Modernized controls improve offshore Abu Dhabi operations

Abu Dhabi Marine Operating Co. (ADMA-OPCO) is investing in automation technologies to optimize safety, productivity, and environmental compliance.

In the Umm Shaif offshore field in Abu Dhabi, it commissioned a new distributed control system, the Bailey INFI90 Open system from Elsag Bailey Process Automation.

Umm Shaif

Named for the area's distinctive coral formations, the Umm Shaif field is in the Arabian Gulf about 85 miles northwest of Abu Dhabi.

The Umm Shaif field produces both crude oil and natural gas. The nearby Zakum field contributes to the district's oil production. Both fields are operated by ADMA-OPCO, a subsidiary of Abu Dhabi National Oil Co. (Adnoc).

The Umm Shaif facility is a "supercomplex" of about ten interconnected platforms that have undergone several modernization and expansion programs since being commissioned in 1976. The complex collects oil and gas from numerous wellheads throughout the Umm Shaif field. Associated gas from the Zakum field is also collected at Umm Shaif.

Although the Arabian Gulf waters are relatively shallow (25-30 m in the Umm Shaif field) and lack severe storms, Elsag Bailey describes the operating challenges as the intense heat (approaching 120° F. during the summer) and salty humidity.

Added to these are the isolation, safety, and environmental concerns associated with any offshore facility.

Faced with aging control systems, ADMA-OPCO began modernizing the systems in 1990.

According to Keith Gordon, Deputy General Manager (Operations), the modernization was required because the fields were developed in an era when process control systems were often more art than science. The new systems will provide real-time process management of information for the operators.

Many of Umm Shaif's controls had been in place for more than 25 years, including many pneumatic devices that lacked the advanced human interface of modern systems.

As part the modernization program, the Bailey systems were installed onboard both the Umm Shaif and Zakum platforms, and at nearby Das Island, where oil and gas from the two fields are processed.

Control system

Elsag Bailey describes the control systems at Umm Shaif as spanning numerous plant-wide operations, partitioned to handle the collection of oil and gas, onboard gas processing, and water injection to the Umm Shaif reservoirs. The control system also supports onboard power generation and is mapped to fully monitor a separate programmable logic controller-based emergency shutdown system.

While the main control center provides a comprehensive window to platform-wide operations, direct responsibility for process control is distributed to three local control rooms and their respective personnel teams.

Elsag Bailey says the human interface in both the central and local control rooms is provided through the color-graphic displays of Bailey's OIS-42 series console. About 50 process control unit cabinets are distributed among five remote marshaling rooms, linked by redundant fiber optic for EMF (electromotive force) protection.

Beyond platform-based operations, the new DCS (distributive control system) also provides links to remote platforms in the Umm Shaif field. The field's gas wells are monitored and controlled from the platform supercomplex. Monitor-only telemetry is maintained with oil well head platforms.

At Das Island, about 35 km away, the new system controls oil and gas processing to meet export specifications. Production from both the Umm Shaif and Zakum fields is exported via tanker.

Commissioning

Completed in early 1997, the modernization at Umm Shaif spanned a period of 2 years. Elsag Bailey estimates that the installation required over 175,000 man-hr of work, supervised by ADMA-OPCO's engineering division. The changeover from the old system was done under "hot" conditions without any loss of production, according to Elsag Bailey.

The scope of work included the installation and commissioning of 15 operator consoles, 50 control cabinets, 8 km of fiber optic, 110 km of conventional cabling, and over 1,200 new field control devices.

The project also included structural and architectural work for 10 local equipment rooms. Personnel and equipment from Elsag Bailey units in the U.K., France, Italy, and Abu Dhabi contributed to the project.