Russian exploration company Rosgeo will drill for gas off the southern coast of South Africa under a $400 million deal with PetroSA to help build the African country’s reserves.

The agreement announced on Monday comes against a backdrop of declining domestic gas reserves that have curtailed output at PetroSA’s gas-to-liquid plant in Mossel Bay.

“The project envisages extraction of up to 4 million cubic metres of gas daily. This will subsequently be delivered to PetroSA’s gas-to-liquids refinery,” PetroSA said in a statement.

The deal was signed on the sidelines of the BRICS block of developing nations meeting in Xiamen, China, and will see Rosgeo use seismic and drilling vessels to explore South Africa’s south coast, where Total also had acreage.