P g here lace Sub HeadinStructures Panel

Self Installing Offshore Platforms – Recent Experience Dr Rodney Pinna

712 Murray Street, West Perth WA 6005 Phone: (08) 9321 3340 • Fax: (08) 9481 4332

E-mail: wa@engineersaustralia.org.au Website: www.engineersaustralia.org.au/wa

Western Australia Division

The Maari Wellhead Platform (WHP) is the second and most recent DrillACE platform engineered and designed by Arup and Clough. Clough were responsible for engineering,procurement, construction and installation activities on the project, with Arup undertaking structural and geotechnical design. The project was undertaken for OMV New ZealandLtd, who is the designated operator of the Maari field. The platform was installed offshore New Zealand in the Taranaki Basin during the second quarter of 2008. Fabrication wascarried out in Lumut, Malaysia. The Maari WHP is located in a water depth ofapproximately 101 m. This presentation describes the factors associated with adopting the DrillACE platformscheme for the Maari location and addresses some of the structural design challengesthat were addressed during the design of the platform. This includes a number ofstructural design issues, such as the loadout analysis, wet tow, design of the jacket todeck connections and bumper guides used during installation. In addition to the design and analysis of the Maari platform, some recent workundertaken as a part of the Yolla Mid Life Enhancement project will be discussed. Thisincludes a jet fire study which made use of CFD analysis to predict member temperatures in the event of a jet fire and nonlinear finite element analysis to predict the ultimate strength of the platform.

The Arup Concept Elevator (ACE) fixed platform is a concept developed by Arup for varying environmental and functional criteria. The ACE platform range comprises a number of designs, ranging from minimum facilities to production platforms. They are differentiated from typical offshore jackets by being self-installing and re-locatable. The first ACE platform installed was the Hang Tuah Production platform in 2000, followed by the Yolla DrillACE installed in 2003. The latest ACE platform, the Maari DrillACE was installed in 2008. Arup have also recently been involved in the Yolla Mid Life Enhancement project, which is looking at modifications to the Yolla platform to convert it from an unmanned to a manned facility.

EVENT DETAILS Date: Tuesday, 19 May 2009 Time: 5.30 pm for a 6.00 pm start Venue: Auditorium Engineers Australia 712 Murray Street West Perth Cost: Free RSVP: Not required

EVENT DETAILS

Date: Tuesday, 19 May 2009 Time: 5.30 pm for a 6.00 pm start Venue: Auditorium Engineers Australia 712 Murray Street West Perth Cost: Free RSVP: Not required

About the Speaker: Dr. Rodney Pinna is an Associate with Arup and is principal engineer for the offshore structural engineering group in Perth. Dr. Pinna graduated from the University of Western Australia (1996) and later completed a PhD (2003). His previous work as a researcherhad a particular focus on the use of reliability analysis for the design of steel jacket structures, and the suitability of API RP-2A for areas outside the Gulf of Mexico. Dr. Pinna also has experience in the use of finite element modelling for advanced structuralanalysis for offshore, aerospace and building structures.

712 Murray Street, West Perth WA 6005 Phone: (08) 9321 3340 • Fax: (08) 9481 4332

E-mail: wa@engineersaustralia.org.au Website: www.engineersaustralia.org.au/wa

Western Australia Division