Because the offshore ultra heavy crude oil is one of the most challenging exploration & production of the Oil&Gas sector, Statoil decided to proceed step by step. Mariner will go first and Bressay will follow one year behind. All the decisions made for Mariner will apply for Bressay.
In Mariner Statoil owns 61.5%, ENI 28.9% and Nautica Petroleum 6%.
Ultra heavy crude fields require pioneering technology in order to be developed that Statoil experienced successfully in the development of the Grane field in Norway and the Peregrino field in Brazil.
Because of the low well flow rates and early water break-through there is a need for many wells, artificial lift, and a process designed to handle large liquid rates and oil-water emulsions.
A total of 145 reservoir targets for production or injection are planned for Mariner. While the number of well slots at the platform is less, this will be solved through use of multi-branch technology, sidetracks and reuse of slots.
To meet with the requirements of the ultra heavy crude oil, Statoil designed the Mariner offshore platform project based on a:
– Production, drilling and quarter (PDQ) platform based on a steel jacket
– Floating storage unit (FSU), to be normally unmanned operated to store the diluent required to help the ultra heavy crude oil fluidity and the oil/water separation process.
The pumping operations will use a combination of 21 electric submersible pumps (ESP) in the down-hole of the wells and 28 water injection pumps on the up-hole to increase the well pressure.
Aker Solutions is actually performing the Front End Engineering and Design (FEED) of the 26,000 t topsides in order to treat 320,000b/d liquids including 80,000 b/d crude oil.
The selected Engineering companies in competition for the Engineering Procurement & Construction (EPC) contracts are the following:
– Kvaerner with Heerema Fabrication Group
– Daewoo Shipbuilding & Marine Engineering with CB&I
– Hyundai Heavy Industries with WorleyParsons
– Samsung Heavy Industries with KBR
Statoil expects to float the calls for tenders for the EPC contracts on mid 2012 for a final investment decision on year end.
The deck construction should start in 2014, so that Mariner full completion and operation is scheduled in late 2016.