Norway's Statoil (STO) said on Thursday its cooperation with Russia's Rosneft in developing the onshore North Komsomolskoye oilfield was compliant with European Union and U.S. sanctions imposed on Russia over the conflict in Ukraine.
Statoil confirmed plans to take a 33 percent stake in the northwest Siberian field under an agreement signed with Rosneft in 2013, a year before sanctions on cooperation in oil production were imposed.
"We continue to be transparent about all our activities and we make sure they are compliant with all relevant sanctions," a Statoil spokesman said in an email, adding that North Komsomolskoye was a conventional oilfield, containing highly viscous crude.
Sanctions ban Western companies from helping Russia produce oil from shale formations in the Arctic and in waters deeper than 150 metres (165 yards).
The spokesman said Statoil planned to sign an agreement on the stake in SevKomNefteGaz LLC, which holds the North Komsomolskoye license, before moving to the next pilot production programme. Statoil will decide on the field's full development later.
He said test production could commence "soon", but declined to provide any timeframe or say when full output might start.
Rosneft said on Thursday that drilling and testing in 2015-2016 helped increase the field's oil and condensate reserves to 111 million metric tonnes, or 813 million barrels based on worldwide average gravity, from 52 million tonnes.
"The start of test production ... will lay the ground for a full-scale field development," it said in a statement.
Reporting by Nerijus Adomaitis