The flurry of news flow started even before last week's announcement, when Iran's Oil Minister Bijan Namdar Zanganeh said in March his country could boost exports by 1 million barrels per day "within a few months" of sanctions being lifted.
Iran is one of the world's largest emerging markets, and is the third largest economy in the Middle East after Turkey and Saudi Arabia, with a total GDP of $US360 billion ($485.1 billion) last year and a population of 78 million.
It will take at least 12 to 18 months to comply with International Atomic Energy Agency checks, and Rystad said the price impact of whatever Iran adds to the oil glut would be cushioned by the amount of production that will have been cut by then in other countries as a result of low oil prices.
"We consider there has been significant overreaction by oil traders on the news flow from the Iran-US negotiations. For comparison, Petrobras just lowered their production target for 2020 by 1.4MMbpd," Rystad head of analysis Per Magnus Nysveen said in a note this morning.
In the US, drillers have slashed to zero the potential of adding up to 2MMbpd this year if all idled rigs were still drilling on the best shale fields.
"All this should be compared with expected oil demand growth of 1MMbpd per year up to 2020 and production decline of 3-4 MMbpd per year for mature fields in the same period," he added.
"The current oversupply of crude oil will be effectively cured by low oil prices thanks to a massive shortfall of development drilling globally, both offshore and onshore.
"So we believe OPEC is able to retake 2MMbpd in sustained market share from non-OPEC suppliers - and Saudi Arabia will gain most of this new market share, despite the recent US agreements with Iran."
However, depending on the speed and depth of the sanctions, Rystad expects Iran will recover 400,000-500,000bpd of its potential overcapacity of 700,000bpd within two years, primarily from the old giant oilfields Agha Jari, Awhaz Asmari, Gachsaran and Marun.
The quality of the added oil is moderately heavy and sour with about 32 degrees API (American Petroleum Institute) density and 2% sulphur content.
While Iran ramped up rapidly to 6MMbpd under the Shah in the 1960s and early 1970s, after the revolution and during the Iran-Iraq War the fields deteriorated and even with the support of European international oilers and Chinese companies, they never recovered to reach more than 4MMbpd between 2005 and 2011.
The oil embargo imposed by the US in 2011 and halt of exports to Europe in 2012 caused a shortfall of 900,000bpd of production over 12 months, of which 200,000bpd has by today already returned to the wellheads, Rystad noted.
The firm said condensate from the giant South Pars offshore field had a potential to increase exports by an additional 500,000bpd from now, but with a lead time of 10-15 years due to complex and slow developments.
Iranian oiler Petropars has successfully implemented Phases 6-8, 12, 15-16 and 17-18 and these platforms should add more than 300,000bpd of condensate over the coming years.
Less optimism, however, is seen in the South Pars phase 11 LNG project, where there is potential of producing 2 billion cubic feet per day gas and 80,000bpd condensate, Rystad said.
"Here, the two previous operators, initially Total, later Petrochina, have been replaced by Petropars as the taxation scheme proved inadequate to incentivize such developments by foreign companies," Nysveen said.
"Ten years after Total was awarded the project, there has still been no development on this mega-project.
"So we believe Iran desperately needs major oil companies to grow its oil production beyond 3.5MMpd and massive investments are required for every barrel above this level."
IHS said this week that should international economic sanctions on Iran be lifted as a result of the nuclear deal signed in Vienna it will open up significant bilateral trade and investment opportunities between the Asia-Pacific economies and Iran.
China is already Iran's largest trade partner, and both China and India are important potential future growth markets for Iranian oil and gas exports.
"For both China and India, Iran is also strategically important from a geopolitical perspective, and this will further underpin the development of economic ties between the Asian BRICS economies and Iran once international sanctions are lifted," IHS Asia Pacific chief economist Rajiv Biswas said.
Prior to the imposition of sanctions on Iranian oil exports, Iran's global oil exports were heavily dominated by exports to China, India, Japan and South Korea.
Biswas said that if sanctions on oil exports from Iran are lifted, this would allow increased Iranian oil exports to its large Asian markets.
"With China and India projected to be key long-term growth markets for oil importation, bilateral energy ties between both the Asian BRICS and Iran are likely to strengthen significantly over the medium term," he said.
"For the Asia Pacific region, Iran remains a key long-term supply source of oil and gas, with the world's fourth-largest proven oil reserves and the world's second-largest conventional natural gas reserves.
"Both China and India are also likely to ramp up their efforts to establish strategic investments in the Iranian oil and gas industry.
"China is Iran's largest market for oil exports, and the easing of sanctions on Iranian oil exports in 2014 have already resulted in a 28% rise in Chinese oil and condensate imports from Iran in 2014, reaching an annual average of around 549,000bpd.
"Although Indian oil imports from Iran were significantly reduced in 2012-13 due to the impact of sanctions on Iranian oil exports, nevertheless Iran still accounted for 7.3% of Indian oil imports in 2014, at around 277,000bpd."
