To accomplish that, Ms. Kessel said, “Mexico is going to have to go to the deep waters of the Gulf of Mexico,” where she estimated there are at least 50 billion barrels in potential oil reserves — more than double the country’s current proven reserves.
International oil executives share the enthusiasm for Mexico’s potential deepwater fields, which lie near rich new American fields. Mexico “potentially has, if not the largest, one of the largest undiscovered deepwater petroleum resources in the world,” said Jon Blickwede, a senior geologist at Statoil, a Norwegian oil company active in the Gulf.
Pemex has stepped up exploration of its deep waters, but it will take specialized expertise and enormous financing to produce oil there. Just one deepwater rig can cost $365 million a year to operate, which is why even companies the size of Chevron and Shell look for partners to share the financial risk.
Carlos Morales, head of Pemex production and exploration, said in an interview that the company was in advanced discussions with foreign companies to develop “new models” of contracts to share costs and technology on land and offshore that would include cash payments. “Without doubt, Pemex is in a key moment in its history,” he said.
Like the government, international oil executives said they were cautiously optimistic some arrangement with Pemex could be worked out. But in the best case, it will be 10 or 15 years before significant production can begin in the deep gulf — and by then, Mexico could already be an oil importer.
Stumbling blocks remain. The recent reforms do not lift constitutional prohibitions that effectively prevent foreign companies from booking Mexican reserves they help discover, which undermines their incentive to sign deals with Pemex.
The Mexican government hopes to interpret the new rules to allow foreign firms to share the profits of new discoveries, but opposition political parties have filed a constitutional challenge to the rules. The case is before the Mexican Supreme Court.
The 1938 nationalization, by the leftist government of Lázaro Cárdenas, came at the end of a long period of revolutionary ferment in Mexico. It occurred amid rising tensions between foreign oil interests, including American companies, and Mexican workers who felt they were being exploited. Schoolchildren learn about it as one of the great assertions of Mexican sovereignty.
An outright reversal of that act is unthinkable in Mexican politics. Carlos Fuentes, the Mexican novelist and former ambassador, said any government leader who would try to change the legal status of oil “would be hanged in the Zócalo,” referring to Mexico City’s main square, though he personally would like to see some arrangement with foreign oil companies worked out.
As a symbol of nationalism and sovereignty, Pemex is run like a government agency, not an oil company. Its budget is set by the Congress, so it cannot plan exploration far in advance. It is burdened by taxes, debt and pension liabilities that limit its ability to spend money discovering new fields.
Mexico’s most important field has long been Cantarell. When production first faltered in the late 1990s, Pemex injected huge amounts of nitrogen gas to raise the pressure and increase production. But experts say the company may have gone overboard, bolstering production so much that the eventual collapse was accelerated.
With production in deep gulf waters still a distant dream, the hope of stabilizing Mexico’s production has centered on the Chicontepec field here, on land. But Pemex’s production forecast, of up to 700,000 barrels a day by 2017, has evaporated as hole after hole came up dry.
Chicontepec is now yielding only 35,000 barrels a day. The oil is contained in small pockets, and wet, hilly terrain makes it difficult to transport gear. Local corn farmers are slowing the drilling by blockading roads, demanding improvements like parks and pavement.
“The oil is down there,” said Sergio Gómez, the Pemex production coordinator in Chicontepec. “The problem is getting it out of the ground.”