The South Pars/North Dome field is a natural-gas condensate field located in the Persian Gulf. It is by far the world's largest natural gas field,IEA, World Energy Outlook 2008 - Chapter 12 - Natural gas resources and production prospects, p.298 with ownership of the field shared between Iran and Qatar. According to the International Energy Agency (IEA), the field holds an estimated of in-situ natural gas and some of natural gas condensates. Ranked against other natural gas fields, it has almost as much recoverable reserves as all the other fields combined. It has significant geostrategic influence.
As of early 2026, before the beginning of the 2026 Iran war, Qatar was producing approximately per day from the field, accounting for around 80% of Qatari government revenues, while daily production on the Iranian side was estimated to be around only . Iran's inefficient exploitation of the shared gas field is often attributed to Western sanctions, isolation and mismanagement. These have also caused the Iranian government to lag behind on pressurization efforts on their side of the field, which causes more gas to migrate to the Qatari side of the field.
On 18 March 2026, the field was attacked by the Israeli Air Force. United States officials denied coordination and approval of the Israeli attack. Initial reports revealed that the damage caused to sections of South Pars gas field make up nearly 12 percent of Iran's total gas production. Iran's Ministry of Petroleum said that a number of facilities were damaged and that a fire at the gas field was being put under control. No casualties were immediately reported. The attack halted output at two refineries with a combined capacity of 100 million cubic metres per day. Parts of the gas field were closed to stop the fire from spreading. Following news of the attack, international oil prices increased from $103 a barrel to $108. Gas prices in Europe increased by 7 percent amid fears of Iranian retaliatory action against energy infrastructure in the Gulf Arab states. Iran halted its gas flows to Iraq, which relies on Iran for between a third and 40 percent of its gas and power needs.
Field geology The field is below the seabed at a water depth of , and consists of two independent gas-bearing formations: Kangan (Triassic) and Upper Dalan (Permian). Each formation is divided into two different reservoir layers, separated by impermeable barriers. The field consists of four independent reservoir layers K1, K2, K3, and K4."Gas Prospective Areas in the Zagros Domain of Iran and in Persian Gulf Iranian Waters". • Search and Discovery. • (PDF)
The K1 and K3 units are mainly composed of dolomites and anhydrites, while K2 and K4, which constitute major gas reservoirs, comprise limestone and dolomite. A massive anhydrite (the Nar member) separates the K4 from the underlying K5 unit which has poor reservoir qualities.H. Rahimpour-Bonab, B. Esrafili-Dizaji, V. Tavakoli (2010) Dolomitization and Anhydrite Precipitation in Permo-Triassic Carbonates at the South Pars Gasfield, Offshore Iran: Controls on Reservoir Quality. The gross pay zone in the South Pars field is approximately 450 m thick, extending from depths of approximately 2750 to 3200 m. Reservoir strata dip gently to the NE. The average thickness of the reservoir units declines from South Pars (some ) to North field (). As in other reservoir structures in neighboring areas, the reservoir in the Qatar Arch is cut by a set of NNW-SSE trending faults. Diagenesis has a major effect on reservoir quality of the field.
The field is a part of the N-trending Qatar Arch structural feature that is bounded by the Zagros fold and thrust belt to the north and northeast.
In the field, gas accumulation is mostly limited to the Permian–Triassic stratigraphic units. These units known as the Kangan–Dalan Formations constitute very extensive natural gas reservoirs in the field and Persian Gulf area, which composed of carbonate–evaporite series also known as the Khuff Formation.
Permian–Early Triassic has been divided into Faraghan (Early Permian), Dalan (Late Permian) and Kangan (Early Triassic) Formations.
Reserves
According to International Energy Agency (IEA) in 2008, the combined structure is the world's largest gas field.
In-place volumes are estimated to be around gas in place and some of natural gas condensate in place.IRAN - The Geology. • APS Review Gas Market Trends. • April 2, 2007 With in place volumes equivalent to of oil1 Barrel of crude oil = 5.8 × 106 BTU (310 billion BOE of gas and 50 billion BOE of natural gas condensate) the field is the world's biggest conventional hydrocarbon accumulation.
The field recoverable gas reserve is equivalent to some of oil and it also holds about of recoverable condensate corresponding of about of oil equivalent recoverable hydrocarbons.
The gas recovery factor of the field is about 70%, corresponding to roughly of total recoverable gas reserves, which is about 19% of world recoverable gas reserves.Eni World Oil and Gas Review 2006 . • ENI.
The estimates for the Iranian section are of natural gas in place and around of recoverable gas which stands for 36% of Iran's total proven gas reserves and 5.6% of the world's proven gas reserves as of 2007.
The estimates for the Qatari section are of recoverable gas, which amounts to almost 99% of Qatar's total proven gas reserves and 14% of the world's proven gas reserves.
+Table 1 - South Pars/North Field gas reserves In-place gas reserveRecoverable gas reservekm3trillion ft3km3trillion ft3South Pars14,000 500 10,000 360North Dome37,000 1300 26,000 900Total51,000 1800 36,000 1260
Note: 1 km3 = 1,000,000,000 m3 = 1 billion m3 = 1 trillion litres
However, since the field is a common field and the reservoir is highly homogeneous, the ultimate recoverable reserves of each country may vary from this technical assessment which only considers the static data and does not include rate of gas migration. So, it is better to say that the ultimate recoverable reserves of each country would be a factor of cumulative gas production by each of them.
