Upper Zakum Offshore Oil Field Development, Abu Dhabi, United Arab Emirates
Upper Zakum Oilfield, located approximately 84km offshore to the north-west of Abu Dhabi islands, has an estimated 50 billion barrels of oil reserves. The field currently produces 640,000 barrels of oil a day (bpd).
Upper Zakum is the second largest offshore oilfield and fourth largest oilfield in the world, and is owned by Zakum Development Company (ZADCO), a joint venture of ADNOC (60%) acting as the operator, ExxonMobil (28%) and Japan Oil Development Company (Jodco-12%).
The production capacity at the field is set to increase to 750,000 bpd following the completion of the UZ750 Project, which is currently underway. The construction works are being implemented in two phases, which are expected to finish in 2017. The project will increase the total production capacity of the field to 750,000 bpd, which will be sustainable for 25 years. The entire project is expected to cost $10bn.
The first phase of the project is being carried out by National Petroleum Construction Co (NPCC) and Technip under an AED3bn ($817m) contract. It will add 100,000 bpd of production capacity to the field.
The second phase is being carried out by Petrofac Emirates through its joint venture Mubadala Petroleum and Daewoo Shipbuilding & Marine Engineering (DSME) under a contract worth $3.7bn. The second phase is expected to increase the production capacity by a further 150,000 bpd.
Details of the Upper Zakum oilfield
The oilfield covers an area of 1,200km² and comprises around 450 wells extending approximately 7,000ft to 8,000ft below the earth's surface. The wells are tied to more than 90 existing platforms. Production from the oilfield started in 1982.
Oil from the field flows through a pipeline network to one of four main processing facilities for treatment. It is further pumped through main oil lines measuring around 55km to Zirku Island for further processing, storage and export.
Details of the UZ750 Project at Upper Zakum
The current UZ750 project involves the construction of four production artificial islands comprising of a central complex which will house the processing facilities, and the north, south and west satellite platforms.
The first phase of the project involves the development of the offshore facilities. It includes the laying of 240km of subsea pipelines, 128km of subsea composite and fibre-optic cables and installing 30,000t of offshore structures such as jackets, riser platforms, flare towers and bridges, and approximately 3,000t of islands modules and bridges.
The second phase involves the development of the facilities on the four artificial islands including wellhead control, manifolds, crude oil process facilities, water injection and gas lift, booster gas compression facilities, oil export pumps, power generation and ancillary utilities, and modification of the existing facilities. Up to 22 production modules comprising a wellhead control and oil processing unit are being constructed as part of the second phase. The facilities are expected to come on stream in 2017.
The project also involves the construction of accommodation facilities for 2,150 people, supporting buildings, and permanent utilities including recreational areas, a mosque, and operations and drilling offices.
In October 2015, Petrofac delivered the first two modules for ZADCO's Upper Zakum, UZ750 project.
Development of artificial islands at Upper Zakum
The islands were developed by utilising new technologies. The extended reach drilling (ERD) technology initially enables the wells to be drilled vertically, following which they can be drilled horizontally to target reservoirs up to several miles away. Another innovative technology being used is the maximum reservoir contact (MRC) which reduces the number of new wells and unlocks tighter areas in the reservoir.
The four islands, which are oval in shape and measure 2,000ft to 2,600ft in diameter, were constructed of sand and rock. The rocks were transported to the site from quarries in the UAE. The islands were constructed on water depths ranging between 5m and 15m.
The construction works for the islands involved 20 million cubic metres of dredging and levelling, and 20 million cubic metres of ground amelioration, and utilised seven million tonnes of stones, artificial fabrics and concrete units for the beach protection. The civil work of four artificial islands was completed in 2015.
The ACCROPODE II technique with assistance provided by Concrete Layer Innovations (CLI) is being implemented to protect the northern and western islands of the project.
Contractors involved with the Upper Zakum development
The project management consultancy (PMC) services for the offshore elements of the project are being provided by AMEC under a $75m contract, while the project management consultancy (PMC) services for the construction of the islands is being carried out by COWI. Amec Foster was awarded an extension to its existing project management services contract, in August 2015.
The feasibility study for the artificial islands was carried out by Ramboll. The construction of the islands is being carried out by National Marine Dredging Company (NMDC).
The contract for the construction of the accommodation and support facilities for the artificial islands was awarded to Habtoor Leighton Group (HLG) in June 2012.
The conceptual engineering and front-end engineering design for the process units on the islands, including several other facilities on the four islands, was provided by Technip. The contract to carry out the availability and reliability study for the project was awarded to Foster Wheeler.
TWMA has been contracted to design, commission and operate an advanced solids control and fluid recovery system for the project. It will provide specialist drilling services, including the handling, transfer, storage and treatment of both oil-based and water-based drill cuttings during the course of the project.
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