The entry specification for any future third party production is dependent upon the point at which such production would enter the Britannia facilities and the composition of production already being processed on the Britannia facilities at that time.

The entry specification will cover areas that affect onward transportation as well as those which impact the Britannia platform itself e.g. slugging limitations and contaminants.

Liquids – Any liquids processed on the Britannia facilities would be transported through the Forties Pipeline System (“FPS”). The exit specification from the Britannia Facilities is the FPS entry specification which is directly negotiable between any prospective user and the FPS operator. However, any exit specification must be achievable with the processing facilities available on Britannia.

Gas – Any gas processed on the Britannia facilities would be transported through the Britannia pipeline for further processing at the SAGE gas terminal at St Fergus. The exit specification from the SAGE gas terminal is the National Transmission System entry specification at that point.

The primary separation system on the Britannia platform consists of a 2-phase HP Separator followed by a 3-phase MP Separator with interstage liquid heating. There are also 2 Test Separators with limited liquid handling capacity.

Gas from the HP and Test Separators is routed to the gas treatment facilities which are described below. Gas from the MP Separator is routed to the MP Compression system where the gas is compressed to the operating pressure of the gas treatment system.

Produced water from the MP Separator is treated in the Britannia platform produced water handling system prior to discharge overboard.

Hydrocarbon liquids from the MP Separator are fiscally metered and pumped into the condensate export pipeline which transports the liquids to the Forties Unity platform where they enter the Forties Pipeline system.

A Bridge Linked Platform (BLP) will be installed alongside the Britannia platform in 2006.  Primary separation facilities will be installed on the BLP for the Callanish & Brodgar fields.

The Callanish primary separation facilities will consist of a single 3-phase Callanish Arrival Separator with associated liquid heating.

The Brodgar primary separation facilities will consist of a 2-phase Brodgar Arrival Separator followed by a 3-phase IP Separator with interstage liquid heating.

Gas from the separators on the BLP will be routed directly to the existing gas treatment system on the Britannia platform or the MP Compression system. Hydrocarbon liquids will be routed to the MP Separator on the Britannia platform.

Produced water from the Callanish Arrival Separator will be routed to the produced water handling system on the BLP. However, produced water from the Brodgar IP Separator will contain a high proportion of MEG for hydrate inhibition purposes and will be routed to the MEG Reclamation system prior to overboard disposal.

Gas from the primary separation and MP Compression systems is routed to the gas treatment system.

The gas treatment system has 2 identical trains and the incoming gas is split equally between them. The gas is initially cooled in the Inlet Gas Coolers to ensure that the export gas meets the cricondenbar specification of 104 barg maximum.

The gas and liquids from the Inlet Gas Coolers are separated in the TEG Contactor Inlet Scrubbers. The liquids from these scrubbers are routed to the MP Separator while the gas is routed to the TEG Contactors where it is contacted with TEG (Tri-Ethylene Glycol) in order to dehydrate the gas to the required specification.

The gas then passes to the Export Compression system which has 2 identical compression trains each consisting of an Export Compressor Scrubber, Export Compressor and Export Compressor Aftercooler.  Gas is exported into the Gas Export Pipeline. This is a dedicated pipeline transporting gas from the Britannia platform to the SAGE terminal at St Fergus.

The design capacity of the Britannia Oil Export system is 68,000 bpd based on operating 2 out of 3 oil export pump trains.

It may be possible to upgrade this capacity by operating all 3 pumps or upgrading the pumps. However this will have implications for fiscal metering, power generation capacity and arrival pressure at Forties Unity.

Based on the original design capacity of the system, limited ullage (<10% of system capacity) will be available until 2009.

The capacity of the export gas compression system is governed by the power of the compressor drivers. Britannia has 2 export compressors driven by GE LM5000 turbines. The maximum base load power available for compression from each turbine is approximately 31 MW.

In terms of mass capacity, export compression capacity on Britannia declines with suction pressure as the discharge pressure is constrained by operating limits at SAGE. The HP Separator operating pressure effectively governs the suction pressure of the export compressors.

Britannia Operator Limited continuously seeks to maximise field deliverability by minimising HP Separator operating pressure and operating the export compressors at maximum power. Given this mode of operation, there is effectively no ullage in the export gas compression system.

However, export gas compression capacity can be made available to 3rd party fields by operating the HP Separator at higher pressures. This will result in back-out of existing production for which compensation will be required.

In addition to the export gas compression system, the MP Gas Compression system compresses separator offgas up to the operating pressure of the gas treatment facilities. The capacity of this system is currently 40 mmscfd but will increase to 80 mmscfd from early 2007 for the introduction of Callanish & Brodgar. Limited ullage (<20% of system capacity) will be available until 2009.

The maximum Britannia gas export capacity is defined by the Britannia Platform Safety Case and by the capacity at SAGE. Both of these constraints limit gas export capacity to 840 mmscfd. The Safety Case limit is based on flare considerations.

Again, it may be possible to upgrade this capacity through technical studies and negotiations with the SAGE operator.

Based on the current limit of 840 mmscfd, limited ullage (<10% of system capacity) will be available until 2009.

Gas for gas lift will be supplied from the discharge of the export compressors. Minimum delivery pressure at the discharge of the export compressors will be in the range of 130 - 140 barg.

Because lift gas is supplied from the export compression system, the same back-out issues arise as mentioned above.

There is an existing gas lift delivery system which would be shared with the Caledonia field. A tee has been installed at the bottom of the gas lift riser to supply additional fields.

The capacity of this system is 55 mmscfd based on metering constraints and the available ullage is in excess of 40 mmscfd.

The design capacity of the produced water handing system on the Britannia platform is currently 12,000 bpd.

The produced water handling system is currently being upgraded, using the best available technology, to ensure compliance with future environmental regulations without decreasing capacity.
 
The ullage available in the system is < 10% and will not increase until the Caledonia field ceases production.

A further produced water handling system will be installed on the BLP for Callanish and Brodgar. The system will be available from early 2007. The design capacity of this system is 30000 bpd. There will be no ullage available in this system for the time being.

The Britannia facilities have no water injection capability.