The Iranian section also holds of condensate in place of which some are believed to be recoverable, while Qatari section believed to contains some of condensate in place and at least some of recoverable condensate.Qatar Petroleum, Speech by Qatar’s Minister of Energy and Industry, Doha, Qatar, May 5, 2003
The field is rich in liquids and yields approximately of condensate per of gas. It has also very high level of well productivity which in average stands for per day per well, while the average natural gas well productivity in Iran is 1.5 million cubic meters per day per well.
Reserve uncertainties
In 2005, QatarEnergy became worried the North Dome's reserves were being developed too quickly, which could reduce reservoir pressure and possibly damage its long-term production potential. In early 2005, the government placed a moratorium on additional development projects at the North Dome pending a study of the field's reservoirs. This assessment is not expected to end until after 2009, meaning new projects are unlikely to be signed before 2010. However, this did not affect projects approved or underway before the moratorium. "Moratorium on North Field development" . • The Peninsula Qatar. • May 10, 2006
The 2005 moratorium by Qatar and the subsequent extension of that raised some questions about the actual proven reserves in Qatari side of the field. There was some news in 2006 that ConocoPhillips drilled unexpectedly dry holes in the North Field and this event was at least a partial catalyst for a revamped perspective on the North field structure and potential.Cohen, Dave. "Questions About the World's Biggest Natural Gas Field". The Oil Drum. June 9, 2006 Further supporting evidence for skepticism about the real scale of Qatari's reserves came from the 2008 exploration round in Qatar to target exploration of gas in the pre-Khuff formation. Even one of the blocks is exactly located beneath the North Dome Field.World Gas Intelligence Vol.XIX, No.51, December 17, 2008 - Page 4
On 29 October 2007, Qatargas CEO Faisal Al Suwaidi stated that the 5-year moratorium on new North Field gas development projects, imposed in 2005, could be extended to 2011 or 2012. The exploration moratorium was lifted by Qatar in April 2017 with the announcement of a new gas project in the southern part of the field.
QatarEnergy issued a bond prospectus on the 5th of July 2021. This bond issue, which was managed by, amongst others Deutsche Bank and J.P. Morgan included proven and confirmed reserve numbers for 2020 of 818.6 and 1756.1 Tcf respectively. QatarEnergy is the only entity that uses the terminology of confirmed reserves and does not provide a definition for it.
The QatarEnergy confidential business plan for 2024 contains a production forecast which implies proven reserves of some 110 Tcf and contingent resources of 85 Tcf as of 2023. No forecast associated with the expansion projects are included in these numbers.
South Pars development
The South Pars Field was discovered in 1990 by National Iranian Oil Company (NIOC). The Pars Oil and Gas Company, a subsidiary of NIOC, has jurisdiction over all South Pars-related projects. Field development has been delayed by various problems - technical (i.e., high levels of mercaptans and foul-smelling sulfur compounds), contractual issues and politics.
Gas production started from the field by commissioning phase 2 in December 2002 to produce of wet gas. Gas is sent to shore via pipeline, and processed at Assaluyeh.
As of early 2026, before the beginning of the US-Iran war, Iran has produced an estimated 2 billion cubic feet per day from the field, compared to 18.5 billion by the much-smaller Qatar. Iran's inefficient exploitation of the shared gas field is often attributed to Western sanctions, isolation and mismanagement. These have also caused the Iranian government to lag behind on pressurization efforts on their side of the field, which causes more gas to migrate to the Qatari side of the field.
NIOC was planning to develop the field in 24 to 30 phases, capable of producing about to of natural gas per day. Each standard phase was defined for daily production of of natural gas, of condensate, 1500 tonnes of liquefied petroleum gas (LPG) and 200 tonnes of sulfur, however some phases have some different production plans.Iran Oil Ministry Annual Bulletin, 5th Edition, (available in Persian)(كتاب نفت و توسعه). Each of the phases is estimated to have an average capital spend of around US$1.5 billion, and most will be led by foreign oil firms working in partnership with local companies.
Development of a South Pars phase by the Norwegian Statoil company has become infamous after extensive reports of misconduct and bribery to the Horton Investments, an Iranian consultancy firm owned by Mehdi Hashemi Rafsanjani, son of former Iranian president Hashemi Rafsanjani. Statoil committed to spending US$300 million to construct three production platforms and a pipeline.^ https://regimechangeiran.blogspot.com/2005/03/rafsanjani-statoil-bribery-covered-in.html The government of Ahmadinejad, who came to power in 2005, favoured local firms over foreign companies in the energy and other sectors.
By the beginning of 2008, phases 1, 2, 3, 4 and 5 had been brought to production and by the end of 2008, phases 6, 7, 8, 9 and 10 were planned to be on stream. Phases 12, 15, 16, 17, 18, 19, 27 and 28 were under different development stages.
On 18 March 2026, during the 2026 Iran war, phases of the Iranian South Pars gas field were struck by an Israeli airstrike. Following the strike, several gas phases were closed.
Project finance