Transocean drillship Deepwater Pontus has been forced to stop working for Shell for almost three weeks since losing a blowout preventer (BOP) when completing a well late last month.

A Shell spokesperson confirmed that a BOP had been dropped to the ocean floor, the second serious incident to hit the drillship in the last six months.

“The incident occurred at approximately 2 am on Saturday, 20 November while the drillship was preparing to move off a well located in the Mars Corridor in the Mississippi Canyon area in the Gulf of Mexico," said the spokesperson.