A new oilfield development project in Abu Dhabi is in its final stages.
The Upper Zakum Oilfield expansion has made great progress. The oilfield, located approximately 84km offshore of the North-West Abu Dhabi islands, currently produces 640,000 barrels of oil a day (bpd), with an estimated 50 billion barrels worth stored in reserves. ZADCO hopes that the new UZ750 project will increase production capacity to 750,000 bpd.
The site is owned by Zakum Development Company (ZADCO) which a joint venture between ADNOC (60%), ExxonMobil (28%) and Japan Oil Development Company (Jodco-12%).
UZ750 is being implemented in two phases. This has cost an estimated $10bn: a solid investment, since the work should increase sustainable production for 25 years.
The project has proved as sizeable as the oilfield. Upper Zakum is gigantic in size; in fact, it is the second largest offshore oilfield and fourth largest oilfield in the world. Oil from the field flows through a pipeline network to one of four main processing facilities for treatment. It is processed further: pumped through main oil lines measuring around 55km to Zirku Island for storage and export.
Before construction, ZADCO had to embark on an assessment of possible build concepts. The assessment results provided a compelling case for change from a conventional oilfield development plan to a new plan: one which consolidates drilling centers and processing facilities on artificial islands. The plan was to make four islands, measuring 2,000ft to 2,600ft in diameter, out of sand and rock. The rocks would be transported to the site from quarries in the UAE. The islands would be constructed on water depths ranging between 5m and 15m.
The works required 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 works were completed in 2015.
The first phase of the project was the development of the offshore facilities. This included laying 240km of subsea pipelines, 128km of subsea composite and fibre-optic cables. Contractors also installed 30,000t of offshore structures such as jackets, riser platforms, flare towers and bridges, and approximately 3,000t of islands modules and bridges. The work was done by National Petroleum Construction Co and Technip under a contract worth AED3bn.
In the second phase of the project, the island facilities were developed. Work was done on wellhead control, manifolds, crude oil process facilities, water injection and gas lift, booster gas compression facilities, oil export pumps, power generation and ancillary utilities. This phase also concerned itself with the modification of the existing facilities. Up to 22 production modules comprising a wellhead control and oil processing unit were constructed. The facilities are expected to come on stream by the end of 2017.
Lastly, but importantly, the project has constructed accommodation facilities for 2,150 people, supporting buildings, and permanent utilities including recreational areas, a mosque, and operations and drilling offices. The built up area amounts to approximately 15,000 sq mts. Furthermore, a 3 sq km-lane road has been constructed. A small power plant, a sewage treatment plant and a reverse osmosis plant have been set to make the camps self-sufficient.
The Upper Zakum development embarked upon many contracts during its time. The project management consultancy (PMC) services for the offshore elements was provided by AMEC under a $75m contract, while the project management consultancy (PMC) services for the construction of the islands has been pursued 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 National Marine Dredging Company (NMDC) has dealt with the construction of the islands.
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 was contracted to design, commission and operate an advanced solids control and fluid recovery system for the project. It provided 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.
ZADCO now have four artificial islands in shallow water to create what INPEX describes as an onshore environment in the offshore field. Unlike the initial Upper Zakum development, made of 450 wells and 90 platforms, the islands provide a sufficiently large footprint to accommodate drilling rigs. The developers have utilized new technologies in Extended Reach Drilling (ERD) and Maximum Reservoir Contact (MRC) to effectively develop the entire field. The station drilling, production equipment and central personnel in offices and living quarters have helped remove the costs associated with platform jacket maintenance and satellites.
Upper Zakum will continue to employ extended-reach drilling and completion technologies to increase offshore production in future development. Future phases will use advanced reservoir characterization and modeling techniques, as well as modularly expanding existing infrastructure and facilities, in order to maximize efficiency and lower costs.
The oilfield is already providing more economic benefits than first imagined. Drilling wells from the man-made islands is now considered cheaper than installing additional offshore platforms, subsea equipment and pipelines. But achievements are not just economic: in recent years, the Upper Zakum development has set several drilling records in the UAE. This includes the longest well at 35,800 ft (10,912 m) measured depth.
According to NMDC, the company who built the islands, their work on the islands has been challenging but worthwhile. NMDC said:
“Success brings with it even more challenges within HSE, by consistently endeavoring in raising our threshold standards, rendering our future performance benchmark even higher. We have realized and accepted this challenge. We are committed to work even harder to enhance our standards and striving to better our best practices and constantly looking at “how the good gets to better and be the best”. Our performance has consistently been good, and experience also tells us that we should not rest on our laurels and be complacent.”
“These are the challenges we are most happy to face. Further as we embark into a number of new business territories, we are fully aware of the dynamic market conditions and the competitive business environment we are likely to encounter. A priority and a necessity for the company is cost optimization – but not at the cost of compromising our HSE record. We have firm development plans and targets set to achieve this on an ongoing basis. All our KPI’s have been set, focused on this and we do acknowledge and foresee the need to deepen our knowledge and understanding to meet the challenges in the years ahead.”
Now that the Upper Zakum oil expansion is almost complete, the next 25 years of production should be fruitful and sustainable. Although oil prices have dropped in recent years, oil is still a major player in Abu Dhabi’s economy. It is projects such as this one that promise to contribute to the country’s wealth year after year.