Gorilla V under construction at Rowan's Vicksburg, Mississippi yard. [21,168 bytes] McDermott's DB 16 [14,600 bytes] CAHT vessel [14,763 bytes]

Marshall DeLuca

World's largest jackup

Rowan is building the world's largest mobile jackup drilling unit - the Super Gorilla V. According to Rowan Drilling, the Super Gorilla V is a Rowan/LeTourneau enhanced Gorilla-class, slotilever, cantilever jackup, and also a mobile, self-elevating, offshore drilling and production platform. The unit is designed for harsh environment exploration and development drilling operations, production platform operations, and simultaneous drilling and production operations.

The Super Gorilla has a variable load of 12,500,000 lb independent of the combined hook, setback and conductor tensioning loads of 3,750,000 lb. The jackup is designed to operate year-round in 400 ft of chart datum water depth satisfying the North Sea 50-year return storm environmental criteria south of the 61st parallel. The design incorporates a 170-ft tall, 40 ft by 40 ft base derrick with a 2,500,000 lb static hook load. The new generation of Gorilla Class jackup also allows fore and aft movement of the sub-base, independent of the cantilever beams, and an industry-first dual mud system with four 7,500 psi WP mud pumps.

Upon expected completion in March 1998, the Gorilla V will begin a contract with Amoco in the UK North Sea. Rowan has also begun the initial stages of construction for a second Super Gorilla class jackup, the Gorilla VI, which is scheduled for delivery in the third quarter 1999.

Supply vessels

Bender Shipbuilding & Repair has won a contract for the construction of two 217.5-ft offshore supply vessels for GulfMark Offshore and an option to purchase two more identical units. The first two vessels will be delivered within the next two years.

The vessels will have dimensions of 217.5 ft by 54 ft by 20 ft, and will be powered by two Caterpillar 3606 main propulsion engines. The vessels' capacities will include 8,000 cu ft of bulk mud; 4,000 bbl of liquid mud; 185,000 gal of fuel; 300,000 gal of fresh/ballast water; and, 1,200 tons of deck cargo. The vessels will be used to carry of 2,800 tons of provisions, fuel, water, liquid mud, and bulk mud cargoes to offshore facilities worldwide.

Derrick barge upgrade

J. Ray McDermott has completed an upgrade on its Derrick Barge 16 to help strengthen the company's opportunities in deepwater Gulf of Mexico. The modifications include the installation of four constant-pitch 2,000 hp, DC-driven, fully azimuthing thrusters; an ABS class II dual redundant dynamic positioning system featuring "hold position" and "track following" modes of operation; and a power generation module consisting of four 2,800 hp, 16-cylinder Alco diesel engine/generator sets along with the AC switchgear, MCC and SCR control house. The upgrade was completed over 10 months at the company's facility near Morgan City, Louisiana.

Support vessel

Halter Marine has signed a contract to build a new class of offshore support vessel called a construction anchor-handling tug supply (CAHT) vessel for worldwide deepwater applications with emphasis on the Gulf of Mexico and West Africa. The vessel will be built for a joint venture between Hvide Marine of Ft. Lauderdale, Florida and Aker Marine Contractors of Houston, Texas at Halter's Moss Point, Mississippi shipyard.

The 16,000 total hp diesel electric vessel will be 279 ft in length, with a 65-ft beam, 26-ft depth, and 22-ft loaded draft. The vessel will feature approximately 1,500 LT of deck cargo capacity, and will be equipped with a diesel-electric Z-drive, azimuthing main propulsion system, dynamic positioning system designed to DPS-0 requirements with capability to DPS-2, and will generate 120 metric tons of bollard pull. The unit will feature a pivoting 300-ton capacity "A" frame crane for lifting over the stern, which will allow the deployment and installation of large suction anchors, templates, and other subsea structures. Delivery of the vessel is scheduled for early 1999 and an option for a second, similar vessel is available to the owners through mid-1998.

Intervention service

PGS Intervention (Petroleum Geo-Services) has unveiled plans for the construction of the Ramform Intervention Services Vessel (ISV), a dynamically positioning vessel for coiled tubing and well intervention services. The 120-meter vessel features a deck area with capacity equaling a deadweight of 20,000 tons, and the recently invented "big reel" tool designed for subsea tubulars that offers speed and ease of use for coiled tubing drilling and other subsea well interventions. The Ramform will work in 75-600-meter depths with riser connected, and features a positioning system with five azimuth thrusters and a transverse tunnel thruster, allowing the vessel to weathervane. The vessel is capable of performing coiled tubing drilling operations, completion activities, subsea construction activities, and cementing operations. The ISV will perform all of its services in the Norwegian and UK sectors of the North Sea and is built to Det norske Veritas class standards.

Semi conversion

TDI-Halter and Diamond Offshore Drilling has signed a letter of intent for the conversion of the 800-man accommodations semisubmersible, Polyconfidence, into a dynamically positioned, deepwater drilling unit to be re-named, Ocean Confidence. The conversion will include stability enhancements with the addition of lower hull sponsons and column blisters, mud system upgrade, crane upgrade, deck extensions, tubular storage additions, riser handling system, BOP handling systems, global strengthening and fatigue enhancements, substructure modifications, and riser tensioning upgrades. The Polyconfidence, currently under contract in the North Sea, was built in 1987, and is expected to be available for conversion in February 1998 and completed in fourth quarter 1999.

Restored tug

Bollinger Algiers, a subsidiary of Bollinger Shipyards, has recently completed the conversion of the Ranger offshore tug. Ranger, a 143-ft tug owned by Caribbean Towing underwent extensive restoration work after being idle for 10 years. Restoration included a new electrical system, interior refinishing, engine and gear foundations, pumps, generators, piping systems, exhaust stack, electronic package, kort nozzles, stern tubes, struts, steering rudders, tanks, reconditioned EMD-16-643-E2 main engines, Lufkin 5-1 marine gears, propellers, shafts, an engine-driven hydraulics, and a hydraulic tow winch.

Copyright 1997 Oil & Gas Journal. All Rights Reserved.

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