Harbour Energy subsidiary LLOG Exploration Co. LLC has let contracts to Seadrill Ltd. for work in the US Gulf of Mexico.

The ultra-deepwater drillship West Neptune was awarded a 365-day contract extension, with operations scheduled to begin this September. The ultra-deepwater drillship West Vela was awarded a program with a duration of 270 days, with an expected start date in August.

The awards add about $260 million to Seadrill’s contract backlog and extend the company’s working relationship with LLOG, the company said in a release Apr. 22.