Operational mistakes and a lack of maintenance led to two near-fatal accidents at Norway's Troll Field and at the Mongstad refinery, operator Statoil ASA (NYSE: STO) said on Jan. 20.

Several incidents at Statoil's offshore and onshore installations in 2016 prompted several investigations by the company and authorities. In November, unions and Norway's safety organization warned that cost-cutting in the industry due to low oil prices could affect safety.

The latest two investigations by Statoil looked into an incident on Oct. 15 involving the loss of control of a well at the Songa Endurance rig in the Troll Field, and a hydrogen leak that occurred on Oct. 25 at the Mongstad refinery.

"This is among the most serious well-control incidents we've had," Statoil's head of technology, projects and drilling, Margareth Oevrum, told a news conference, in reference to the accident at Troll.

The well control incident led to a gas leak that pushed seawater more than 30 meters up the derrick before the well was closed by the BOP about one minute later. A derrick supports the drilling apparatus on an oil rig.

A gas leak due to a break in a corroded pipe socket at the Mongstad refinery led to the facility's shutdown and evacuation.

The link between the incidents at the drilling rig and the refinery was lack of understanding of the risks, and not efficiency improvements or cost cutting, a Statoil spokesman said.

"Maintenance is decided by technical conditions, not economic consideration," he said.

Nobody was injured in the accidents, but Statoil said both could have led to loss of life if the safety equipment had failed or if the gas had been ignited.

"If the gas had caught fire, this incident could have caused fatalities," said Jens Oekland, the head of Statoil's marketing, midstream and processing unit, referring to the event at the Mongstad refinery.

Two people were in the vicinity when high-pressure hydrogen-rich gas was released.

Statoil said its investigation showed maintenance at Mongstad was wrongly prioritized due to lack of understanding of the risk, and also saidit would step up maintenance in the next two years.

"In this case, our risk management was inadequate. We made the wrong priorities," Oekland said.

Statoil also said it would not use the downhole valves, which were unintentionally opened during the well control accident at Troll, as barriers against the reservoir.

Norway's Labour Minister has appointed an independent commission to investigate the link between cost-cutting efforts and industry accidents.

In December, Statoil released reports on two other accidents, one of which injured five people, including two students on work placement, but the company said it had not found evidence linking those events to its cost cuts.