A major field was discovered in 1973 but contains extra heavy crude[dubious – discuss], which due to special refining needs is considered unviable at this time.
[1] While the reserves are overwhelmingly extra heavy crude, pockets of lighter tight oil, as well as natural gas, are also found in the basin.
[2] In March 2006, Mexican President Vicente Fox announced that Pemex would invest US$37.5 billion over the next 20 years on the oil fields of Chicontepec.
Pemex's chief executive estimates that 20,000 wells are to be drilled in order to exploit this field.
Intensive drilling has taken place in Chicontepec in recent years, starting with a contract for 500 new wells offered in December 2008.