Prevents Marine Biofouling Permanently
Bio-Shield® is an optimum anti-foulant coating for offshore structures. It contains two proven materials -- copper-nickle and SPLASHTRON® splash zone protection
-- which were selected to work together as a unit.
Bio-Shield® - bio keeps marine growth from attaching to conductors and platform members in the first place, allowing designers to take full advantage of the cleaner profiles, and eliminating the necessity of any expensive removal operations.
The copper-nickle compound was chosen because of its long history as an effective anti-foulant, its ease of fabrication, and its comparatively low cost. SPLASHTRON was selected as the insulating layer for several reasons:
It bonds strongly to metal, both steel and copper-nickle
It has proven to have a very long service life in the harsh splash zone environment.
It is a good electrical insulator
It provides a bonus in corrosion protection for the metal surface to which it is attached.
Marine life, such as algae, barnacles, and mussels, has been the scourge of shipbuilders for centuries. Marine growth also has become a serious problem for offshore operators and platform designers today. While there has always been advantages to keep marine growth off of ship hulls to maintain speed, save fuel, and keep ships working instead of in drydock, it is vitally important to prevent biofouling on offshore platforms for different reasons. In many areas of the world, marine life - such as barnacles, mussels and algae - don't build up much more than an inch or two. However, in many areas such as offshore California and the North Sea (anywhere waters are relatively cold and thus hold more nutrients), biofouling can build up to as much as 36" thick. At these levels it becomes dangerous since weight increases the strength requirements of the platform.
Depending upon the type of growth, biofoulants can weigh up to 150 pounds per cubic foot. It becomes dangerous due to the added area for wave loading and drastically reduces the fatigue life of a platform. Also, the danger of platform overturn is increased. When biofouling becomes excessive, about 6" thick or more, platforms must be constructed much stronger than normally would be necessary, or the growth must be removed regularly.
Shell Development Co., in cooperation with MARK Tool Co., worked together to produce Bio-Shield®. MARK Tool Co. manufactures Bio-Shield by license under Shell's U.S. patent number 4,415,293.