HMM: Two October surprises could boost oil prices above $50.

The first potential shock Croft and her team at RBC are monitoring is a debt default by Venezuelan oil giant Petroleos de Venezuela SA. Oil production from the state-owned PDVSA has steadily slipped as the country grapples with a financial crisis after the collapse in crude prices in 2014 and years of economic mismanagement.

“They have $3.5 billion in national oil company debt coming due in October-November. If they default, that could be significant for Venezuela’s production outlook,” Croft told CNBC’s “Squawk on the Street” on Tuesday.

Lower crude production from Venezuela would tend to support the oil market, which has been oversupplied for years.

The second surprise would come if the United States abandons an international deal that lifted sanctions on Iran. President Donald Trump could refuse to certify that Iran is complying with an accord that puts limits on its nuclear program. That could lead to the renewal of sanctions, which could impact Iran’s oil production.

A spike would provide relief to American frackers, who have trouble turning a profit at today’s prices. And taking Iran or Venezuelan oil off the market would give American frackers more opportunity to take market share.

Both of which would tend to drive prices back down.