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, 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.
This gas field covers an area of , of which (South Pars) is in Iranian territorial waters and (North Dome) is in Qatari territorial waters. The local names are relative to the owning country. The "North" Dome is to the southwest from "South" Pars.
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. A number of phases at the gas field were shut down 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.
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.
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. 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 PermianâÂÂTriassic stratigraphic units. These units known as the KanganâÂÂDalan Formations constitute very extensive natural gas reservoirs in the field and Persian Gulf area, which composed of carbonateâÂÂevaporite series also known as the Khuff Formation.
PermianâÂÂEarly Triassic has been divided into Faraghan (Early Permian), Dalan (Late Permian) and Kangan (Early Triassic) Formations.
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. With in place volumes equivalent to of oil (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.
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.
Note: 1 km<sup>3</sup> = 1,000,000,000 m<sup>3</sup> = 1 billion m<sup>3</sup> = 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.
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.
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.
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. 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.
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.
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. 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. 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.
As of December 2010, about $30 billion had been invested in South Pars gas fields' development plan. It was estimated that the amount would reach over $40 billion by 2015. The Ministry of Petroleum in Iran said in a revised statement in 2011 that Iran will invest some $90 billion between 2011 and 2015 ($60 billion will be allocated to the upstream sector and the rest to the downstream sector). In 2024, Iran scheduled a $70 billion plan to maintain gas pressure and keep vital petrol production.
Economic studies showed with the operation of each South Pars phase, one percent was added to the country's gross domestic product (GDP), while phase 12 was expected to add more than three percent of GDP.
As at 2012, some 400 Iranian companies were taking part in the development of the South Pars gas field through supplying equipment to related projects.
Table Sources: NIOC, Pars Oil & Gas Company, Shana and Media
While several phases of South Pars gas field are still waiting for development and the ongoing development phases are facing delays, NIOC authorities are conducting negotiations for development of other Iranian offshore gas fields like North Pars, Kish, Golshan, Ferdows and Lavan.
Many Iranian energy analysts believe that NIOC authorities should focus on full development of South Pars field prior to conduction of any new project for development of other undeveloped Iranian offshore gas fields.
The priority of South Pars full development is not only due to its shared nature with Qatar, but also with huge capability of the field to add significant liquid production to Iranian liquid export capacity.
On 27 February 2009, one of the members of Iranian Parliaments criticized lack of attention on the importance of acceleration of South Pars field development and the field development delays.
By the end of 2008, Qatar's cumulative production from the field was two times higher than Iran's cumulative production from the field. Qatar produced about of natural gas in the period of 1997 to 2008, while Iran produced about of natural gas in the period of 2003 to 2008. The 2:1 ratio of Qatar's cumulative gas production from the field to Iran's is forecasted to continue at least for the short term: by the end of 2011, Qatar's total cumulative production from the field will reach of natural gas, while Iran's will stand at of natural gas in the same year. The ratio is maintained mainly because Qatar's annual production is almost twice the Iranian production level.
In 2011, Qatar will reach an annual production capacity of natural gas per year, while in that year Iran's production capacity will reach per year. If Iran could implement all of its South Pars planned development projects on time, then it would reach the production capacity of of natural gas per year, not earlier than 2015.
The most important impact of delays and lower production in Iranian side would be migration of gas to the Qatari part and a loss of condensate yield due to decreased field pressure.
The North Dome, also known as North Field, was discovered in 1971, with the completion of Shell's North West Dome-1 well.
With falling oil and associated gas production, and depletion of the Khuff reserves, developing the North field became imperative. In 1984 it was decided that development would occur in phases. Phase 1 involved installing production, processing, and transport facilities for of natural gas per day to serve local utilities and produce 5,000 tons per day of propane, butane, gasoline, and naphtha. In 1989 a gas sweetening plant and sulfur processing unit were added. Phase one was online by early 1991. Gas from North Field phase one has been primarily used for local demand, and injection into the Dukhan field. Phase two was expected to involve selling North Field gas to its neighbors, possibly through a Gulf Cooperation Council (GCC) gas grid. Phase three involved exporting to Europe and Asia. Even before the Persian Gulf War, this phase ran into trouble. To justify the investment, QatarEnergy needed two large-scale long-term supply contracts. Despite efforts from QP managing director Jaber al-Marri, contracts were not forthcoming. This switched emphasis to domestic outlets. In 1988, a firm of international consultants presented a plan to QP for developing domestic projects to utilize Qatari gas. Suggestions included an aluminum smelter, a ferro-alloy production plant, methanol production facilities, and expansion of petrochemical and fertilizer operations.
Qatar rapidly expanded its production and exports from North Dome Field. Here are a number of milestones:
Subsequent phases of the North field development provided feedstock to LNG plants at Ras Laffan Industrial City. By 2025, North Field through Ras Laffan produced 77 million tonnes of LNG, expected to increase to 126 million tonnes by 2027.
As of early 2026, before the beginning of the US-Iran war, Qatar has produced approximately 18.5 billion cubic feet per day from the field, accounting for around 80% of Qatari government revenues, and supplying around 20% of the world's LNG. During the war, 10,000 employees were evacuated, and activities shut down. The Iran attack may postpone the planned expansion by a year.
The ORYX GTL plant was commissioned in early 2007, as the first operational GTL plant in Qatar. The plant nameplate capacity is , however, the plant has faced technical challenges and did not reach full capacity during the first year of operation. Modifications recommended by Sasol assist with overcoming this shortfall and production capacity was reached/ maintained from 2009 onwards. The plant uses of natural gas from the Al Khaleej Gas project. The ORYX GTL project uses Sasol's Slurry Phase Distillate (SPD) process.
The project is under construction and will be the world's largest GTL plant which will have the capacity of of middle distillates and significant quantities of LPG and condensate. The first of two GTL trains is planned to start production in 2011. Around of natural gas will be supplied from the North field to the project. Shell has 100% of the equity in the integrated upstream and plant project. In March 2026, the plant was damaged by an attack from Iran.
Table 3. North Field production plan (million cubic feet per day).
Table sources: QatarGas, QatarEnergy and internet