The reservoirs are formed from carbonate breccia of Late Cretaceous age, the rubble from the asteroid impact that created the Chicxulub Crater.

[12] However, Cantarell had much smaller oil reserves than Ghawar, so production began to decline rapidly in the second half of the decade.

Luis Ramírez Corzo, head of PEMEX's exploration and production division, announced on August 12, 2004 that the actual oil output from Cantarell was forecast to decline steeply from 2006 onwards, at a rate of 14% per year.

[14] Analysts theorize that this rapid decline is a result of production enhancement techniques causing faster short-term oil extraction at the expense of field longevity.

[6] In 2008, Pemex expected Cantarell's decline to continue to 2012 and eventually stabilizing at an output level of around 500,000 barrels per day (80,000 m3/d).

Pemex planned to spend 6 billion US dollars until 2017 to stop the decline and maintain production level at around 325,000 barrels per day for another decade.

In order to try to maintain heavy crude production in the Bay of Campeche, PEMEX was focusing its efforts on the development of the Ku-Maloob-Zaap complex in an adjacent area, which can be connected to the existing facilities of Cantarell.