Energy giant Chevron has announced its deepwater drill ship has commenced operations in deepwater US Gulf of Mexico under a five-year contract with Transocean, the world’s largest offshore drilling company.

The drill ship Discoverer Clear Leader has well drilling capacity under 12,000ft of water to a total depth of 40,000ft, Chevron said.

The ship will start work at Chevron’s deepwater projects in Tahiti and Jack/St Malo.

A second vessel, the Discoverer Inspiration, is expected to be delivered in early 2010.