Al Shaheen Oil Field

Al Shaheen, Qatar’s biggest offshore oil field, lies 180km north of Doha, in Block 5 in the Qatar peninsula. It is one of the world’s biggest and most complex oil fields, producing 300,000 barrels of oil per day.

The giant Al Shaheen oil field is operated by North Oil Company, which is a joint venture between Qatar Petroleum (70%) and Total (30%). NOC will operate the field for a period of 25 years ending in 2042. Oil production is mainly via exploration and production sharing agreements (EPSA) with foreign oil companies in partnership with Qatar Petroleum (QP) on behalf of the Government of Qatar. Qatar has proved recoverable oil reserves of 15.2 billion barrels. The field produces 100 million barrels of oil a year, accounting for 45% of Qatar’s oil production.

In January 2010, Overseas Shipholding Group (OSG) delivered the floating storage and offloading (FSO) unit Asia to the Al Shaheen field. OSG and Euronav own the 432,023dwt FSO Asia.

Maersk placed an order for another vessel with OSG, FSO Africa, to operate on the field, but cancelled the contract in January 2010 due to delays in the delivery of the vessel.

Offshore Qatar block 5

In 1992, Maersk discovered the 3,500km² block 5 off the coast of Qatar. It received $2bn in funding as the company explored the possibilities of establishing commercial oil production. Maersk invested $2.5bn in the development of the Al Shaheen field.

The exploration and exploitation rights included block 5 geological formations above the Khuff Formation, containing the ‘north field’, 6,000km² north-west of the Qatari peninsula, the world’s largest non-associated natural gas field.

Whether the oilfield was sustainable, despite being hydrocarbon, due to low permeability, limited thickness and geological complexity was initially questionable. It has since been successfully developed, mainly due to cutting-edge technology.

Al Shaheen early developments

Appraisal wells in the field were completed in 1994, along with the acquisition, processing and interpretation of 2D and 3D seismic data. Maersk Oil’s horizontal well technology has been utilised since 1994, drilling wells up to 31,000ft in length.

Production facilities were extended in 1995-96 with new subsea export pipelines, an additional single-point mooring loading buoy, new process facilities and a STAR-type wellhead platform.

Figures from 2003 estimated reserves of 780 million barrels of oil. The facilities were expanded in 2004, following further development plans in 1996 and 2001, with three additional platform locations.

A 2004 EPSA with QP covered the 139km² block 5 extension area, north-west of the Al Shaheen field. A$5bn investment was scheduled for the region in late 2005. The agreement comprised a work programme of geological and geophysical studies and well drilling.

In 2005, a Maersk-QP Field Development Plan (2005 FDP) called for the drilling of more than 160 production and water injection wells during a six-year period from 2006, along with three offshore platform locations with production and accommodation facilities; 18 new platforms in total.

In March 2010, Maersk completed the installation of 15 new platforms and related offshore facilities at the field under the Al Shaheen 2005 FDP. Installation of 131 of the 160 production and water injection wells were also completed. The remaining wells were completed by May 2010.

The platforms are interconnected by 18 120km-long subsea pipelines with power distributed via five 40km-long subsea cables.

Maersk Oil also agreed to build and operate facilities for the delivery of associated gas to QP for use at their onshore plants.

Block 5’s production in the first quarter of 2006 amounted to 240,000bpd, with 450,000bpd of water injection capacity. In 2009, oil production reached approximately 300,000bpd.

The Al Shaheen oil field details

Al Shaheen oil field comprises 33 platforms and more than 300 wells. As many as 20 pipelines connect six production installations, plus export pipelines for oil and gas. In addition to multi-phase, water injection, produced water and gas pipelines include four low-pressure wet gas pipelines.

The multiple offshore platforms are accessed utilising the Ampelmann A-type gangway placed on the Bourbon Gulf Star. The system is deployed in the field for both project and maintenance purposes.

Power and automation technology group ABB received a $26m order to serve as the main electrical and instrumentation vendor (MEIV) for two Maersk Oil Qatar oil platforms.

Contractors involved

Siemens supplied five SGT-700 gas-turbine driven compressor sets to ensure export-gas compression on three different platforms, and one spare SGT-700 core engine as well as complete automation system for 15 fixed platforms.

CiTECH supplied four CiBAS C100 WHRU units for CE/ED/GD Al Shaheen platforms, under a subcontract with Siemens. Ramboll was involved in carrying out the brown field design for the project.