Further Subsea Development – The MBS Re-search Project and Subsea Demonstrator

Dipl.-Ing. Axel Jäschke
Joh. Heinr. Bornemann GmbH, Germany

Bornemann – way and strategy to go Subsea
Today, Bornemann is specialist in producing, supplying and installing multiphase pumps and multiphase boosting systems in all kind of surface installation, both on- and offshore. The key technology is based on the very well approved and best suitable twin-screw design.

Fig.1: Installation of subsea pumps in the GOM
During the last years the installation of oil production equipment on the sea-bed developed as a new technological challenge with its own new solutions and requirements.

10 years ago Bornemann decided to follow the ambitious trend of the subsea market. We de-veloped the subsea-twin-screw multiphase pumps and the first installations have been suc-cessfully completed and set in operation under field condition. The MPA subsea research proto-type is in operation since about 4 years, the DEMO2000 SMPC, converted for the LYELL installation is running since 2 years with more than 14.000 accumulated operating hours, and the BP KING pumps have been started some months ago.

This year Bornemann decided to extend the subsea activities. The target is to qualify our-selves as a supplier of a complete subsea booster in 2009. In addition to other development activities a two-track development plan has been set up:

1. MBS research project (from 2007 to 2009)

2. Real 1MW prototype (ready in 2009)

Fig.2: Key markets and technical demand

Even though in future the main business for Bornemann will remain the surface market for liquid-, multiphase- and wet-gas-boosters, there are some good reasons to investigate into the development of subsea solutions, because:
· subsea development is a technology driver with significant output for surface equip-ment
· subsea market as a business driver – we expect orders for up to 20 subsea boosters during the next years
· Bornemann has a unique technical concept – applied for patent

1st development path: MBS and Demonstrator (BSB 6)

Fig.3: Multiphase Boosting System Subsea

MBS – Multiphase Boosting System – is a three year research and development project, started January 2007, which is partly sponsored by the German government. The main focus of the MBS project is on creating know-how about long distance power transmission and speed control for the multiphase pump as well as on designing a Multiphase-Twinscrew-Motor to generation power from the well flow.

Other issues of interest are the development of a Multiphase-Jet-Booster (MJB, patent pend-ing) to be used as a 1st stage wet-gas compressor and the interaction of the subsea environ-ment and pumping systems.

Fig.4: Intended location for the installation of the Multiphase-twinscrew-motor

Fig.5: Performance extension of the MPP System by the multiphase jet pump, depending on operat-ing conditions

The precompression of the gas volume flow will allow either to handle much more volume with the existing equipment, or to save simply energy to do the same job and to be able to install smaller and less cost intensive equipment for new installations.
Depending on the process conditions, the MJB can increase the system efficiency up to 100%.

In 2009, a small but real subsea pump (BSB 6), labelled as Demonstrator, will present first re-sults of the MBS research project. Highlight of the Demonstrator will be the vertical installa-tion of a twin-screw multiphase pump in combination with a Voith torque converter. The new design of integrating a hydrodynamic speed-converter will offer several important advantages as:
- simple unloaded start of the motor
- simple heat up procedure of the system
- full speed range for the pump
- smooth transmission of pump load peaks to the motor and the electrical power supply system
- full subsea control of the pump speed and the production flow rate

Fig.6: MBS Demonstrator with integrated hydrodynamic speed variation.

2nd development path: BSB 9 – Prototype
The double-pressure-compensated (DPC, patent pending) subsea-booster cartridge de-sign will be the key component of the BSB 9 Prototype. It will include the well approved pumping cartridge (similar to BP-KING), the oil-filled but water tolerant 1 MW motor-cartridge, coupling, instrumentation, subsea-control box (electronic canister), oil cooler circuit, pressure control system for the lube oil pressure, etc.

Fig.7: DPC Double Pressure Compensated Cartridge Concept, qualification in 2009

The prototype will be rated for 5000 psi and 2000 meter water depth, and it will show, that even 10000 psi and water depths up to 3000 meter will be possible in future. The proto-type will be ready for testing in 2009. In cooperation with industrial partners Bornemann will be qualified in 2009 to be a commercial partner for the oil- and gas industry for subsea projects.