SOCAR and BP (NYSE: BP) have signed a new production-sharing agreement (PSA) on April 26 for the joint exploration and development of Block D230 in the North Absheron basin in the Azerbaijan sector of the Caspian Sea.

The PSA was signed in London, in the presence of U.K. Prime Minister Theresa May and Azerbaijan’s President Ilham Aliyev, by Rovnag Abdullayev, president of SOCAR, and BP Group CEO Bob Dudley.

“We have a long tradition of successful cooperation with BP. I believe that the synergies between modern upstream technology and unique historical experience, embodied in both companies, create a solid basis for our continued success,” Abdullayev said. “Being based on fair and equal conditions, today’s agreement will become an important milestone in the pursuit of the highest degree of efficiency in the joint development of the natural resources of Azerbaijan.”

Block D230 lies some 135 km (84 miles) north-east of Baku in the Caspian Sea. It covers an area of some 3,200 sq km (1,235 sq miles) and has not previously been explored. It has water depths of 400 m to 600 m (1,312 ft to 1,968 ft) and anticipated reservoir depths of about 3,500 m (11,482 ft).

Under the PSA, which is for 25 years, BP will be the operator during the exploration phase holding a 50% interest while SOCAR will hold the remaining 50% interest.

The signing of the PSA follows the memorandum of understanding for exploration of Block D230, which was agreed in May 2016.