of these in the mature North Sea and likely to be tapped as low-cost tie-backs to existing facilities, according to the country’s petroleum agency.
These finds account for total recoverable resources of more than 4.1 billion barrels of oil equivalent, or 15% of proven volumes in existing fields and discoveries of around 27.7 billion boe - over half of estimated remaining recoverable resources of 52.2 billion boe, including contingent volumes.
Around half of the resource tally for discoveries lies in the North Sea and many of these have recoverable volumes of less than 63 million boe, making subsea tie-backs the most probable development scenario, the Norwegian Petroleum Directorate (NPD) stated in its annual resource report.
These include Frigg-Gamma-Delta, Tornerose, Eirin and Trine, while there are larger discoveries farther north including OMV’s Hades-Iris in the Norwegian Sea, with about 140 million boe, and the Austrian operator’s Wisting find in the Barents Sea, with about 440 million boe.
The agency said that, while the average size of discovery has declined over the past two decades, these have become more profitable to develop due to technological advances by the industry and more cost-effective solutions.
Consequently, there have been 33 development plans approved in the current decade for discoveries with an average size of about 150 million boe, compared with 10 plans for finds with an average size of about 1 billion boe in the 1970s, according to the NPD.
Many of these have been for subsea tie-back projects involving satellite discoveries, such as Aker BP’s Valhall Flank West, as successful infill drilling campaigns by the likes of Equinor and Aker BP have turned up finds that can be economically developed using nearby field infrastructure.
The NPD stated that around 80 discoveries, amounting to roughly 3.1 billion boe, are likely to be developed by phasing them into existing or future infrastructure, mostly through subsea tie-backs.
“Maintaining existing infrastructure and utilising its spare capacity are important preconditions for realising the assets in the discovery portfolio,” the agency said, adding “it is also important that new facilities are built with enough flexibility to accept additional resources”.
Furthermore, reserves in existing fields have increased by nearly 9 billion boe in the period from 2000 to 2018 - equivalent in size to three Johan Sverdrup fields - due to measures to enhance recovery and improved operational efficiency, as well as lower costs.
The NPD said cost control and efficiency gains have cut the average cost of a production well by 40%, while operating costs on most fields have been reduced by around 30% since 2013.
“New solutions, including automation and remote operation, improved use of data and more efficient operation, could further reduce costs and help to increase production even more,” it stated.
The agency urged operators to carry out further exploration near existing fields so that discoveries can be generated to utilise spare processing capacity as production drops, thereby reducing unit costs and prolonging field lifetimes.
There have been 32 exploration wells drilled off Norway so far this year, turning up 10 discoveries including Aker BP's find at the Liataarnet prospect in the North Sea.
Subsea tie-in solutions could also be relevant for larger finds, with seven of the 10 biggest discoveries off Norway set to be developed in this way for an estimated investment of more than Nkr60 billion, according to the NPD.
These include Equinor’s Grane Area Northern Development (Grand) in which several discoveries are set to be tied into the Grane platform.
The agency also sees estimated investments of Nkr130 billion to jointly develop discoveries with combined resources of 1.2 billion boe as standalone projects, including redeveloping and phasing in fields that have been shut down such as Froy.
The NPD said technological advances, market changes and new infrastructure could facilitate redevelopment of fields that have been shut down and 10 projects have been identified to recover an additional 251 million boe from six shut-down fields, including Tor near ConocoPhillips-operated Ekofisk.
The agency has also estimated that tight reservoirs at 42 discoveries and fields could harbour in-place resources of as much as 12.6 billion boe and a study revealed that about 2.2 billion boe could be tapped using enhanced oil recovery techniques.