Sonardyne Snags Life-of-Field Contract for Petrobras' Cascade, Chinook

BMT Scientific Marine Services Inc. has chosen Sonardyne International to supply an integrated acoustic positioning and telemetry system for Petrobras America's Gulf of Mexico Cascade Chinook field. The system forms part of an extensive life-of-field integrity monitoring system for five Free Standing Hybrid Risers (FSHRs).

The Cascade Chinook field development is the first use of an FPSO (Floating Production Storage and Offloading) system in the Gulf of Mexico. All risers, umbilicals and monitoring system transceivers are integrated into a turret buoy which can be disconnected from the FPSO allowing it to move off-station when there is a threat to the facility.

The selection follows the successful development and deployment by BMT and Sonardyne of a similar system for a deepwater field in Brazil.

The acoustic instrumentation is configured to monitor the position of each riser tower and the turret buoy in relation to the seabed. Integrated sensors will also monitor depth, temperature, inclination and sound speed. The integrated modem or telemetry functionality will also transfer the data from BMT’s load and attitude monitoring system on each riser tower to the turret buoy at the central location.

The turret buoy is fitted with a number of transceivers to ensure a line of sight to each riser tower without obstruction by the risers or mooring lines. These transceivers are controlled by BMT's monitoring system in the FPSO's turret to acquire position, sensor and load monitoring data. In the event of a disconnection the system continues to record data which can later be downloaded by the FPSO or another vessel. The system uses Sonardyne Wideband® signal architecture that enables remote high speed and reliable data communications through water.

The integrity monitoring system will provide valuable data about the movement and loading on hybrid riser systems during extreme weather. The system demonstrates a growing demand for reliable subsea remote integrity monitoring that has been enabled by the high performance of Sonardyne’s Wideband® acoustic positioning and data communication systems and BMT's proven subsea strain and motion sensing systems.

The most significant aspect of Petrobras's Cascade and Chinook development in the Gulf of Mexico is the company's intent to deploy a Floating Production, Storage and Offloading (FPSO) facility to accept production from the two fields. Petrobras plans to fast track the development of both the FPSO and the fields.

According to Petrobras, the schedule calls for installation of the FPSO early in 2010 with first production in the first quarter of 2010. The FPSO will be located in approximately 2,600m of water, will be the first in the US Gulf of Mexico and will be the world's deepest FPSO to date.


Cascade and Chinook are located in the Walker Ridge block, around 300km (180 miles) south of the Louisiana coast. Petrobras is the operator of both the Cascade and Chinook units, owning 50% and 66.67% of the fields respectively. The remaining 50% of Cascade is owned by Devon Energy Corporation, while Total E&P owns the remaining 33.33% of Chinook.

KBR's wholly owned subsidiary, Granherne, was awarded a three-year contract for engineering services. Granherne will be providing technical support for design of the hull for the Early Production System (EPS), Floating Production Storage and Offloading system (FPSO), and later phase Full Field Development (FFD).

The fields will be developed two subsea wells in Cascade and one subsea well in Chinook, approximately 30km south of Cascade. Each well will be drilled to an approximate depth of 27,000ft, and based on reservoir performance. Petrobras may expand production to additional subsea wells on each field.


Petrobras awarded FMC Technologies a $200 million contract to supply subsea systems. Subsea electric submersible pumps will boost production from subsea to the FPSO. The contract calls for the delivery of four horizontal subsea trees, three manifolds, control systems, and two subsea horizontal electric submersible pumping systems. Deliveries are expected to start in the final quarter of 2008.

Petrobras signed a contract with Heerema Marine Contractors (HMC) for the installation of the Chinook infield flowlines. The two pipe-in-pipe flowlines are each 12 miles long with a 14in casing pipe carrying a 9in inner pipe, and will be installed in water depths ranging from 8,000ft to 8,800ft (2,440m to 2,680m) as part of the phase one. The Chinook pipe-in-pipe project is scheduled for offshore execution in Spring 2009.

Petrobras awarded Aker Kvaerner a $65 million contract to supply subsea power cables and control umbilicals. Aker Kvaerner is to supply 230,000ft (70km) of high-voltage power cables and static and dynamic steel tube. The umbilicals will be made using Aker Kvaerner's patented carbon-fibre rod technology.

Project management, engineering and manufacturing will be at Aker Kvaerner's Mobile, Alabama, facility. Delivery of the cables and umbilicals is scheduled for mid-2009.

Free-standing hybrid risers, used to transport oil and gas from the subsea flowline to the FPSO and gas from the FPSO to the export pipeline.


The FPSO is specified to have 600,000 barrels of oil storage capacity, 80,000bpd processing capacity, and 16mmcfpd of natural gas export capacity. It will feature a disconnectable turret buoy, allowing the FPSO to move offsite during severe weather events such as hurricanes. It is moored by a polyester mooring system linked to torpedo piles and vertical loaded anchors.

The crude will be offloaded via a shuttle tanker. Petrobras selected BW Offshore the contract to convert, install, and operate the FPSO. The $740m contract will cover delivery and installation of an APL disconnectable submerged turret production buoy and mooring system.

Bristol-based DPS was awarded the EPC contract for the crude stabilisation and flare modules that will form an integral part of BW Offshore's design. DPS will also be responsible for managing the process and piping interfaces for the entire process topsides.