By 1981 the Cantarell complex was producing . However, the production rate dropped to in 1995. The nitrogen injection project, including the largest nitrogen plant in the world, installed onshore at Atasta Campeche, started operating in 2000, and it increased the production rate to , to in 2002 and to of output in 2003, which ranked Cantarell the second fastest producing oil field in the world behind Ghawar Field in Saudi Arabia. However, Cantarell had much smaller oil reserves than Ghawar, so production began to decline rapidly in the second half of the decade. Unfortunately, the nitrogen has migrated into the gas, lowering its heating value and thus, economic value, and soon will require treatment to remove the nitrogen from the gas, to be able to use the gas as a fuel.