Joint venture yields cost saving deepwater compressor
3 Sep 2002
GE Oil & Gas and Kvaerner Eureka have recently completed the joint development of a subsea compression module designed to reduce the cost of deepwater oil and gas field exploitation.
The module is said to feature a 2.5 megawatt Blue-C Subsea Centrifugal Compressor developed by GE Oil & Gas. The module, the first of its kind for the industry, is being introduced at the Offshore Northern Seas International Conference.
The GE-Kvaerner Eureka development effort was among the projects approved for the DEMO 2000 program, which was launched by the Norwegian government to support the development of subsea systems to economically recover natural gas from deepwater fields.
Until now, it has not been profitable to exploit many natural gas subsea fields, particularly those at depths of 500 metres or more, due largely to the cost of conventional offshore platforms.
According to a statement, the Blue-C compressor module is a turnkey system capable of handling natural gas at pressures up to 130 bar. It will be installed on the seabed and can transport the well stream to a central platform or directly to an on-shore site, at distances of up to 80-100 kilometres.
The new subsea compressor module includes a variable-speed electric motor, a planetary gearbox and a centrifugal compressor. The booster station also includes a separator module, to divide the incoming fluid into gas and liquid; and a multiphase pump, for pumping the liquid. The entire module is pressurised at inlet pressure, eliminating the need for dry gas seals.
To validate the innovative design and minimise any risks in the field for future systems, GE Oil & Gas and Kvaerner Eureka have completed thermodynamic, mechanical and endurance testing on a prototype, 850-kilowatt power unit in GE Oil & Gas test facilities.
The first 2.5-megawatt subsea module to be built will undergo a technological qualification process under actual operating conditions, on a subsea gas field.
Initially the module will be installed on a platform to perform pre-qualification tests, and then it will be submerged in a depth of approximately 300 metres to continue the testing.
Feasibility studies with several oil companies have already been performed for several potential locations in the North Sea, for both gas boosting and gas re-injection applications.
