BW Offshore brings STP system to Brazil

New Wave Media

September 27, 2010



BW Offshore’s technology division APL is set to make its South American debut following a contract win to supply Maersk Contractors with a Submerged Turret Production (STP) system for use in Brazil’s Peregrino field.

Maersk Contractors is converting one of its new VLCCs into an FPSO for the project and APL will design, fabricate and deliver an internal turret and mooring system for integration inside the FPSO. This includes the STP buoy/turret, the APL swivel stack and mooring lines. APL will also deliver the STP compartment structures.
“We are very pleased to be the selected partner for this project and to have the opportunity to continue providing technology and services to one of our key clients,” says Arild Saudland, project manager APL.
The Peregrino field, located 85 kilometers off the Brazilian coast in the south-western part of the Campos Basin, sits in water 100 meters deep. It is estimated to have reserves of 500 million barrels and first oil is scheduled for 2010 with a production rate of 100,000 bbl/d.
The STP system is a key to the development as it provides mooring for the FPSO along with the connection point for the risers and umbilicals (power cables to the wellhead platforms). Once connected to the STP buoy, the FPSO can weathervane around the STP turret where the mooring lines, geo-stationary risers and umbilicals are connected. The first development phase comprises two drilling and wellhead platforms (WHP) and one FPSO.
The limited space available for the STP compartment (the cylindrical structure that extends from the main deck to the hull bottom ) was a challenge. In order to minimize changes to the ship’s internal structure, the design was adapted to the constraints. The STP compartment concept design, involving all internal equipment and access stairways/platforms was approved and procurements completed without any major issues arising.
The STP buoy for this project has 15 risers and umbilical slots. For this slot diameter, this is close to the maximum number of slots that this buoy size can take. The combination of the STP compartment and buoy design has resulted in a highly efficient turret design.
The STP field installation started in the second half of 2009. This is APL’s second STP contract with Maersk Contractors, following the delivery of an STP system for the Vincent field development off Australia’s northwest coast.
BW is also going to be introducing the first FPSO to the GOM, it will also be including a STP buoy to the GOM. This project is with Petrobras Americas for its Cascade and Chinook plays and will soon be able to prove its concept, as 2010 is promising to be a year with many hurricanes passing through the GOM. The possibility of easily releasing the buoy before the arrival of hurricanes and the speed advantages a FPSOs has when compared to traditional rigs gives it a significant advantage in avoiding the storms and also in the time it take to be able to resume production after the storm passes.
Claudio Paschoa
Photo Courtesy of BW Offshore
Paschoa, Claudio
Claudio Paschoa is Marine Technology Reporter's correspondent in Brazil.