New type of drillship comes to the U.S. Gulf of Mexico

The first of a new type of “compact” deepwater drillships jointly designed by Shell and Noble Corporation recently arrived in the U.S. Gulf of Mexico. After completing commissioning and acceptance testing this month, the drillship Noble Bully I will go to work at Shell’s Mars B Olympus.

Based on an GustoMSC PRD 12000 MP design and built by China’s Shanghai Shipyards and outfitted and completed by Singapore’s Keppel Shipyards, the Noble Bully I is the first of two Bully rigs that can be equipped to drill in water depths of up to 10,000 ft, with a maximum drilling depth of 40,000 ft. There are accommodations for 156.

Classed by DNV, 1A1 Ship Shaped Drilling Unit DYNPOS-AUTR, BIS, ICE-05, the Noble Bully I will drill in a water depth of about 8,250 ft. It is expected to be under contract until December 2016. The full contract dayrate is $440,000 to $445,000. The Noble Bully I has a main deck length of 615 ft and breadth of 127 ft 9 in.

The Bully rigs also feature a compact box-type drilling tower, known as a Multi-purpose Tower (shown at right), instead of a conventional derrick. As the name indicates, a Multi-purpose Tower is designed to maximize productivity and safety, yet it allows for a significantly smaller vessel when compared to other deep water drill ships of similar capacity.

The Bully drillships will use a subsurface BOP. They will be equipped to operate in 8,250 ft of water, but that can be extended with the addition of more riser.

However, unlike conventional drilling operations on Mobile Offshore Drilling Units,  the Bully rigs can also use a Surface BOP drilling technique. This means that the well control system, including he BOP stack, are not located on the seabed, but instead on the surface just below the drill floor. To allow for the surface BP operations, the drill floor is located 80 ft above the waterline, providing the space for the mechanical handling of the BOP, T-joint and subsea trees.

The ships also feature an attention to energy efficiency, use less fuel and are shorter and lighter than comparable drill ships. The dynamically positioned Noble Bully I and Noble Bully II can be maneuvered at a favorable angle toward wind, waves, and currents, and feature ice-class hulls. Shell and Noble have increased the automated technology on the Bully rigs, increasing personnel safety on board.

Sister vessel Noble Bully II is expected to begin operations early next year in Brazil.

December 7, 2011