The Al-Shaheen oil field is one of the world’s most complex oil fields. Image courtesy of Heerema Aegir.
The Al-Shaheen oil field contributes to approximately 45% of Qatar’s total oil output. Image courtesy of Heerema Aegir.
The Gallaf batch 1 project at the Al-Shaheen oil field was completed in November 2020. Image courtesy of PTSC.

The Al-Shaheen oil field located off the coast of Qatar is one of the biggest oil fields in the world. Comprising 33 platforms and more than 300 production and water injection wells, it is also considered to be one of the most complex oil fields in the world.

Located in Block 5, offshore Qatar, the oil field has a proven oil reserve of more than 15bn barrels. It currently produces more than 300,000 barrels of oil a day or 100 million barrels of oil a year, accounting for approximately 45% of the country’s oil output.

Production at the giant offshore field was first started in 1994 by Maersk Oil under an exploration and production sharing agreement (EPSA) signed with Qatar Petroleum in 1992.

The field ownership and operation was taken over by North Oil Company, a joint venture of Qatar Petroleum (70%) and Total (30%), for 25 years in July 2017.

For maintaining Al Shaheen’s production capacity, the current development phase, called the Gallaf project, was launched in November 2018.

The Gallaf project is being developed in three phases with phase one completed in November 2020.

Al-Shaheen oil field details

The Al-Shaheen oil field occupies approximately 2, 214km2 in Block 5 off the northeast coast of Qatar, approximately 80km north of Ras Laffan. The average water depth in the field area is approximately 60m.

The crude produced at the field is stored in two of the world’s largest double-hulled floating storage and offloading (FSO) vessels and is simultaneously exported from a single buoy mooring (SBM).

Al-Shaheen oil field development

North Oil Company has been implementing a phased approach to the development of the Al-Shaheen oil field since assuming operatorship in 2017.

A total of 17 wells were drilled under the phase one development plan as of 2018, while the phase two development, called the Gallaf project, includes the installation of eight new wellhead platforms (WHPs) at the field in three batches.

In batch-1, three new WHPs have been installed and connected to the existing platforms, while the remaining two batches will involve two and three new WHPs respectively.

Contractors involved in the Gallaf project

Heerema’s heavy lift vessel Aegir was contracted for the installation of the Gallaf 1 project. The project scope included installing three topsides weighing between 2,000-2,500t and three bridges weighing between 700-1100t.

Ampelmann was contracted to supply-type gangway system for NOC’s chartered Bourbon Gulf Star DP2 72 PAX support vessel in December 2017.

The engineering, procurement, construction, installation, commissioning (EPCIC) contract for the Al Shaheen Field’s Gallaf batch 1 was awarded to PTSC Mechanical and Construction (PTSC M&C) in November 2018.

Novenco was contracted for the heating, ventilating, and air conditioning (HVAC) system installation at the three new platforms as part of the Gallaf project in June 2019.

Sembcorp was awarded a contract worth approximately £304m ($406m) to assist in redevelopment efforts at the Al Shaheen and Tyra fields under the Gallaf Batch 2 in December 2019.

The scope of the contract covers the engineering, procurement, construction, installation, commissioning, and the offshore brownfield integration of two platforms that are planned for commissioning by December 2021.

Previous contracts

Maersk Oil contracted Ramboll to perform the brownfield design study which included the design modification of existing platforms and carrying out discrimination study for the smooth tie-in of the new platforms to the existing power system and pre-FEED study in 2006. Ramboll collaborated with Doris Engineering to execute the contract.

Siemens was contracted to supply four Siemens SGT700 Gas Turbines, while Citech was subcontracted by Siemens for the supply of the concentric integral bypass and silencer (CiBAS) waste heat recovery unit (WHRU) for the Al Shaheen CE/ED/GD platforms.

Sembcorp Marine Offshore Platforms was contracted to construct a 36-man accommodation and helideck for the project. The contract was implemented during July 2006 and June 2008.