New drillship beats a path for deepwater

Described as the first of its kind by owners Conoco and R&B Falcon Corporation, Deepwater Pathfinder started a five-year work programme drilling in the Gulf of Mexico earlier this year.

The first vessel capable of drilling in water depths of up to 3,000m, it is due to drill three or four wells for Conoco this year, and successfully discovered oil on the first well it spudded, the Magnolia Prospect in the Gulf of Mexico.

Subsequently, Deepwater Pathfinder discovered a high-quality oil reservoir on Conoco`s K2 exploration well in the Gulf of Mexico on Green Canyon Block 562, about 180 miles south of New Orleans.

The discovery prompted the company to praise the drillship`s performance – which is exceeding its expectations in terms of cycle time and technological capability – as it made ready to begin drilling in Mississippi Canyon Block 1002, at 2,290m the deepest prospect it has drilled to date.

Although technically the highlight of the vessel is its sophisticated dynamic positioning (DP) system – which enables Deepwater Pathfinder to counter the force of winds, waves and currents and continue drilling in the weather conditions associated with a ten-year storm in the Gulf of Mexico – the vessel is also the first drillship incorporating triple-redundant power generation and distribution functions.

The company claims no other drillship has been designed to meet such stringent safety standards, and that no other vessel makes use of such sophisticated, computerised control of rig floor operations, thus virtually eliminating human involvement in the operation of much traditional drilling equipment, while maintaining conventional, manual back-up facilities.

Designed by the Conoco/R&B Falcon team in advance of contractual negotiations for construction of the ship enabled the companies to describe exactly what was required to the yards interested in building Deepwater Pathfinder, and price the contract accordingly.

The companies also assembled an integrated project team at Samsung with expertise in drilling, marine engineering, construction and project management. This team also oversaw the construction and installation of the topsides, thus saving significant time during the construction process, and reducing the cost of the overall build.

Completed by Samsung Heavy Industries` Koje shipyard in Korea, Deepwater Pathfinder is unique in a number of respects. At in excess of 220m length, it is very much larger than what was the largest drillship in the world, Glomar Explorer, although it is somewhat smaller than the latest addition to Transocean`s fleet, Discoverer Enterprise, and has a particularly high variable deck load of around 20,000t.

Its storage capacity is also notable: 100,000 bbls of oil for extended well test operations; 490,560 bbls of water ballast; 28,300 bbls of fuel oil; 17,610 bbls of drill water; 3,140 bbls of base oil; and 6,290 bbls of brine.

Deepwater Pathfinder also has a very large deck area, capable of being loaded to 3,400t, capacity enough for materials for a couple of wells, thus avoiding the need to re-supply operations between drilling operations.

And, uniquely for a drillship construction project, the Samsung was responsible not just for the construction of the hull, but for the drilling equipment and delivery and installation of all other topsides equipment as well.

Capable of drilling in water depths of up to 3,053m with simultaneous well testing, Deepwater Pathfinder and its sisters can drill to 7,633m below the seafloor, while its storage capability – 100,000 bbls – provides ample opportunity to for extended well test operations. Drilling takes place through the 12.8m x 12.8m moonpools with which they are fitted.

The ship`s hullform is designed to provide both the excellent manoeuvrability required when using its DP system and thrusters, and a good transit speed, thus avoiding the need for towing.

Deepwater Pathfinder`s length, breadth and draught reflect the required storage capability, the requirement to handle the stresses associated with drilling, and the need to ensure that the ship has suitable motion characteristics and accommodate the topsides.