Tyrihans is developed with five subsea templates, and is connected to the Kristin platform.

The seething waves roll over Tyrihans. Down below, at a depth of 270 metres, it is only fish that inspect the installations on a daily basis. Everything else takes place via a broadband connection with the Kristin platform, some 30 kilometres away.

Click the illustration for an overview of the area around Tyrihans.

Newly developed well and pipeline technology ensures a high recovery rate for the resources in the field, and the wellstream is routed through the world's longest electrically-heated offshore pipeline to the Kristin platform for processing.

"Routing the wellstream through a 43-km long pipeline is nothing short of a quantum leap. In time, we will be able to push distances even further," says head researcher Per Gerhard Grini.

Statoil discovered Tyrihans way back in 1982, but the field had to wait on the sidelines until 8 July 2009, when development of new technology and proximity to the other fields on Haltenbanken made it possible to start production from the field.

The field is a complete subsea development tied back to existing installations and infrastructure on the Kristin and Åsgard fields. Exploitation of existing facilities gives the field good profitability.

Pump on the seabed

For the first time ever, untreated seawater is taken into a pump on the seabed, and then pumped down into the reservoir for pressure support and stablisation of the oil zone. The newly developed subsea pump will be supplied with electricity from a subsea cable from Kristin. The field will also receive pressure support from gas injected from the Åsgard B platform.

"Tyrihans is a success. The field has delivered well above the targets in its first production period, and provides an important contribution to Statoil's production," says operations vice president Eileen Buan

She tells us that the field has a regularity approaching 100 per cent:

"It is particularly gratifying that we have achieved these results without serious health, environment or safety incidents," says the pleased operations vice president.

 

• The field includes the Tyrihans Sør deposit, which is an oil field with a gas cap, and Tyrihans Nord, which is a gas and condensate field with a thin oil zone. The recoverable reserves are 186 million barrels of oil and condensate, and 41.5 billion standard cubic metres of gas.
• The Tyrihans wellstream is routed through the world's longest electrically-heated offshore pipeline (43 kilometres) to Kristin for processing. The gas is exported from Kristin through the Åsgard transport pipeline to land, while the oil and condensate is routed through a pipeline to the Åsgard C storage ship for further transport by tanker.