ARAMCO Awards $125-Million Order For Four Self-Elevating Platforms
ARAMCO has awarded a contract to Verolme Brazil (VERB) for the construction of four selfelevating platforms. The contract is valued at more than $125 million. The platforms were designed by Gusto Engineering of Schiedam, Holland.
Three will be used for wellservicing and fire-fighting, and the fourth for maintenance operations on production platforms, light construction work, and the repair of underwater pipelines. While it is fairly common for self-elevating platforms to be used for such purposes, the requirements laid down by ARAMCO render the design of these units unique in many ways. First, the platforms must operate in water depths ranging from eight to 180 feet and be capable of moving from one location to another under their own power. Second, the presence on the seabed of numerous pipelines precludes the use of the four-point mooring system normally employed to keep a platform in position during jackingup and jacking-down. Finally, the design had to allow for threeknot currents in the operational area and the sudden storms which can occur in the Arabian Gulf. The requirements resulted in platforms with relatively large dimensions to permit operation in only 8 feet of water. For movement between locations, and positional stability during jackingup and jacking-down each platform is equipped with four Schottel- Lips 1,360-hp steerable thrust- ers with controllable-pitch propellers. Model tests conducted at Duisburg showed that a speed of two knots can be obtained with only one-foot of water beneath the keel, and six knots in deeper water.
In view of the frequent movements between locations and the need to minimize the risk of damage to subsea pipelines, the platforms will be equipped with a high-speed jacking system. Designed by Gusto, the system is of the hydraulic type and enables the platform to be raised at a rate of about 6 feet/min.
In designing these platforms for ARAMCO, Gusto Engineering's role was not limited to the provision of a basic design, but embraced a design package including specifications, calculations and drawings to the classification requirements of the American Bureau of Shipping.