Systems and methods for installation of clamshell devices around an element

Abstract

Systems and methods for remotely installing a clamshell device around an element, the clamp system comprising a body; and at least one set of clamps supported by the body, the set suitable for holding and releasing the clamshell device selected from the group consisting of vortex-induced vibration reduction devices and drag reduction devices, wherein at least one clamp comprises a cam surface adapted to engage the element and close the clamp about the element.

Description

RELATED APPLICATION DATA [0001] This application claims priority to U.S. Provisional Application 60 / 751,503, filed Dec. 19, 2005. U.S. Provisional Application 60 / 751,503 is herein incorporated by reference in its entirety. [0002] This application is related to U.S. patent application Ser. No. 11 / 083,833, filed Mar. 18, 2005, having Attorney Docket Number TH1853-03; U.S. patent application Ser. No. 10 / 383,154, filed Mar. 6, 2003; U.S. patent application Ser. No. 10 / 032,710, filed Oct. 19, 2001. U.S. patent application Ser. No. 11 / 083,833, U.S. patent application Ser. No. 10 / 383,154, and U.S. patent application Ser. No. 10 / 032,710 are herein incorporated by reference in their entirety.FIELD OF THE INVENTION [0003] In one aspect, the invention relates to systems and methods for installing clamshell devices around an element. DESCRIPTION OF THE RELATED ART [0004] Whenever a bluff body, such as a cylinder, experiences a current in a flowing fluid environment, it is possible for the body ...

AI Technical Summary

Benefits of technology

[0017] One aspect of the invention provides a clamp system for remotely installing a clamshell device around an element, the clamp system comprising a body; and at least one set of clamps supported by the body, the set suitable for holding and releasi

Problems solved by technology

These vibrations are caused by oscillating dynamic forces on the surface, which can cause substantial vibrations of the structure, especially if the forcing frequency is at or near a structural natural frequency.

The vibrations may be largest in the transverse (to flow) direction; however, in-line vibrations can also cause stresses, which are sometimes larger than those in the transverse direction.

If the frequency of this harmonic load is near the resonant frequency of the structure, large vibrations transverse to the current can occur.

These vibrations can, depending on the stiffness and the strength of the structure and any welds, lead to unacceptably short fatigue lives.

In fact, stresses caused by high current conditions in marine environments have been known to cause structures such as risers to break apart and fall to the ocean floor.

For instance, a riser pipe that is vibrating due to vortex shedding will generally disrupt the flow of water around it more than a stationary riser.

This may result in more energy transfer from the current to the riser, and hence more drag.

The major drawback to teardrop shaped fairings is the cost of the fairing and the time required to install such fairings.

However, strong currents can also occur at great depths causing VIV and / or drag of risers and other underwater structures at those greater depths.

However, using divers to install VIV and / or drag reduction equipment at greater depths subjects divers to greater risks and the divers cannot work as long as they can at shallower depths.

Bubbles formed in the blood of a diver who ascends too rapidly cause the diver to experience the debilitating symptoms of the bends.

Likewise, elongated structures with excessive VIV and / or drag forces that extend far above the ground can be difficult, expensive and dangerous to reach by human workers to install VIV and / or drag reduction devices.

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