Press Esc to close



For full content view: Log in Now!

  • Lightweight risers increase rigs’ water depth ratings

    J. Lehner and T. Marvel

    As water depths increase, risers for drillships and semisubmersibles become some of the most critical components of the drilling operation. Risers must be strong enough to maintain integrity during deployment and operation; be light enough to be handled and supported by the floating drilling unit; and be constructed of materials that resist corrosion while exposed to seawater. Lightweight, alloy risers provide a means of increasing the water depth rating of floating rigs by as much as 50% without requiring expensive upgrades, Fig. 1. Because of their lightweight construction, alloy risers are easier to handle, require fewer buoyancy devices, and can enable floating rigs to increase their water depth capabilities, when compared to conventional steel risers. The first generation of lightweight deepwater (DW) risers has been used successfully for nearly a decade on two drillships and a semisubmersible rig in Brazil, while drilling in water depths as great as 7,200 ft.

This area of the site is restricted. In order to gain access, please either Log In, or subscribe to World Oil.

Two options are available to you for creating an account.

1. Get a Free Trial Subscription to World Oil Magazine and gain immediate access to select content on World Oil Online.

Start a Free Trial Subscription and gain immediate access to the complete current issue of World Oil Magazine. Plus, you’ll receive 3 upcoming issues of World Oil Magazine in print or digital format.* You also receive access to the Energy Events Calendar, Industry Statistics and WO Wire’s news and industry coverage.

Free Trial

2. Purchase a subscription to World Oil magazine and gain immediate and complete access to World Oil Online. As a Total Access subscriber you will have access to all areas of the site available to registered users and free subscribers as well as having access to such premium content areas as:

  • The Archives section containing over ten years of complete magazine archives,
  • The WO DataHub's engineering tables and directories,
  • The World Oil annual forecasts, including past predictions,
  • Select World Oil technical handbooks,
  • And much, much more!


Physical copies of this content may be available for purchase. Visit the Reprints & Back Issues section.

If you are already a paid subscriber and do not have access, please email



Engineering Data Tables

World Oil's specialized upstream Engineering Data Tables featuring the Drill Bit Classifier, Tubing Tables and more. Get Total Access today.


2013 Fracturing Technology

2013 Fracturing Technology