The focus of this presentation will be to discuss and evaluate major concerns in the development of Long Stroke Ram-Style Tensioners, as an enabling technology to address the upcoming demands of the Offshore Industry as it pushes to drill and produce in ultra-deep water. The increasing demand on riser tensioners to accommodate higher riser loads with longer stroke capability in ultra-deep water is pushing technology beyond what has been currently developed in the industry.
As Drilling and Production recovery for oil and gas expands into water depths in excess of 8,000ft, tensioner technology is being challenged to provide realistic and cost effective solutions. As riser tensioners increase in size and capacity to accommodate high riser loads, well bay configurations and tensioner interfaces have a significant impact on the design of the support vessel. Tensioner stroke lengths are increasing rapidly in response to larger vessel offsets, heave displacements and updated Regulatory requirements for survival conditions. These long stroke high capacity tensioners are influencing well bay design. Specifically, the stack up clearance between decks, number of risers, jumper hose layout, riser spacing, production tree clearance and motions, equipment maintenance and access. It takes an iterative design effort to integrate all of these elements into a cost effective workable solution.
There are two major tensioner configurations used in the industry today; the ram or push up style and the rod in tension or pull up style. Both tensioner styles have various pros and cons inherent in each configuration. Numerous factors are considered when selecting a tensioner for a particular project or vessel type such as operator preference, load ring accessibility, well bay configuration, tensioner capacity, component serviceability and cost.