Project Launched to Elevate Sustainable Production to 750 BOPD

Project Launched to Elevate Sustainable Production to 750 BOPD

ZADCO, on behalf of its shareholders, has a strategic target to increase the production rate from Upper Zakum from 550 thousand to 750 thousand barrels of oil per day by 2017, sustainable for 25 years.

Initially the development plan to achieve these targets was based on an additional 25 Wellhead Platform Towers, together with hundreds of kilometers of new flow lines. Major facilities upgrades on existing satellites and the central processing platform were also planned. Inherent in these development plans was the need to more than double the jack-up drilling rig fleet in order to achieve the necessary production build-up rate. The flexibility to manage long term reservoir performance, well integrity issues, corrosion and aging of existing structures and subsea flow lines has led ZADCO to seek out a better and more economical future development concept.

ZADCO embarked on an assessment of possible alternative concepts and the findings provided a compelling case for change from the conventional development plan to one that consolidates drilling centers and processing facilities on artificial islands, and utilizing new technologies in Extended Reach Drilling (ERD) and Maximum Reservoir Contact (MRC) to effectively develop the entire field.

ZADCO’s plans to increase production to 750,000:

ZADCO’s mandate to achieve sustainable production of 750 MSTBD based on full field development, including areas of lower reservoir quality, is a challenging task.Different options were evaluated, including continuing with the current Wellhead Platform Tower approach. This involved adding many new wellhead towers, hundreds of kilometers of flow lines,hundreds of new wells, significant well workover requirements, and investing in substantial gas injection expansion and gas capturing facilities. ZADCO's evaluation determined this to be a high cost, low development flexibility approach that had significant logistical and operating issues associated with it. Top

The artificial islands concept:

In collaboration with ZADCO shareholder ExxonMobil, the concept of artificial island based drilling and production centers was evaluated and found to be an attractive forward development plan. To support this concept, ZADCO’s own drilling division was established and high-technology extended-reach drilling (ERD) was employed. ExxonMobil has extensive experience with this technology, for example at the Sakhalin field in Russia. Additionally, the use of Maximum Reservoir Contact (MRC) technology, offers the opportunity to reduce the required number of new wells and unlock tighter areas in the reservoir.Although these technologies have been applied in other parts of the world, they are new to the region and the projected scale of application is unprecedented.

Historically, ZADCO has drilled wells of approximately 10,000 feet. However, with this new technology, it is planning to reach 30,000 to 35,000 feet. To date, ZADCO has completed drilling a pair of MRC wells, each almost 20,000 feet total drilled length – both wells setting several drilling records for ZADCO. The data from these pilots will help to design future drilling and completion designs. Many of the wells on the islands will be complex and expensive wells but their contribution will be much higher than historic UZ wells. This will improve production performance, optimize the well count, and minimize capital investments. ExxonMobil is a key enabler for the application of this drilling technology and they will be supported by NDC and industry leading directional drilling and completion service providers to ensure success in the execution stage. These drilling technology advances will be supported through the new ZADCO drilling organization as well as utilizing the Technology Center, established and operated by ExxonMobil, and co-located within the ZADCO HQ, to provide full access for ZADCO staff to ExxonMobil’s proprietary technologies, tools and best practices. Top

Advantages of using artificial islands

Artificial islands provide a more flexible and robust development base for the redevelopment of the UZ field. This will significantly reduce life-cycle development costs and enable long term maximum recovery levels to be achieved. The ‘green fields’ development on islands accelerates oil development rate, is safer and more capital efficient. Gas lift application on the islands will be much easier than from WHPT and will help improve long term reservoir recovery. The current development plan has the potential to extend the production plateau for up to more than 15 years and significantly delay the need for full field EOR / WAG application and investment. Top

Leading the way

The redevelopment of the UZ field will present many technological and operating ‘firsts’ for ZADCO which will provide opportunities for additional development applications in the Gulf. The centralized drilling and production centers coupled with ERD and MRC technologies open opportunities in offshore shallow waters. Across the ADNOC group, ZADCO is the pioneer, being the first to intensively apply such complex drilling completions in terms of extended reach drilling (ERD) and with higher reservoir contact (MRC).Top