Caspian crude oil export pipeline completed

Engineering contractor Kvaerner E&C plc, London, has announced completion of a pipeline to export early oil production from Chirag field in the Caspian Sea.

The 115,000 b/d capacity pipeline extends 830 km from Sangachal, south of Baku in Azerbaijan, to Supsa on Georgia's Black Sea coast, and delivered first oil on Apr. 6, although commissioning was completed on May 27.

Kvaerner built the pipeline and an export terminal at Supsa under contract to the Azerbaijan International Operating Co. (AIOC) venture and the Georgia Pipeline Co.

The pipeline has six pumping stations and two pressure-reducing stations. Kvaerner was responsible for detailed engineering, procurement, and construction management.

Construction work on the Azeri section of the pipeline was carried out by local contracting alliance Tekfen-Azfen, while the Georgian section was built by the local MontazhSpetsMsheni alliance.

Expandable capacity

Roberto Pirani, vice-president, pipeline systems, at Kvaerner, told OGJ that the pipeline diameter is 21-in. (530 mm). The original plan was to incorporate two existing sections of pipeline, but that later proved to be unusable.

Pirani said the capacity of the pipeline is expandable and that a number of studies are under way to study options for anticipated increased production from the Caspian Sea in the future (see related article, p. 21).

The main options under study are to double the capacity of the Sangachal-Supsa line by installing new pump stations or to build a new pipeline, dubbed the Main Export Pipeline (MEP).

Pirani noted that the new line is already transporting beyond its nominal capacity.

The planned capacity for the MEP is 1 million b/d (OGJ, June 22, 1998, p. 36).

However, Pirani said the need for increased export capacity hinges on oil prices, further discoveries in the Azeri sector of the Caspian Sea, and the capability of markets to absorb further exports.

Project details

The pipeline was built to western specifications, with pipeline sections made in Greece and Japan and imported through the Georgian Black Sea port of Poti for distribution along the route by road and rail.

Pirani said work on the project began in 1996, with construction split roughly into two sections, each with three pumping stations. The Azeri team built the longer section, but the Georgian team's section covered the roughest terrain and incorporated the two pressure-reducing stations.

The four 250,000 bbl storage tanks at the Supsa marine terminal were built on columns filled with gravel, to stabilize the structures in soft soil and to protect against earthquakes.

The loading terminal has capacity to deliver 875,000 b/d of oil and can handle tankers up to 150,000 dwt. These are loaded typically in 1.5 days, through a catenary anchor leg mooring buoy located 3 km offshore, in 50 m of water.

At the existing Sangachal terminal, Kvaerner installed new connecting pipelines, pumps, and a pigging unit, plus a control and communications center.

Pirani said that the pipeline's pumping stations are in remote locations and have on-site power generation. The engines for the pumps run on crude oil, which comes from small treating plants at each station. The pumps are started on diesel fuel.