Gas transport from the fields to onshore treatment plants, as well as transport of sales gas to the consumer marked in Europe was traditionally carried out by the oil companies in joint ventures. However, as the discovery of more and more gas on the Norwegian Continental Shelf (NCS) materialised, it became obvious that a consolidated network would be advantageous to all parties involved.

Gas, as retrieved from the subsea oil and gas fields, normally contains considerable amounts of NGL (Natural Gas Liquids) like ethane, naphtha, propane, iso butane and normal butane which have greater commercial value than methane, the sales gas distributed to domestic and industrial consumers. The only sensible way to land natural gas for treatment and separation, and further distribution of sales gas is through a network of high pressure and low-pressure pipelines.

Gassled
As at 1 January 2003, most transport systems were united in one large joint venture called Gassled. The oil and gas companies operating on the NCS own the company. The company has no employees and is organized through various committees with specific tasks. Gassled is the formal owner of the infrastructure in connection with gas transport from NCS. The owners are Petoro (38.293%), Statoil ( 20.379%), Hydro (11.134%), Total (9.038%), Esso (5.179%), Shell (4.681%), Mobil (4.576%), and Norsea Gas (3.018%) ConocoPhillips (2.033%) and Eni (1.669%).

In January this year, the ownership of the Kollsnes processing plant was transferred from the owners of the Troll field to Gassled. The gas processing plant at Kollsnes was completed in 1996 as part of the Troll field and owned by the same companies that own the field. The main purpose of the plant was to process the gas from the Troll field for further transport to the marked in Europe.

Gassco
Gassco was founded by the Ministry of Oil and Energy in Norway in May 2001 taking over the operating responsibility for all gas from the NCS from 1 January 2002. The company is 100 percent state owned. The establishment of Gassco meets EU requirements for organizing gas transport in the European gas market as stated in the gas marked directive. In addition to being the operator for Gassled, Gassco is also the operator for the joint ventures Haltenpipe, Norne gas transport system, Zeepipe terminal in Belgium and Dunkerque terminal DA in France.

Gassco’s main tasks are system management and capacity administration of the impressive 6,600 kilometres of gas pipelines, ranging from 42- to 16-inch and further development of the infrastructure and terminals. The owners have authorizes Gassco to enter into agreement concerning technical services with subcontractors. These agreements will, among other things, include daily operating tasks and see to that the technical integrity and maintenance of the transport system is carried out in order to maintain the technical integrity of the installations.

Kårstø Expansion Project (photo: Statoil ASA)

Increased Capacity in Zeepipe
The growing demand in Europe for gas from the NCS has led to a recommendation from Gassco to boost the capacity in the pipelines Zeepipe IIB and Zeepipe IIA. These transport gas from the Kollsnes processing plant to the risers Draupner (IIB) and Sleipner (IIA). From the risers the gas is transported through other pipelines to Belgium, Germany, France and UK. The capacity of Zeepipe IIB will be increased from 59.5 million standard cubic meters (Scm) to 71 million Scm per day meeting orders from October 2005. Capacity of Zeepipe IIA will be increased from 55,4 million Scm to 72 million Scm from 2006. In total this upgrading represents an investment of NOK 130 millions.

Gassco’s Cost Reduction Program
The activities that Gassco is responsible for will to reduce the cost with at total of NOK 0.5 billion within 2008. The improvement program aim to reduce operating cost with 20 percent and was approved by the governing committee of Gassled in May as a measure to improve the competitiveness of NCS. The improvements are based on the assumption that they will not affect safety and regularity and consist of 13 different partial projects. It is, among other things, considered to remove the elderly compressor platform H7 in the Norpipe system and introduction of more effective working processes onshore.

Kårstø Processing Plant
Kårstø gas processing plant has a key role in treating and transporting gas and condensate from important fields on the NCS. The first gas arrived at the plant in July 1985, and the first sales gas went to Emden in October the same year. Originally the plant was designed to treat gas from fields in the northern part of the North Sea, and this is still a central task for the plant.

The Kårstø plant receives gas from fields on the NCS through the Statpipe and Åsgard pipeline transport systems. The plant receives condensate from the Sleipner area, where the condensate is stabilized and fractionalized in a separate plant set to work in October 1993. From Kårstø the stabilized condensate is shipped to customers. LPG is separated and split into propane, iso butane normal butane and naphtha. Propane is stored in caverns with a total capacity of 90,000 tonnes. August 2000 saw a new plant for ethane coming online with a production capacity of 620,000 tonnes per year. The product is sold through long-term agreement with customers and shipped from the plant. Sales gas is transported to pipelines to customers in UK and continental Europe.

KEP 2005, Kårstø Expansion Project 2005
The intention of the project is to equip the Kårstø processing complex to handle gas from Statoil’s Kristin project. Rich gas from this field will be transported from the field to the plant through the existing Åsgard Transport trunk line. NGL will be separated from the gas and exported by ship to countries all over the world, while the remaining sales gas will be sold to markets in continental Europe and UK. The KEP 2005 expansion project has a budget of roughly NOK 5.75 billion and is expected to come into operation 1 October 2005. Statoil is the technical service provider at Kårstø, and is implementing KEP2005 on behalf of Gassco.

The project will increase processing capacity for rich gas at Kårstø by 44 percent and also increase annual ethane recovery capacity by more tan 50 percent from 620,000 tonnes to 950.000 tonnes. The bulk of construction work is taking place is taking place this year. When completed, this will make Kårstø the biggest export port for NGL in Europe and the third biggest in the world.

(photo: Statoil ASA)