Azeri-Chirag-Gunashli (ACG) Oil Field, Caspian Sea, Azerbaijan

The ACG (Azeri-Chirag-Gunashli) field lies 120km off the coast of Azerbaijan in 120m of water and contains 5.4 billion barrels of recoverable oil. The overall investment reached $20bn, that also includes amount spent on BTC export pipeline.

Participants of the huge Azeri-Chirag-Gunashli offshore field include BP - operator with 34.1367% of stakes, ChevronTexaco - 10.2814%, SOCAR - 10%, INPEX - 10%, Statoil - 8.5633%, ExxonMobil - 8.006%, TPAO - 6.75%, Devon Energy - 5.6262%, Itochu - 3.9205% and Delta Hess - 2.7213%. The production sharing agreement was signed in September 1994.

Chirag-1 platform

Chirag early oil project (EOP) is a single offshore platform, producing over 125,000bpd. Production commenced in November 1997. The field will reach the end of its productive life by 2024. Central, West and East Azeri complex were developed under phases I and II and Deepwater Gunashli portion was developed under phase III.

Chirag-1 is an offshore production, drilling and quarters (PDQ) platform located 120km east of Baku in the Caspian Sea. Chirag facilities include a 24-slot PDQ platform with water-injection equipment, a 176km-long 24in oil pipeline to the receiving terminal at Sangachal, a 48km-long 16in gas pipeline to the oil rocks, a 12km-long 18in gas pipeline to Central Azeri, and a compression and water injection platform. The Chirag platform has both production and water-injection wells to handle water injection to increase oil recovery.

Crude comes ashore by pipeline to the Sangachal terminal south of Baku. Most is carried in the 850km western export pipeline which has a capacity of 140,000pd (peak 160,000) to the Georgian port of Supsa on the Black Sea. Some portions of the oil from Sangachal is also exported via a northern pipeline to the Russian Black Sea port of Novorossiysk. Tankers are used to ship the crude from Supsa and Novorossiysk.

Central Azeri platform

The Central Azeri (CA) is an offshore PDQ platform located approximately 128m of water, 100km east of Baku in the Caspian Sea. The Central Azeri facilities include: a 48-slot PDQ platform, a 30in oil pipeline from CA to the Sangachal Terminal, a 28in gas pipeline from CA to the Sangachal Terminal and the expansion of the existing onshore terminal at Sangachal.

Production from CA field began in February 2005 under phase I of the development. This comprised two platforms built at the Amec-Tekfen-Azfen (ATA) yard, one for production and the other for compression and to provide water injection services to the Central, West and East Azeri platforms. Output from Central Azeri totalled 93,000bpd in 2005, and that from eight pre-drilled wells, rising to 240,000bpd later. The total capacity for the platform is 420,000bpd.

West Azeri platform

West Azeri (WA) came on stream in 118m of water in December 2005 from three predrilled wells. The WA facilities include a 48-slot PDQ platform and a 30in oil pipeline connecting to the expanded onshore Sangachal terminal.

Associated gas from WA flows via subsea pipelines to a CA compression and water injection platform for reinjection for pressure maintenance or to be used as fuel. Surplus gas will be exported to the Sangachal terminal.

East Azeri platform

East Azeri (EA) is an offshore 48-slot PDQ platform located 100km off the Baku coast in the Caspian Sea. This platform has been in operation since 2006 with production capacity of 800,000bpd. The Dada Gorgud completed the eight-well pre-drilling programme in December 2005. These are tied back to the platform once they are installed offshore.

The EA topsides construction has been carried out at the Baku Deepwater Jackets Factory (BDJF) yard, with all of the modules and the drilling derrick installed onto the integrated deck.

Gunashli field platform

Deepwater Gunashli (DWG) complex is the third phase of development of the Azeri-Chirag-Gunashli (ACG) field in the Azerbaijan sector of the Caspian Sea. ACG field reserves expected to be produced during the PSA period are approximately 1.25 billion barrels.

The first oil from DWG complex was received on 20 April 2008. On plateau, the DWG complex will produce approximately 320,000bpd, thus bringing the total ACG production rate to a level of over a million barrels a day.

The DWG complex is located in a water depth of 175m on the east side of the Gunashli field. The complex comprises two bridge-linked platforms, a 48-slot drilling, utilities, and quarters (DUQ) platform, and a process, gas compression, water injection and utilities (PCWU) platform.

Production export off the complex is via two 30in oil pipeline tie-ins and a single 28in gas pipeline tie-in into pre-installed pipeline junctions located on the Azeri field subsea export pipelines to the onshore Sangachal terminal.

Uniquely, three subsea water injection wells have been installed in the DWG development. Production from DWG will be boosted by subsea water injection intended to ramp-up oil production by increasing pressure through injecting seawater into DWG reservoir.

Compression and water injection platform (CWP)

The bridge is linked to the Central Azeri platform. CWP provides water and gas injection services to the Central, West and East Azeri platforms. It manages associated gas export and provides electrical power using ten Rolls-Royce turbines.

Oil and gas exports: Baku-Tbilisi-Ceyhan (BTC) pipeline

The BTC pipeline carries only ACG oil and Shah Deniz condensate. In the future volumes will include those from the North Caspian. BTC is a world-class pipeline that creates substantial revenues for the transit countries. It helps to strengthen economic and political links between Azerbaijan, Georgia, Turkey and the West.

The BTC shareholders are: BP (30.1%), AzBTC (25.00%), Chevron (8.90%), StatoilHydro (8.71%), TPAO (6.53%), ENI (5.00%), Total (5.00%), Itochu (3.40%), INPEX (2.50%), ConocoPhillips (2.50%) and Hess (2.36%).

A total of 326 million barrels of crude oil were exported from Ceyhan between 2006 and the first quarter of 2008. In the first quarter of 2008 the total volume of oil and condensate exported via BTC was about 62 million barrels.

The pipeline celebrated the 400th cargo lifting from the Ceyhan Terminal in Turkey on 6 March 2008. About 453 tankers were loaded at Ceyhan with a total of about 356 million barrels (about 48 million tons) of crude oil transported via BTC and sent to world markets.