Royal Dutch Shell CEO Ben van Beurden discussed opportunities in Iran with the country's Oil Minister Bijan Namdar Zanganeh last month; while France's Total and Italy's Eni have also had meetings with the Islamic Republic's minister recently. BP could also be among the first beneficiaries of the new deal.
If sanctions are eventually lifted, Iran could allow Total to resume construction of a 2 billion cubic feet per day LNG export facility.
Under the new terms if sanctions are lifted, US firms will be allowed to sell or lease commercial passenger aircraft to Iran as long as they procure licenses from the US government, giving companies such as New York-listed Boeing an opportunity.
Bloomberg reported in May that federal documents revealed ExxonMobil had hired a lobbying firm founded by Oklahoma Republican Don Nickles to work on the sanctions - though the US major hastily released a clarifying statement denying the report, saying US firms were prohibited from doing business with Iran.
At the very least, Exxon was believed to be tracking US government work on Iranian sanctions that have locked out US oilers from the Islamic Republic for more than 30 years.
Even India is understood to be preparing to ask Iran for rights to develop the Farzad-B gas field, which Indian multinational ONGC discovered in 2008.
The trade freeze had stopped India from claiming rights to invest nearly $US7 billion ($9.38 billion) in the biggest gas discovery ever made by an Indian company overseas.
That angle got more interesting yesterday when Israel's envoy to India Daniel Carmon said India was aware of his country's concerns over the Iran deal.
"Our Indian friends are aware of Israel's and its neighbours' grave concerns about the deal," Carmon said.
Amid all this, the strict, decades-old US restrictions on doing business with Iran which predate the nuclear crisis and relate to other concerns like terrorism support and human rights abuses, will remain in place.
"US persons and banks will still be generally prohibited from all dealings with Iranian companies, including investing in Iran, facilitating cleared country trade with Iran," a senior US administration official said at a briefing on Tuesday.
Yet IPAA president Barry Russell warned the deal between P5+1 nations China, France, Germany, Russia, the UK and the US would soon put America's oil producers at a competitive disadvantage on the global marketplace.
He used the deal as leverage to push for the US' oil export ban to be lifted - which is where his views align with the oil companies themselves.
"As soon as Iran is permitted to export its surplus oil on the world market, why can't we allow our own companies to do the same with their American-made surplus of crude oil?" he asked.
"It's an action that would lower gasoline prices for American consumers while positioning the United States more powerfully in the international energy arena.
"It's past time to lift the 1970s-era ban on crude exports, which makes no sense for a nation that has surpassed Saudi Arabia and Russia as the world's leading oil producer in 2015. It's not only good national security policy, it's good for American energy self-sufficiency."
Iran has suggested it could double its crude oil exports soon after sanctions are lifted, which could lead to about 1 million new barrels of oil per day entering the world market, according to the US Energy Information Agency.
US law currently prohibits most unprocessed American crude from being sold overseas, but does not limit the sale of refined petroleum products, such as gasoline, diesel and jet fuel to foreign buyers.
Russell said that with no opportunity to export their crude oil surpluses to the world marketplace, American producers - "companies that have been one of the most significant factors in America's economic recovery" - were forced to sell their product at a significant discount, store their crude supplies, or slow production by laying down rigs and laying off American workers.
IPAA and its member companies have made lifting the export restrictions on the US' surplus of crude oil a top priority for 2015.
Last week, Russell sent a letter to President Barack Obama urging further administrative leadership on lifting outdated restrictions on US crude oil exports. Last month, he sent a letter to House Energy and Commerce Committee Chairman Fred Upton, a Republican, in support of his recent comments on US crude oil exports.
IPAA also voiced its support for legislation authored by Senate Energy and Natural Resources Committee chair Republican Lisa Murkowski and Democrat Senator Heidi Heitkamp, which seeks to lift the ban on oil exports.
