Subsea compressor lifted into place at Kårstø

Aibel has built a new Kårstø testing facility for Statoil which is designed to test subsea compressors. This week the pilot compressor was hoisted into place in the test pool.

Foto Statoil 2
The compressor was supplied by Aker Solutions. It was set in a frame in Egersund before it came to Kårstø and was hoisted into place in the test pool on Tuesday. Photo: Statoil.

"Yes, it was lifted into place on Tuesday morning. It weighs 265 tons, and represents an important milestone for the project," says Ole Kristian Halvorsen, Project Manager in Aibel.

Simulates the seabed

Aibel won the contract for the engineering, procurement and construction of the test facility for subsea compressors at Kårstø in the summer of 2011.

"The pressure in the reservoir decreases as the gas is taken out. Powerful compressors are required to send the gas on to the processing. Usually compressors are on the platforms, but now Statoil will try placing them on the seabed in the Åsgard field," explains Halvorsen.

And before that happens, the compressors will be carefully tested at Kårstø.

"We've built a test centre that consists of a big test pool and a complete new test facility. The electro-compressor will be placed in the pool for necessary cooling. Parts of the facility simulates that the compressor is below sea level. The voltage loss in electrical cables of lengths that are to reach the bottom of the sea is a large part of what has to be simulated. High-voltage work has therefore been a major part of our installation," says Halvorsen.

The project has been named K-LAB SST (Sub-Sea Test Project). The test facility was handed over to Statoil in the summer. Aibel has put in 300,000 hours’ work on the project. Photo: Aibel.

Historical significance

A total of about 150 Aibel employees have been involved in the work on the test facility. The contract is worth about NOK 400 million.

The new test facility is attached to the Kårstø metering and technology laboratory, the K-lab. And now the first compressor is in place.

Now that the compressor is in place in the test pool, Aibel has 24 days to complete the hook-up work. Then 45 days of tests follow. Photo: Aibel.

"In all, four compressors will be made to start with. The first one is just a pilot, and will remain at Kårstø to be used for further testing. It's the next three that will be going out onto the field. The first of these will come to Kårstø in January 2014. The offshore testing will begin early in 2015," explains Halvorsen, and continues:

"The subsea compressors on Åsgard are a very important project in Norwegian oil history. Today major rebuilding often has to be done on platforms to make room for more powerful compressors. If they can be placed on the seabed in the future, it will be a milestone for the industry.