Switzerland-based driller Transocean Ltd. said Dec. 28 that it signed a rig design and construction management contract and a five-year drilling contract with Chevron Corp.'s Chevron U.S.A. Inc. for one of its two dynamically positioned ultra-deepwater drillships.

The drilling contract, subject to design, construction and delivery requirements, has an estimated backlog of US$830 million, excluding mobilization and reimbursables.

The drillship, under construction at the Jurong shipyard in Singapore, will feature dual 20,000-psi blowout preventers, net hook-load capacity of three million pounds, a 165-ton active heave compensating crane and an enhanced dynamic positioning system. The rig's power plant will also be configured to comply with Tier III International Maritime Organization emissions standards.

Operations are expected to begin in the Gulf of Mexico in the second half of 2021.

In the event of termination for convenience by the customer, Transocean will be compensated for its incremental 20,000-psi subsea investment in the rig. Additionally, a termination for convenience occurring after April 2020 would result in a substantial termination fee.