A/S Norske Shell has successfully completed system testing of the world’s first subsea gas compression system with a full subsea power supply, transmission, and distribution system. At the heart of the system is GE Oil & Gas’ Blue-C subsea compressor – a 12.5 MW, fully marinized, vertically orientated centrifugal compressor.
The Ormen Lange Pilot was a first of its kind and was designed to test a full scale integrated subsea compression system in submerged conditions with real hydrocarbons. It has been run by A/S Norske Shell and its license partners Petoro, Statoil, Dong, and ExxonMobil since 2011 at Shell’s test facility at Nyhamna in Norway where the gas from the Ormen Lange field reaches shore.
GE has been a key collaboration partner with Shell in the development of the compression system and has supplied a number of technologies, including the compressor and the world’s first subsea power supply, transmission, and distribution system. The system enables operators to conduct gas compression on the seabed, reducing the need to introduce additional power generation on nearby offshore facilities.
“We are very proud of what we have achieved in partnership with Shell,” said Neil Saunders, President & CEO, Subsea Systems & Drilling, GE Oil & Gas. “We leveraged the GE store, using our domain expertise and heritage across the GE portfolio, including rotating machinery, power electronics, high voltage designs, and subsea production systems. Today, we are designing the next generation of compact and modular subsea compression systems to unlock new possibilities for power and processing worldwide.”
The compressor was driven by an electrical package provided by GE’s Power Conversion business. The high-speed motor and the high-power drive are capable of operating hundreds of meters below the sea level, according to GE.
The GE technologies that were tested as part of the Ormen Lange Pilot include:
Blue-C subsea compressor
- Operating pressure up to 175 bar
- Up to 18,000 m3 hourly production flow
- Vertical arrangement: electric motor on top; Single shaft line (rigid coupling)
- 3000 to 11,000 rpm operating speed
- 12.5 MW electric motor; natural gas cooled, 6.6 kV/1.6 kA
- 3 canned radial Active Magnetic Bearings; 1 canned axial Active Magnetic Bearing
Subsea Power Supply, Transmission and Distribution System
- Subsea Switchgear (SWG) – supplies power and protection to multiple loads from a single cable to shore, providing significant savings in cable and installation costs.
- Subsea Variable Speed Drives (VSD) – takes output from the subsea switchgear, and provides the optimal frequency for the individual supply lines feeding the compressor and pump.
- Subsea Uninterruptible Power Supply (UPS) – supplies power and protection to all the subsea compression station auxiliary loads, ensuring continuous supply of power during system disruptions to protect the subsea compressor and ensure a safe shut-down process.
- MECON Dry-Mate Connector 145/700 – enables power transmission at 145kV for a 120km tie-back distance.
IFOKUS Electric Actuators – anti-surge actuators developed for 80kN fail open operation.
NAXYS Acoustic Leak Detection System – used during the submerged pit testing to monitor for potential gas leakages as well as operation of rotating machinery and power modules.