Thirty-two years have passed since the signing of the "Contract of the Century."

Operativ Media reports that September 20 is celebrated in Azerbaijan as Oil Workers' Day—a professional holiday for oil and gas sector workers—and the anniversary of the Production Sharing Agreement (PSA) for the development of the Azeri-Chirag-Deepwater Gunashli (ACG) block of fields in the Azerbaijani sector of the Caspian Sea, known as the "Contract of the Century."

The celebration of this day as a professional holiday was officialized by a decree signed by the national leader of the Azerbaijani people, Heydar Aliyev, on August 16, 2001.

The choice of this date for the professional holiday is linked to the signing of the agreement on the joint development of the ACG block and production sharing between the State Oil Company of Azerbaijan (SOCAR) and 11 foreign oil companies from six countries in Baku on September 20, 1994.

Initially signed for a period of 30 years, the ACG agreement was ratified by the Milli Majlis on December 12, 1994, and entered into force on December 14, 1994. This agreement was the first major investment made by Western multinational companies in any country of the former Soviet Union and is known as the "Contract of the Century."

Following the ratification of the agreement, the Azerbaijan International Operating Company (AIOC) was established to implement the project on behalf of the foreign shareholders cooperating with SOCAR and the Azerbaijani government. Initially, AIOC was formed by 11 major foreign oil companies representing six countries—the United Kingdom, the United States, Russia, Norway, Turkey, and Saudi Arabia (bp, "Amoco", "Unocal", "LUKoil", "Statoil", "Exxon", TPAO, "Pennzoil", "McDermott", "Ramco" and "Delta Nimir").

Since June 1999, bp has assumed the role of operator for AIOC.

The ACG oil field is located in the Azerbaijani sector of the Caspian Sea, approximately 100 km east of Baku. The ACG megastructure encompasses the Balakhany VIII and X, as well as the upper and lower Fasila reservoirs, located at a depth of 2,000 to 3,500 meters beneath the Caspian Sea.

The development of the field has been carried out in several stages: production from the "Chirag" field began in 1997 under the Early Oil Project (EOP). This was followed by the "Azeri" Project "Phase 1"—production from "Central Azeri" started in early 2005. The subsequent second phase covered the "West Azeri" and "East Azeri" platforms, where production began in December 2005 and late 2006, respectively. Under the next, third phase of the ACG development, production from the "Deepwater Gunashli" platform started in April 2008. These phases were followed by the Chirag Oil Project, which included the "West Chirag" platform. The first oil from this platform was extracted on January 28, 2014. The latest project related to the development of the ACG field is the "Azeri Central East" project, which was sanctioned in 2019.

Recognizing the success of the ACG field development, the Azerbaijani government and ACG partners signed an amended and restated agreement on September 14, 2017, extending the ACG contract until the middle of the century.

The new agreement enables the government and investors to maximize the economic benefits of ACG for Azerbaijan and the companies over the next 30 years, and to invest more than $40 billion in capital in this world-class field.