North Field, the world’s biggest single non-associated natural gas field, lies offshore north-east Qatar peninsula.

The field is owned by Qatar Petroleum and is operated by its subsidiary Qatargas.

Qatar Petroleum announced the expansion of the gas field in April 2017 after revoking its 12-year self-imposed ban on field development.

The expansion will increase Qatar’s liquefied natural gas (LNG) production capacity from 77 million tonnes per annum (Mtpa) to 110Mtpa, which accounts for an LNG production capacity increase of approximately 43%.

First gas from the expansion project is expected to be produced by the end of 2023. The project is in line with Qatar’s National Vision 2030, which aims for more sustainable development by 2030.

North Field expansion project details

The expansion project includes the development of four new LNG trains and eight wellhead platforms, from which 80 new wells will be drilled. Eight offshore jack-up drilling rigs will be installed and four offshore 38in trunk lines with 28in diameter intra-field pipelines will be laid, along with power and fibre optic subsea cable rings.

The project will enable the production of 32Mtpa of LNG, 4,000t per day of ethane, 260,000 barrels per day of condensate, 11,000t per day of liquefied petroleum gas (LPG), and approximately 20t per day of pure helium.

Feed gas of approximately 4.6 billion standard cubic feet per day will be piped to onshore facilities from the southern part of the North Field.

Details of the new living quarter platform

An additional living quarter topside with five levels is being developed on the North Field Bravo platform, which will accommodate 90 people.

Four-legged jackets, which will be 59m-high and weigh 754t, will be installed in the soil at a minimum water depth of 53m. The 2,253t topside will feature six-deck floors, a crane, three laydown areas, and a steel-structured helipad weighing 174t.

Additionally, four living quarter jacket piles with a total length of 1,637m will be installed. Six 10m bridges between existing living quarters and the new living quarters will be built.

Contractors involved

Qatargas placed an engineering, procurement, construction and installation (EPCI) contract with McDermott for the eight new offshore jackets of the platforms in April 2019. The jackets will be fabricated at the McDermott facilities located in Batam, Indonesia, and transported offshore for installation by Derrick Barge 50 and Derrick Barge 27 vessels.

McDermott also received the front-end engineering and design (FEED) contract for the project in November 2019.

BASF agreed to provide two technologies, marketed under the brand name OASE^® and Flexsorb^™, to Qatargas for gas removal and gas treatment for the new LNG trains, in April 2019.

Gulf Drilling International was contracted to provide six offshore jack-up drilling rigs, while Northern Offshore Drilling Operations received the contract for the remaining two rigs.

The FEED contract for the onshore facilities of the project was awarded to Japanese engineering firm, Chiyoda Corporation. The scope of work includes development of a basic design for adding three mega LNG production trains of 7.8 million tonnes per day capacity along with pre-investment for the fourth train.

Rosetti Marino received the EPCI contract for the additional living quarter topside in May 2017. The quarters will be fabricated at the Nakilat-Keppel Offshore & Marine (N-KOM) fabrication yard in Ras Laffan Industrial City, Qatar. The quarters will be shipped to the site for installation in February 2020.

TECON SOW designed the additional living quarter platforms. MentorIMC Group is responsible for managing the expansion project.

North Field project background and reserves

Natural gas on the north-east coast of Qatar was discovered in 1971 and 15 appraisal wells have been drilled at North Field over 14 years.

The gas field covers more than 6,000km² and holds more than 900 trillion standard cubic feet (tcf) of recoverable reserves, which is equivalent to approximately 10% of the known reserves in the world.

Qatar imposed a moratorium to evaluate the impact of the growing output from the reservoir in 2005.