Oil is now up 60 percent from where it bottomed in February, just five days before Saudi Arabia, Russia, Qatar and Venezuela said they would freeze production if others participated.
"I think there's a lot invested now in a successful conclusion to this meeting so it would seem real easy to disappoint come Monday," said John Kilduff, partner at Again Capital. Analysts say oil has seen most of the gains it would get from a freeze agreement, and Kilduff believes it could even trader lower on the news.
Some analysts do not expect a deal, and others say it's still unclear how close the key players are to an accord. Interfax also reported that Russia said Iran was not critical to a production deal.
"The headlines are just reflecting the optimism from the Russian camp," said Chris Weafer, senior partner at Macro-Advisory. "The Russians say there will be a freeze agreement because they want one, and they have no other choice. It's quite clear that the Saudis don't want to go to this meeting. This is something they've been almost dragged into, and they've indicated they prefer decisions stay within OPEC."
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Focus has centered on the differences and tensions between Iran and Saudi Arabia, particularly since Saudi Arabian Deputy Crown Prince Prince Mohammad bin Salman made it clear that the kingdom would only agree to a freeze if Iran and others also participated.
Iran has said it would attend the meeting but it would not freeze output. Iran has been restoring barrels to the market since the sanctions against its oil sales were lifted. Its goal is to bring back 1 million barrels within a year.
"Were it not for the Iran issue, you could count on there being a freeze. I think with this meeting in Doha, there's so much invested in it, there's the likelihood it will end with some kind of agreement, though one that will have some sort of ambiguity in it," said Yergin.
He said even if there's not a detailed accord, there could be some type of deal that leads to a bigger agreement with a further meeting.
"What is still to be determined is how much additional oil Iran could put in the market on a sustained basis," said Yergin. "These prices demonstrate why the exporters will try to find a way to cooperate again."
Weafer also said there may be a conditional type of agreement that comes out of the meeting.
"For Saudi, this has always been about market share. If everybody agrees to freeze current market share, the Saudis would probably go along with that. If they see more Iranian oil coming back to the market, it will mean a reduction in their market share and they won't agree to that," Weafer said.
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As for Russia, companies there are producing as much as they can so a freeze would not be difficult. He said Western sanctions have made them unable to get financing to increase production.
"They all hope to reach a deal, but the country that may not care is Saudi Arabia," said Helima Croft, head of commodity strategy at RBC Capital Markets. "Until we have a comment from a Saudi official who is connected to MBS (bin Salman) ... I'm not going to believe it."
Croft said prices would react differently based on the various potential outcomes of Sunday's meeting. Worst case for prices would be if the meeting broke up and there was acrimony. The best case would be an agreement with the promise of more to come, such as an actual cut.
The other outcomes are more neutral for prices and more likely — a freeze with no further promises or a looser deal with the promise of another meeting where a deal could be reached, she said.
Weafer said any deal could also quickly unravel and the focus will shift to the June OPEC meeting. "That will be the key meeting that will determine where the oil price goes over the next 12 to 18 months," he said.
"If there's disappointment in the weekend, we probably go back down to where we were two weeks ago, $38. Five or six dollars we could lose ... if there's not a clear statement," he said.
Weafer said Saudi Arabia will also want to see that U.S. shale drilling continues to decline, but that's not likely if prices continue moving higher.
The latest weekly data on U.S. production and inventories is released Wednesday by the Energy Information Administration at 10:30 a.m. EDT. U.S. production was reported at 9 million barrels a day last week, well off its peak of 9.6 million barrels a year ago.
The sharp increase in U.S. production several years ago helped lead to the current glut, as OPEC producers and Russia continued to pump.
Yergin said production will return if oil prices continue to rise. "It brings some back at $45 and it brings a lot more back at $60. That is the range it starts to stabilize at — the high $40s you could start to stabilize U.S. output," he said.
Oil prices are still well below the level many producing nations need to maintain their budgets. Fitch Ratings on Tuesday cut the credit rating for Saudi Arabia, citing the impact of low oil prices on its finances.
Fitch Ratings lowered Saudi Arabia's long-term foreign and local currency ratings to AA-minus from AA, and retained a negative outlook. Fitch said it sees oil between $35 and $45 and that has has major negative implications for Saudi Arabia's fiscal and external balances.
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It noted the Saudi central government deficit widened to 14.8 percent of GDP in 2015, compared to a deficit of 2.3 percent in 2014 and surpluses in the preceding four years. It expects the deficit to GDP to narrow just slightly this year as oil prices recover. Saudi Arabia is expected to meet its financing needs by disposing of foreign financial assets but it is also raising debt and borrowing from banks.
But Fitch also pointed to changes in the way the royal family governs with the rise of 30-year-old bin Salman. He is deputy to Crown Prince Mohammad bin Nayef.
"Control over economic policymaking has been concentrated in the hands of Prince Mohamed bin Salman, the deputy crown prince and son of the king who is also chairman of the Council on Economic and Development Affairs as well as defense minister. This may have contributed to an acceleration of the economic policymaking process, but has also reduced the predictability of decision-making. The degree of support for this accumulation of power from other parts of the royal family is uncertain," Fitch wrote.
The ratings agency also said geopolitical risk is high relative to Saudi Arabia's "AA"-rated peers. "Tensions have risen between Saudi Arabia and its long-standing regional rival Iran, and are expected to persist, although a direct confrontation is highly unlikely. Saudi Arabia's military intervention in Yemen and in Syria shows a greater assertiveness in foreign policy," Fitch wrote.
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Croft said she expects the producers will still try to get a deal, as they all are feeling the pain of lower prices. They all face budget shortfalls and possible debt downgrades. In order to get a deal, Iran would need to come to the table with some sort of production agreement that would be viewed as acceptable to Saudi Arabia, but that could prove difficult, she said.
The final decision on Saudi participation is up to bin Salman and the kingdom is the key to the deal.
"They need to come to an agreement, and if they don't get an agreement they have to manage the optics," said Croft.
"If it ends in recriminations, that's where you have a sell-off," said Croft, but she does not see that as the most likely scenario. "The Russians are really trying to make this thing work."