The return of Venezuela’s top opposition leader from exile is exposing a fault line in the oil sector between established companies that likely welcome a political transition and another group of operators that has benefited from opaque deal-making under a US-supported interim administration.

After seven failed attempts to go home, Nobel Peace Prize Laureate María Corina Machado finally reappeared in the country on Sunday, drawing huge crowds as she traveled toward the capital Caracas. The reemergence of the country’s most popular politician is raising pressure to convene elections, rebuild democratic institutions and reestablish rule of law.

Such developments would encourage major publicly traded companies to once again plow capital into the oil sector, industry experts say, decades after their assets in the country were expropriated.

But those experts also warn that the same scenario would mean more scrutiny for less well-known companies, often without clear evidence of financial or technical capacities, that secured oil assets since January, when President Nicolás Maduro was deposed.

“Most investors in the oil sector, though not all of them, would probably like to see a full transition to democracy and a legitimately elected government that would give greater security to their property rights,” said Venezuelan economist and University of Denver academic Francisco Rodríguez. “There is, however, an important group of stakeholders that doesn’t see it that way.”

While Venezuela has, by some measures, the world’s largest oil reserves of crude, it has suffered from decades of mismanagement, corruption and a lack of investment. Late President Hugo Chávez seized ExxonMobil Holdings Corp. and ConocoPhillips’ oil assets in the 2000s, leaving Chevron Corp. as the only US oil major still operating in Venezuela.

The oil sector’s outlook looks dramatically different under acting President Delcy Rodríguez. With US support, the country has signed a flurry of deals with new investors to boost production. Rodríguez said earlier this month she expects almost $76 billion of investment in oil and gas over the next five years.

Commitments thus far have focused on mature fields and projects where capital can be recovered relatively quickly, and could lift Venezuelan oil production to about 1.7 million to 1.8 million barrels a day within two to three years, said Francisco Monaldi, director of the Latin America Energy Program at Rice University’s Baker Institute.

However, Monaldi added, pushing output above 3 million barrels a day, close to Venezuela’s historical peak, would require much larger investments in new fields and stronger legal and institutional guarantees.

That point was echoed by Exxon Chief Executive Officer Darren Woods in January, who said his company’s potential return to Venezuela would require “significant changes” to the country’s legal and commercial framework, including durable investment protections.

“We’re not going to see large-scale investment by the oil majors until there’s an election,” said David Goldwyn, head of the energy advisory group at the Atlantic Council, a think tank in Washington.

Whether Machado’s return translates into meaningful political change remains uncertain. Francisco Rodríguez has warned of “possible paralysis,” as investors wait to see when elections will be held, whether Machado can participate and whether the opposition remains united.

Machado has proposed privatizing much of the oil industry, restoring competitive bidding and establishing an independent regulator, while supporting any agreements that abide by Venezuela’s constitution.

Under that scenario, longstanding oil agreements with established operators that predate Maduro’s removal are unlikely to be affected, according to Monaldi. But newer contracts could face greater scrutiny, particularly those awarded to companies without established operating records or where it’s unclear how the deals were granted.

Francisco Rodríguez singled out the accord signed by North American Blue Energy Partners Inc., or Nabep, as the most prominent example. Nabep, led by Venezuelan businessman Alejandro Betancourt, reached an agreement in August to secure a 100-year concession to operate 17 oil fields. The US also agreed to take a 35% stake in the company, giving it preferential access to Nabep’s oil.

US Secretary of State Marco Rubio defended the structure of the Nabep agreement Monday, saying the US partnership gives the certainty it needs to raise private capital and expand production before Venezuela’s political transition is complete. He said disagreement over the deal is separate from the push for elections and democracy in Venezuela.

However, Goldwyn said Venezuelan oil deals are likely to face greater scrutiny from Congress after November’s US midterm elections, potentially adding more risk even before Venezuela completes a political transition.

Machado has said Betancourt was responsible for “obscene corruption” and would not be a viable business partner in a future government, while criticizing his record in Venezuela’s electricity sector.

“Nabep is not a political entity,” a company spokesperson said in an emailed statement. “We are focused on what we do best: producing oil and increasing production — for the benefit of the people of Venezuela and the energy security of the Western Hemisphere alike.”Goldwyn said Machado has a “delicate line to walk” between asserting her own position inside Venezuela and avoiding a rupture with the Trump administration. She wants to reassure investors that property rights and legitimate contracts will be respected, while also pushing for more transparent and competitive deals and scrutinizing agreements she considers questionable, like Trump’s arrangement with Nabep.

“Even if you get a sweet deal from the government of Delcy Rodríguez, the stability in the long run is not solved,” Monaldi said. “And so you would like a resolution relatively early.”