Norwegian giant Statoil held a press conference earlier today (20 January) to discuss the investigations of two very serious incidents with safety issues that could have been fatal to the crew onboard

On 15 October, a serious well control incident occurred during well plugging by the Songa Endurance semisubmersible drilling rig at the Troll field in the Norwegian North Sea.

Just days later, Statoil also experienced an onshore incident at the Mongstad processing complex.

Although no one was injured in either incident, the company says there could have been the loss of life. Statoil’s internal investigation unit studied the incidents thoroughly, in addition to the Petroleum Safety Authority Norway (PSA).

“We are taking both these incidents seriously. Openness is vital to our safety work, and the investigation reports are important contributions for us to learn from the incidents. If we are to make the right decisions and carry out the right measures we need to get everything on the table,” says Margareth Øvrum, Statoil executive vice president for Technology, Projects and Drilling in Statoil.

At the Troll field, the well control incident led to a gas leak that pushed seawater more than 30m up the derrick, before the well was closed by the annular preventer inside the blowout preventer (BOP) about one minute later.

Statoil’s internal investigation defines the incident to have a high degree of seriousness, and concludes that at worst it could have led to loss of life if the safety equipment had failed to function as intended, or if the gas had been ignited.

According to the company’s investigation, the BOP was quickly activated and stopped the gas leak, and five gas detectors automatically turned off equipment that could have produced sparks. The report concludes that two main findings have weakened the barriers and helped gas reach the drill floor.

In the first finding, it was revealed that existing downhole valves were used as barriers against the reservoir and were unintentionally opened.

The other main finding is related to the annular preventer inside the BOP that should have been closed before the operation was started, because it was not possible to measure the pressure below the wellhead sealing.

“After the incident some immediate actions were taken to ensure that the downhole valves are not used as barriers, and a deeply set plug was reintroduced as a barrier during use of vertical Christmas trees,” Statoil says. The investigation report points out several other actions that are currently being taken by the Norwegian giant.

“This is a very serious well control incident. The actions taken will improve our ability to assess risk, both before and during operations. We will share our experience from this incident with the rest of the industry,” says Øvrum.

The following day of the Troll well control incident, Statoil experience a fire at the Statfjord A platform, in which the company also launched an investigation, along with the PSA.

In late-December, Statoil said “several incidents” occurred in the Autumn of 2016 that caused the company to find out whether there were any connections between the incidents and Statoil’s improvement programs.

Source: www.oedigital.com