Top five offshore oil fields by remaining reserves

Umar Ali 28 May 2019 (Last Updated January 31st, 2020 07:43)

Companies invest heavily in oil fields to meet the world’s demand for energy. Offshore Technology profiles the top offshore fields by remaining reserves.

Top five offshore oil fields by remaining reserves
The Upper Zakum oil field, one of the world’s largest offshore fields. Credit: ExxonMobil.

Oil and gas companies invest heavily in developing oil fields to meet the world’s growing demand for energy. But with resources declining, which fields have the most oil left?

World’s biggest oil fields: Ranking the top five

Offshore Technology profiles the largest offshore fields by remaining reserves.

1. Marjan Complex- 17,238,800,384 boe

The Marjan Complex, located off Saudi Arabia’s east coast, is comprised of the Marjan, Maharah, Lawhah and Hamur offshore fields.

The field is operated by Saudi Aramco, the world leader in oil production and one of the largest and most profitable companies in the world.

With remaining reserves of over 17.2 billion barrels of oil equivalent (BBOe), the Marjan Complex is the field with the largest reserves in the world. These remaining resources are comprised of 15,623.71 million barrels (MMbbl) of liquid reserves and 9,747.96 billion cubic feet (Bcf) of natural gas reserves. Production at the field is at about 50,000 barrels of oil equivalent per day (boepd).

Saudi Aramco has continued to develop the Marjan Complex, awarding engineering contracts in September 2018 and February 2019 for the company’s largest upstream development project in 2019.

2. Safaniya – 17,136,224,734 boe

The Safaniya field is also owned by Saudi Aramco and is located 200km north of the city of Dhahran in the Persian Gulf.

Safaniya was discovered in 1951 and has been in production since 1957. It is operated with more than 624 production wells and a series of different platforms.

While the Safaniya field is the second-largest offshore oil field by remaining reserves with over 17.1 BBOe, it is the world’s largest field by recoverable resources with 37 billion barrels of oil reserves and 5,360 billion cubic feet of natural gas.

Safaniya is midway through its field life, having recovered approximately 54% of its total resources. Total production at the field is around one million boepd.

3. North Field Expansion- 11,509,802,413 boe

The North Field Expansion located offshore Qatar is anticipated to come online in 2023, peaking at 4600.0 MMcfd by 2045 with a projected field life of 58 years. Qatar Petroleum is the operator of the field, with 100% operating interest in the expansion project.

The North Field Expansion is the third-largest field by remaining resources, with total recoverable reserves of over 11.5 BBOe. These resources are comprised of 2,083.24 MMbbl of liquid reserves and 56,554.84 Bcf of natural gas reserves.

Located off the north-east shore of the Qatar peninsula and encompassing an area of around 6,000km2, the North Field is one of the largest non-associated natural gas fields in the world.

The planned drilling programme in the North Field is part of Qatar Petroleum’s expansion project to increase the country’s liquefied natural gas (LNG) production capacity from 77 million tonnes per year (Mtpa) to 110 Mtpa by 2024.

4. Zuluf – 11,366,711,770 boe

The Zuluf field is another Saudi Aramco-owned project, located approximately 40km off Saudi Arabia’s northeast coast in about 40 metres of water.

Zuluf has yet to reach the midpoint of its field life, having recovered 34% of its total recoverable reserves. The field has remaining reserves of over 11.3 BBOe, comprised of 11,072.35 MMbbl of liquid reserves and 1,766.64 bcf of natural gas reserves. Total production at the Zuluf field is around 764 boepd.

Saudi Aramco announced a major expansion to develop Zuluf’s heavier crude reservoirs in November 2017. It is expected to add 600,000 bopd of heavy crude oil to Saudi Aramco’s operations by 2023.

5. Upper Zakum – 11,064,572,697 boe

Located approximately 84km off the north-west shore of Abu Dhabi, the Upper Zakum oil field is the world’s second-largest offshore oil field in the world by recoverable resources and the fifth-largest by remaining reserves.

The current production capacity of the field is about 728,000 barrels of crude per day. The Upper Zakum field has recovered 33.4% of its 16 BBOe recoverable resources, with remaining reserves of just over 11 BBOe.

The Upper Zakum field was discovered in 1963 and brought on stream in 1967. It is owned and operated by Zakum Development Company, a joint venture of Abu Dhabi’s National Oil Company, with a 60% operating interest in the field. Partners in the project ExxonMobil (28%) and the Japan Oil Development Company (12%).

Expansions for the field over the next few years are expected to increase Upper Zakum’s production capacity to 750 boepd, eventually increasing further to one million boepd by 2024.