Casing head gas from platforms in central, western and eastern parts of Azeri field is supplied to Sangachal Terminal via 28 inch subsea gas pipeline to distributive system of Azerigaz CJSC to use on the local market. A portion of casing head gas extracted at Chirag platform is directed to SOCAR's compressor station (the State Oil Company of Azerbaijan) to Oil Rocks field via 16 inch subsea gas pipeline. The rest of the gas from Azeri–Chirag–Guneshli platforms are pumped through intra field subsea gas pipeline to a platform for repeated pumping in a layer to support layer pressure. As of September 2009, 164.2 million tonnes of oil and 37 billion cubic meters of associated gas have been produced and 80.3 million cubic meters of water and 13 billion cubic meters of gas have been injected into layers since the beginning of production in ACG fields in 1997.