Hydraulic tensioners are widely used to provide tension and stiffness to vertical risers on spar and tension leg platform floating production facilities. Their performance directly affects dynamic response of the risers and the global motions of the floating system. The coupling effect of the tensioners, risers and vessel becomes increasingly important as the water depth increases into the ultra deep. This paper evaluates key performance parameters of long-stroke high-tension hydraulic tensioners for ultra deepwater application. It derives the fundamental equations and evaluates key performance parameters and their impact on the riser and vessel responses. This paper also proposes data measurement locations and methods to collect field data for calibrating these key performance parameters for future hydraulic tensioner design. The key tensioner performance parameters are the gas constant and the cylinder friction. In addition for a typical spar riser configuration, the keel joint friction also plays an important role in the overall riser performance. Their importance increases as water depth increases to 8,000 feet and beyond due to the nature of the coupling effect, long stroke and high tension requirements. Gathering of full scale-test data for these parameters has been costly. With several 7000 to 8000 feet risers and tensioners to be installed in the next few years, a method of collecting field data and its analysis for calibrating against the current assumptions of these parameters is proposed.

This content is only available via PDF.
You do not currently have access to this content.