RIASSUNTO
Abstract
The use of floating production systems ( FPS ) in offshore oil and gas developments is proliferating around the world. The Zaafarana Oil Field, which was discovered in late 1990 is located in approximately 60 meters of water, 7 kilometers off the west coast of the north Gulf of Suez, Egypt. The field consists of a conventional not normally manned wellhead/drilling platform tied into a floating production, storage and offloading facility (FPSO). Processing, storage and offloading of the oil is conducted on a dedicated tanker, the 'Al Zaafarana' which is permanently located in the field.
This paper shows, in a systematic way, the management approaches, process design considerations, field operations and other environmental practices utilized to implement a proactive Environmental Management System (EMS) for the FPSO operations. The EMS comprises the elements listed below which will be discussed in details through this paper:
The Environmental Policy
Environmental Impact Assessment (EIA)
Environmental Design Features and Process
Environmental Risk Assessment and Contingency Planning
Field Environmental Management
The results presented in this paper illustrate that: Through efficient environmental management acceptable environmental standards can be achieved for a FPS facility, such as the 'Al Zaafarana'.
It was necessary to use modern assessments methods to determine the environmental hazards and demonstrate that the FPS was a controllable facility producing acceptable environmental risks compared with other production development options.
Utilizing a FPS incorporating a reliable environmental management system has been a challenge both on technical and managerial grounds.
Background
The Zaafarana Oil Field lies within the North Zaafarana block in the north Gulf of Suez off the coast of Egypt, (Fig. 1). British Gas Egypt, holds the rights to this block. The field was discovered in late 1990 and has estimated reserves of 40 - 50 MMBO. The field was developed by Zaafarana Oil Company; which is a joint operating company owned by the Egyptian General Petroleum Corporation, British Gas Egypt S.A., Union Pacific Petroleum Suez Limited and Yukong Limited.
The Zaafarana development comprised a wellhead platform and a FPSO (Fig. 2). The platform is located about 1 km from the south bound shipping lane, approximately 6.5 km east of the coast in 57m of water. The platform consists of a 4 leg jacket supporting a 2 - level deck for wellhead and production test equipment. It operates as a not normally manned platform. Oil is transferred from the platform to the FPSO via a sub sea pipeline. All power is supplied by subsea cables from the FPSO.
The FPSO is a dedicated tanker which is planned to be located in the field for at least 10 years. The tanker being used is the 'Al Zaafarana'. The vessel is a steam turbine tanker and is classed with DNV as a floating production and storage unit. An outline specification of the vessel is contained in (Table 1). The FPSO is permanently moored approximately 800m south-west of the wellhead platform. processing and storage of the crude is conducted onboard. Treated oil is stored in the tanker prior to tale via export tankers. Current production is about 21,000 BFPD of 23 API oil and the gas to oil ratio is low, averaging about a GOR of 6. Associated gas is cold vented from the deck processing equipment.
Particular environmental concerns were evident from the feasibility stage once a FPS had been selected as the development option, especially as the area is designated as a special area under the MARPOL convention. These were the large stored inventory of crude oil, proximity to the south bound shipping lane, cargo offloading, closeness to the shoreline, local fisheries and coastal tourist development plans for the region. To balance this there were inherent advantages to the FPS option. P. 753