Trelleborg’s offshore operation has partnered with Landing String Solutions LLC, after being approached to create the world’s first composite buoyancy system deployed on a drill pipe landing string.
Patented by Landing String Solutions LLC, the buoyancy system manufactured by Trelleborg features 100% composite materials - no metallic components - ensuring that no damage is caused to the well.
This is the first time buoyancy has been used within the drilling riser. The use of buoyancy on the landing string allows the Drilling Contractor to deploy larger amounts of casing, thus reducing rig time, maximising efficiencies and reducing cost. The new buoyancy system is designed to offset the landing string weight by up to 80% in some cases and will enable safer and more cost-effective deepwater oil and gas operations.
Chris von Eberstein, General Manager at Landing String Solutions LLC, confirms: "A large number of ultra deepwater well designs require 16 in. and other long casing strings to be run at unprecedented lengths. The deep well design's longer casing requirements can result in extreme loads – dynamic and static – approaching, equaling and/or exceeding the design safe working load of even the six plus generation rig's hoisting system. Working at, or near, design working load presents safety and environmental concerns. Should component failure occur in the hoisting system while handling extreme loads, it may result in personal injury and damage to equipment and the environment.
“However, by partnering with Trelleborg we’ve now produced the world’s first buoyancy system which is utilised inside the riser on the landing string, while running casing, reducing its weight and the hook load to a manageable level.”
Trelleborg’s low-density syntactic foam system consists of a combination of hollow glass microspheres and macrospheres to provide uplift. The rugged exterior protective skin provides excellent abrasion and impact resistance to avoid damage during handling and installation. In addition, all buoyancy installation hardware is fully composite. The buoyancy system is qualified for a maximum pressure rating of 6000 psi.
Mark Angus Executive Vice President within Trelleborg’s offshore operation, states: “The buoyancy design will enable the use of heavier landing strings and allow rigs to run longer. In addition, 16 in. diameter casing can be utilised in longer lengths than previously possible, allowing Drilling Contractors to use older rigs that do not have the same tensioning capability of the latest 6th and 7th generation drilling rigs. This design could eliminate the requirement for tie-back liners and will expand the operating range of third, fourth and fifth generation drilling rigs to step into field depths where previously only ultra-deepwater rigs could operate.”
The system has been successfully field-tested in the Gulf of Mexico and has been proven for a maximum pressure rating qualified to 6000 psi.
Adapted from a press release by David Bizley