Subsea/Surface Systems

At Hyundai Heavy Industry's construction yard in Ulsan, South Korea, the superlift method was used to mate the Na Kika topsides. Superlift allows large topside structures to be installed in one piece onto the top of a large hull structure.

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Superlift mates Na Kika topsides

At Hyundai Heavy Industry's construction yard in Ulsan, South Korea, the superlift method was used to mate the Na Kika topsides. Superlift allows large topside structures to be installed in one piece onto the top of a large hull structure. The lift is performed onshore, using strand jacks rather than cranes. Hyundai pioneered the superlift technique. Prior to the Na Kika lift, Hyundai had used this technique to mate the topsides to the hulls of two deepwater drilling rigs. Na Kika was the first application of this heavy lift technique on a floating development system.

For the Na Kika superlift, the four topsides modules were fabricated on eight large lifting beams, and the hull was fabricated on a set of skidways adjacent to the superlift site. Four large jacking towers were erected on the interior of the topsides, and eight jacking legs were erected on the exterior. A total of 38 strand jacks, each made up of 37 wires, were located at the top of the lifting towers and jacking legs and attached to the lifting beams. Also, 7,000 metric tons of steel were required in the superlift structure to lift the 12,000-metric-ton topsides.

To mate the topsides for Na Kika, the superlift had to accomplish several steps. First, the system raised the topside modules 50 m. From this position, the east and west pontoons were skidded under the topsides. This done, the south hull assembly was skidded under the topsides, followed by the north hull assembly. With all hull components positioned to provide best fit of deck legs to hull support stools, the components were welded out. The final step was to set the topsides down on the hull.

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Superlift used on Na Kika topsides.
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The integrated hull and topsides are scheduled to be loaded out of the yard sometime this month.

KOP to deliver 10,000-ft umbilical

Kværner Oilfield Products (KOP) has been selected to provide a 10,000-ft steel tube umbilical for Amerada Hess' Garden Banks block 215 Cong-er extension well No. 6, in water depths of 1,260-1,450 ft. The infield umbilical includes super duplex steel tubing and electric cables with operating pressure capacity of up to 15,000 psi. Installation is planned for an offset distance of approximately 10,000 ft. The umbilical will be manufactured in KOP's new industrial complex in Mobile, Alabama, which is currently under construction and scheduled to be in production in 2Q 2003.

New bulk mixer system

A new system has been developed to address a number of environmental and practical issues concerning the production and handling of drilling fluids. The system includes several benefits, among them, more efficient packaging and transportation of dry drilling fluids products, dust-free dispensing of dry products at the rig, combining of dry products with liquids in a mixing system that minimizes waste, and maximum monitoring and control.

Bulk Mixer Inc. said its drilling fluids packaging and mixing system has been in continuous operation for nine months on Noble Drilling's Jim Thompson semisubmersible rig in the deepwater Gulf of Mexico. Construction of the Bulk Mixer system on the rig was completed in February 2002 at the direction of Shell Exploration and Production Company.

Using the Bulk Mixer system, base fluids are combined with dry chemicals at the rig in a closed, dust-free mixing vessel. The system uses a high-volume, high-shear mixer for rapid and efficient preparation of drilling fluids on the rig. For mixing polymers, the system uses a high-volume, high-shear inline pump in tandem with the main mixer vessel.

The large bulk-mixing tank is the centerpiece of the system, using technology already successful in other industries. The Bulk Mixer provides homogenous mixing of drilling fluids five times faster than with the hopper system, the company says, with no cutting sacks or worker exposure to harmful chemicals or dust. When hooked directly to a pneumatic feed line from the rig's barite bulk storage, the Bulk Mixer mixes barite 10 times faster than traditional systems to keep up with lost circulation and other well-emergency demands.

The mixer has numerous input and output capabilities. It can accept input of product from bulk bags; the rig's bulk barite supply, via pneumatic line; or polymer tanks. It can also accept input in the form of liquid additives. As an added input, the mixer has an auxiliary hopper to accommodate product that is used in small quantities or is unavailable in bulk form. After mixing is complete, the mixer can send the finished drilling fluid through several outputs to various locations where it is needed including the active mud pit, cementing unit, downhole, or auxiliary mud pits.

Bulk Mixer provides complete mixing of chemicals, allowing mud properties to be managed more easily. None of product is wasted. This avoids unmixed chemicals lost over the shakers, which is shown to be up to 30% of dry chemicals mixed by the conventional hopper method.

Precise control of the Bulk Mixer operation is obtained by pushbuttons at the unit's console. Mixer, pump, and blower functions are controlled by lighted on-off buttons. An emergency shutoff button is included. Automated valves are also controlled at the console. There is no chemical spillage, waste, or dust. Because the Bulk Mixer is self-cleaning, there is no need for confined space cleanout when the mixer is used to mix cement spacers.

The bulk bags used by the system are reusable, eliminating waste disposal problems created by paper sacks, pallets, and shrink-wrap. The monitoring system built into the Bulk Mixer provides continuous readout of mud weight in the active system, as well as mud quantity and mud weight in the Bulk Mixer.

According to the manufacturer, studies have shown that, using the conventional "hopper" system, barite is mixed at the rate of 200 to 300 sacks per hour. Actual performance by the Bulk Mixer over several months on the rig shows that the Bulk Mixer mixes barite at the rate of 50 sacks per minute, or in other words, 3,000 sacks per hour. Bulk gel is mixed in the Bulk Mixer at the same rate, 10-times faster than hopper mixing.

One rig worker cutting sacks can normally achieve a rate of 40 to 50 sacks per hour. One man, operating the Bulk Mixer system, using bulk bags, can mix 2,000 lbs of material in 5 to 10 minutes.

FMC subsea service agreement with Statoil

FMC Energy Systems has signed a two-year extension of its existing subsea service agreement with Statoil to provide technical services and subsea equipment. The agreement includes an option for two more years beyond the initial term.

The agreement comprises technical services in connection with completion, workover, installation, maintenance, and other activities associated with subsea field development. The contract also includes provision of additional equipment for Statoil-operated fields previously supplied by FMC Kongsberg Subsea, FMC Energy Systems' Norway-based subsidiary.

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