The dynamically positioned semisub Atwood Condor is expected to go to work for Shell at the end of August this year. The 39-month contract will begin once the rig is assigned from Hess, which is currently using it.

Shell will drill in the Gulf at a dayrate of about $555,000 through November 2016, and the contract "will supersede the remainder of the existing contract with Hess", Atwood said in a statement.