Subsea favored over Spar, FPSO in Egypt's first deepwater gas project
Long tieback to shore
The Scarab/Saffron development is location in the West Delta offshore Egypt.
The first deepwater development in the Mediterranean Sea offshore Egypt will feature a variety of new technologies including a remote long-distance tieback to shore with no surface facility. The field, Scarab/Saffron, is also Egypt's largest gas field development to date.
The decision to develop this field by subsea means illustrates the fact that as new technology gains a foothold in the industry, subsea tiebacks are becoming a cost-effective solution for the development of remote deepwater fields. Burullus Gas Company is the developer and the operator of the field.
A variety of floating solutions was considered for this field, according to Will Dick, Project General Manager, but in the end, a solution involving a subsea tieback made economic sense. Scarab/Saffron is primarily a gas field with some oil condensate, and this and other factors led to the subsea solution, Dick said. The nature of the find and type of environment were not conducive to the use of a Spar or FPSO. Both did not compare favorably with subsea development.
The wells will be tied back through a network of subsea flowlines and manifolds and an export pipeline system will transport the production to an onshore gas processing plant. The onshore plant will process the gas for injection into the National Gas Transmission System, via a newly installed gas export pipeline. The initial development will consist of eight wells. There are currently no plans to tie back satellite fields, but Dick said there would be enough flexibility built into the system to accommodate other developments, if ongoing exploration is successful.
Apart from the economic advantage, a long distance subsea tieback development concept provides a high level of safety, avoiding the need for offshore manning, helicopters, supply, and standby vessels. Well control will be managed from onshore via multiplexed electro-hydraulic umbilicals linked to subsea control modules, located at each of the wellhead trees and manifolds.
The Scarab/Saffron field is located 90 km north of Alexandria in 700 meters water depth. The site is near the base of the Nile Delta, where the seabed and geological conditions reflect thousands of years of sedimentary deposit by the Nile River. Dick said the pipeline tieback design for this project would need to accomodate for the steep gradient from field location to the shore.
While methanol inhibitor will be injected into the production stream to avoid the formation of hydrates, a certain flow velocity within the pipeline system must be maintained to avoid condensate hold-up problems. The challenge is therefore to design the pipeline size and control system to allow for a maximum turn-down to satisfy variations in gas demand, coupled with the need to ensure adequate gas flow rates to avoid any problems with the condensate. Furthermore, the line must be large enough to handle maximum initial flow volumes and the potential for increased flow from future tie-ins.
As part of the development, Burullus awarded a management contract to a joint venture of Bechtel and Intec Engineering, referred to as the Deep Water Managing Contractor (DMC). Responsibility for the project execution and project management will be led by Bechtel. Intec will provide the deepwater technology expertise for the offshore part of the project.
BG International is the operator with partner Edison International on the concession, whereas Burullus Gas Company is the operator of the field. The two companies signed a concession agreement with the Egyptian General Petroleum Corp. (EGPC) after a successful exploration project last August. The fact that this project was approved in only four months is a result of BG's relationship with the Egyptian government.
Dick said Egypt produces very skilled engineers, but needed a partner with experience in deepwater technology. As interest grows in developing the country's offshore deepwater resources, the technology transfer that is incorporated into the Scarab/Saffron development philosophy will allow Egyptian engineers and managers to develop the appropriate deepwater skills.
Production from the field is estimated at over 500 MMcf/d. The gas will be piped to onshore facilities for sale in Egypt's rapidly expanding domestic market. In this area of the gas supply business, BG is playing a lead role in the Nile Valley Gas Co. (NVGC), which is assisting in the development of the Egyptian domestic market through construction of transmission infrastructure in Upper Egypt.
As is customary in Egypt, signature of the Gas Sales Agreement resulted in the formation of a joint venture company between EGPC (50%), BG (25%), and Edison (25%) to manage the implementation of this project with the intention to commence gas production in January 2003. The company, formed by this joint venture, is the Burullus Gas Company, whose Chairman is Tarek El Attar.
To assist in achieving the goals of the project, a small project management team (PMT) comprised of experienced BG International, Edison, and EGPC engineers and managers was assigned to work with the managing contractor. The DMC and client project teams will be located initially in Houston, and thereafter in London to complete front-end engineering and undertake the procurement of the offshore packages.
Detailed design for the project will be executed in two phases. The offshore engineering design will be undertaken in London while detailed engineering of the onshore facilities will be undertaken in Cairo with Bechtel's Egyptian partner, ENPPI.
"This is a world-class development and we are extremely pleased to be the first to bring deepwater technology to Egypt," Peter Dranfield, President and General Manager of BG Egypt said. "We see this as the first in a series of deepwater developments in the Nile Delta and the transfer of this specialized technology of EGPC is a key ingredient of our approach to the project.
"The full support of EGPC in designing the contracting strategy has enabled us to make rapid progress with the appointment of a first class venture between Bechtel and Intec as the DMC. With this continued support, we look forward to delivery of first gas in January 2003."