HOUSTON—Equinor says conditions in the area of its northernmost-operated field under development in the Arctic are not considerably more severe than other regions where it operates, but the company is preparing for icy conditions that could come its way.
Morten Opsal, Equinor’s drilling and well manager for the Johan Castberg development in the Arctic, shared insight on some of the steps being taken as the company and partners Eni and Petoro move toward first oil in 2022.
“The topside layout has been optimized to reduce the negative consequences of this risk and we have done full-scale testing on the lifeboats for icing,” Opsal said during the recently held Arctic Technology Conference in Houston.
He added that the risk for icebergs in the Johan Castberg area, which is about 100 km north of the Snøhvit Field in the Barents Sea, is low with the frequency being less than one per 10,000 years.
However, “there are uncertainties in these statistics we need to take that into account. So we have done extensive studies of ice hull interactions for the FPSO to see how we can optimize that and some reinforcement has been done to the hull due to the local ice pressure,”Opsal said. “In general we see that the Johan Castberg FPSO is a robust design in moderate ice conditions. …In general, ice risks will be handled by use of operational measures,” including production shutdown.
Floating structures are frequently impacted by winds, waves and currents, Opsal said. Johan Castberg will likely be no exception.
Companies like Equinor have been progressing exploration and development plans in the Arctic, which has returned to the spotlight—particularly in Norwegian waters—following the market downturn.
Besides Equinor, Lundin Petroleum is advancing appraisal drilling and testing at the Alta/Gohta discovery in the Southern Barents Sea. In September, the company said results from an appraisal well and an extended production test in the license were better than expected. Lundin expects to increase the gross resource range of between 115 MMboe and 390 MMboe for the discovery.
In addition, OMV has found more than an estimated 1 billion barrels of oil in at the Wisting Field in the Barents Sea. Here, like its Arctic neighbors, OMV is also assessing ice risks.
Exploration and development in the area have benefited from the Gulf Stream, which brings warm waters and milder climates to the area. Norway’s Barents Sea is ice-free during the summer. But companies must still assess risks associated with weather conditions like polar lows that can spark elevated wind speeds and change wind directions to safely produce hydrocarbons.
“We do have occurrences of polar lows,” Opsal said, adding these are not always easy to capture on traditional weathercasts. So the operator is relying on low-pressure risk forecasts.
Plans are to develop Johan Castberg—comprised of the Skrugard, Havis and Drivis discoveries—with a winterized FPSO.
The hull of the ship-shaped FPSO for Johan Castberg is under construction by Sempcorp Marine in Singapore with the turret being built by SBM Offshore in Dubai. The vessel will measure 350 m in length and 55 m in width and will have a processing capacity of 190,000 barrels per day and storage capacity of 1.1 million barrels (MMbbl). The turret system will be moored in a water depth of about 370 m.
Developers have also had to design for an uneven seabed due to ice scoring for placement of the field’s 10 subsea templates. The winterization strategy for the FPSO includes helideck heating, wind chill protection of the turret and ice protection for escape ways as well as wind chill protection of star towers and ice protection for lifeboats.
“We’re also installing a permanent reservoir monitoring system on the seabed on all the three fields’ structures,” Opsal said. “That is seismic sensors with cables that permanently install on the seabed so we can do regular seismic updates to see the production development and injection development over time.”
At a water depth between 350 m and 400 m, the shallow-water development will have 30 wells, 10 subsea templates and two satellites. Drilling operations will start in late summer or fall 2019, Opsal said, later pointing out that a minimum of 13 wells are needed to reach the startup production profile.
Recoverable reserves for the field are estimated at between 450 MMbbl and 650 MMbbl.
Equinor and partners cut the costs of Castberg from NOK 100 billion to between 45 and 50 billion by changing the design concept. Changes included switching from a semisubmersible platform with a pipeline to shore to an FPSO and reducing the number of wells from 40 to 30. The breakeven fell from about $80/bbl to less than $35/bbl.
Following Norway’s approval of the field development plan in June, analyst Rystad Energy said the project was “poised to generate some NOK 264 billion ($33 billion) in profits.”
First oil is anticipated by fourth-quarter 2022.