Seadrill and US authorities are to launch investigations after one person died following an unspecified incident on board a drillship working for Kosmos Energy in the US Gulf of Mexico on Sunday.

ENERGY EXPLORED: SUBSCRIBE TO ACCELERATE

Gain valuable insight into the global oil and gas industry's energy transition from ACCELERATE, the free weekly newsletter from Upstream and Recharge. Sign up here today.

A contractor working for Allrig died following the incident on board the Seadrill-owned West Neptune at 1:30pm central standard time on 24 January, a Seadrill spokesperson said in a brief statement.

Kosmos said in its own statement that it learned of the fatality at about 1:45pm central time on the same day.

Neither Seadrill nor Allrig, in a separate brief statement, gave any details of the nature of the incident that led to the fatality.

Details of the deceased have also not been released.

'Root cause investigation'

"Seadrill is providing support to the West Neptune crew at this difficult time and wishes to express its condolences to the family of the deceased," the rig operator's statement continued.

"The US Coast Guard and Bureau Safety and Environmental Enforcement were immediately notified and will undertake an investigation on the drillship in the coming days.

"Seadrill together with representatives from Kosmos Energy and Allrig will also undertake a root cause investigation."

Allrig said: "Our thoughts are with the deceased’s family at this difficult time and we are currently providing ongoing support to them and to all other Allrig contractors and employees affected by the incident.

"A full investigation is under way and Allrig will be working closely with all interested parties to establish the root cause of the incident."

The West Neptune was drilling for Dallas, Texas-based independent Kosmos on Mississippi Canyon Block 727 at the time of the incident.

'We will do everything we can to ensure this never happens again' - Kosmos

"Drilling activities have been suspended since the incident," Seadrill said in its statement, issued on Monday evening.

Kosmos' statement said the rig was working on the Kodiak 2 well completion at the time of the incident.

Richard Clark, president of the oil company's Gulf of Mexico business unit, said: “On behalf of everyone at Kosmos Energy, my deepest sympathies go out to the family and friends of the man who died. They have suffered a tremendous loss.

"As the incident is investigated and the facts come to light, we will do everything we can to ensure this never happens again.

"We have already begun to share initial learnings from the incident with our peer companies, engaging with more than 20 operators in the US Gulf of Mexico."

In late November, Seadrill was awarded a firm one-well contract with Kosmos for the West Neptune at $178,000 a day, in a deal valued at $9 million.

The seventh generation unit was built in 2014 and can operate in waters of 12,000 feet depth and drill to up to 40,000 feet.