Nicolas Maduro, president of Venezuela, speaks during a swearing in ceremony for the new board of directors of Petroleos de Venezuela SA (PDVSA), Venezuela's state oil company, in Caracas, Venezuela, on Tuesday, Jan. 31, 2017. Carlos Becerra | Bloomberg | Getty Images

One week before Venezuela faces a critical debt payment, the distressed petrostate is already late on a series of smaller bills — and no one can say exactly why. The nation's state-owned oil giant, Petroleos de Venezuela, SA, has two major bond payments totaling about $2 billion coming due in the next two weeks. While the market expects the company, better known as PDVSA, to avoid default, the missed payments have rattled investors and raised fresh questions about how long embattled President Nicolas Maduro's regime might last. "You're cutting close to the edge of not enough money in the checking account to pay the bills," said Ray Zucaro, chief investment officer at RVX Asset Management, an asset manager specializing in emerging and frontier markets. Last week, Venezuela missed five coupon payments totaling nearly $350 million tied to the debt of PDVSA, the government and the utility Electricidad de Caracas. That stoked a minor sell-off in a number of outstanding bonds.

As for the upcoming payments, the first is due next Friday. The price of that bond dipped from a one-year high of $86.80 last week to $83.48 on Monday. It has rallied from a 12-month low of $62.50 on Aug. 1. PDVSA needs to pay $841 million in principal, plus interest, on that bond. It's a critical moment for Venezuela because a default is seen as hastening Maduro's demise. Making matters worse, the collateral against the bond is Citgo, PDVSA's Houston-based refining and retail subsidiary. The following week, on Nov. 2, a nearly $1.2 billion PDVSA bond is maturing. Total outstanding obligations for 2017 are about $3.4 billion, and there's no grace period for the two biggest payments. As Venezuela's economic and political crisis worsens, foreign reserves have dwindled to just $9.9 billion. But analysts and money managers say more than half of that could be in gold and illiquid assets. The market currently puts the odds of a Venezuelan default at 15 percent, according to an analysis by RVX Asset Management, but Zucaro said he believes the chances are closer to 40 percent. The environment is deteriorating, he said, as Venezuela's latest election results are being questioned and as sanctions on the country expand to include measures that prevent it from raising new funds. Given the severe cash crunch, it's possible that Venezuela skipped out on the five coupon payments, which have a 30-day grace period, in order to allocate those funds to the payment due on the Oct. 27 bond, Zucaro said.