The annual decline rate of oil production at the Azeri-Chirag-Deepwater Gunashli (ACG) field has fallen from around 12% in 2023 to about 3% currently. BP attributes the improvement to additional drilling carried out with SOCAR and the use of modern technologies.
At the long-producing ACG field, the main challenge has been slowing the natural decline in output while extracting the maximum result from remaining reserves. Seven drilling rigs are currently working around the clock at the field to achieve this.
In the first nine months of 2026, 17 new wells were drilled and brought into operation. Of these, 12 are producing oil, three are for water injection, and two for gas injection. By comparison, only 11 wells were completed in the same period last year, marking an increase of about 55%.
This year, repair and restoration work on seven subsea wells in the Deepwater Gunashli area was carried out from the subsea construction vessel “Khankendi” rather than from a platform. The operation also marked the first use of riserless light well intervention technology in BP’s history of operations in the Caspian basin, freeing up more platform capacity for drilling.
Stimulation work was carried out using a dedicated vessel on 10 additional wells across the Deepwater Gunashli, Central Azeri and West Chirag areas to boost output. At the Central Azeri platform, gas re-injection capacity into the reservoir was expanded by 20% as part of an expansion project.
Multilateral well technology tested for the first time
This year marked the first use of multilateral well technology at the ACG field. Well C44, drilled from the West Azeri platform, became the first well of its kind in the Caspian Sea. Of the three such wells planned for the year, two — C44 and D41 — have already come online, and such drilling is set to expand in 2027-2028.
A 4D seismic survey programme running from 2024 to 2028 is underway to more accurately assess the field’s reserves. The programme’s cost is projected to reach around $370 million.
To date, approximately $47 billion has been spent on developing the ACG field, which has produced nearly 4.7 billion barrels of oil in total. In addition, more than 63 billion cubic metres of associated gas have been delivered to the Azerbaijani state.
