On 14 September 2017, the Government of Azerbaijan and the State Oil Company of the Republic of Azerbaijan (SOCAR) and BP, Chevron, INPEX, Statoil, ExxonMobil, TP, ITOCHU and ONGC Videsh signed an agreement to extend PSA for ACG fields until 2049.  Azeri-Chirag-Gunashli (ACG, Azerbaijani: Azari-Araq-Gun-Li) or Azeri-Chirag-Deepwater Gunashli is an oil deposit complex in the Caspian Sea, about 120 kilometres off the coast of Azerbaijan. It consists of oil fields of Azeri and Chirag, and the deep part of the Gunashli oil field. An estimated total construction area is 432.4 square kilometres.  It is developed by Azerbaijan International Operating Company, a consortium of international oil companies, and operated by BP on behalf of the consortium. ACG fields estimate the achievable reserves between 5 and 6 billion barrels (790 to 950 million cubic meters) of oil. At the end of 2005, the production rate of eight drills drilled on the wharf was about 240,000 barrels per day (38,000 m3/d).  On 14 September 2017, INPEX CORPORATION (INPEX) and ITOCHU Corporation entered into production-sharing agreements (PSA) for the Azeri-Chirag-Gunashli field (ACG) with the state oil company of the Republic of Azerbaijan (SOCAR) for a further 25 years. The MOL Group entered Azerbaijan in 2019 by acquiring 9.57 per cent of the Azeri Chirag-Gunashli (ACG) oil field and an effective 8.9 per cent share in the Baku-Tbilisi-Ceyhan (BTC) pipeline, which transports crude oil to the Mediterranean port of Ceyhan. The agreement was reached in April 2020. MOL is the third field partner of ACG, a large Caspian Sea oil field operated by BP that began production in 1997.
ACG will increase its production by about 20 mbpd (the authorisation production action changes with the oil price environment due to the production sharing agreement). The Ministry of Energy recalls that BP Exploration, SOCAR and Uzbekneftegaz signed a Memorandum of Understanding in May 2018 and a joint research agreement in May 2019 to assess the exploration potential of the three investment blocks in the Ustyurt region. “In the past, a series of working meetings have been held with the participation of specialists from the Ministry of Energy, Ouzbeekneftegaz, bp and SOCAR, and a number of phased agreements have been concluded,” the report says. The West Azeri drilling modules arrived in Baku in August 2004 and the rig started in May 2005. The topsides of the platform were installed in September 2005 and production began in January 2006.  Ostazer`s drilling modules and quarters arrived in Baku in June 2005 and the rig was launched in March 2006. The top was installed in March 2006 and production began in October 2006.  The second stage was the development of the Azerbaijani field. The development of the Azerbaijani field began in 2002. Residential areas of central Azerbaijan arrived in Baku in July 2003 and drilling modules arrived in Baku in July 2003. The Central Azeri jacket was completed in March 2004.
To receive additional oil, the Sangachal terminal was modernized in March 2003. Following the installation of the Central Azeri pipeline, Azerbaijan`s central platform was commissioned in July 2004. The platform was installed in October 2004 and production began in February 2005. The Azeri Topside Central Water Compression and Injection Platform was launched in July 2005. It injected the first gas in May 2006 The emergence of the Azeri-Chirag-Gunashli development began in the early 1990s.