The design process
Richmond manufactured two kinds of rollers for the project, with the following specifications:
Drilling guide roller (DGR)
- Weight: 714 kg
- Diameter: 711.2 mm
- Length: 1,308.1 mm
Completion guide roller (CGR)
- Weight: 231 kg
- Diameter: 398.8 mm
- Length: 508 mm
According to NuStar, the roller design needed to have a defined curvature for a 254 mm radius for the CGR, which has a diameter of 398.8 mm, and a defined curvature for a 1,524 mm radius for the DGR, which has a diameter of 711.2 mm.
The rollers were also manufactured to take into account NuStar’s required design impact loading of 13.6 t and 27.2 t respectively at high frequency.
Innovations on the project
Richmond Engineering Department Manager Breon Winslow-Moore said that each of the three 508 mm CGR rollers required the company to process over 450 kg of polyurethane in one single casting.
“To achieve this, we needed to run two machines at the same time to process the material at the required flow rate, ensuring the material did not begin to set before the pour was complete,” said Mr Winslow-Moore.
“This was a new company record for the largest single polyurethane castings”.
The guide roller structure will now be used to constrain drill pipe/riser movement caused by sea currents in the vessel, as well as to transfer some of the loading induced by these currents against drill pipes and risers via the guide structures to the moon pool working carts.
Getting the job done on time and on budget
According to NuStar Technologies Engineering Director Teo Sim Guan, Richmond was selected as the pipe roller supplier due to its excellent track record, quality product and services.
“We knew Richmond through previous trade show contacts, knew their product and services through their website and their good project track [record],” said Mr Teo.
Richmond was also able to meet NuStar’s strict timing requirements in its supply of the rollers.
According to Mr Teo, the quality of the end products was extremely satisfactory, and in line with NuStar Technologies’ business philosophy of providing innovative solutions to challenging land and offshore engineering projects.
For more information visit www.richmondau.com